Browsing by Subject "Lipid quality"

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    Effects of dietary Peroxidized lipids on the growth performance and metabolic oxidative status of nursery pigs
    (2014-06) Hanson, Andrea R.
    Supplemental lipids and lipid rich ingredients with high concentrations of polyunsaturated fatty acids may peroxidize during processing and storage. Exposure to heat, air, moisture, and other pro-oxidants accelerate peroxidation, and peroxidation is impeded by antioxidants. Metabolic oxidative stress occurs when pro-oxidants overload the antioxidant capacity of an animal. This dissertation explores the impact of lipid peroxidation in DDGS and corn oil on the growth performance, health, and metabolic oxidative status of young pigs. An extensive summary of published research revealed that feeding peroxidized lipids to pigs and broilers reduced growth, feed intake, and gain efficiency by 11.2, 7.5, and 4.3%, respectively, and resulted in metabolic oxidative stress. Similar, negative effects were confirmed in 2 additional experiments which evaluated increasing dietary levels of peroxidized corn oil. Our findings suggest the magnitude of reduction in growth depends on the conditions used to peroxidize corn oil. However, in a separate experiment, the dietary inclusion of a highly peroxidized source of DDGS did not affect the growth performance of nursery pigs. Numerous compounds are produced and degraded during peroxidation, and some of these products have been associated negatively animal health and performance. The dynamic nature of peroxidation creates a challenge for nutritionists and formulators assessing the feeding value of dietary lipids. An in vitro experiment was conducted to compare several indicators of peroxidation when heating refined corn oil at either 185°C or 95°C. Results suggest that thermal processing and storage conditions should be considered when selecting indicators of peroxidation, but this information is seldom available. An additional experiment was conducted to assess peroxidation in distillers corn oil and DDGS during storage in the presence or absence of antioxidants. Peroxidation increased during 28 d of storage at 38°C and 90% relative humidity. However, peroxidation was attenuated partially by antioxidants. Our results clearly demonstrate negative effects of dietary peroxidized lipids on the growth performance and metabolic oxidative status of nursery pigs. Future research is necessary to develop an accurate model for predicting reductions in growth performance and metabolic oxidative status when feeding diets containing peroxidized lipids.
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    Evaluation of dietary factors limiting caloric and nutritional efficiency in pork production
    (2021-08) Hung, Yuan-Tai
    Swine nutrition research goes beyond diet formulation and feeding pigs. When considering a systems approach, swine nutrition research is indispensable to improve food security, animal well-being, animal health, sustainability, and the environmental impact of production systems. The One Health concept has emerged to ensure optimal health outcomes toward animals, humans, and the environment. This can be achieved in the swine industry by optimizing nutrient utilization of pigs and removing antimicrobial growth promoters (AGPs) from diets. With the aim to improve pig production performance, four studies were conducted to investigate dietary factors that limit caloric and nutritional efficiency of pigs. Research in chapters 2 and 3 indicated that lipid peroxidation has detrimental effects on animal health and growth performance of swine and poultry fed iso-caloric diets, whereas adding antioxidants enhance lipid stability preventing further lipid peroxidation of supplemental lipids, reducing incidence of oxidative stress in pigs. Research in chapter 4 revealed that diets with increased viscosity induced by dietary fiber changed intestinal morphology and digestive enzyme activities with decreased energy and nutrient digestibility in pigs. Research in chapter 5 characterized growth-related responses in the intestine of pigs fed AGPs, shedding light on the potential mechanisms of growth-promoting effects of antimicrobials that could guide the discovery of AGP alternatives. In this dissertation, a novel approach combining swine nutrition research and digestive physiology was adopted to pinpoint dietary factors limiting nutrient utilization and growth in pigs. The main findings from this research on feeding lipids, dietary fiber, and AGPs will help develop sustainable feeding programs for pigs and achieve One Health.