Author :
Ghorbani, G. R.,Jackson, J. A.,Hemken, R.
Abstract :
Two replicate studies were conducted to determine the performance of holstein calves fed varying amounts of endophyte-infected tall fescue. Calvse were housed in environmentally controlled (32 C, 45,humidity) chambers. Diets consisted of: 1) control (endophyte-free),2) 7.5,, or 3) 15,infection. All calves were allowed to adapt to environmental chambers and diets for 7 d prior to treatment period (28 d). Feed intake, rectal temperature, and respiration rates were recorded daily on all calves. Serum prolactin was recorded weekly. No significant difference was observed in daily feed intake (4.5, 4.38, 4.73 Kg/d), rectal temperature (39.94, 39.60, 39.42 C), respiration rate [67.2, 70.4, 65.5 breaths in contsper minute (CPM), serum prolactin (63.7, 8.7, 40.1 ng/ml), or average daily gain (.03, -.28, 0.0kg/d). These data suggest that 7.5,and 15,infection may be tolerated without depression of animal performance for growing calves.
