Feed producers: here’s how to deal with fats shortages and high costs

feed mill

By Marisabel Caballero, Global Technical Manager, EW Nutrition

COVID-19 and its aftermath, the Russia-Ukraine war, and climate change have all contributed to the current crisis. Energy price increases, supply chain difficulties, and raw material availability and rising prices are all consequences felt deeply across the animal production sector. It is now time that the industry puts in place mitigation plans and starts taking action.

Cost and availability of fats – a looming problem

The lockdowns during the COVID-19 pandemic in 2019/2020 caused a rapid drop in energy demand and therefore a cut in global oil production. In 2021, as normality was recovered, it was met an energy supply-demand imbalance leading to a global supply chain crisis that further stressed the delivery of energy sources. In 2022, one of Europe’s driest summers compounded by the Russian-Ukrainian war have greatly contributed to the increasing energy prices.

With two of the largest suppliers of grains and oil – Russia and Ukraine – at war, the global food supply and prices are also compromised. These two countries provide the world with more than 20% of all wheat and barley, 15% of corn and 60% of sunflower oil (FAO, 2022).



Moreover, corn and soybean yields in South America also fell sharply in 2019-20 and 2021-22 due to the impact of La Nina and are expected to continue being low in the next season.

Biofuels and animal production compete for crops

Biofuels have been seen as a solution to decrease fossil-fuel energy dependance. Before the war, global biofuel production was at a record high. However, in the current crisis, biofuels may be a contributor to the rise in food prices, as they use a significant percentage of feed-production crops. Only in the US, around 30% of the corn production goes into biofuels, while biodiesel accounts for 40% of soybean oil use (O’Malley & Searle, 2021).

For the animal production industry, maintaining performance and profitability during price hikes involves a combination of strategies. Feed production accounts for up to 70% of meat production costs. With the soaring energy and raw material crisis, feed production costs are on the spot.

The impact of fat in pelleting process output

Oils and fats generally are added to animal feeds as a rich source of energy and other essential nutrients. For the feed production unit, fats can be a pellet quality and energy output enhancer.

During the pelleting process, fat can increase production output, save energy, and prolong the production life of the die as it can act as a lubricant during the process. The feed ingredients contain fat, and a portion of fat/oil is usually added in the mixer. Too much in-mixer fat addition (higher than 2%) negatively affects pellet quality, and when fat is too low (no addition), the production rate decreases. Fats and oils are also added through a pellet coating system, which has been demonstrated to improve pellet quality.

In fats/oils high cost and shortage scenarios, feed production managers and nutritionists are faced with the challenge of production with higher constraints. In-mixer fat addition has consequences in throughput. However, in-mixer moisture addition facilitates conditioner steam penetration into the feed particles. With that, the efficiency of the process may be partially recovered.

Solving the efficiency & quality equation

Simply adding water into the mixer does not give optimal results: Surfactants, on the other hand, improve moisture penetration into the feed particles and increase lubrication at pellet die point. By reducing the surface tension of water, surfactants enable the feed particles to absorb and distribute the moisture uniformly.

Improved moisture retention facilitates the starch gelatinization during mash conditioning and passing through the pellet die. This is important to make the pellet more durable and the feed more digestible. It also reduces friction and hence the energy required for the pelleting process (improving milling efficiency). At the same time, surfactants aid with pellet water retention, minimizing feed shrinkage without increasing water activity, thus curbing feed microbial growth.

What difference can an effective surfactant make?

The effect of adding SURF•ACE to diets with different levels of fat was evaluated in more than 40 feed mills, with production capacities ranging from 5 to 20 tons per hour. SURF•ACE is added to water sprayed during mixing. This solution lubricates the mash feed, improves steam penetration and starch gelatinization, and thus reduces friction in the pellet die. The results show that, relative to pure water, the addition of SURF•ACE increases press throughout (t/h) by up to 25%.


Prioritize efficiency to compensate current challenges

Operating in a tight margin environment, feed mills always need to prioritize efficiency. The advantages of using SURF•ACE feed mill processing aid are clear: reduced energy consumption without compromising pellet quality; moisture optimization; and higher productivity.

During times of increasingly high ingredient and energy costs, it is even more important to utilize savings opportunities at every production stage.

From basketball to feed milling: a common tactic for winning in 2022

header basketball court

By Ivan Ilic, General Technical Applications Manager, EW Nutrition


It has been a rough couple of years for the world. And from climate change to war, all negative impacts have reverberated down to feed millers.

  • Climate change affected raw material prices and availability
  • COVID-19 impacted shipping costs and manpower
  • War impacted energy prices and raw material availability

And that´s without even considering market trends toward sustainability, shifting resources to biofuel, and so on.

With all these challenges going on, working to improve feed mill efficiency has lately kept me extremely busy. I´ve been traveling and talking to customers around the world about SurfAce and how we bring benefits in energy cost savings, process efficiency, moisture optimization, and so on. But when I am at home, I take a walk every evening in the woods near my house. I often use the time to reflect on personal and professional issues.

Some weeks ago, I found myself thinking about the European Basketball Championship that was about to start. In Serbia, basketball is a national sport. The head coach of the Serbian national team decided not to call one of our best players to the national team. Lots of people criticized this decision, as for the past few years he has been one of the top players in Europe.

So, I started to think about choosing a team over a star. How do you balance your strong points to make sure of a win? (Yes, there is a connection to feed mills. I´m getting there.)

Winning through strategy rather than showmanship

Bozidar Maljkovic is a Serbian legend, who trained several winning teams, among which the European champion team Limoges. This was a French team he picked up mid-season, with moderate resources on the basketball court as well as outside it. The entire 1993 Euro season, Maljkovic chose to play extreme defense and score a very low number of points. In the finals, he played against a big favorite: Benneton Treviso, a wealthier team that, at that time, had a roster of excellent players. He won the game using the same strategy: tight defense, highly tactical game. A championship won not on artistic merit but on strategy.

After that final game, his good friend and well-known coach of Treviso, Petar Skansi, accused Maljkovic that he was destroying the basketball game with that tactic. Maljkovic answered to Skansi in more or less these words: you give me Kukoc (Treviso´s best player) and I´ll win on a different tactic.

When I remembered this episode during my walk, I suddenly saw a pattern in basketball coaching and feedmill management.

Know your objective

As in basketball, in feed milling you must be clear about your target, your main objective. In Maljkovic´s case, the objective was not to make basketball games attractive for the public, just as it was not to his objective to showcase his players. His target was to win the Euro title.

The same goes for the feed mill. Sure, you have several objectives, but there must be a main one. Say your primary objective is to maximize profit. If that is the case, then the next step is to be sure of what the market demands. This way you can avoid spending money for added value on something that the market is unwilling to pay for.

Know your players

Once you know what outcome you can deliver and what the market is prepared to pay for, the next step is analytics.

You must dive deep into your feed mill and get all the data on your “players”: raw materials, technology, people, machines, parameters, logistics etc. You must understand the current status and capabilities of your players, with advantages and limitations. Your job is to use them to the best of their capabilities in order to achieve your objective.

Know the interconnections between players

Just as every player depends on others, also feed mill processes are related and interdependent. If you want to have fine grinding, you will achieve better PDI, but it will cost more energy in milling and the result may not be as good for some categories of animals. Is this efficient and acceptable? It all depends on your main objective.

Balancing between pros and cons and walking that thin line is what efficiency means. With these challenges looming large, finding that balance will be the main task in feed milling.

Be curious

“Be curious” is one of the values of our company, but I would prompt anyone to adopt it. Play with parameters, support operators to do it, and find the point that yields maximum return for your specific objective.

Literature without your own data is fiction. In literature you can find data that says, for instance, that for every 15°C you have 1% more moisture. You can also find literature that says you have 1% more moisture for every 12°C or every 17°C. But what is the ratio in your feedmill? If you do not know, you are still not diving deep enough.

You need to figure out the interconnected factors in your own production. If you calculate by the books and official recommendations, you are adjusting work in some other feed mill, not yours. Yes: guidance is very important to understand relations and to be aware of margins. But inside those margins, you have to find your own numbers.

Find the least opportunity cost

Very often I see goals that are rebels without a cause. Take PDI, for instance. PDI is an important value, no doubt. It has been shown that better PDI correlates with better FCR etc.

However, when you set a target value for PDI you need to be sure that future investment in increasing PDI is relevant to your customers – and that they are willing to pay for that. Even if you are an integrator, first do the math on the benefits and the cost. With rising costs not just for you but also for your end customers, make sure the market can support the premium you are struggling to deliver. If you are sure, then find the most adequate way to win it. You can increase your PDI in lots of different ways, so you will need to calculate the least opportunity cost.

Production is a game of interdependencies. So is any team sport, in fact. When a coach makes a decision to put a star player in the spotlight, there may be a show but not always a win.

In a feed mill, the end game is always played around winning. It is a complex tactic of balancing all players and getting the most in your very specific circumstances. Our job is to identify and maximize these „synergies” in each specific case – and I can confirm that each case is different. In the end, Kukoc may have played the same game in Jugoplastika or Treviso, but no two feed mills are quite the same; even in same feed mill, two lines will not be adjusted the same way.

Keep coccidiosis under control – naturally!

header image poultry broiler shutterstock 1733838041

By Inge Heinzl, Madalina Diaconu, Ajay Awati

Often you have an extensive coccidiosis control program in place. You don’t observe any clinical signs of coccidiosis. However, at the end of the cycle, you record significantly lower body weight and a higher FCR. There is a high probability that your animals have subclinical coccidiosis. This article digs deeper into understanding why birds don’t perform as they should, why subclinical coccidiosis occurs on the farm, and why drug resistance is an important factor.

Subclinical coccidiosis – a silent enemy

Clinical coccidiosis is clearly characterized by severe diarrhea, high mortality rates, reduced feed/water intake, and weight loss. By contrast, subclinical Coccidiosis does not display any visual signs and often remains undetected.

According to De Gussem (2008), the damages caused by subclinical coccidiosis can reach up to 70% of the total cost of coccidiosis control treatments, ranging from US$ 2.3 billion to US$ 13.8 billion/year in 2020 worldwide (De Gussem, 2008; Ferreira da Cunha, 2020; Blake et al., 2020).

Monitoring coccidiosis occurrence on the farm

There are several tools available to evaluate the level of infection. The most common ones are:

Lesion scoring – is used to evaluate the damages caused by coccidiosis in the intestinal tract. Lesion scoring gives insight into the severity of the infection. Furthermore, based on the location of lesions in the GI tract, it is possible to determine the plausible Eimeria spp. responsible for the infection.

OPG (Oocyst per gram) – the number of oocysts per gram of feces indicates the level of shedding of oocysts in the manure, litter, and, eventually, in the farm environment. OPG levels may not give the exact severity of the infection in the bird but certainly provide a clear idea of its likely spread within the flock.

Ways to deal with coccidiosis on the farm

Different tools are widely used to prevent and treat coccidiosis:

Anticoccidials:                  Chemicals, ionophores

Vaccination:                       Natural strains, attenuated strains

Bio-shuttle:                        Vaccine + ionophore

Natural anticoccidials:   Phytomolecules

These coccidiosis control programs are used depending on the farm history and the severity of the infection. Traditionally, treatment was heavily dependent on chemicals and ionophores. However, rampant and unbridled use of ionophores leads to resistance in Eimeria spp. on the farm, the failure of the control program, and significant performance losses, with high mortality due to coccidiosis. Therefore, the tools mentioned above are inserted in rotation or shuttle programs to minimize the generation of resistances. In a rotation program, the anticoccidial changes from flock to flock. In a shuttle program, the anticoccidial changes within one cycle according to the feed (Chapman, 1997).

However, this strategy is often not 100% effective due to a lack of diversity and overuse of certain tools within programs. The rigorous financial optimization of the program leads to the use of cost-effective but marginally effective solutions. These factors over the period weaken the program, which seems to work well but leads to resistance to anticoccidial drugs and sets up subclinical coccidiosis.

Resistances have been reported in the US (Jeffers, 1974, McDougald, 1981), South America (McDougald, 1987; Kawazoe and Di Fabio, 1994), Europe (Peeters et al., 1994; Bedrník et al., 1989; Stephan et al., 1997), Asia (Lan et al., 2017; Arabkhazaeli et al., 2013), and Africa (Ojimelukwe et al., 2018). Chapman and co-workers (1997) even stated that resistances were documented for all anticoccidial drugs employed at this time, and new products have not been approved for decades.

Resistance and subclinical coccidiosis can be approached naturally

When an anticoccidial has lost its effectiveness due to excessive use, some resistant coccidia survive. They can cause a mild course of the disease, subclinical coccidiosis, driving the costs high. Reducing the occurrence of resistance and subclinical coccidiosis can significantly decrease the expenses of coccidiosis control programs and, eventually, the cost of production.

Increasing consumer pressure to reduce the overall usage of drugs in animal production has driven innovation efforts to find natural solutions that can be effectively used within coccidiosis control programs. However, this shift was not easy for the producers. Lack of reliable data, poor understanding of the mode of action, lack of quality optimization, and unsubstantiated claims led to the failure of many earlier-generation natural solutions.

However, the consumer-driven movement to find natural solutions to animal gut health issues has recently led to relentless innovation in this area. Knowledge, research, and technological developments are now ready to offer solutions that can be an effective part of the coccidia control program and open opportunities to make poultry production even more sustainable by reducing drug dependency.

For centuries, phytomolecules have been used for their medicinal properties and effects on the health and well-being of animals and humans. In the case of coccidiosis, tannins and saponins have been proven to support animals in coping with this disease. Tannic acids and tannic acid extracts strengthen the intestinal barrier by reducing oxidative stress and inflammation (Tonda et al., 2018). On the other hand, saponins lessen the shedding of oocysts, improve the lesion score, and, in the case of an acute infection, the occurrence of bloody diarrhea (Youssef et al., 2021).

These natural substances can be integrated into shuttle or rotation programs to reduce the use of anticoccidials and, therefore, minimize resistance development.

Pretect D: Coccidiosis programs can be strengthened naturally!

In an EU field trial conducted with more than 200 000 birds, Pretect D (a natural phytogenic-based product designed to increase the efficacy of coccidiosis control) was used in the shuttle program together with ionophores. The trial provided excellent results on zootechnical performance (figures 1-4).

Figures 1-4: Zootechnical performance of broilers with Pretect D included in the shuttle program

Trials show that Pretect D supports the efficiency of coccidiosis control programs by impairing the Eimeria development cycle when used in combination with vaccines, ionophores, and chemicals as part of the shuttle or rotation program:

  • It protects the epithelium from inflammatory and oxidative damage
  • It promotes the restoration of the mucosal barrier function

Table 1 exemplifies one way of including a natural solution (Pretect D) in actual coccidiosis control programs.

Table 1: Exemple of including Pretect D into coccidiosis control programs

Natural solutions suit both farmers and consumers

With phytomolecules partly replacing anticoccidials in rotation or shuttle programs, the use of anticoccidials in poultry production can be decreased. On the one hand, this answers consumers’ demand; on the other hand, it leads to a push-back of resistances in the long run. The returning effectiveness of the anticoccidials can reduce subclinical coccidiosis, leading to lower costs spent on this disease and a higher profit for the farmers.


Arabkhazaeli, F., M. Modrisanei, S. Nabian, B. Mansoori, and A. Madani. “Evaluating the Resistance of Eimeria spp. Field Isolates to Anticoccidial Drugs Using Three Different Indices.” Iran J Parasitol. 8, no. 2 (2013): 234–41.

Bedrník, P., P. Jurkovič, J. Kučera, and A. Firmanová. “Cross Resistance to the IONOPHOROUS Polyether Anticoccidial Drugs IN Eimeria Tenella Isolates from Czechoslovakia.” Poultry Science 68, no. 1 (1989): 89–93. https://doi.org/10.3382/ps.0680089

Blake, Damer P., Jolene Knox, Ben Dehaeck, Ben Huntington, Thilak Rathinam, Venu Ravipati, Simeon Ayoade, et al. “Re-Calculating the Cost of Coccidiosis in Chickens.” Veterinary Research 51, no. 1 (2020). https://doi.org/10.1186/s13567-020-00837-2

Chapman, H. D. “Biochemical, Genetic and Applied Aspects of Drug Resistance in Eimeria Parasites of the Fowl.” Avian Pathology 26, no. 2 (1997): 221–44. https://doi.org/10.1080/03079459708419208.

De Gussem, M., and S. Huang. “The Control of Coccidiosis in Poultry.” International Poultry Production 16, no. 5 (2008): 7–9.

Ferreira da Cunha, Anderson, Elizabeth Santin, and Michael Kogut. “Editorial: Poultry Coccidiosis: Strategies to Understand and Control.” Frontiers in Veterinary Science 7 (2020). https://doi.org/10.3389/fvets.2020.599322

Jeffers, T. K. “Eimeria Acervulina and E. Maxima: Incidence and Anticoccidial Drug Resistance of Isolants in Major Broiler-Producing Areas.” Avian Diseases 18, no. 3 (1974): 331. https://doi.org/10.2307/1589101

Kawazoe, Urara, and J. Di Fabio. “Resistance to DICLAZURIL in Field Isolates OfEimeriaspecies Obtained from Commercial BROILER Flocks in Brazil.” Avian Pathology 23, no. 2 (1994): 305–11. https://doi.org/10.1080/03079459408418998

Lan, L.-H., B.-B. Sun, B.-X.-Z. Zuo, X.-Q. Chen, and A.-F. Du. “Prevalence and Drug Resistance of Avian Eimeria Species in Broiler Chicken Farms of Zhejiang PROVINCE, CHINA.” Poultry Science 96, no. 7 (2017): 2104–9. https://doi.org/10.3382/ps/pew499

McDougald, L. R. “Anticoccidial Drug Resistance in the Southeastern United STATES: POLYETHER, IONOPHOROUS Drugs.” Avian Diseases 25, no. 3 (1981): 600. https://doi.org/10.2307/1589990

McDougald, Larry R., Jose Maria Silva, Juan Solis, and Mauricio Braga. “A Survey of Sensitivity to Anticoccidial Drugs in 60 Isolates of Coccidia from Broiler Chickens in Brazil and Argentina.” Avian Diseases 31, no. 2 (1987): 287. https://doi.org/10.2307/1590874

Ojimelukwe, Agatha E., Deborah E. Emedhem, Gabriel O. Agu, Florence O. Nduka, and Austin E. Abah. “Populations of Eimeria Tenella Express Resistance to Commonly Used Anticoccidial Drugs in Southern Nigeria.” International Journal of Veterinary Science and Medicine 6, no. 2 (2018): 192–200. https://doi.org/10.1016/j.ijvsm.2018.06.003

Peeters, Johan E., Jef Derijcke, Mark Verlinden, and Ria Wyffels. “Sensitivity of AVIAN EIMERIA Spp. to Seven Chemical and Five Ionophore Anticoccidials in Five Belgian INTEGRATED Broiler Operations.” Avian Diseases 38, no. 3 (1994): 483. https://doi.org/10.2307/1592069

Stephan, B., M. Rommel, A. Daugschies, and A. Haberkorn. “Studies of Resistance to Anticoccidials IN Eimeria Field Isolates and Pure Eimeria Strains.” Veterinary Parasitology 69, no. 1-2 (1997): 19–29. https://doi.org/10.1016/s0304-4017(96)01096-5

Tonda, RM, J.K. Rubach, B.S. Lumpkins, G.F. Mathis, and M.J. Poss. “Effects of Tannic Acid Extract on Performance and Intestinal Health of Broiler Chickens Following Coccidiosis Vaccination and/or a Mixed-Species Eimeria Challenge.” Poultry Science 97, no. 9 (2018): 3031–42. https://doi.org/10.3382/ps/pey158

Youssef, Ibrahim M., Klaus Männer, and Jürgen Zentek. “Effect of Essential Oils or Saponins Alone or in Combination on Productive Performance, Intestinal Morphology and Digestive Enzymes’ Activity of Broiler Chickens.” Journal of Animal Physiology and Animal Nutrition 105, no. 1 (2020): 99–107. https://doi.org/10.1111/jpn.13431

Antioxidants and phytomolecules mitigate quality degradation in broiler breasts

white chickens farm

By Inge Heinzl and Ajay Bhoyar, EW Nutrition

Genetic selection for faster growth of breast muscle in broilers may lead to increased incidences of different types of muscle degeneration. Downgrading the affected breast fillets results in high economic losses for the poultry meat industry.

The article discusses the three important myopathies impairing the breast muscles, their impact on the meat industry, influencing factors, and how to cope with these challenges.

Muscle degeneration heaps up with faster broiler growth

According to Sirri and co-workers (2016), breast fillets from broilers with 3.9 kg live weight carry a higher risk for myopathic lesions. Studies in different countries revealed that myopathies in broilers are not neglectable:

Country Myopathy Number of breasts examined Conditions Occurrence Reference
Italy WS 28,000 broilers commercial 12 % Petracci et al., 2013
Italy WS 70 flocks; always 500 of 35,000 breasts randomly examined commercial 43%, with 6.2% considered severe Lorenzi et al., 2014
Italy WS 57 flocks commercial 70.2 % (medium)-82.5 % (heavy-weight) Russo et al., 2015
Italy WS 16,000 samples commercial 9 % moderate22 % severe Petracci in Baldi et al., 2020
Brazil WS 25,520 commercial 10 % Ferreira et al., 2014
USA WS 960 (week 6)+ 960 (week 9) experimental Score 1: 78.4 % (wk 6)
29.9 % (wk 9)
Score 2: 14.0 % (wk 6)
53.9 % (wk 9)
Score 3:0 % (wk 6)
15.1 % (wk 9)
Kuttapan et al., 2017
Brazil WB commercial 10-20 % Carvalho, in Petracci et al., 2019
Italy WB 16,000 samples commercial 42 % moderate
18 % severe
Petracci, in Baldi et al., 2020
China WB 1,135 breast fillets commercial 61.9% Xing et al., 2020
USA WB 960 (week 6)+ 960 (week 9) experimental Score 1: 32.5 % (wk 6)
33.2 % (wk 9)
Score 2: 7.9 % (wk 6)
36 % (wk 9)
Score 3: 1.96 % (wk 6)
15.6 % (wk 9)
Kuttapan et al., 2017
Italy SM 16,000 samples commercial 4 % moderate
17 % severe
Petracci in Baldi et al., 2020
Brazil SM 5,580 samples commercial 10 % Montagna et al., 2019


Figure 1: Different myopathies in broilers (R. Baileys)

As the appearance of products is one of the most important arguments for the purchase decision, these myopathies are serious issues; the downgrading of the breast quality results in a lower reward for the producer. Kuttapan et al. (2016) estimated that 90 % of the broilers are affected by wooden breast and white striping (see below), causing about $200 million to $1 billion of economic losses to the U.S. poultry industry per year.

Wooden Breast (WB), a result of the proliferation of connective tissues

The muscle affected by the wooden breast is bulging and hard, is covered with clear, viscous fluid, and shows petechiae (see figure 2). The myopathy of the pectoralis major is “pale expansive areas of substantial hardness accompanied by white striation” (Kuttapan, 2016; Huang and Ahn, 2018; Sihvo et al., 2013). It is characterized by microscopically visible polyphasic myodegenerations with fibrosis in the chronic phase. At approximately two weeks of age, it appears as a focal lesion but then develops as a widespread fibrotic injury (Papah et al., 2017). WB can be detected by palpating the breast of the live bird.

Figure 2: Comparison of a severe wooden breast (on the left) and a healthy breast fillet (on the right)

Source: Kuttapan et al., 2016

According to Kuttapan et al. (2016), the anomaly is caused by circulatory insufficiency and increased oxidative stress resulting in damage and degeneration. Its occurrence rose with increasing growth and slaughter weights of the birds. Wooden breast is more common in male than female broilers as they show an increased expression of genes related to the proliferation of connective tissues (Baldi et al., 2021).

The hardness of the meat, a 1.2 – 1.3 % higher fat content (Soglia et al., 2016, Tasoniero et al., 2016), and the worse appearance lead to a degradation of the fillet quality (Kuttappan et al., 2012). The reduction in the water holding capacity of muscle results in toughness before and after cooking.

White Striping (WS), a result of fiber degeneration

The characteristics of WS are white striations parallel to the muscle fibers. A microscopic examination of these white stripes reveals an accumulation of lipids and a proliferation of connective tissue occurring in breast fillets and thighs (Kuttappan et al., 2013a; Huang and Ahn, 2018). Kuttapan et al. (2016) adapted a scoring system for the evaluation of the severity of WS, which he had established earlier (Kuttapan et al., 2012)(see picture 1). It was concluded that broilers fed a diet with high energy content led to higher and more efficient growth (improved feed conversion, higher live and fillet weights) but also to a higher percentage of fillets showing a severe degree of white striping.

Figure 3: Different degrees of white striping

  • 0 = normal (no distinct white lines)
  • 1 = moderate (small white lines, generally < 1 mm thick)
  • 2 = severe (large white lines, 1-2 mm thick, very visible on the fillet surface)
  • 3 = extreme (thick white bands, > 2 mm thickness, covering almost the entire surface of the fillet
  • (scoring and image source: Kuttapan, 2016)


Moreover, the WB and WS can simultaneously occur in the same muscle (Cruz et al., 2016; Kuttappan, Hargis, & Owens, 2016; Livingston, Landon, Barnes, & Brake, 2018).

Spaghetti Meat (SM), a result of decreased collagen linking

The condition of Spaghetti Meat was first mentioned by Bilgili (2015) under “Stringy-spongy”. SM is characterized by an insufficient bonding of the muscles due to an immature intramuscular connective tissue in the pectoralis major. The fiber bundles composing the breast muscle detach, and the muscle gets soft and mushy and resembles spaghetti pasta (Baldi et al., 2021). Probably due to the reduced collagen-linking degree, the texture of SM fillets is smoother after cooking (Baldi et al., 2019). In contrast to wooden breast, SM cannot be noticed in the living animal. Meat severely impacted by SM is downgraded and can only be used in further processed products, whereas slightly affected meat can be sold in fresh retailing (Petracci et al., 2019).

Another possible explanation for this myopathy may be the enormous development of the breast muscle. The thickness of its upper section might reduce muscular oxygenation by compressing the pectoral artery (Soglia et al., 2021). The spaghetti structure generally appears mainly in the superficial layer and less in the deep ones.

Oxidative stress – one link in the chain of causes for myopathies

Oxidative stress is a result of impaired blood supply

Oxidative stress is one key factor of myopathies in breast muscle. Selection for faster growth, especially for more breast meat yield, during the last 10-20 years led to increased muscle fiber diameter. The higher pressure of the surrounding fascia on the muscle tissue compresses the blood vessels, leading to a decreased blood flow, resulting in insufficient oxygen supply (hypoxia) and limited removal of metabolic by-products (Lilburn et al., 2019) from the muscle tissue. Hypoxia as – well as hyperoxia – plus the deficient removal of metabolic waste, promote the generation of free radicals (Kähler et al., 2016; Strapazzon et al., 2016; Petrazzi et al., 2019). If the endogenous antioxidant system cannot efficiently eliminate these ROS by using endogenous and exogenous antioxidants, the ultimate effect is increased oxidative stress.

Soglia and co-workers (2016) reported higher TBARS (Thiobarbituric acid reactive substances) and protein carbonyl levels, signs of oxidative stress, in severe wooden breast muscle tissue. The oxidative stress hypothesis was also supported by gene transcription analysis conducted by Mutryn et al. (2015) and Zambonelli et al. (2017).

Oxidative stress causes damage

ROS (reactive oxygen species) or free radicals are highly reactive. They can cause damage to the DNA, RNA, proteins, and lipids in the muscle cells (Surai et al., 2015), leading to inflammation and metabolic disturbances, and, in the end, the degeneration of muscle fibers (Kuttapan et al., 2021). If the regenerative capacity of the muscle cells does not countervail against the damages caused by oxidative stress, fibrous tissue and fat accumulate and lead to myopathies such as wooden breast (Petracci et al., 2019)

Oxidative stress can be managed

To support the animals in coping with oxidative stress, combining two approaches, an external and an internal, makes sense. This entails protecting feed at the same time as protecting the animal.

Chemical antioxidants preserve feed quality and prevent oxidation

Chemical antioxidants such as ethoxyquin, BHA, and BHT efficiently prevent feed oxidation. These antioxidants prevent the oxidation of unsaturated fats/oils and maintain their energy value. They are scavengers for free radicals, protect trace minerals like Zn, Cu, Mg, Se, and Vit E from oxidation and spare them to be used in the body for different metabolic processes as well as for the endogenous antioxidant system.

Antioxidant capacity of Santoquin M 6 in feed confirmed in a trial

In a trial conducted by Kuttapan et al. (2021), Santoquin M 6, a product based on ethoxyquin, was tested concerning its ability to minimize the oxidative damage caused due to the feeding of oxidized fat. A control group receiving oxidized fat in feed was compared to a group receiving oxidized fat plus 188 ppm Santoquin M6 (≙125 ppm ethoxyquin). The main parameters for this study were TBARS in the breast muscle, the incidence of wooden breast, and the live weight on day 48.

Results indicated that the inclusion of Santoquin M 6 reduced the level of TBARS in the breast muscles, demonstrating a lower level of oxidative stress in the breast muscles. Additionally, it improved the 48-day live weight by 131 g.


The results also indicated that the inclusion of Santoquin M 6 reduced the incidence of severe woody breasts (Score 3) by almost half. It can be concluded that the inclusion of Santoquin in the broiler feed not only improves the production performance but also help mitigate the impact of breast muscle degradation due to increased oxidative stress.

Phy­tomolecules act as natural antioxidants and reduce lipid oxidation in breast muscles

Inside the body, phy­tomolecules help to mitigate oxidative stress by the direct scavenging of ROS and the activation of antioxidant enzymes. Phytogenic compounds like Carvacrol and thymol possess phenolic OH-groups that act as hydrogen donors (Yanishlieva et al., 1999). These hydrogens can “neutralize” the peroxy radicals produced during the first step of lipid oxidation and, therefore, retard the hydroxyl peroxide formation. The increase in serum antioxidant enzyme activities and a resulting lower level of malondialdehyde (MDA) can be caused by cinnamaldehyde (Lin et al., 2003). MDA is a highly reactive dialdehyde generated as a metabolite in the degradation process of polyunsaturated fatty acids.

Antioxidant capacity of phytomolecules demonstrated in broilers

A trial with 480 Cobb male chicks (3 treatments, 8 replicates) was conducted at the University of Viçosa (Brazil). The breast muscles of the birds fed a blend of phy­tomolecules showed lower MDA levels and thus reduced lipid oxidation compared to the negative control, but also to the birds fed an antibiotic.

The impact of breast muscle degradation in broilers can be mitigated

The downgrading of broiler meat due to increased incidence of breast muscle myopathies is a common issue, resulting in the significant economic losses to the broiler meat producers. Oxidative stress caused due to due faster growth rate and various other stressors, including the oxidation of feed and feed ingredients, can contribute to increased incidence of woody breast and white striping. Different nutritional and management strategies are employed to reduce WB and WS in broiler production. The inclusion of synthetic antioxidants to control the oxidation in feed as well as phytomolecules to support the endogenous antioxidant system can be a part of promising tools to mitigate the impact of breast myopathies and reduce economic losses in broiler production.



Alnahhas, Nabeel, Cécile Berri, Marie Chabault, Pascal Chartrin, Maryse Boulay, Marie Christine Bourin, and Elisabeth Le Bihan-Duval. “Genetic Parameters of White Striping in Relation to Body Weight, Carcass Composition, and Meat Quality Traits in Two BROILER Lines Divergently Selected for the Ultimate PH of the Pectoralis Major Muscle.” BMC Genetics 17, no. 1 (2016). https://doi.org/10.1186/s12863-016-0369-2.

Baldi, Giulia, Francesca Soglia, and Massimiliano Petracci. “Current Status of Poultry Meat Abnormalities.” Meat and Muscle Biology 4, no. 2 (2020). https://doi.org/10.22175/mmb.9503.

Baldi, Giulia, Francesca Soglia, and Massimiliano Petracci. “Spaghetti Meat Abnormality in Broilers: Current Understanding and Future Research Directions.” Frontiers in Physiology 12 (2021). https://doi.org/10.3389/fphys.2021.684497.

Baldi, Giulia, Francesca Soglia, Luca Laghi, Silvia Tappi, Pietro Rocculi, Siria Tavaniello, Daniela Prioriello, Rossella Mucci, Giuseppe Maiorano, and Massimiliano Petracci. “Comparison of Quality Traits among Breast Meat Affected by Current Muscle Abnormalities.” Food Research International 115 (2019): 369–76. https://doi.org/10.1016/j.foodres.2018.11.020.

Boerboom, Gavin, Theo van Kempen, Alberto Navarro-Villa, and Adriano Pérez-Bonilla. “Unraveling the Cause of White Striping in Broilers Using Metabolomics.” Poultry Science 97, no. 11 (May 28, 2018): 3977–86. https://doi.org/10.3382/ps/pey266.

Carvalho, Leila M, Josué Delgado, Marta S Madruga, and Mario Estévez. “Pinpointing Oxidative Stress behind the White Striping Myopathy: Depletion of Antioxidant Defenses, Accretion of Oxidized Proteins and Impaired Proteostasis.” Journal of the Science of Food and Agriculture 101, no. 4 (2020): 1364–71. https://doi.org/10.1002/jsfa.10747.

Editors, AccessScience. “U.S. Bans Antibiotics Use for Enhancing Growth in Livestock.” Access Science. McGraw-Hill Education, January 1, 1970. https://www.accessscience.com/content/u-s-bans-antibiotics-use-for-enhancing-growth-in-livestock/BR0125171.

Ferreira, T.Z., R.A. Casagrande, S.L. Vieira, D. Driemeier, and L. Kindlein. “An Investigation of a Reported Case of White Striping in Broilers.” Journal of Applied Poultry Research 23, no. 4 (2014): 748–53. https://doi.org/10.3382/japr.2013-00847.

Hashemipour, H., H. Kermanshahi, A. Golian, and T. Veldkamp. “Effect of Thymol and Carvacrol Feed Supplementation on Performance, Antioxidant Enzyme Activities, Fatty Acid Composition, Digestive Enzyme Activities, and Immune Response in Broiler Chickens.” Poultry Science 92, no. 8 (2013): 2059–69. https://doi.org/10.3382/ps.2012-02685.

Huang, Xi, and Dong Uk Ahn. “The Incidence of Muscle Abnormalities in Broiler Breast Meat – a Review.” Korean journal for food science of animal resources 38, no. 5 (October 2018): 835–50. https://doi.org/10.5851/kosfa.2018.e2.

Kolakshyapati, Manisha. “Proteoglycan and Its Possible Role in ” Wooden Breast ” Condition in Broilers.” Nepalese Journal of Agricultural Sciences 13 (September 1, 2015): 253–60.

Kuttappan, V.A., B.M. Hargis, and C.M. Owens. “White Striping and Woody Breast Myopathies in the Modern Poultry Industry: A Review.” Poultry Science 95, no. 11 (2016): 2724–33. https://doi.org/10.3382/ps/pew216.

Kuttappan, V.A., C.M. Owens, C. Coon, B.M. Hargis, and M. Vazquez-Añon. “Incidence of Broiler Breast Myopathies at 2 Different Ages and Its Impact on Selected Raw Meat Quality Parameters.” Poultry Science 96, no. 8 (2017): 3005–9. https://doi.org/10.3382/ps/pex072.

Kuttappan, V.A., H.L. Shivaprasad, D.P. Shaw, B.A. Valentine, B.M. Hargis, F.D. Clark, S.R. McKee, and C.M. Owens. “Pathological Changes Associated with White Striping in Broiler Breast Muscles.” Poultry Science 92, no. 2 (2013): 331–38. https://doi.org/10.3382/ps.2012-02646.

Kuttappan, V.A., Y.S. Lee, G.F. Erf, J.-F.C. Meullenet, S.R. McKee, and C.M. Owens. “Consumer Acceptance of Visual Appearance of Broiler Breast Meat with Varying Degrees of White Striping.” Poultry Science 91, no. 5 (2012): 1240–47. https://doi.org/10.3382/ps.2011-01947.

Kuttappan, Vivek A., Megharaja Manangi, Matthew Bekker, Juxing Chen, and Mercedes Vazquez-Anon. “Nutritional Intervention Strategies Using Dietary Antioxidants and Organic Trace Minerals to Reduce the Incidence of Wooden Breast and Other Carcass Quality Defects in Broiler Birds.” Frontiers in Physiology 12 (2021). https://doi.org/10.3389/fphys.2021.663409.

Kuttappan, Vivek A., Megharaja Manangi, Matthew Bekker, Juxing Chen, and Mercedes Vazquez-Anon. “Nutritional Intervention Strategies Using Dietary Antioxidants and Organic Trace Minerals to Reduce the Incidence of Wooden Breast and Other Carcass Quality Defects in Broiler Birds.” Frontiers in Physiology 12 (2021). https://doi.org/10.3389/fphys.2021.663409.

Kähler, Wataru, Frauke Tillmans, Sebastian Klapa, Inga Koch, Julia Last, and Andreas Koch. “Oxidativer Stress Durch Hyperbare Hyperoxie Und Dessen Wirkung Auf Periphere Mononukleäre Zellen (PBMC) – Eine Übersicht Über Den Aktuellen Forschungsstand Am Schifffahrtmedizinischen Institut Der Marine.” Wehrmedizinische Monatsschrift 60, no. 2 (2016): 50–55.

Lake, Juniper A., and Behnam Abasht. “Glucolipotoxicity: A Proposed Etiology for Wooden Breast and Related Myopathies in Commercial Broiler Chickens.” Frontiers in Physiology 11 (2020). https://doi.org/10.3389/fphys.2020.00169.

Lilburn, M.S., J.R. Griffin, and M Wick. “From Muscle to Food: Oxidative Challenges and Developmental Anomalies in Poultry Breast Muscle.” Poultry Science 98, no. 10 (2019): 4255–60. https://doi.org/10.3382/ps/pey409.

Lin, Chun-Ching, Sue-Jing Wu, Cheng-Hsiung Chang, and Lean-Teik Ng. “Antioxidant Activity of Cinnamomum Cassia.” Phytother. Res. 17 (August 7, 2003): 726–30. https://doi.org/ https://doi.org/10.1002/ptr.1190.

Linden, Jackie. “Deep Pectoral Myopathy (Green MUSCLE Disease) in Broilers.” The Poultry Site, August 9, 2021. https://www.thepoultrysite.com/articles/deep-pectoral-myopathy-green-muscle-disease-in-broilers.

Lorenzi, M., S. Mudalal, C. Cavani, and M. Petracci. “Incidence of White Striping under Commercial Conditions in Medium and Heavy Broiler Chickens in Italy.” Journal of Applied Poultry Research 23, no. 4 (2014): 754–58. https://doi.org/10.3382/japr.2014-00968.

Martindale, L., W.G. Siller, and P.A.L. Wight. “Effects of Subfascial Pressure in Experimental Deep Pectoral Myopathy of the Fowl: An Angiographic Study.” Avian Pathology 8, no. 4 (1979): 425–36. https://doi.org/10.1080/03079457908418369.

Montagna, FS, G Garcia, IA Nääs, NDS Lima, and FR Caldara. “Practical Assessment of Spaghetti Breast in Diverse Genetic Strain Broilers Reared under Different Environments.” Brazilian Journal of Poultry Science 21, no. 2 (2019). https://doi.org/10.1590/1806-9061-2018-0759.

Mutryn, Marie F, Erin M Brannick, Weixuan Fu, William R Lee, and Behnam Abasht. “Characterization of a Novel Chicken Muscle Disorder through DIFFERENTIAL Gene Expression and Pathway Analysis Using Rna-Sequencing.” BMC Genomics 16, no. 1 (2015). https://doi.org/10.1186/s12864-015-1623-0.

National Chicken Council. “Per Capita Consumption of Poultry and LIVESTOCK, 1965 to Forecast 2022, in Pounds.” National Chicken Council, June 28, 2021. https://www.nationalchickencouncil.org/about-the-industry/statistics/per-capita-consumption-of-poultry-and-livestock-1965-to-estimated-2012-in-pounds/.

Papah, Michael B., Erin M. Brannick, Carl J. Schmidt, and Behnam Abasht. “Evidence and Role Of Phlebitis and LIPID Infiltration in the Onset and Pathogenesis of Wooden Breast Disease in MODERN Broiler Chickens.” Avian Pathology 46, no. 6 (2017): 623–43. https://doi.org/10.1080/03079457.2017.1339346.

Petracci, M., F. Soglia, M. Madruga, L. Carvalho, Elza Ida, and M. Estévez. “Wooden-Breast, White Striping, and Spaghetti MEAT: Causes, Consequences and Consumer Perception of Emerging Broiler MEAT ABNORMALITIES.” Comprehensive Reviews in Food Science and Food Safety 18, no. 2 (2019): 565–83. https://doi.org/10.1111/1541-4337.12431.

Petracci, M., S. Mudalal, A. Bonfiglio, and C. Cavani. “Occurrence of White Striping under Commercial Conditions and Its Impact on Breast Meat Quality in Broiler Chickens.” Poultry Science 92, no. 6 (2013): 1670–75. https://doi.org/10.3382/ps.2012-03001.

Ruberto, Giuseppe, and Maria T Baratta. “Antioxidant Activity of SELECTED Essential Oil Components in Two Lipid Model Systems.” Food Chemistry 69, no. 2 (2000): 167–74. https://doi.org/10.1016/s0308-8146(99)00247-2.

Russo, Elisa, Michele Drigo, Corrado Longoni, Raffaele Pezzotti, Paolo Fasoli, and Camilla Recordati. “Evaluation of White Striping Prevalence and Predisposing Factors in Broilers at Slaughter.” Poultry Science 94, no. 8 (2015): 1843–48. https://doi.org/10.3382/ps/pev172.

Schulze, Dieter. “Aktuelles Aus Der Broilermast .” Presentation – 7. Tagung des VET Arbeitskreises Geflügelforschung Tiergesundheit beim Nutzgeflügel, Rust, 2018.

Sihvo, H.-K., K. Immonen, and E. Puolanne. “Myodegeneration with Fibrosis and Regeneration in the Pectoralis Major Muscle of Broilers.” Veterinary Pathology 51, no. 3 (May 26, 2014): 619–23. https://doi.org/10.1177/0300985813497488.

Sirri, F., G. Maiorano, S. Tavaniello, J. Chen, M. Petracci, and A. Meluzzi. “Effect of Different Levels of Dietary Zinc, Manganese, and Copper from Organic or Inorganic Sources on Performance, Bacterial Chondronecrosis, Intramuscular Collagen Characteristics, and Occurrence of Meat Quality Defects of Broiler Chickens.” Poultry Science 95, no. 8 (2016): 1813–24. https://doi.org/10.3382/ps/pew064.

Soglia, Francesca, Luca Laghi, Luca Canonico, Claudio Cavani, and Massimiliano Petracci. “Functional Property Issues in Broiler Breast Meat Related to Emerging Muscle Abnormalities.” Food Research International 89 (2016): 1071–76. https://doi.org/10.1016/j.foodres.2016.04.042.

Strapazzon, Giacomo, Sandro Malacrida, Alessandra Vezzoli, Tomas Dal Cappello, Marika Falla, Piergiorgio Lochner, Sarah Moretti, Emily Procter, Hermann Brugger, and Simona Mrakic-Sposta. “Oxidative Stress Response to Acute Hypobaric Hypoxia and Its Association with Indirect Measurement of Increased Intracranial Pressure: A Field Study.” Scientific Reports 6, no. 1 (2016). https://doi.org/10.1038/srep32426.

Surai F, Peter. “Antioxidant Systems in Poultry Biology: Superoxide Dismutase.” Journal of Animal Research and Nutrition 01, no. 01 (2016). https://doi.org/10.21767/2572-5459.100008.

Tasoniero, G., M. Cullere, M. Cecchinato, E. Puolanne, and A. Dalle Zotte. “Technological Quality, Mineral Profile, and Sensory Attributes of Broiler Chicken Breasts Affected by White Striping and Wooden Breast Myopathies.” Poultry Science 95, no. 11 (2016): 2707–14. https://doi.org/10.3382/ps/pew215.

United Nations. “How Your Company Can Advance Each of THE SDGS: UN Global Compact.” How Your Company Can Advance Each of the SDGs | UN Global Compact. Accessed August 31, 2021. https://www.unglobalcompact.org/sdgs/17-global-goals.

Xing, T., X. Zhao, L. Zhang, J.L. Li, G.H. Zhou, X.L. Xu, and F. Gao. “Characteristics and Incidence of Broiler Chicken Wooden Breast Meat under Commercial Conditions in China.” Poultry Science 99, no. 1 (2020): 620–28. https://doi.org/10.3382/ps/pez560.

Zambonelli, Paolo, Martina Zappaterra, Francesca Soglia, Massimiliano Petracci, Federico Sirri, Claudio Cavani, and Roberta Davoli. “Detection of Differentially Expressed Genes in Broiler Pectoralis Major Muscle Affected by White Striping – Wooden Breast Myopathies.” Poultry Science 95, no. 12 (2016): 2771–85. https://doi.org/10.3382/ps/pew268.


Organic acids: How the mode of action delivers benefits | INFOGRAPHIC

feed quality silos kv

Download this comprehensive A3 infographic to understand how organic acids can benefit your operation. For further questions or feedback, we’ll be happy to hear from you.

Contact Us

How nutritionists can adjust feed formulation costs – and still keep all value

feed price increase

By Fellipe Barbosa and Marisabel Caballero


More than five months after the start of the war in Ukraine, we are facing severe challenges in many aspects of our daily lives. The livestock industry is not excepted: the conflict affects the availability and prices of grains, fertilizers, oil, and biofuel, with the latter two having a direct impact on freight rate and shipping time.

Livestock producers face challenging times and must be rational and creative to continue managing profitable operations.

Increased prices for feed materials and energy 

Which strategies are available?

Maintaining performance and profitability during price hikes generally requests a combination of different nutritional strategies to, at least partially, compensate for the higher costs:

  • using alternative feed ingredients such as by-products (while considering their limitations in terms of inclusion and quality)
  • eliminating or reducing safety bands (especially to already used by-products)
  • revising the use of feed additives according to current challenges in feed ingredients and at farms
  • following on the previous one: strategic uses of enzymes, emulsifiers, and feed additives that may help the animals to improve their FCR.

By-products can partly compensate for high feed-ingredient prices

Over the last few decades, industrial and agricultural by-products from crops, vegetables, and fruit processing have been widely evaluated and used in livestock. As a result, many studies have been conducted to determine the nutritional composition of straws and residues from food manufacturing.Now more than ever, by-products are needed since more of the leading agricultural products will be taken to feed the human population instead of animals.

Agricultural by-products can be classified into various types: straws,  brans, midds, cakes, meals, and industry residues, among others. Their price is typically lower than traditional energy and protein sources, making them suitable alternative ingredients to potentially reduce the overall cost of the diet.

Wheat milling by-product

The use of by-products – to what must be paid attention?

To guarantee safety and effectiveness, just as with any other feedstuff, it is necessary to check the nutrient composition of the alternative ingredients using feed composition tables and laboratory analysis. Besides the composition and nutrient concentration, the availability of these nutrients and palatability are critical parameters to consider. The feed/animal producer, when purchasing by-products, should:

  • try to find his by-product sources close to the feed production site to reduce costs with logistics and transportation
  • collect and test samples right after the by-products are delivered
  • check if the feed mill is ready to handle and process those ingredients, especially when they are bulky or have flowability issues;
  • compare the difference in animal performance and cost per unit produced when using traditional grain-soybean meal diets vs. by-product ingredients.

Processing for improving by-products’ quality

The safety and nutritional availability of by-products can be improved by chemical, physical, and biological treatments. Physical processes, such as drying, grinding, peeling, pelleting, extruding, and expanding, increase surface area and can deactivate certain anti-nutritional factors. Biological processes include the use of enzymes and microbial fermentation to tackle anti-nutritional factors and increase the nutritional value and digestibility of by-products.

Be aware of the possible risks of by-products!

With all the economic benefits and positive impacts on animal performance, we must not lose sight of the possible risks and health issues that by-products might imply.

Mycotoxins can be a problem

Most agricultural by-products have a higher moisture content than traditional ingredients. High-fiber and high-moisture materials can quickly become contaminated by molds that produce mycotoxins, undermining animal performance or even leading to death (Juan et al., 2017; Peng et al., 2018).

Fusarium ssp. produce mycotoxins such as fumonisins, trichothecenes (DON, T-2 toxin) or zearalenone

Anti-nutritional factors negatively impact animal health

In addition, some agro-industrial by-products contain anti-nutritional factors (glycoalkaloids, tannins). These substances impair feed digestibility and affect animal performance (Jimenez-Moreno et al., 2019). Also, a high fiber content in the diet containing by-products limits the performance (Pereira et al., 2019).

Additives can help with cost reduction

Due to the increase in feed prices, it is also necessary to review the strategies for using feed additives in animal production. Enzymatic complexes or packages, mannanases, phytases, and xylanases, among others, might be a helpful option to maximize the yield of existing diets. For example, Edward et al. (2000) reviewed the benefits of using phytase for better phosphorus utilization in the diet (a raw material that also suffers from price increases since much of it is imported from China). However, the enzymes must be used properly. Nutritionists trying to create profitable formulations must check the availability of the substrate before including the enzyme in their formulation.

Other feed additives such as toxin binders reduce the exposure of animals to possible increased levels of mycotoxins. Gut health-improving additives such as pro/pre-biotics, phytomolecules, and MCFAs support gut health and performance, achieving similar levels as traditional diets.

These applications should be thoroughly evaluated as the return from their application may be interesting in increased by-products diets.

Using by-products in poultry means balancing several factors

In poultry feeds, using by-products to increase sustainability and cost-reduction is supported by ample research and practice, especially in feed for broilers and laying hens. Research focuses on finding the risks of the inclusion of various by-products and thus the levels at which their inclusion doesn’t hurt health and performance.

In summary, to use by-products in poultry diets, their cost, availability, nutritional composition, anti-nutritional factors, quality, as well as interaction and cost-effectiveness with feed additives (e.g., enzymes, toxin binders) must be considered to avoid or diminish the factors hindering animal health and performance.

Several factors must be considered when using by-products in poultry nutrition

DDGS are a valuable source of proteins – but limited inclusion

DDGS provide protein, energy, water-soluble vitamins, xanthophylls, and linoleic acid (Abd El-Hack et al., 2015). However, it also contains anti-nutritional factors such as non-starch polysaccharides (NSP) (Pedersen et al., 2014). A further disadvantage is their high danger of mycotoxin contamination (Schaafsma et al., 2009), even though Wang et al. (2007) and Damasceno (2020) indicate that up to 16% of DDGS can be included in broilers’ diets without negatively affecting health, performance, and meat characteristics.

Rice brans are one of the main available grain by-products

Rice brans constitute 10% of the paddy rice and thus represent a considerable global volume of the available grain by-products. As a feed ingredient, it is rich in protein, starch, fat, vitamins, and some trace minerals (Sanchez et al., 2019). Due to their susceptibility to oxidation (rancidity) and anti-nutritional factors such as phytase and trypsin inhibitors (Gallinger et al., 2004), the limit recommended for this by-product in poultry is around 10% (Hosseini et al., 2020; Sanchez et al., 2019).

Wheat by-products – optimally used with enzymes

Wheat by-products can also be a substitute for whole grains in poultry feeds; however, their NSP content can affect the viscosity of the digesta (Knudsen, 2014). When combined with enzymes (e.g., xylanase), wheat midds can be included in broiler and layer diets up to 30% without changes in performance (Abudabos, 2011; Salami et al., 2018). Dietary fiber has gained special attention due to its various beneficial effects on poultry. In this direction, moderate amounts of wheat bran – a source of insoluble fiber – have shown improved antioxidant status, gizzard development, intestinal digestive enzyme activities, and morphology in broilers (Shang et al., 2020).

By-products support pigs’ performance

When by-products are fed to pigs, swine nutritionists have reported that many of them can support pig growth and finishing performance and meat quality as well as immune response, milk yield, and milk quality in reproductive animals, among other productive parameters (Yang et al., 2021). For instance, Dong et al. (2019) concluded that, from a nutritional perspective, ingredients such as highland barley, buckwheat, glutinous broomcorn millet, non-glutinous broomcorn millet, and Chinese naked oat could potentially substitute corn in livestock feeding. Or as another example, Liu et al. (2019) suggest in their study that mulberry leaf can contribute to improvements in meat quality, with no adverse effects on the growth performance of finishing pigs. (Dong et al., 2019).

Pigs are susceptible to antinutritional factors

Especially pigs are susceptible to anti-nutritional factors

There are many different types of anti-nutritional factors that work in various ways. In swine feed, common anti-nutritional factors lower protein and amino acid digestibility and increase endogenous amino acid losses (Souffrant, 2001). This effect causes reductions in carcass yield for finishing pigs (Soto et al., 2019).

Options are available to compensate for the higher feed prices

Nutritionists have several options to optimize animal performance in the context of price increases. However, it is necessary to have a more holistic view of the business to know which of all the alternatives are the most suitable for each system. Understanding the strengths and weaknesses of each ingredient and feed additive and considering them in the light of literature and field data will yield the best understanding of how to use them effectively in successful animal production.


Stop endotoxins from decreasing animal performance

e coli shutterstock 347266496

By Marisabel CaballeroGlobal Technical Manager Poultry, and Sabria Regragui Mazili, Editor

Find out why endotoxemia threatens animal production and how intelligent toxin mitigation solution SOLIS MAX can support endotoxin management.

Figure 1: Structure of Lipopolysaccharide

The quick guide to endotoxins (LPS) and what to do about them

Lipopolysaccharides (LPS) are a constant challenge for animal production. LPS, which are also known as endotoxins, are the major building blocks of the outer walls of Gram-negative bacteria (see figure 1). Throughout its life cycle, a bacterium releases these molecules upon cell death and lysis. When endotoxins are released into the intestinal lumen of chickens or swine, or in the rumen of polygastric animals, they can cause serious damage to the animal’s health and performance by over-stimulating their immune system.

LPS may induces inflammation and fever, lowering feed intake, and redirecting nutritional resources to the immune response, which results in hindered animal performance.

Endotoxins depress animal performance

One of the biggest issues caused by endotoxemia is that animals reduce their feed intake and show a poor feed conversion rate (FCR). Why does this happen? The productive performance of farm animals (producing milk, eggs, or meat) requires nutrients. An animal also requires a certain baseline amount of nutrients for maintenance, that is, for all activities related to its survival.

As a result of inflammation, endotoxemia leads to a feverish state. Maintenance needs to continue; hence, the energy required for producing heat will be diverted from the nutrients usually spent on production of milk, eggs, meat, etc., and performance suffers. This is amplified because the immune reaction also requires resources (e.g., energy, amino acids, etc. to produce more immune cells).

The inflammation response can result in mitochondrial injury to the intestinal cells, which alter the cellular energy metabolism. This is reflected in changes to the levels in adenosine triphosphate (ATP), the energy “currency” of living cells. A study by Li et al. (2015) observed a respective reduction of 15% and 55% in the ATP levels of the jejunum and ileum of LPS-challenged broilers, compared to the unchallenged control group.

piglet study by Huntley, Nyachoti, and Patience (2017) found that LPS-challenged pigs retained 15% less of the available metabolizable energy and showed 25% less nutrient deposition (figure 2). These results illustrate how animal performance declines during endotoxemia.

  • Control treatment (CON) = Pigs fed by a basal diet
  • Immune system stimulation treatment (ISS) = Pigs given LPS (E. coli serotype 055:B5) injection

Figure 2: Retained Energy as % of ME intake and nutrient deposition of pigs in metabolic cages (adapted from Huntley, Nyachoti, and Patience, 2017)

A loss of energy retained due to a reduction in available metabolizable energy leads to losses in performance as the amount of energy available for muscle production and fat storage will be lower. Furthermore, the decrease in feed intake creates a further energy deficit concerning production needs.

Endotoxin tolerance

The repeated exposure to LPS leads to the production of anti-inflammatory cytokines, as a reaction of the body to prevent tissue damage due to the excessive inflammation. This immunosuppression during stress may lead to an increased risk of secondary infection and poor vaccination titers.

LPS tolerance, also known as CARS (compensatory anti-inflammatory response syndrome) essentially depresses the immune system to control its activity. This “regulation” can be extremely dangerous as an excessive depression of the immune system leaves the organism exposed to the actual pathogens.

The way forward: Natural endotoxin mitigation with SOLIS MAX

The quantity of Gram-negative bacteria in an animal intestine is considerable; therefore, the danger of immune system over-stimulation through endotoxins cannot be taken lightly. Stress factors – that are not uncommon in animal production – affect the microbiome (favoring gram-negative bacteria) and also decrease the intestinal barrier function, which leads to the passage of LPS into the bloodstream

Animals suffering from endotoxemia are subject to severe metabolic dysfunctions. If they do not perish from septic shock (and most of them do not), they are still likely to show performance losses. Moreover, they at great risk of immunosuppression caused by CARS, the immune system “overdrive” discussed above.

Fortunately, research shows that EW Nutrition’s SOLIS MAX effectively binds bacterial toxins, helping to prevent these scenarios.

In vitro trial shows SOLIS MAX’ effectiveness against bacterial endotoxins

Binding endotoxins in the gastrointestinal tract, especially during stress situations in animal production, can help to mitigate the negative impact of LPS on the animals. It reduces the endotoxins passing into the bloodstream and entering the organism.

SOLIS MAX is a synergistic combination of natural plant extracts, yeast cell walls, and natural clay minerals. An in vitro study conducted at a research facility in Germany evaluated its binding performance for LPS derived from E. coli.

To test the efficacy of SOLIS MAX in binding endotoxins, 0.1% (w/v) of SOLIS MAX was resuspended in endotoxin-free water, with and without a challenge of 25,2568 EU/ml. After one hour, the solutions were centrifuged and the supernatants tested for LPS using Endo-LISA test kits.

The results show that 1 mg of SOLIS MAX adsorbs 20 endotoxin units (EU) of E. coli endotoxin, which corresponds – for this challenge – to an 80% adsorption rate (figure 3).

Figure 3: SOLIS MAX effectively adsorbs E. coli endotoxins

Endotoxin solution SOLIS MAX: Stabilize gut health, support performance

The detrimental impact of LPS can be mitigated by using a high-performance solution such as SOLIS MAX. To prevent negative health and performance outcomes for the animal it is important to stabilize the challenged intestinal barrier and to support the balance of the gut microbiome. Binding endotoxins before they can exert their damaging impact is the primary objective, which SOLIS MAX achieves through the intelligent interaction of natural plant extracts. This can be expected to yield positive results in terms of production levels and the prevention of secondary infections, preserving animal health and farms’ economic viability.


Adib-Conquy, Minou, and Jean-Marc Cavaillon. “Compensatory Anti-Inflammatory Response Syndrome.” Thrombosis and Haemostasis 101, no. 01 (2009): 36–47. https://doi.org/10.1160/th08-07-0421.

Huntley, Nichole F., C. Martin Nyachoti, and John F. Patience. “Immune System Stimulation Increases Nursery Pig Maintenance Energy Requirements.” Iowa State University Animal Industry Report 14, no. 1 (2017). https://doi.org/10.31274/ans_air-180814-344.

Li, Jiaolong, Yongqing Hou, Dan Yi, Jun Zhang, Lei Wang, Hongyi Qiu, Binying Ding, and Joshua Gong. “Effects of Tributyrin on Intestinal Energy Status, Antioxidative Capacity and Immune Response to Lipopolysaccharide Challenge in Broilers.” Asian-Australasian Journal of Animal Sciences 28, no. 12 (2015): 1784–93. https://doi.org/10.5713/ajas.15.0286.

Pushing the microbiome in the right direction – with phytomolecules!

gut bacteria

by Dr. Inge Heinzl, Editor

From day 1, young animals are confronted with the pathogens of their environment. Feed and feed ingredients also significantly increase exposure to microbes. This article will look closely at three critical bacteria in poultry production. The trials of phytomolecules-based products shared in this article prove the unique benefit of lowering harmful pathogens while simultaneously sparing health-promoting microbes. The targeted selection of the blend’s phytomolecules contributes to this distinctive mode of action.

E. coli can be valuable… and dangerous

E.coli are commensal bacteria that usually belong to the natural gut flora. However, there are several E. coli strains that, due to certain virulence factors, can cause disease. These bacteria are called avian pathogenic E. coli or APEC. The disease ‘Colibacillosis’ can occur in different forms:

  • Omphalitis – a noncontagious infection of the navel and/or yolk sac in young poultry
  • peritonitis – inflammatory response on “internal laying” (yolk material in the peritoneum)
  • salpingitis – inflammation of the oviduct
  • cellulitis – discoloration and thickening of the skin, inflammation of the subcutaneous tissues
  • synovitis – lameness with swollen joints
  • coligranuloma (Hjärre disease) – lesions similar to tuberculosis, not of economic importance
  • meningitis, and
  • septicemia or blood poisoning.

Since some of the E. coli strains can sometimes be transmitted vertically to offspring, it is crucial to keep the pathogenic pressure in the parent generation as low as possible (Mc Dougal, 2018).

Due to the, mostly in young chicks, common use of antibiotics, E. coli strains resistant to ß-lactam antibiotics (ESBL-producing E. coli) or fluoroquinolones (e.g., Enrofloxacin) have developed.

Clostridium perfringens: the cause of necrotic enteritis

Clostridium perfringens belong to the normal caecal flora. However, its overgrowth in the intestine is linked to necrotic enteritis, causing estimated losses of up to USD 6 billion yearly in global poultry production, which corresponds to USD 0.0625 per bird (Wade and Keyburn, 2015). Necrotic enteritis can occur in a clinical and a subclinical form.

In the case of clinical necrotic enteritis, the birds suffer from diarrhea resulting in wet litter and increased flock mortality of up to 1 % per day (Ducatelle and Van Immerseel, 2010). Mortality rates sometimes sum up to 50 % (Van der Sluis, 2013). If birds die without clinical signs, it may be peracute necrotic enteritis.

The subclinical version, however, is more critical. Due to the lack of symptoms, it often remains undetected and, therefore, not treated. Mainly through the impaired utilization of feed, representing 65-75 % of the total costs in broiler production, subclinical necrotic enteritis permanently impacts production efficiency (Heinzl et al., 2020).

Salmonella enterica: a zoonosis relevant for birds and humans

Most concerning in (non-typhoid) salmonellosis is that it can be transferred to humans. The transmission occurs via direct contact with an infected animal, consuming contaminated animal products such as meat or eggs, contact with infected vectors (insects or pets) or contaminated equipment, or cross-contamination in the kitchen. Frozen or raw chicken products, as well as the eggs, are frequent causes of animal-origin Salmonella infections in humans.

Salmonella is the more critical the younger the birds. If the hatching eggs already carry salmonellae, the hatchability dwindles. During their first weeks of life, infected chicks show higher mortality and systemic infections.

Adult animals usually do not die from salmonellosis; often, the infection remains unnoticed. During an acute salmonella outbreak, the animals might show weakness and diarrhea. They lose weight, resulting in decreased egg production in layers.

Trials with phytomolecules show promising results

To check if phytomolecules-based products can effectively influence gut flora, a product specially designed for gut health (Ventar D) was tested for its antimicrobial activity. Additionally, the extent to which the same blend impacted the beneficial bacteria, such as Lactobacilli, was evaluated.

Trial 1: phytomolecules act against E. coli and Salmonella enterica

The in vitro study using the agar dilution method was conducted at a German laboratory.

The bacteria (Salmonella typhimurium and ESBL-producing E. coli) stored at -80°C were reactivated by cultivating them on Agar Mueller Hinton overnight. After this incubation, some colonies were picked and suspended in 1 ml 0.9% NaCl solution. 100 µl of the suspension were pipetted and evenly spread (plate spread technique) on new Agar Mueller Hinton containing different concentrations of a phytomolecules-based product (Ventar D): 0 µg/mL – control; 500 µg/mL; 900 µg/mL; 1.250 µg/mL and 2.500 µg/mL. After 16-20 h incubation at 37°C, growth was evaluated. The results can be seen in pictures 1 and 2:

Figure 1: E. coli exposed to different concentrations of Ventar D (upper row from left to right: control 0 µg/ml, 500 µg/ml, 900 µg/ml; lower row from left to right: 1250 µg/ml and 2500 µg/ml)

E. coli colonies exposed to 900 µg/mL of Ventar D’s phytogenic formulation were smaller than the control colonies. At 1250 µg/mL, fewer colonies were detected, and at 2500 µg/mL, growth couldn’t be seen anymore.

The salmonella colonies showed a similar picture; however, the reduction could be seen from a concentration of 1.250 µg/ml of Ventar D onwards (picture 2).

Figure 2: Salmonella enterica exposed to different concentrations of Ventar D (upper row from left to right: control 0 µg/ml, 500 µg/ml, 900 µg/ml; lower row from left to right: 1250 µg/ml and 2500 µg/ml)

Trial 2: Phytomolecules inhibit Clostridium perfringens and spare Lactobacilli

In this trial, the bacteria (Clostridium perfringens, Lactobacillus agilis S73, and Lactobacillus plantarum) were cultured under favorable conditions (RCM, 37°C, anaerobe for Clostr. perfr., and MRS, 37°C, 5 % CO2 for Lactobacilli) and exposed to different concentrations of Ventar D (0 µg/ml – control, 500 µg/ml, 750 µg/ml, and 1000 µg/ml).

The results are shown in figures 3a-d.

Figure 3a: control, 0 µg/ml

Figure 3b: 500 µg/ml

Figure 3c: 750 µg/ml

Figure 3d: 1000 µg/m


In the case of Clostridium perfringens, a significant reduction of colonies could already be observed at a concentration of 500 µg/ml of Ventar D. At 750 µg/ml, only a few colonies remained. At a Ventar D concentration of 1000 µg/ml, Clostridium perfringens could no longer grow.

In contrast to Clostridium, the Lactobacilli showed a different picture: only at the higher concentration (1250 µg/ml of Ventar D), Lactobacillus plantarum and Lactobacillus agilis S73 showed a slight growth reduction (figures 4 and 5).

Figure 4: Lactobacillus plantarum exposed to 0 (left) and 1250 µg/ml (right) of Ventar D

Figure 5: Lactobacillus agilis S73 exposed to 0 (left) and 1250 µg/ml (right) of Ventar D

Improve gut health by positively influencing the intestinal flora

The experiments show that even at lower concentrations, phytomolecules impair the growth of harmful bacteria while sparing the beneficial ones. Phytomolecule-based products can be regarded as a valuable tool for controlling relevant pathogens in poultry and influencing the microflora composition in a positive way.

The resulting better gut health is the best precondition to reducing antibiotics in animal production.

Global mycotoxin report: Jan-June 2022 | Find the pain points

myco map 22

by  Marisabel Caballero and Vinil Samraj Padmini, EW Nutrition GmbH

The pressure of climate change is taking a severe toll – not just on weather-dependent industries, but already on society in general. For feed and food, the impact is already dramatic. Extreme weather events, increased temperatures, and rising carbon dioxide levels are facilitating the growth of toxigenic fungi in crops, severely increasing the risk of mycotoxin contamination. Once feed is contaminated, animal health can be impacted, with chain reactions affecting productivity for animal farming, as well as, ultimately, the quality and availability of food.

*** Download the full report for an analysis of mycotoxin contamination risks around the world

Acidifiers support piglets after weaning

8 piglet photo last page

By Dr. Inge Heinzl, editor

In piglet production, high productivity, meaning high numbers of healthy and well-performing piglets weaned per sow and year, is the primary target. Diarrhea around weaning often gets in the way of achieving this goal.

Up to the ban of antibiotic growth promoters in 2006, antibiotics were often applied prophylactically to help piglets overcome this critical time. Zinc oxide (ZnO) application is another measure that cannot be used anymore to prevent piglet diarrhea. Effective alternatives are required.

Weaning – a critical point in piglets’ life

Weaning stress is well-known to have a negative impact on the balance of the intestinal microflora and gastrointestinal functions (Miller et al., 1985). Suckling piglets have a limited ability to produce hydrochloric acid, but nature has a solution to compensate for this inadequacy. The lactobacilli present in the stomach can use the lactose in the sow’s milk to produce lactic acid (Easter, 1988). In nature, the piglets would start to eat small amounts of solid feed at about three weeks when the sow’s milk production no longer covers their nutrient demand. By increasing the feed intake, the piglets stimulate hydrogen chloride (HCl) production in their stomachs.

In piglet production, where weaning occurs at three or four weeks of age, the piglets are still not eating considerable amounts of solid feed. It is often the case that 50 % of the piglets take feed at the earliest after 24 h, and 10 % accept the first feed only after 48 h (Brooks, 2001). Additionally, hard grains in the diet can physically damage the small intestine wall, reducing villus height and crypt depth (Kim et al., 2005).

Only a minor production of HCl, no more lactose supply for the lactobacilli, varying feed intake, and high buffering capacity of the feed lead to a pH of >5 in the stomach.

The higher stomach pH is partly responsible for problems after weaning

A pH higher than 5, besides causing direct effects on the microflora in the stomach, has consequences for the whole digestive tract and digestion.

A high pH is favorable for certain microorganisms, including coliforms (Sissons, 1989) and other acid-sensitive bacteria such as Salmonella typhimurium, Salmonella typhi, Campylobacter jejuni, and V. cholerae (Smith, 2003).

  1.  Lower activity of proteolytic enzymes

    In the stomach, the conversion of pepsinogen to pepsin, which is responsible for protein digestion, is catalyzed under acid conditions (Sanny et al., 1975). Pepsin works optimally at two pH levels: pH 2 and pH 3.5 (Taylor, 1959). With increasing pH, the activity decreases; at pH 6, it stops. Therefore, a high pH can lead to poor digestion and undigested protein arriving in the intestine. There, it can be used as “feed” for harmful bacteria, leading to their proliferation. Barrow et al. (1977) found higher counts of coliforms in piglets’ intestinal tract two days after weaning, while the number of lactobacilli was depressed.

    In the lower parts of the gastrointestinal tract (GIT), the final products of the pepsin protein digestion are needed to stimulate the secretion of pancreatic proteolytic enzymes. If no final products arrive, the enzymes are not activated, and the inadequate protein digestion continues. Additionally, gastric acid is the main stimulant for bicarbonate secretion in the pancreas, neutralizing gastric acid and providing an optimal pH environment for the digestive enzymes working in the duodenum.

  2. Expedited digesta transport

    The stomach pH also influences the transport of digesta. The acidity of the chyme leaving the stomach and arriving in the small intestine is decisive for the amount of digesta being transferred from the stomach to the small intestine. Acid-sensitive receptors provide feedback regulation to prevent the stomach from emptying until the duodenal chyme can be neutralized by pancreatic or other secretions (Pohl et al., 2008). Therefore, a higher pH in the stomach leads to a faster transport of the digesta, resulting in worse feed digestion.

  3. Proliferation of microorganisms

    A high pH is favorable for certain microorganisms, including coliforms (Sissons, 1989) and other acid-sensitive bacteria such as Salmonella typhimurium, Salmonella typhi, Campylobacter jejuni, and V. cholerae (Smith, 2003).

    Elevated stomach pH + incomplete immune system = diarrhea

Acidifiers can mitigate the adverse effects of weaning on piglets

To overcome this critical time of weaning and maintain performance, acidifiers can be a helpful tool. They improve gut health, stimulate immunity, and serve as nutrient sources – while also positively affecting feed and water hygiene.

What are acidifiers?

Acidifiers’ role in pig nutrition has evolved from feed preservatives to stomach pH stabilizers, compensating for young pigs’ reduced digestive capacity (Ferronato and Prandini, 2020). They are now used to replace antibiotic growth promoters and ZnO, which were applied for a long time to mitigate the negative effects of weaning.

In general, both organic and inorganic acids and their salts feature in animal nutrition. They can be added to the feed or the water.

Organic acids: Commonly used with good results

Feed acidifiers are usually organic acids, including fatty and amino acids. Their carboxyl functional group is responsible for their acidic specificity as feed additives (Pearlin et al.,2019). Their pKa, the pH where 50 % of the acid occurs in a dissociated form, is decisive for their antimicrobial action. In animal nutrition, acids with pKa 3-5 are typically used (Kirchgeßner and Roth, 1991).

Organic acids used as feed additives can be divided into three groups:

  •  Simple monocarboxylic acids such as formic, acetic, propionic, and butyric acid
  •  Carboxylic acids with a hydroxyl group such as lactic, malic, tartaric, and citric acid
  • Short-chain carboxylic acids with double bonds – fumaric and sorbic acid.

The primary acids for pig nutrition are acetic, fumaric, formic, lactic, benzoic, propionic, sorbic, and citric acids (Roth and Ettle, 2005).

Inorganic acids – the low-cost version

Inorganic acids are cheaper than organic acids, but their only effect is to decrease the pH. Additionally, they are extremely corrosive and dangerous liquids due to their strong acidity in a pure state (Kim et al., 2005).

Salts are easier to handle

The advantage of salts over free acids is that they are generally odorless and easier to handle in the feed manufacturing process due to their solid and less volatile form. Higher solubility in water is a further advantage compared to free acids (Huyghebaert and Van Immerseel, 2011; Roth and Ettle, 2005; Partanen and Mroz, 1999). The better handling and higher palatability make acid salts a more user-friendly method to apply acids to feed and water without compromising their efficacy (Luise et al., 2020).

The salts are mainly produced with calcium, potassium, and sodium. They include calcium formate, potassium diformate, sodium diformate, and sodium fumarate.


A mixture of diverse acidifiers combines the different characteristics of these substances. Perhaps, there may be synergistic effects. Acid blends are more and more used as feed additives. They have a wider-ranging action than single substances.

Roth et al. (1996) showed that a combination of formic acid with various formats is more effective than the application of formic acid alone.

The main effects of acidifiers

Acidifiers support piglets during the critical time after weaning through different modes of action. The final results are:

  • Improvement in gut health
  • Increase in growth performance
  • Stabilization of the immune system.

1.    Improvement in gut health

As shown in figure 1, the improvement in gut health relies on the antimicrobial effect of organic acids and the decrease in the stomach’s pH.

1.1     Organic acids directly attack bacteria

Organic acids not only act through their pH-decreasing effect but also directly attack pathogens. Due to their lipophilic character, organic acids can pass the bacterial cell membrane when they are in their undissociated form (Partanen in Piva et al., 2001). The lower the external pH, the more undissociated acid can pass the membrane.

Within the cell, the pH is higher. Hence, the organic acid dissociates and releases hydrogen ions, reducing the cytoplasmic pH from alkaline to acid. Cell metabolism is depressed at lower pH. Therefore, the bacterial cell needs to expel protons to get the cytoplasmic pH back to normal. As this is an energy-consuming process, more prolonged exposure to organic acids kills the bacterium. Additionally, the anions staying within the cell disturb the cell’s metabolic processes and participate in killing the bacterium.

Studies from Van Immerseel et al. (2006) revealed that many fermentative bacteria could let their intracellular pH decline and prevent increased acid penetration. Bacteria with a neutrophil pH, however, react more sensitively.

1.1     Decreased pH reduces non-acid-tolerant pathogens

There is a direct effect of pH on the microflora. Some pathogenic bacteria are susceptible to low pH. The proliferation of, e.g., E. coli, Salmonella, and Clostridium perfringens is minimized at a pH<5. Acid-tolerant bacteria such as lactobacilli or bifidobacteria, however, survive. Many lactobacilli can produce hydrogen peroxide, which inhibits, e.g., Staphylococcus aureus or Pseudomonas spp. (Juven and Pierson, 1996).


Already Fuller (1977) showed in in vitro experiments that certain bacteria such as Streptococci, Salmonella, and B. cereus don’t grow in an environment with pH 4.5 or even die (Micrococcus). In contrast, Lactobacilli are not so susceptible to this low pH. Using the same binding sites as harmful bacteria, they suppress coliforms, for example. Kirchgeßner et al. (1997) found a stronger reduction of E. coli than Lactobacilli and Bifidobacteria in different gut segments when exposed to 1.25 % formic acid.

1.2     Recovery of eubiosis through reduction of substrate

The reduction of the pH through organic acids maintains or stimulates the secretion of proteolytic enzymes in the stomach (pepsin) and pancreatic enzymes. Additionally, the acid leaving the stomach is partly responsible for regulating gastric emptying (Ravindran and Kornegay, 1993; Mayer, 1994). Both effects by improving protein digestion, reduce the fermentable substrates arriving in the hindgut. This decreases the quantity of fermentable substrate arriving in the intestine and, therefore, the growth of undesired pathogens.

2. Promotion of growth

2.1     Enhanced digestion of macronutrients

As explained above, the acidity in the stomach is responsible for the activation and stimulation of enzymes. Additionally, the lower pH keeps the feed in the stomach for longer. Both result in better digestion.

The improved utilization of nutrients leads to higher daily gain and better feed conversion. In pigs, the growth-promoting effect of organic acids is particularly pronounced during the first few weeks after weaning (Roth and Ettle, 2005). Some examples of the growth-promoting effect of formic and propionic acid feature in table 1.

Table 1: Influence of two commonly used organic acids in animals on growth performance

Varying results are mainly due to the character of the organic acid, the dosage, the buffering capacity, and the possible reduction of feed intake in case of a high dosage (Roth and Ettle, 2005).

2.2     Improved utilization of minerals

Minerals are essential for metabolic processes and, thus, healthy growth. Chelated minerals show a higher digestibility. Acidic anions of the acidifiers form complexes (chelates) with cationic minerals such as Ca, Zn, P, and Mg. The resulting higher digestibility and absorption lead to decreased excretion of supplemented minerals and, therefore, to a lower environmental burden. Kirchgeßner and Roth (1982), e.g., reported an improved absorption and retention of Ca, P, and Zn with the addition of fumaric acid. However, there are also trials showing no effect of acidification of the diet on mineral balance (Radecki et al., 1988).

Phytic acid

Another factor influencing the absorption of minerals, mainly phosphorus, is the amount of intrinsic or microbial phytase in the diet (Rutherfurd et al., 2012). The enzyme phytase releases phosphorus out of phytic acid and increases its bioavailability. Partanen and Mroz (1999) showed that organic acids improve the performance of phytase and, therefore, the bioavailability of phosphorus in the diet.

Besides a better utilization by the animal, improved absorption of minerals means preserving the environment and direct cost-saving, as mineral supplements are expensive.

2.3     Stimulation of gut and stomach mucosal morphology

An intact gut mucosa with a preferably high surface is vital for efficient nutrient absorption. Many trials show that organic acids improve the condition of the mucosa:

Organic acids stimulate cell proliferation

In an in vitro trial with pig hindgut mucosa, butyric acid stimulated epithelial cell proliferation in a dose-dependent manner (Sakata et al., 1995).

Blank et al. reported that fumaric acid, being a readily available energy source, may have a local trophic effect on the small intestines’ mucosa. Due to faster recovery of the gastrointestinal epithelial cells after weaning, this trophic effect may increase the absorptive surface and digestive capacity in the small intestines.

Organic acids influence villi length and crypt depth in the gut

Ferrara et al. (2016) observed a trend toward longer villi with a mixture of short-chain organic acids and mid-chain fatty acids, compared to the negative control.

The addition of Na-butyrate to the feed leads to increased crypt depth, villi length, and mucosa thickness in the distal jejunum and ileum, according to Kotunia et al. (2004). However, the villi length and mucosa thickness were reduced in the duodenum.

According to Gálfi and Bokori (1990), a diet with 0.17% sodium butyrate increased the length of ileal microvilli and the depth of caecal crypts in pigs weighing between 7 and 102 kg.

Organic acids strengthen stomach mucosa

Mazzoni et al. (2008) reported that sodium butyrate applied orally at a low dose influenced gastric morphology and function (thickening the mucosa), presumably due to its action on mucosal maturation and differentiation.

2.4    Pigs can use organic acids acid as an energy source

Organic acids are usually added to the feed in small doses. As some organic acids are intermediary products of the citric acid cycle, they are an energy source after being absorbed through the gut epithelium by passive diffusion. Their gross energy can be fully metabolized (Pearlin et al., 2019; Roth and Ettle, 2005; Suiryanrayna and Ramana, 2015).

The gross energy supply varies according to the acid. Roth and Ettle (2005) determined values between 6 kJ/g (formic acid) and 27 kJ/g (sorbic acid). Pearlin et al. (2019) calculated that 1 M of fumaric acid generates 1.340 kJ or 18 M ATP; this is comparable to the energy provision of glucose. Citric acid’s energy provision is similar; acetic and propionic acid require 18 and 15 % more energy to generate 1 M ATP.

Acidifiers improve immune response

The immune system, especially at the sensitive life stage of weaning, plays an essential role for the piglet. Acidifiers have been shown to stimulate or support the immune system. Ahmed et al. (2014) showed that citric acid (0.5 %) and a blend of acidifiers composed of formic, propionic, lactic, phosphoric acid + SO2(0.4 %) significantly increased the level of serum IgG. IgG are part of the humoral immune system. They mark foreign substances to be eliminated by other defense systems.

In a trial conducted by Ren et al. (2019), piglets receiving a mixture of formic and propionic acid showed lower concentrations of plasma tumor necrosis factor-α, regulating the activity of diverse immune cells. Furthermore, interferon-γ and interleukin (Il)-1ß were lower than in the control group after the challenge with E. coli (ETEC). In this trial, the addition of organic acids to the feed alleviated the inflammatory response in a way comparable to antibiotics.

In a nutshell

Organic acids are no longer seen as pure acidifiers but as growth promoters and potential antibiotic substitutes due to their positive effect on the gastrointestinal tract. Their main effect, the decrease of pH, entails consequences from inhibiting pathogenic bacteria and improved digestion to enhanced health and growth.
Research indicates that acidifiers can be a viable alternative to antibiotic growth promoters and ZnO for ensuring healthy piglet production after weaning.