{"id":146264,"date":"2021-04-26T12:59:20","date_gmt":"2021-04-26T10:59:20","guid":{"rendered":"https:\/\/ew-nutrition.com\/moisture-optimization-feed-quality-mill-efficiency\/"},"modified":"2023-06-09T09:11:47","modified_gmt":"2023-06-09T07:11:47","slug":"moisture-optimization-feed-quality-mill-efficiency","status":"publish","type":"post","link":"https:\/\/ew-nutrition.com\/us\/moisture-optimization-feed-quality-mill-efficiency\/","title":{"rendered":"Moisture optimization: How to safeguard feed quality and feed mill efficiency"},"content":{"rendered":"
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by Technical Team, EW Nutrition<\/span><\/em><\/p>\n

In light of climatic challenges, variability in raw material quality and technical constraints, it can be challenging for feed manufacturers to optimize the water content in compound feed. <\/strong><\/p>\n

In combination with high temperatures, too much moisture in feed can favor the growth of mold. Molds spoil feed by depleting energy and nutrients and rendering the feed unpalatable. Even worse, some molds release toxins harm animals\u2019 health and performance. On the other hand, too little moisture in feed has a negative impact on feed digestibility and pellet durability, increasing the level of fines, process loss and energy consumption, while decreasing press yield (Moritz et al., 2002<\/a>).<\/p>\n

In this article, we look at how the right choice of processing aid is key to sustainably boosting feed mill efficiency. A concerted focus on moisture management when preconditioning the mash feed prior to pelleting allows feed producers to reap both economic and feed quality benefits.<\/p>\n

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Why moisture management requires both surfactants and organic acids<\/h1>\n

Moisture management starts with monitoring certain indicators. The moisture content measures the total amount of water contained in a substance, usually expressed as a percentage of the total weight. Feed manufacturers track the moisture contents of raw materials, mash feed, and pellets during all processing stages \u00a0to optimize quality, yields, and profitability.<\/p>\n

For the purpose of preventing mold growth, however, another indicator is even more critical: water activity (aw<\/sub>) is technically defined as the ratio of partial vapor pressure of water in a substance to the partial vapor pressure of pure water under the same temperature and pressure conditions. What this captures is the energy state of water in a substance, i.e. its potential for (bio)chemical activity, including the growth of bacteria, yeasts, and molds. Simply put, microorganisms will usually not grow below a certain water activity level, and the higher the water activity, the higher the chance of microbial growth (Roos, 2003<\/a>).<\/p>\n

Minimum water activity (aw<\/sub>) for growth and toxin production of toxigenic fungi affecting grains<\/h5>\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n
<\/td>\n<\/td>\nMinimum aw<\/sub><\/strong><\/td>\n<\/tr>\n
Fungal species<\/strong><\/td>\nMycotoxin<\/strong><\/td>\nGrowth<\/strong><\/td>\nToxin production<\/strong><\/td>\n<\/tr>\n
Aspergillus flavus<\/em><\/td>\nAflatoxin<\/td>\n0.78 \u2013 0.84<\/td>\n0.84<\/td>\n<\/tr>\n
Aspergillus parasiticus<\/em><\/td>\n0.84<\/td>\n0.87<\/td>\n<\/tr>\n
Aspergillus ochraceus<\/em><\/td>\nOchratoxin<\/td>\n0.77<\/td>\n0.85<\/td>\n<\/tr>\n
Penicillium aurantiogriseum<\/em><\/td>\n0.82 \u2013 0.85<\/td>\n0.87 \u2013 0.90<\/td>\n<\/tr>\n
Penicillium viridicatum<\/em><\/td>\n0.80 \u2013 0.81<\/td>\n0.83 \u2013 0.86<\/td>\n<\/tr>\n
Aspergillus ochraceus<\/em><\/td>\nPenicillic acid<\/td>\n0.77<\/td>\n0.88<\/td>\n<\/tr>\n
Penicillium aurantiogriseum<\/em><\/td>\n0.82 \u2013 0.85<\/td>\n0.97<\/td>\n<\/tr>\n
Penicillium patulum<\/em><\/td>\nPatulin<\/td>\n0.81<\/td>\n0.95<\/td>\n<\/tr>\n
Penicillium expansum<\/em><\/td>\n0.82 \u2013 0.84<\/td>\n0.99<\/td>\n<\/tr>\n
Aspergillus clavatus<\/em><\/td>\n\u2212<\/td>\n0.99<\/td>\n<\/tr>\n
Fusarium verticillioides<\/em><\/td>\nFumonisins<\/td>\n0.88<\/td>\n0.93<\/td>\n<\/tr>\n
Fusarium proliferatum<\/em><\/td>\n0.88<\/td>\n0.93<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

Adapted from Magan, Aldred, and Sanchis (2004)<\/em><\/p>\n

Can we condition feed with pure water?<\/h2>\n

Why does this matter? The intense friction during grinding and mixing results in heat; subsequently, moisture from the mash feed is lost in the form of vapor. These losses need to be mitigated, when the feed is too dry, the milling equipment cannot function optimally and the pellet quality deteriorates. However, simply adding water does not work well: Pure water does not readily bind to the feed; it effectively \u201csits on top\u201d of the feed surface, increases the feed\u2019s water activity and thus becomes a perfect substrate for microbial growth. Plus, pure water steam largely evaporates again when the feed is cooled.<\/p>\n

Surfactants<\/h3>\n

Hence, at the conditioning phase, it is critical to add surfactants to the hydrating solution. Surfactants change the way water behaves: by reducing the surface tension of water, they enable the feed particles to absorb the water and ensure that it is evenly distributed throughout the feed. There are numerous beneficial effects as improved moisture retention<\/p>\n