Zinc Metabolism and Homeostasis in Ruminants as Affected by Dietary Energy Intake and Growth Rate 1

Abstract

Summary

Decreasing energy and protein intake in young ruminants resulted in lower weight gain and nitrogen balance. This was accompanied by reduced stable zinc absorption and retention both as milligrams/day and as a percentage of intake. Similarly, ⁶⁵Zn absorption and retention were reduced. Nitrogen balance was well correlated with stable zinc and ⁶⁵Zn retention (r = 0.67 and 0.49, respectively). These data support the concept that regulation of zinc homeostasis is controlled at the tissue level and is closely related to protein deposition changes.

The authors thank Mr. Y. G. Martin for technical assistance and Mrs. Dan E. Fowler for editorial assistance.