Abstract
A trial involving 512 beef calves was conducted in a commercial research feedlot to determine the effect of bovine respiratory disease (BRD) on performance parameters and carcass characteristics. Two hundred and fifty-six calves that were deemed to be “sick” (S) from BRD were allocated to 16 pens and 256 calves that were considered to be “well” (W) were allocated to another 16 pens. The outcome variables that were measured included average daily gain (ADG), daily dry matter intake (DDMI), dry matter intake to gain ratio (DM:G), BRD treatment rate, death loss, carcass traits, and net profit per pen.
The data were partitioned into several time intervals including processing (P) to day −1, day 0 to day 27, day 28 to day 55, day 56 to day 83, day 84 to day 111, day 112 to day 139, day 140 to slaughter, day 0 to slaughter (0-Slaugh), and processing to slaughter (P-Slaugh). However, the most important interval was from processing to slaughter.
For the interval P-Slaugh, there were no significant (p≥0.05) differences between the S and W groups with respect to ADG and DM:G. Also, for the interval 0-Slaugh, the DDMI was similar for both groups. There were no significant (p≥0.05) differences between the S and W groups for carcass weight, average fat, grade fat, rib eye area, marbling score, cutability estimate, or carcass grade distribution.
The BRD treatment rates in the S and W groups were 6.6% and 4.7%, respectively. The mortality rates in the S and W groups were 0.78% and 0.39%, respectively. Also, there were no deaths attributable to BRD in either group.
In the economic model, there was no significant (p≥0.05) difference between the S and W groups with respect to net profit per pen.
We conclude that this trial did not validate the concept that BRD impacts performance parameters, because a sufficient disease challenge was not present. However, this study provides several observations that will enhance the experimental design of future studies that attempt to quantify the total economic impact of BRD.
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- Andrews A. H. Factors affecting the incidence of pneumonia in growing bulls. Vet Rec. 1976 Feb 21;98(8):146–149. doi: 10.1136/vr.98.8.146. [DOI] [PubMed] [Google Scholar]
- Church T. L., Radostits O. M. A retrospective survey of diseases of feedlot cattle in Alberta. Can Vet J. 1981 Feb;22(2):27–30. [PMC free article] [PubMed] [Google Scholar]
- Cole N. A., McLaren J. B., Irwin M. R. Influence of pretransit feeding regimen and posttransit B-vitamin supplementation on stressed feeder steers. J Anim Sci. 1979 Aug;49(2):310–317. doi: 10.2527/jas1979.492310x. [DOI] [PubMed] [Google Scholar]
- Frank G. H. Pasteurella haemolytica and respiratory disease in cattle. Proc Annu Meet U S Anim Health Assoc. 1979;(83):153–160. [PubMed] [Google Scholar]
- Harland R. J., Jim G. K., Guichon P. T., Townsend H. G., Janzen E. D. Efficacy of parenteral antibiotics for disease prophylaxis in feedlot calves. Can Vet J. 1991 Mar;32(3):163–168. [PMC free article] [PubMed] [Google Scholar]
- Howard L. M. Three key dilemmas in international health. Am J Public Health. 1972 Jan;62(1):73–78. doi: 10.2105/ajph.62.1.73. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Jensen R., Pierson R. E., Braddy P. M., Saari D. A., Lauerman L. H., England J. J., Keyvanfar H., Collier J. R., Horton D. P., McChesney A. E. Shipping fever pneumonia in yearling feedlot cattle. J Am Vet Med Assoc. 1976 Sep 1;169(5):500–506. [PubMed] [Google Scholar]
- Loew F. M. A theoretical effect of fever on feed efficiency in livestock. Can Vet J. 1974 Oct;15(10):298–299. [PMC free article] [PubMed] [Google Scholar]
- Martin S. W., Meek A. H., Davis D. G., Thomson R. G., Johnson J. A., Lopez A., Stephens L., Curtis R. A., Prescott J. F., Rosendal S. Factors associated with mortality in feedlot cattle: the Bruce County Beef Cattle Project. Can J Comp Med. 1980 Jan;44(1):1–10. [PMC free article] [PubMed] [Google Scholar]
- Thomas L. H., Wood P. D., Longland J. M. The influence of disease on the performance of beef cattle. Br Vet J. 1978 Mar-Apr;134(2):152–161. doi: 10.1016/s0007-1935(17)33539-x. [DOI] [PubMed] [Google Scholar]
- Yates W. D. A review of infectious bovine rhinotracheitis, shipping fever pneumonia and viral-bacterial synergism in respiratory disease of cattle. Can J Comp Med. 1982 Jul;46(3):225–263. [PMC free article] [PubMed] [Google Scholar]