|Dozier Iii, William|
Submitted to: Poultry Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/31/2008
Publication Date: 6/15/2008
Citation: Dozier III, W.A., Corzo, A., Kidd, M.T., Schilling, M.W. 2008. Dietary Digestible Lysine Requirements of Male and Female Broilers From Forty-Nine to Sixty-Three Days of Age. Poultry Science 87:1385-1391.
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. This research determined the digestible lysine requirement as 0.88 and 0.81%, respectively, for male and female broilers from 49 to 63 days of age based on growth and meat yield variables.
Technical Abstract: Experiments were conducted to evaluate digestible (dig) Lys requirements of male and female broiler chickens from 49 to 63 d of age. A dose-response diet consisting of corn, soybean meal, and corn gluten meal was formulated to be adequate in dig amino acid concentrations with the exception of Lys. L- Lys.HCl was added to the dose-response diet to create 7 experimental diets. Dig Lys concentrations of experimental diets ranged from 0.50 to 1.04% in increments of 0.09%. Variables measured consisted of true dietary Lys digestibility, feed intake, dig Lys intake, BW gain, feed conversion, mortality, abdominal fat weight and percentage, carcass weight and yield, and total breast meat weight and yield. In experiment 1, dig Lys of the dose-response diet was determined as 0.51% with cecectomized roosters. In experiment 2, dig Lys requirements of male broilers for BW gain, feed conversion, breast meat weight, and breast meat yield were 0.86, 0.88, 0.90, and 0.90%, respectively, based on 95% of the minimum and maximum responses. From 49 to 63 d of age, male broilers optimized growth and meat yield measurements with approximately 3.0 g of dig Lys intake. In experiment 3, dig Lys requirements of female broilers were estimated as 0.79 and 0.83%, respectively, for BW gain and feed conversion. Dig Lys intake necessary to optimize growth performance was 2.8 g per bird during 49 to 63 d of age. These results indicate that dig Lys requirement for males was higher for breast meat yield than growth performance variables. Conversely, no requirement for breast meat yield was estimated with females.