|Qiu, X. - BEIJING, CHINA|
|Arthington, J - UNIVERSITY OF FLORIDA|
|Olson, T - UNIVERSITY OF FLORIDA|
Submitted to: Journal of Animal Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: May 31, 2007
Publication Date: February 12, 2007
Citation: Qiu, X., Arthington, J.D., Riley, D.G., Chase, C.C., Phillips, W.A., Coleman, S.W., Olson, T.A. 2007. Genetic effects on acute-phase protein response to the stresses of weaning and transportation in beef calves.. Journal of Animal Science. 85:2367-2374. Interpretive Summary: Stress of calves at weaning and the stress experienced by transported steers adversely affects many aspects of the animal's well-being, which results in substandard performance and increased costs associated with recovery. Stress of various kinds initiates production of specific proteins (called “acute-phase” proteins) that aid in the animals ability to cope. We measured the circulating levels of acute-phase proteins in 7 month old weaned calves (taken 0, 24, 72 hours after weaning) and on the steers when they were transported 2,200 km (24 hours) to Oklahoma (samples taken at the time of shipment, upon arrival, and 24 and 72 hours after arrival). Diverse breeds (Angus, Brahman, and Criollo) differed substantially in levels of circulating proteins as a response to stress. Some circulating proteins in crossbred animals were elevated as compared to the average of their purebred mates. This increased level (superiority for production traits) is called heterosis or hybrid vigor, and is generally a good thing. However, it is uncertain whether the elevated levels of circulating proteins are beneficial or detrimental to efficiency. On the average, Angus and Criollo calves had lower and higher levels, respectively, of one key protein. These results imply that choice of breeds in mating schemes could be employed to alter levels of circulating protein response to stress in calves. Additional work is needed to determine beneficial or optimal levels of these circulating proteins, and how different stressors affect levels in different breeds of cattle used in United States beef production systems.
Technical Abstract: The objective herein was to estimate heterosis and breed effects in purebred and crossbred Romosinuano, Brahman, and Angus on acute-phase protein response to weaning and transportation. Calves were weaned in September of 2002, 2003, and 2004 at approximately 7 mo of age. Approximately 28 d after weaning steers were transported 2,200 km (24 h) to Oklahoma. Concentrations of three acute-phase proteins (ceruloplasmin, fibrinogen, and haptoglobin) were measured in blood samples. Calves (steers and heifers) were sampled at weaning, and 24 and 72 h post-weaning. Transported steers were sampled prior to shipment, upon arrival, and 24 and 72 h after arrival. Combinations of the following fixed effects were investigated: sire breed, dam breed, sampling time, birth location, calf gender (weaning only), year, cow age, and interactions. Effects of special interest were sire breed x dam breed as indication of breed group of calf, and the three-way interaction of sire and dam breeds and sampling time. Weaning age and BW were investigated as linear and quadratic covariates. Sire of calf within sire breed was a random term. The correlation structure of repeated measures was determined by comparison of information criterion values for different structures within each analysis. In general, plasma acute-phase protein concentrations in weaned calves increased with sampling time. Concentrations in transported steers increased through sampling at 24 h after arrival, and then decreased. Significant estimates of heterosis were detected for Brahman-Angus haptoglobin concentrations at weaning (3.82 +/- 1.38, 44%), and for Romosinuano-Angus fibrinogen concentrations at weaning (11.4 +/- 5.5 mg/dL, 10%) and in transported steers (22.5 +/- 8.4 mg/dL, 20%). The direct effect of Romosinuano was to increase (P < 0.004) ceruloplasmin concentrations of weaned calves (4.1 +/- 0.9 mg/dL) and of transported steers (3.9 +/- 1.3 55 mg/dL). The direct effect of Angus was to lower ceruloplasmin concentrations in weaned calves ( -3.9 +/- 1.2; P = 0.001). Significant maternal effects were detected at weaning for ceruloplasmin concentrations in Romosinuano ( -1.4 +/- 0.5 mg/dL) and Angus (1.6 +/- 0.7 mg/dL) and fibrinogen concentrations in Brahman calves ( -17.7 +/- 8.8 mg/dL). These data imply that acute-phase protein concentrations in response to weaning and transportation are affected differently by cattle breed.