Date of Award
Program or Major
Master of Science
The experiment compared the effects of chlortetracycline (CTC), lasalocid (L), and the combination (LCTC) on dairy heifers. Forty calves, 12 wk of age, were assigned to control (C), L (1 mg/kg BW/d), CTC (350 mg/d), or LCTC. Individual DMI was measured daily. Skeletal measures, BW, BCS, blood urea N and glucose concentrations were measured weekly. Calves received an external marker to estimate apparent total tract nutrient digestibilities. Total collection of urine was obtained from 20 calves to determine N retention. The DMI was higher (P=0.01) for CTC versus L and C, and DMI was lower for L versus LCTC. ADG was highest (P=0.10) for CTC. Withers height was shortest (P<0.01) for L. The BCS was higher (P<0.01) for CTC and LCTC. Treatments were not effective at improving nutrient utilization or N retention. The results indicate that CTC increases DMI, ADG, and BCS.
Greenbacker, Kelly Anne, "The effects of chlortetracycline, lasalocid, and the combination on growth, health, apparent total tract nutrient digestibility, and nitrogen retention of post-weaned dairy heifers" (2010). Master's Theses and Capstones. 572.