Increasing amino acid density improves growth performance and processing yield in Cobb 700 × MV broilers

Summary The objective of this study was to evaluate the effect of digestible essential AA density (dEAA) on the performance and processing yield of straight-run Cobb 700 × MV broilers. Broilers were fed a control diet based on the breeder’s nutrient recommendations or one of four treatments consisting of 5 % incremental increases in dEAA density over the control (+5 %, +10 %, +15 %, and +20 % dEAA). The digestible lysine (dLys) content of the control diets was 1.18, 1.07, 0.96, and 0.89 % during the starter (0 to 12 d), grower (12 to 26 d), finisher (26 to 36 d), and withdrawal (36 to 49 d) diets, respectively. Broilers fed the increased dEAA were heavier at 12, 26, and 36 d as compared to those fed the control, and cumulative FCR (0 to 49 d) was decreased by 6 and 8 points when dEAA was increased over the control diet by +10 % and +15 %, respectively. A 5.75 % increase in boneless-skinless breast yield as compared to the control diet was observed when broilers were fed the +20 % dEAA diet. A 4.6 % increase in tenderloin yield was observed when broilers were fed the +10 % dEAA diet, but no further increase was observed with the +15 % or +20 % dEAA diets. Fat pad yield was observed to decrease from 1.56 % to 1.11 % as dEAA increased from the control diet to +20 % dEAA diet, respectively. Overall, the improvements to growth performance and processing yields observed in this study support the feeding of increased dEAA diets to Cobb 700 × MV broilers.