ARS | Publication request: DIETARY LYSINE NEEDS OF LATE-DEVELOPING HEAVY BROILERS

Submitted to: Archives of Animal Nutrition
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: March 5, 2005
Publication Date: March 15, 2005
Citation: Corzo, A., Dozier III, W.A., Kidd, M.T. 2005. Dietary lysine needs of late-developing broilers. Poultry Science. 85:457-461.

Interpretive Summary: Market weights of broiler chickens have increased to meet the demand for breast fillets and value-added products. Breast meat is relatively high in lysine (7%) compared with other amino acids. Amino acids/crude protein has a pronounced impact on diet cost; diet cost represents approximately 65% of the cost for live production. This research determined the lysine need of heavy broilers as 0.93% of the diet based on growth responses of meat yield. A 1% improvement in breast meat yield occurred among the treatments translating to approximately 5 million dollar increase in revenue for a broiler company producing 1 million broilers weekly grown to heavy weights. On a National basis, this represents about 168 million dollars annually.

Technical Abstract: Two studies were conducted to determine the response of late-developing broiler males and females, respectively, to dietary lysine from 42 to 56 days of age. Regression analysis was performed to estimate dietary lysine requirements. Female broilers did not respond to dietary lysine for any variable measured. Gradient additions of lysine improved feed conversion linearly (P < 0.01) with male broilers. Fillet weight, tender weight, and their composite had a linear increase (P < 0.05) with lysine supplementation in male broilers. Carcass yield, fillet yield, and total breast meat yield displayed quadratic responses, resulting in lysine optimization dietary levels of 8.8, 9.3, and 9.3 g/kg, respectively in male broilers. Based on results from this study, high-yield male broilers should be fed a minimum of 9.3 g/kg of total dietary lysine (8.5 g/kg digestible) from 42 to 56 days of age. Lack of response on female broilers suggests that less dietary lysine may be needed for adequate growth.