Evaluating the response of Cobb MV x Cobb 500 broilers to varying amino acid density regimens for a small bird program.

Authors: HIRAI, R - Mississippi State University; MEJIA, L - Cobb-Vantress, Inc; COTO, C - Cobb-Vantress, Inc; CALDAS, J - Cobb-Vantress, Inc; MCDANIEL, C - Mississippi State University; WAMSLEY, K - Mississippi State University

Submitted to: Journal of Applied Poultry Research
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/11/2019
Publication Date: 12/16/2019
Citation: Hirai, R.A., Mejia, L., Coto, C., Caldas, J., Mcdaniel, C.D., Wamsley, K.G. 2019. Evaluating the response of Cobb MV x Cobb 500 broilers to varying amino acid density regimens for a small bird program.. Journal of Applied Poultry Research. 28(4):943-962. https://doi.org/10.3382/japr/pfz055.
DOI: https://doi.org/10.3382/japr/pfz055

Interpretive Summary: Feed costs represent a significant amount of money needed to rear poultry; therefore, as precise as nutritionists can get with formulation, the more money saved. As genetics change, the nutrition needed to optimize bird performance and health can also change. This study utilized new broiler genetics and tested their resulting performance and processing when fed diets varying in nutrient composition (specifically, amino acid concentration). Two processing weights were targeted to determine economic return (day 32 and 35). Data produced from this research demonstrated that feeding a high density diet for birds grown to 32 days and a very high density diet for birds grown to 36 days is most economical. These results can be utilized by the poultry industry to reduce grow-out costs, which can help decrease the cost of poultry products to consumers.

Technical Abstract: Primary breeder companies are continuously striving to improve existing commercial broiler crosses to increase performance and reduce cost. The objective of this study was to evaluate the response of a new commercial broiler cross (Cobb MV × Cobb 500) under 4 different amino acid density (AAD) regimens on live performance and carcass yield during a 36 d grow-out period with 2 processings to collect data at 32 and 35 d. Two basal diets were formulated to low AAD (LAAD, digestible lysine, dLys 1.08, 0.95, and 0.87% for starter, grower, and finisher) and very high AAD (VHAAD, dLys 1.39, 1.26, and 1.12%). Medium and high AAD (MAAD and HAAD) diets were created by mixing the LAAD and VHAAD diets at ratios of 66.6:33.3 and 33.3:66.6, respectively. This was a randomized complete block design with 12 replications/treatment (16 birds/pen, 0.07 m2/bird). Feed intake/bird was reduced (P < 0.05) when birds were fed the VHAAD diet at 0–32 and 0–35 d. As AAD increased, FCR decreased significantly in a stepwise manner by approximately 4 points at each AAD level (P < 0.05). Feeding higher levels of AAD improved broiler live performance and carcass yields. At 33 d, birds fed the HAAD diet had the highest potential gross profit/bird, and at 36 d, birds fed the VHAAD diet had the highest potential gross profit/bird. Further research should evaluate the effects of feeding increased AAD diets to male and female Cobb MV × Cobb 500 separately, as well as in different feeding phases and longer grow-out periods.