Document Type

Thesis - Open Access

Award Date


Degree Name

Master of Science (MS)


Animal Science

First Advisor

Robbi H. Pritchard


Ranchers are continuously looking for ways to produce heavier, healthier calves at sale time. There are many on-ranch management practices performed to accomplish this, including early weaning, creep feeding, preconditioning and implanting. However, over time results may be variable. Before deciding on a certain method for handling a calf crop, ranchers must carefully evaluate their own situation, including facilities, labor, feed and pasture conditions. Feedlot operators should also be aware of previous management of calves since preshipment practices may affect performance in the feedlot. In an effort to evaluate the preconditioning program in South Dakota, performance of preconditioned and nonpreconditioned calves was monitored on the ranch and in the feedlot. Preconditioned calves have been noted for their ability to start on feed quickly and remain healthier during the initial days in the lot, but overall performance to slaughter must also be considered. This study may assist the rancher and feedlot operator in estimating the economic value and production efficiency of preconditioned calves. The effects of diet energy density, supplemental antibiotic feeding and implanting with zeranol on calf performance and health were also determined.

Library of Congress Subject Headings

Beef cattle -- Feeding and feeds

Calves -- Preconditioning

Beef cattle -- Growth

Beef cattle -- Performance records



Number of Pages



South Dakota State University