Abstract
No significant differences in plasma corticosterone concentrations were noted among chicks fed diets containing 16 to 25% protein or diets containing 2,800, 3,200, or 3,600 kcal metabolizable energy per kg to 6 wk of age. The ingredients used in diet formulation did, however, affect plasma corticosterone. Higher plasma corticosterone was associated with 2,800-kcal diets containing high concentrations of cornstarch and no cereal grains compared with 2,800-kcal diets containing low concentrations of cornstarch and cereal grains. In a second experiment, chicks were fed diets containing different concentrations of lysine and methionine from hatching to 4 wk of age. Half the chicks on each dietary treatment were conditioned to handling by daily gentling. Plasma corticosterone concentrations were reduced in the conditioned chicks. Plasma corticosterone increased during a period of up to 15 min after catching when the chicks were kept in a box prior to drawing blood samples. Excess dietary lysine significantly reduced plasma corticosterone in the gentled chicks but not in the control chicks.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have