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This Article Full Text (PDF) All Versions of this Article: jas.2008-0883v1 86/11/3146    most recent Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Step, D. L. Articles by Confer, A. W. Search for Related Content PubMed PubMed Citation Articles by Step, D. L. Articles by Confer, A. W.

Effects of commingling beef calves from different sources and weaning protocols during a 42-day receiving period on performance and bovine respiratory disease

D. L. Step^*, C. R. Krehbiel, H. A. DePra, J. J. Cranston, R. W. Fulton^**, J. G. Kirkpatrick^*, D. R. Gill, M. E. Payton, M. A. Montelongo^** and A. W. Confer^**

^* Departments of Veterinary Clinical Sciences and , ^** Veterinary Pathobiology, Center for Veterinary Health Sciences , Department of Animal Science, Division of Agricultural Sciences and Natural Resources; and Department of Statistics, College of Arts and Sciences, Oklahoma State University, Stillwater, OK 74078

dl.step{at}okstate.edu

Abstract

The study objective was to determine health and performance of ranch calves from different pre-conditioning strategies during a 42-d receiving period when commingled with calves of unknown health histories from multiple sources. Steer calves from a single source ranch (RANCH) were weaned and immediately shipped to a feedlot (WEAN, initial BW = 247 ± 29 kg); weaned on the ranch for 45 d before shipping, but did not receive any vaccinations (WEAN45, initial BW = 231 ± 26 kg); or weaned, vaccinated with modified live viral vaccine, and held on the ranch for 45 d before shipping (WEANVAC45, initial BW = 274 ± 21 kg). Multiple-source steers were purchased through auction markets (MARKET, initial BW = 238 ± 13 kg), and upon receiving, a portion of ranch-origin steers from each weaning group were commingled with a portion of MARKET cattle (COMM). The experimental design was completely randomized with a 2 x 3 +1 factorial arrangement of treatments. Factors were RANCH vs. COMM and weaning management (WEAN vs. WEAN45 vs. WEANVAC45) as the factors; MARKET cattle served as the control. Calves of WEAN, WEAN45, and MARKET were vaccinated on arrival at the feedlot. Ranch-origin calves tended (P = 0.06) to have greater ADG than COMM or MARKET calves, although ADG was not affected (P = 0.46) by weaning management. Across the 42-d receiving period, DMI was not affected (P = 0.85) by cattle origin. However, MARKET, WEAN45, and WEANVAC45 calves consumed more (P < 0.001) DM than WEAN calves. Gain efficiency was not affected (P > 0.11) by treatment. Ranch-origin calves were less (P < 0.001) likely to be treated for bovine respiratory disease than MARKET calves; COMM calves were intermediate. Calves that were retained on the ranch after weaning (WEAN45 and WEANVAC45) were also less likely to be treated (P = 0.001) than MARKET or WEAN calves. As expected, differences in morbidity related to differences in health costs. Calves of WEAN45 and WEANVAC45 had lower (P < 0.001) health costs than MARKET and WEAN calves. On arrival, serum haptoglobin concentrations were greater (P < 0.001) in MARKET and WEAN compared with WEAN45 and WEANVAC45 calves. Calves from a single source that are retained on the ranch for 45 d after weaning exhibit less morbidity and lower health costs during the receiving period at the feedyard than when cattle are commingled or trucked to the feedyard immediately after weaning.

Key Words: bovine respiratory disease • calves • commingling • performance • stress