THE EFFECT OF ALTERING THE DIETARY ARGININE TO LYSINE RATIO ON THE BREAST MEAT YIELD OF BROILER-CHICKENS AT MODERATE AND HIGH-TEMPERATURES

In 4 experiments broilers were housed at moderate or high temperatures and fed diets containing arginine:lysine (arg:lys) ratios ranging fro m 1.01 to 1.45 from 3 weeks of age until reaching a processing weight of 2.2 kg. The effects of temperature and arg:lys ratio on breast meat yield were determined. In the first 3 experiments, increasing the arg :lys ratio increased breast meat yield at moderate temperatures and re duced breast meat yield at high temperatures. Hypothesised response cu rves are presented to explain the different responses in breast meat y ield to arg:lys ratio at moderate and high temperatures. Expt 4 was de signed to test the validity of the hypothesised response curves. The p attern of the responses obtained from this experiment supports the hyp othesis.