Investigating environment -friendly diet formulation strategies
Abstract
Nitrogen and phosphorus from animal waste and agricultural by-products can profoundly impact water and soil quality. Diet formulation on a digestible amino acid basis reduces nitrogen excretion. Formulation on a digestible amino acid basis requires reliable estimates of amino acid digestibility. Apparent ileal digestibility of amino acids in corn, pearl millet, oat groats, sorghum, and soybean meal was measured in barrows using the difference method of diet formulation. The results indicate that the difference method of diet formulation represents a viable application for assessing amino acid digestibility of feedstuffs in pigs. True digestibility of amino acids in corn, soybean meal, and wheat by-products (bakery meal, red dog, wheat middlings) used in duck diet formulation was assessed. Cecectomized and intact ducks were subjected to precision feeding and collection methodologies to evaluate the influence of hindgut microflora on nutrient digestibility. The results suggest that variation in amino acid digestibility between cecectomized and intact ducks is considerable for low-protein ingredients, but differences in digestibility are less pronounced with higher amino acid intakes. Similar precision feeding and collection methodologies were employed to characterize the metabolizable energy (ME) of several cereal grains (corn, barley, pearl millet, sorghum, triticale). The study demonstrated the potential utility of pearl millet and sorghum in feed formulation for ducks based on comparable ME to corn. Some agricultural wastes are characterized by high nitrogen and phosphorus contents. Swine and duck nutrient balance assays were employed to evaluate co-products from a pork processing plant and a commercial microbial fermentation unit. The fermentation co-product was observed to have no feeding value due to poor ability to support nitrogen retention in pigs and ducks. Antinutritional compounds restrict the use of certain ingredients in diet formulation by exerting negative effects on nutrient availability. The effect of new xylanase and phytase preparations on performance of young pigs was investigated. Xylanase in a corn-soybean meal diet failed to influence pig performance, but improvements in growth and feed efficiency were effected by phytase addition to diets. In conclusion, incorporation of nutrient digestibility and exogenous enzyme research findings in commercial diet formulation will aid efforts to reduce the negative environmental impact of animal production.
Degree
Ph.D.
Advisors
Adeola, Purdue University.
Subject Area
Livestock|Environmental science
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