Valine requirements for immune and growth responses in broilers from 3 to 6 weeks of age

Abstract

1. Four experiments were conducted to evaluate valine (Val) requirements in Ross 508 broilers from 3 to 6 weeks of age. Common diets were fed to broilers until 3 weeks of age.

2. Growth and carcass measurements were taken in all experiments. Immune responsiveness measurements were taken in Experiments 1 and 2.

3. Birds given 7·2 g Val/kg of diet in Experiment 1 had more abdominal fat than birds given 8·2 g Val/kg of diet, but there were no differences in growth or other carcass measurements. Because growth performance was not reduced in birds given 7·2 g Val/kg of diet, Val concentration was reduced to 6·4 g Val/kg of diet in Experiments 2 and 3.

4. Increasing Val from 6·4 to 8·7 g Val/kg of diet resulted in linear increases for BW gain, feed efficiency and Val intake in male birds, and Val intake in female birds. Quadratic responses to increasing dietary Val were not observed in any experiment. There were no effects of Val on innate or adaptive immunity.

5. A nonessential amino acid mixture containing the same nitrogen content as the L-Val additions in Experiment 4 was added and tends to support the idea that the responses to Val were specific and not due to increases in total nitrogen.

6. Dose responses to Val resulted in male, but not female, birds given 7·3 g Val/kg of diet having improved BW gain and feed efficiency compared with birds receiving 6·4 g Val/kg of diet.

Acknowledgements

This is Journal Article Number J10702 from the Mississippi Agricultural and Forestry Experiment Station supported by MIS-322140. Use of trade names in this publication does not imply endorsement by the Mississippi Agricultural and Forestry Experiment Station of the products, nor similar ones not mentioned. Mention of trade names or commercial products in this publication is solely for the purpose of providing specific information and does not imply recommendation or endorsement by the US Department of Agriculture. This research was funded in part by proceeds from Ajinomoto Heartland. Appreciation is extended to Ajinomoto Heartland (Experiments 1, 2, and 3) and the Degussa Corporation (Experiment 4) for amino acid analyses of the experimental diets. Support from the students and staff in the Department of Poultry Science is greatly appreciated.