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Physiological
Responses of Brahman and Hereford Steers to Loading and Transportation
DaShaunte
Coleman, Richard Browning, Jr., Erica Lane, and Chastity Bradley
Cooperative
Agricultural Research Program
Seminar Series
Tennessee State University, Nashville, TN
February 26, 2003
A study was
conducted to determine how loading and transit affected body weight,
white blood cell counts, and metabolic intermediates in Brahman (Bos
indicus; n = 7) and Hereford (Bos taurus; n = 7) steers.
Brahman are perceived to be a highly temperamental breed. Steers were
either transported (89 km, 1 h), loaded and immediately unloaded, or
held in a pen throughout the treatment period (4 h) to assess
physiological changes. The experiment was in a complete crossover
design. Cattle were weighed and bled one day before treatment,
immediately after treatment, and one day after treatment. Whole blood
was used for white blood cell assessment. The plasma was harvested from
blood samples for glucose analysis by spectrophotometry and cortisol
determination by radioimmunoassay. Cortisol increased (P<0.01)
immediately after loading and after transport. Glucose increased
(P<0.01) only in transported steers. White blood cell counts decreased
(P<0.03) after loading, but increased (P<0.01) after transport. Each
blood constituent returned to pre-treatment levels by 24 h after
treatment. Steers transported experienced 3.1% (P<0.01) weight loss and
those held in the pen lost 1.4% (P<0.01) of body weight. Weight loss was
not detected as a result of loading and unloading. Breed of steer did
not modify any responses. Holding, loading, and transit elicited unique
physiological responses that were significant, but transient. Brahman
did not appear more sensitive to these common beef cattle management
practices.
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