THE USE OF TRAINER COWS TO REDUCE STRESS IN NEWLY ARRIVED FEEDLOT CALVES

K. S. Schwartzkopf-Genswein, J. M. Stookey, D. L. Godson, J. M. Watts, G. Flannigan and C. Waltz. University of Saskatchewan, Saskatoon,SK.

Two hundred and forty-eight calves (270 (+/-) 2 kg) of mixed breed were randomly allotted to trainer cow (TC) and no cow (NC) treatments to determine the effect of the presence of a "trainer" animal on the health and performance of newly arrived feedlot calves. The treatments were compared by measuring weight gain, antibiotic treatment rates, immune function and behaviour. Calves in the TC group were housed with a pregnant unfamiliar cow accustomed to the feedlot pen while the NC group were housed in the absence of a cow. Upon arrival at the feedlot all calves were ear-tagged and vaccinated with Clostridial and Pasteurella haemolytica vaccines and housed in groups of 8-13, in 22 separate feedlot pens. Calves were weighed and had rectal temperatures (RT) taken on d 0, 3, 7, 14, 21, and 28 after arrival. Calves were considered "sick" and administered antibiotics on each weigh day if they had a RT of 40.5 C or higher. Blood samples were collected via venipuncture on d 0, 3, 7, and 21. Samples were analyzed for serum haptoglobin (an acute phase protein) concentrations and leukotoxin antibody titers using an ELISA based immunoassay. Behavioural observations were made using instantaneous scan sampling at 10 min intervals for a 9 h period in the first 3 d. On d 4-10 observations were made between 0800-1000 and 1500-1700 h only. Behaviours recorded included the amount of time the calves spent walking, lying, standing, drinking and feeding.

Average Daily Gain data

TC calves had lower average daily gains (ADG) than NC animals on d 3 (P < .05). No treatment differences in antibiotic treatment rates, haptoglobin or antibody titers were observed.
 

Behaviour data

TC calves had higher standing and lower lying frequencies than NC calves (P < .05). TC calves were observed to eat and drink more frequently than NC animals (P < .05) however, this was not reflected in their ADG. Results indicate that the presence of a cow in the pen of newly arrived feedlot calves does not appear to improve calf health or performance. However, based on feeding behaviour the cow may help to draw calves up to the feed bunk.