Effects of timing of chlortetracycline in combination with decoquinate on growth performance, health, and carcass characteristics of feeder steers
DOI:
https://doi.org/10.21423/bovine-vol48no2p120-128Keywords:
receiving cattle, BRD, chlortetracycline, decoquinate, animal health, bacterial diseases, calves, carcass quality, carcasses, coccidiosis, drug combinations, dry matter, feed conversion, feed conversion efficiency, feedlots, growth rate, infections, liveweight gain, morbidity, parasites, performance traits, protozoal infections, respiration, respiratory diseases, steers, parasitosesAbstract
Steer calves (n=1690) were used in a 220-day study to evaluate the effects of chlortetracycline (CTC) plus decoquinate (DEQ) on health and performance of feedlot cattle. Treatments were (1) control (CON); (2) CTC+decoquinate early (CTC+DEQ Early), and (3) CTC+decoquinate delayed (CTC+DEQ Delayed). Ten mg of CTC/lb (22 mg/kg) body weight (BW) was fed daily for 5 consecutive days beginning either on day 0 (Early) or day 6 (Delayed); decoquinate was fed at 22.7 mg/100 lb (45.4 kg) BW for 28 days. There were 6 pens per treatment, and 85 to 105 steers per pen. Steers in the CTC+DEQ groups had higher (P<0.01 to 0.05) dry matter intake and average daily gain than CON steers, but feed efficiency did not differ among treatments. Respiratory morbidity and re-treatment rates were lower (17 vs 23%, and 11 vs 22%, respectively, P<0.01) for steers in the CTC+DEQ groups than for those in the CON group. Timing of the initial CTC treatment had minimal effect on health and performance; however, feeding CTC for at least 10 days during the receiving period reduced morbidity and improved overall performance.
