Effects of digestible lysine intake level on Cobb 500 broiler breeder hen reproductive performance

Abstract

SUMMARY A study was conducted to examine the reproductive parameters of Cobb 500 broiler breeder hens fed different daily consumption levels of digestible Lys (mg/hen per day). In total, 240 Cobb 500 broiler breeder pullets and 40 cockerels, 20 wk of age, were obtained from a commercial black-out rearing house and placed in individual cages. A common breeder diet (16% CP, 3.0% Ca, 0.65% digestible Lys) was fed from 20 to 24 wk of age. Experimental diets were fed from 24 to 42 wk of age. The treatment 1 diet was corn and soybean meal based and formulated to a digestible Lys intake of 1,000 mg/hen per day. The remaining 3 treatments consisted of a diet composed primarily of corn and corn distillers dried grains with solubles (DDGS) and had 3 different levels of digestible Lys intake: 1,000 (DDGS-1,000), 800 (DDGS-800), and 600 (DDGS-600) mg/hen per day. The study was a completely randomized design, and each treatment was replicated 6 times. Each replicate consisted of a group of 10 hens. Hens were artificially inseminated on wk 25, 30, 35, and 41 with 50 μL of undiluted semen obtained from the Cobb 500 roosters. Hen-day egg production and egg weight were observed to be similar among all treatments. Fertility parameters were unaffected by the digestible Lys intake levels fed. Additionally, hatchability was unaffected, likely because early dead, middle dead, late dead, contaminated, and pipped eggs were similar for all treatments. Feeding digestible Lys below 1,000 mg/hen per day did not affect broiler breeder reproductive performance; therefore, Lys may be in dietary surplus concentrations for commercial breeders under current practical conditions.