Submitted to: Journal of Animal Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/5/2000
Publication Date: 5/1/2001
Citation: Mavromichalis, I., Kerr, B.J., Parr, T.M., Albin, D.M., Gabert, V.M., Baker, D.H. 2001. Valine requirement of nursery pigs. Journal of Animal Science. 79:1223-1229.
Interpretive Summary: There are no relevant empirical estimates of the valine requirement for young pigs as estimated in the National Research Council Subcommittee on Swine Nutrition, 1998. As environmental issues with nitrogen losses from swine operations becomes more pressing and as the availability of crystalline amino acids becomes more economically viable, understanding amino acid limitations in low crude protein diets and their desired concentration in feeding programs for optimal production and minimal nitrogen excretion is paramount. Results from six experiments show that depending upon dietary ingredients and crude protein level, that valine can be limiting animal performance, and consequently potential excretion of dietary nitrogen into the environment. In addition, data supports nutritional requirements of valine as estimated by the National Research Council Subcommittee on Swine Nutrition, 1998. Research results described in this report provides nutritionists at swine production units and feed companies vital data on the exact needs of dietary valine to properly formulate young pig diets to optimize growth performance and to minimize nitrogen excretion.
Technical Abstract: Six experiments were conducted to determine the true digestible valine requirement of 5- to 20-kg pigs. Experiments 1 and 2 developed and validated a valine-deficient diet for 5- to 10-kg and 10- to 20-kg pigs, respectively. Both diets were demonstrated to be deficient in valine and when supplemented with crystalline L-valine, supported performance equivalent to typical nursery diets. In Exp. 3, true ileal digestibility of valine in the two basal diets was determined in eight pigs fitted with a simple T-cannula at the terminal ileum. Another four pigs received an enzymatically hydrolyzed casein-based diet to determine endogenous contributions to collected ileal digesta. The two diets were found to have true valine digestibilities of 82% (5- to 10-kg pigs) and 86% (10- to 20kg pigs). In Exp. 4, 80 weaned pigs (5.8 kg) were offered the basal diet fortified with five incremental doses (0.08%) of L-valine. Broken-line analysis revealed a true digestible valine requirement of 0.86% ?0.03%. In Exp. 5, the true digestible valine requirement of 10- to 20-kg pigs was estimated with 120 pigs (10.9 kg) using the second basal diet fortified with six incremental doses (0.05%) of L-valine. The data suggested a digestible valine requirement of approximately 0.775%, which was reevaluated in Exp. 6, wherein pigs did not respond to levels of digestible valine higher than 0.775% valine. In conclusion, requirement estimates were 2.50 and 2.22 g of true digestible valine per megacalorie of ME for 5- to 10- and 10- to 20-kg pigs, respectively. These empirical estimates are in close agreement with recent estimates of the National Research Council Subcommittee on Swine Nutrition of 2.48 and 2.11 g of true digestible valine per megacalorie of ME, respectively.