|Purswell, Joseph - Jody|
Submitted to: Journal of Applied Poultry Research
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 4/10/2009
Publication Date: 10/16/2009
Citation: Dozier, W.A., Corzo, A., Kidd, M.T., Tillman, P.B., Purswell, J.L., Kerr, B.J. 2009. Digestible Lysine Requirements of Male Broilers From 14 to 28 Days of Age Subjected to Different Environmental Conditions. Journal of Applied Poultry Research. 18:690-698.
Interpretive Summary: Feed cost represents 65% of the total live production cost for broiler chickens that supports an industry that produces 8 billion birds annually. Large percentage of the cost of the diet is protein/amino acid contributing ingredients. Lysine is the second limiting amino acid for broiler chickens when fed corn-soybean meal diets. Dietary amino acid requirements can be influenced by environmental conditions. This research evaluated digestible lysine requirements of male broilers from 14 to 28 days of age subjected to environmental conditions emulating winter and summer months. Digestible lysine intakes that corresponded to the optimum digestible lysine response based on a dietary percentage were estimated at 1,280 and 1,404 mg/d for environmental conditions emulating summer and winter production, respectively. These results suggest the dietary lysine need varied considerably with broilers reared in environmental conditions emulating winter vs. summer production when expressed on a digestible lysine intake basis.
Technical Abstract: Dietary amino acid requirements are influenced by environmental conditions. Two experiments examined growth responses of Ross × Ross TP 16 male broilers fed diets varying in digestible (dig) Lys concentrations from 14 to 28 d of age under different environmental conditions. Experiment 1 was conducted in July 2007, whereas Experiment 2 was initiated during October 2007. In each experiment, dietary treatments consisted of 6 concentrations of dig Lys and a positive control. Digestible Lys ranged from 0.90 to 1.25% in increments of 0.07% and 0.92 to 1.32% in increments of 0.08%, for Experiment 1 and 2, respectively. Linear and quadratic improvements were observed for BW gain and feed conversion in Experiment 1 and 2, respectively. In Experiment 2, dig Lys requirement was estimated at 1.19% based on quadratic broken-line model and quadratic regression equation. Digestible Lys intakes that corresponded to the optimum dig Lys response based on a dietary percentage were estimated at 1,280 and 1,404 mg/d for Experiment 1 and 2. These results suggest the dietary Lys need varied considerably with broilers reared in environmental conditions emulating winter vs. summer production when expressed on a dig Lys intake basis.