Submitted to: Journal of Applied Poultry Research
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/15/2007
Publication Date: 9/15/2007
Citation: Dozier III, W.A., Purswell, J.L., Kidd, M.T., Corzo, A., Branton, S.L. 2007. Apparent Metabolizable Energy Needs of Broilers from 2.0 to 4.0 kg as Influenced by Ambient Temperature. Journal of Applied Poultry Research. 16:206-218. 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 60 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 $0.02 to $0.10/bird when compared with decreasing amino acid density, under moderate ingredient cost and moderate breast meat prices. This translates to additional $26,000 to $100,000 per week for a complex processing 1 million broilers.
Technical Abstract: Two experiments (Exp.) were conducted to assess dietary amino acid density responses on broiler live performance, meat yields, and economics from 36 to 60 d. In Exp. 1, broilers were fed a common feeding program to 35 d. Dietary treatments were high (H), moderate (M), and low (L) amino acid density from 36 to 47 d of age and H or L amino acid density from 48 to 60 d of age. Dietary treatments were HHHH, HHHL, HHML, and HHLL during a 60 d production period. In Exp. 2, common diets were provided from 1 to 47 d of age. Dietary treatments were H, M, L, and sub-optimum (S) amino acid density and fed from 48 to 60 d of age. In Exp. 1, increasing dietary amino acid density to HHHH improved cumulative feed conversion over the HHML and HHLL fed birds. Broilers provided the HHHH regimen had less abdominal fat percentage and more total breast meat yield than the HHLL fed birds. In Exp. 2, broilers fed the HHHH feeding regimen had improved feed conversion and lower abdominal fat percentage compared with the other treatments. Decreasing dietary amino acid density from HHHH to HHHS reduced total breast meat on an absolute and relative basis. Decreasing dietary amino acid density to HHML (Exp. 1) and HHHL (Exp. 2) did not affect breast meat yield. In general, feeding HHHL (Exp. 1) and HHHH regimens (Exp. 2) had advantages in gross feed margins over the other dietary treatments with diverse diet cost and meat price scenarios.