Estimation of Arginine Requirements for Male Broile rs Grown at High Altitude from One to Twenty-one Days of Age

Abstract

Arginine (Arg) requirements of male broilers (Ross 308) reared at high altitude (2100 m above sea level) during the 1-to 3-week period was estimated in a graded supplementation method, in which six diets (230 g kg -1 CP and 3200 Kcal ME kg -1 ) with Arg increments of 1.25 g kg -1 were applied to four pens of fifteen birds each. D ietary Arg content of the experimental groups ranged from 10 g kg -1 (80% of the NRC recommendation) to 16.25 g kg -1 (130% of the NRC recommendation). Body weight gain, feed : gain ratio, and plasma nitric oxide (NO) concentration were determined as response criteria. Arginine requirements for maximal body weight gain and optim al feed: gain during the 21 days under study were estimated to be 15.3, and 15.1 g k g -1 of diet, respectively. The estimated Arg requirement based on the response in plasma NO was 15.6 g kg -1 . In conclusion, broilers receiving dietary Arg of 15 g kg -1 had the best performance. Data obtained for the individual factors are by far the highest value s reported for Arg requirements. Keywords: Amino acids, Chicken, Growth stage, Needs.