Project Number: 6227-21310-009-87
Project Type: Nonfunded Cooperative Agreement

Start Date: Apr 15, 2012
End Date: Dec 31, 2012

Objective:
Our research objectives include evaluating the influence of steroid implants on stress hormones, fecal shedding of E. coli O157:H7 and Salmonella, and growth and carcass traits in weaned, crossbred calves to determine if differences within prolactin, heat-stress protein (HSP), and lactate dehydrogenase (LDH) genes are related to stress hormone concentrations, fecal shedding of pathogens, or steer growth and carcass traits.

Approach:
Bull calves will be castrated or remain intact, and be dewormed and vaccinated. Blood and fecal samples will be collected. Calves will receive either an estradiol, a trenbolone acetate, or no implant. Animals will be transported approximately 40 miles to induce shipping stress. Calves will be pastured and provided feed supplementation for 150 days. Additional samples will be collected and animals will be sent to feedyard. Once the feedyard phase is complete, carcass data will be obtained.