Submitted to: Poultry Science Association Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 3/10/2004
Publication Date: 7/25/2004
Citation: Thornton, S.A., Pharr, G.T., Corzo, A., Branton, S.L., Kidd, M.T. 2004. Valine needs for immune responses in male broilers from day 21 to 42. Poultry Science Association Meeting. v. 83(Suppl. 1). p. 325. Abstract T94. Interpretive Summary: abstract only, no summary required
Technical Abstract: A number of studies have evaluated the impact of Met, Arg, Lys, and Thr on immune responses of broilers. Although a limited amount of research exists evaluating Val needs for immunity in broilers, these studies point to its adequacy as being important to support normal immunity. Because Val can become limiting in broiler diets, especially those based on vegetable protein sources, two experiments were conducted to evaluate Val needs for cellular and humoral immunity in Ross 508 male broilers from 21 to 42 d. Birds in Experiment 1 were fed 3 dietary treatments with Val levels at 0.72%, 0.82% (accomplished by adding L-Val), and 0.82% (corn and soybean meal control equaling NRC (1994)). Experiment 1 measurements included: a hypersensitivity test to phytohemaglutinin-P (PHA-P) on d 35 and 36 (2 birds/pen); relative immune organ weights at d 42 (1 bird/pen); and a primary antibody response to SRBC on d 34 and 41 (2 birds/pen). Birds in Experiment 2 were fed 3 dietary treatments with Val levels at 0.64%, 0.73%, and 0.78%. Experiment 2 measurements included: a hypersensitivity test to Concanavalin A and Pokeweed mitogen on d 40 and 41 (2 birds/pen); relative immune organ weights at d 42 (1 bird/pen); a primary antibody response to SRBC on d 34 and 41 (2 birds/pen). Cell quantification of BU1 receptors on spleenic cells at d 42 (1 bird/pen) was measured in treatments with 0.64% and 0.78% Val. In Experiment 1 there was a significant decrease (P = 0.08) for relative spleen weight in birds fed the 0.72% Val diet compared to birds fed the 0.82% corn and soybean meal control diet, however; significant differences did not occur for relative bursa and thymus weights. There were no significant differences in SRBC or PHA-P responses in Experiment 1. In Experiment 2, significant differences did not occur for any parameter tested. The results indicate that as CP is reduced in broiler diets to the extent of a marginal Val deficiency, the immune system of the birds should not be compromised.