Theses and Dissertations


Leonel Mejia

Issuing Body

Mississippi State University


McDaniel, Christopher D.

Committee Member

Corzo, Alejandro

Committee Member

Peebles, Edgar D.

Committee Member

Kidd, Michael T.

Date of Degree


Document Type

Dissertation - Open Access


Poultry Science

Degree Name

Doctor of Philosophy (Ph.D)


College of Agriculture and Life Sciences


Department of Poultry Science


The effect of decreasing digestible lysine (dLys) intake by broiler breeder (BB) hens from 35 to 45 wk of age on their reproductive performance and performance of their progeny was evaluated. Two types of diets were fed: a diet from commercially available ingredients consisting of dLys intakes of 1,200 (IDL) and 1,010 mg/hen/day (ID) and a semi-purified diet with dLys intakes of 1,010 (SPL) and 600 mg/hen/day (SP). Hens fed the SPL and SP diets had lower hen-day egg production compared to BB hens fed the IDL and ID diets. Fertility and hatchability of eggs set were lowest (P <0.05) for hens fed the SPL diets. Chick weight at hatch was lower (P<0.05) for those that came from the SP and SPLed hens, but 42 and 56 day body weights (BW) were similar for all treatments. Marginal improvements (P<0.10) in FCR were seen at 42 and 56 days for chicks from IDed hens compared to IDL hens. A decrease in daily intake of dLys appeared to improve BB reproductive performance when hens were fed a semi-purified diet and the same response was not observed in hens fed a diet from commercially available ingredients. Furthermore, the progeny study revealed marginal improvements in some live performance parameters. In a second study, a diet based from corn-soybean meal and formulated to a dLys intake of 1,000 mg/hen/day (CS) and three diets composed primarily of corn, soybean meal, and DDGS with 1,000 (DDGS-1,000), 800 (DDGS-800), and 600 (DDGS-600) mg of dLys/hen/day were fed to evaluate the reproductive performance of BB hens from 24 to 42 wk of age. Feeding diets composed of commercially available ingredients with dLys intake levels below 1,000 mg/hen/day did not impact BB reproductive performance. Reduced BW, carcass and breast weight, and higher (P<0.05) back half weight at 42 days of age was observed from broilers that came from 26 wk old BB hens fed the DDGS-600 diet. Reducing dLys intake in later BB hen ages did not impact progeny performance or carcass characteristics. This suggests that Lys may be in dietary surplus concentrations for commercial breeders under current practical conditions.