Determination of the optimal digestible arginine to lysine ratio in Ross 708 male broilers

This study was conducted to establish the optimal digestible arginine (dArg) to digestible lysine (dLys) ratio of Yield Plus Male 3 Ross 708 male broilers from 1 to 14 d of age, 1 to 25 d of age (experiment 1), and 25 to 42 d of age (experiment 2) based on growth performance, feed utilization, and processing yields. Diets were comprised of corn, wheat middlings, corn gluten meal, poultry meal, and soybean meal, and formulated to be surfeit in limiting amino acids except dArg. For both experiments, dietary treatments were arranged in a randomized complete block design. Optimum values calculated were obtained from quadratic broken line methodology. In experiment 1, the dArg/dLys ratio for optimizing BW gain and feed conversion ratio (FCR) was determined to be 106 for both variables from 1 to 14 d of age, and 105 and 108 from 1 to 25 d of age, respectively. In experiment 2, the optimum dArg/dLys value was estimated to be 129 and 116 for BW gain and FCR, respectively, during the 25 to 42 d period. Optimum dArg/dLys values for carcass yield, breast weight, and breast yield were estimated to be 136, 112, and 109, respectively. Absolute and relative weights of thighs increased linearly (P , 0.001) with progressive increases in dArg/dLys. The results of this study suggest that the optimum dArg/dLys necessary to maximize performance increases as the bird ages.

Automated summary

The study aimed to determine the optimal digestible arginine (dArg) to digestible lysine (dLys) ratio for Yield Plus Male 3 Ross 708 male broilers at different stages of growth. The results showed that the optimum dArg/dLys ratio increases with age. In experiment 1, the optimal ratios were 106 and 105/108 for different age ranges, while in experiment 2, the optimal ratios were 129 and 116 for different growth stages.