|Dozier Iii, William|
|Kidd, W - MISSISSIPPI STATE UNIV|
|Corzo, A - MISSISSIPPI STATE UNIV|
|Anderson, J - MISSISSIPPI STATE UNIV|
Submitted to: Journal of Applied Poultry Research
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: March 15, 2006
Publication Date: November 20, 2006
Citation: Dozier III, W.A., Kidd, W.A., Corzo, A., Anderson, J., Branton, S.L. 2006. Growth performance, meat yield, and economic responses of broilers provided diets varying in amino acid density from thirty-six to fifty-nine days of age. Journal of Applied Poultry Research. 15:383-393. 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. Approximately 70% of the feed cost for producing broilers in the range of 3.7-4.0 kg occurs from 5 to 9 weeks of age. Large percentage of the cost of the diet is protein/amino acid contributing ingredients. Results from this research indicate that feeding diets high in amino density from 36 to 59 d had greater gross feeding margins than birds fed lower amino density diets. For example, feeding a diet high in amino acid density increased gross return margin from $0.007 to $0.043/bird when compared with decreasing amino acid density, under moderate ingredient cost and moderate breast meat prices. This translates to additional $7,000 to $43,000 per week for a complex processing 1 million broilers.
Technical Abstract: Providing diets formulated to a high amino acid density to broilers early in life improves subsequent growth performance and meat yield. Diets formulated to high amino acid concentrations beyond five wk of age may increase breast meat yield but may not be economically justified. The study examined growth responses, meat yield, and economics of broilers provided diets varying in amino acid density from 36 to 59 d of age. Birds were given a four-phase feeding program: starter (1 to 17 d), grower (18 to 35 d), withdrawal1 (WD1; 36 to 47 d), WD2 (48 to 59 d of age). All birds were fed a common feeding program until 35 d of age and the diets were formulated to a high amino acid density. Broilers were provided diets characterized as being high (H), moderate (M), or low (L) in amino acid density for the WD1 and WD2 periods. Dietary treatments were HHLL, HHML, HHMM, HHHH, HHHM, and HHHL from 36 to 59 d. Cumulative feed conversion was improved when the HHHH feeding regimen was fed, whereas other final live performance measurements were not affected. Decreasing amino acid density to HHLL and HHHL limited yields of breast fillets, tenders, and total white meat when compared with the HHHH regimen. As amino acid density decreased from HHHH to HHHM, HHMM, and HHML, carcass yield and breast meat yield were not affected. In general, providing the HHHH feeding regimen increased economic gross feeding margin compared with the other dietary treatments.