Skip to main content
ARS Home » Southeast Area » Mississippi State, Mississippi » Poultry Research » Research » Publications at this Location » Publication #177936


item KIDD, M
item CORZO, A
item MILLER, E
item Dozier Iii, William

Submitted to: Poultry Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/25/2005
Publication Date: 4/15/2005
Citation: Kidd, M.T., Corzo, A., Hoehler, D., Miller, E.R., Dozier III, W.A. 2005. Broiler responsiveness (ross x 708) to diets varying in amino acid density. Poultry Science. 84:1389-1396.

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. Dietary amino acids influence the growth rate of broilers as well as the yield of the carcass parts. This research evaluated responses of broilers to diets varying in amino acid density during a 55 day production cycle. Results indicated that broilers provided diets high in amino acid density had predicted economic advantages of $0.05/bird more income over feed costs.

Technical Abstract: Sex-separate male and female broilers (2,592 broilers; Ross x 708) were placed in 144 floor pens (12 replications/treatment) and fed diets containing high (H) and moderate (M) amino acid density from 1 to 55 d of age. Diets were formulated using ileal digestible amino acid ratios to Lys. Six dietary treatment combinations (MMMMM, HMMMM, HHMMM, HHHMM, HHHHM, and HHHHH) were implemented in five diet phases (1 to 5, 6 to 14, 15 to 35, 36 to 45, and 46 to 55 d of age). Male birds were heavier (P < 0.05) and had lower (P < 0.05) feed conversion, abdominal fat, and breast yield than female birds. Birds fed H diets in the first three phases had optimal (P < 0.05) BW and feed conversion (d 35, and 45), and optimal (P < 0.05) feed conversion at d 55. Breast meat yield (d 35) and carcass yield (d 35 and 55) were highest (P < 0.05) in birds fed H diets in the first three phases; however, differences in 55 d breast meat yield did not occur. Results indicate that amino acid needs of Ross x 708 broilers are most critical from 1 to 35 d of age. Predicted economic margins were advantageous in birds fed H diets resulting in 0.12 and $0.05/bird more income over feed costs at 35 and 55 d, respectively, in comparison to birds fed M diets.