{"id":219328,"date":"2024-07-09T07:45:51","date_gmt":"2024-07-09T05:45:51","guid":{"rendered":"https:\/\/ew-nutrition.com\/oxidative-inflammatory-stress-reproductive-sows\/"},"modified":"2025-08-14T17:20:22","modified_gmt":"2025-08-14T15:20:22","slug":"oxidative-inflammatory-stress-reproductive-sows","status":"publish","type":"post","link":"https:\/\/ew-nutrition.com\/us\/oxidative-inflammatory-stress-reproductive-sows\/","title":{"rendered":"Oxidative & Inflammatory stress in reproductive Sows"},"content":{"rendered":"

By <\/span>Dr. Inge Heinzl, Editor and Technical Team, EW Nutrition<\/span><\/em><\/p>\n

 <\/p>\n

One of the biggest challenges in swine production is keeping the modern, hyperprolific sow healthy and in good shape so that she can wean large, healthy litters and maintain her high reproductive performance.<\/p>\n

Unfortunately, sows often suffer from stress and increased systemic inflammation around farrowing and during lactation. This leads to impaired feed intake and disturbed endocrine homeostasis, negatively affecting reproductive and litter performance.<\/p>\n

The key to increasing the efficiency of pig production is to reduce the metabolic burden of sows while maintaining the reproductive performance of high-yield sows. A deep understanding of the complex interplay between environmental factors, sow well-being, health, and productivity is necessary to implement enhanced nutritional regimens and meticulous management practices.<\/p>\n

Why does oxidative stress occur in today\u2019s sows?<\/h2>\n

Nowadays, hyperprolific sows produce between 30 and 40 weaned piglets per year and are at a higher risk of suffering from stress. What are the reasons?<\/p>\n

A high number of piglets causes oxidative stress<\/h3>\n

Oxidative stress occurs when reactive oxygen species (ROS) are produced faster than the body’s antioxidant mechanisms can neutralize them and cause damage to lipids, proteins, and DNA. During gestation, the sow needs high amounts of energy to provide for the fetuses. This energy is produced in the placental mitochondria. The placenta, therefore, is a place of active oxygen metabolism during gestation and a source of oxidative stress. In hyperprolific sows, a higher number of fetuses need even more energy to grow. Consequently, ROS production and the risk for intrauterine growth retardation (IUGR) increases (Figure 1). Moreover, evidence shows that the body\u2019s antioxidant potential is reduced in late gestation and after parturition (Szczubial, 2010<\/a><\/span>), resulting in increased oxidative stress biomarkers (Yang, 2023<\/a><\/span>). Increased milk production for large litters demands a substantial amount of energy, risking similar oxidative distress. Therefore, both the final phase of gestation and the subsequent lactation period are predestined for oxidative stress, which has been demonstrated by reduced TEAC (Trolox equivalent antioxidant capacity) levels during these phases (Lee et al., 2023<\/a><\/span>).<\/p>\n

\"SOW<\/p>\n

Figure 1. Illustration of the effect of oxidative stress on the fetus: intrauterine growth retardation (IUGR) (adapted from Yang et al., 2023)<\/span><\/h3>\n

Heat and ambient stress also contribute<\/h3>\n

The reproductive sow produces lots of heat. \u00a0From the beginning of gestation, the sow\u2019s thermoneutral zone decreases. This, however, does not always correspond with the ambient conditions. Especially during the last days of gestation, the discrepancy is exceptionally high as everything is prepared for the newborn piglets, which need a temperature of about 27-35\u00b0C. The sow, on the contrary, would be happy with 18-22\u00b0C. Additionally, changes around farrowing \u2013 moving to the farrowing unit, social stress, change of feed, and the preparation for parturition \u2013 exert additional stress for the sows.<\/p>\n

Why does the inflammation level increase?<\/h2>\n

After parturition, systemic inflammation is a normal phenomenon: the reproductive organs have sustained injuries during the parturition process and require remodeling. Inflammation is a natural and desired process, to repair the tissues and return to a normal status. However, inflammation is increased in modern sows, adversely affecting their inflammatory balance. Some possible underlying reasons are:<\/p>\n

    \n
  1. The high numbers of piglets need a lot of space in the uterus, often leading to damage of the uterine tissue and an inflammatory response in the sows. Lee et al. (2023)<\/a><\/span> found significantly (p<0.10) higher TNF-\u03b1 concentrations in sows with litters of 15-20 piglets than in sows with 7-14 piglets. TNF-\u03b1 is a biomarker of inflammation.<\/li>\n
  2. Pathogenic infections – particularly infections of the reproductive tract – can induce a prolonged or excessive inflammatory state. A further reason can be the need for more obstetric interventions in hyperprolific sows, which can injure the birth canal or the uterus.<\/li>\n
  3. Imbalanced nutrition: Excessive backfat is associated with a higher expression of proinflammatory cytokines, and feed contaminated with mycotoxins can impair the sow\u2019s immunocompetence.<\/li>\n<\/ol>\n

    Biomarkers can inform us about the oxidative status<\/h2>\n

    Biomarkers are naturally occurring molecules that help us identify diseases or physiological processes. They provide insights into the oxidative state and inflammatory processes.<\/p>\n

    Anti-oxidative biomarkers<\/h3>\n

    To check the anti-oxidative capacity, the \u201cbeneficial\u201d substances, or antioxidants, can be quantified. These substances can neutralize free radicals or be neutralized by them. Higher levels of antioxidants indicate better antioxidant capacity; when antioxidants are abundant, fewer oxidizable substances have undergone oxidation.<\/p>\n

    Examples of antioxidant biomarkers:<\/u><\/p>\n

    Total Antioxidant Capacity (T-AOC)<\/strong>: represents the synergistic interaction effects of all antioxidants in a matrix (E.g., diet or body fluids). It\u2019s a global measure of non-enzymatic antioxidant efficiency. Various assays, like Trolox Equivalent Antioxidant Capacity (TEAC), <\/strong>which measures a substance’s antioxidant capacity compared to Trolox, can measure T-AOC.<\/p>\n

    Glutathione Peroxidase (GSH-Px)<\/strong> belongs to the peroxidase family and converts hydrogen peroxide to water.<\/p>\n

    Catalase (CAT)<\/strong>: scavenges ROS. Its activity can predict oxidative stress.<\/p>\n

    Superoxide Dismutase (SOD)<\/strong>: catalyzes the dismutation of superoxide radicals to oxygen and hydrogen peroxide.<\/p>\n

    Oxidative biomarkers<\/h3>\n

    Oxidative stress biomarkers, the \u2018negative\u2019 substances, can also serve as general biomarkers. These include free radicals with oxidant capacity or intermediate\/final oxidation products. Ideally, their levels should be minimized.<\/p>\n

    Examples of oxidative stress biomarkers:<\/u><\/p>\n

    Thiobarbituric acid reactive substances (TBARS)<\/strong>: to measure lipid peroxidation products in cells, tissues, and body fluids.<\/p>\n

    Reactive oxygen species<\/strong> (ROS) or free radicals: <\/strong>unstable, oxygen-containing molecules that react with other molecules in a cell. They might damage DNA, RNA, and proteins and cause cell death. Hydrogen Peroxide (H\u2082O\u2082)<\/strong> is a ROS produced during normal cellular metabolism, which causes oxidative damage at excessive levels.<\/p>\n

    Malondialdehyde (MDA): <\/strong>a final product of oxidative fat degradation and, therefore, a biomarker for lipid peroxidation.<\/p>\n

    Pro-inflammatory biomarkers<\/h3>\n

    Like oxidative stress, the interplay between pro- and anti-inflammatory signals helps develop the proper immune response for the appropriate duration.<\/p>\n

    Examples of Pro-inflammatory biomarkers or molecules produced in the case of inflammation: <\/u><\/p>\n