Supplemental chromium and bovine respiratory disease vaccines for stressed feeder calves

Abstract

Performance, morbidity, serum Cortisol, plasma ascorbate (AsA) and serum tri-iodothyronine (T3) were evaluated in crossbred steer calves purchased at sales in Ontario. Thirty-three steers were randomly assigned to each of control; vaccination with Infectious Bovine Rhinotracheitis, Parainfluenza-3, Bovine Viral Diarrhea, and Bovine Respiratory Synctial Virus vaccine and P. haemolytica vaccine; 0.14 ppm supplemental chelated Cr; and Cr plus vaccines, for the 49 d trial. Supplemental Cr plus vaccine increased (P < 0.05) daily gain and feed intake during the first 28 d. Furthermore, vaccination increased (P < 0.05) 28 d gain for mid-performing steers. Vaccines, Cr and Cr plus vaccines did not reduce morbidity (P > 0.05); however, the Cr-supplemented group had fewer relapses (P < 0.05). Rectal temperature was reduced in both vaccinated and Cr-supplemented calves on days 10–16 post-arrival. Serum cortisol was reduced (P < 0.05) in vaccinated calves and morbid Cr-supplemented calves on day 28 post-arrival. The ratio of free to total T3 on day 7 and day 14 post-arrival, and AsA on day 14 post-arrival was greater (P < 0.05) for calves receiving supplemental Cr plus vaccines. Results confirm previous reports of the beneficial effect of Cr on performance, and indicate some additive effects of Cr and vaccines with respect to daily gain and plasma ascorbate. Key words: Chromium, vaccines, ascorbic acid, tri-iodothyronine, stress, calves