Performance and nutrient utilization in goats fed various levels of zinc under endotoxin mediated stress condition

A study was conducted to assess the effects of different levels of dietary zinc (Zn) on the performance, nutrient utilization, and nitrogen (N) balance in goats under endotoxin mediated biotic stress conditions. The trial period for current study was nine weeks. Thirty male growing goats of 12-month age and 13±0.2 kg BW were assigned to six groups based on body weight and body condition score. The CON, Zn1, and Zn2 were fed 30.33, 55.05, and 75.50 ppm Zn respectively under normal condition without biotic stress; whereas ECON, EZn1, and EZn2 were fed 30.33, 55.05, and 75.50 ppm Zn, respectively under biotic stress conditions induced by a low-dose endotoxin (0.2 μg/kg BW) treatment at weekly intervals for the last six weeks. Results showed that there were no significant effects on nutrient intake or digestibility, growth, and N balance due to either feeding higher levels of Zn or biotic stress. However, the serum Zn concentration was elevated in the groups fed higher zinc levels in both conditions. It is concluded that higher Zn up to 75.5 ppm in the diet of goats reared with or without biotic stress induced by repeated exposure of low-dose endotoxin does not affect nutrient utilization and performance but increases serum Zn levels under normal or endotoxin stress conditions.