The influence of slaughter on blood composition in cattle

Abstract

In this study the effects of blood sampling, transportation and slaughter on certain blood variables (sodium, potasium, chloride, glucose, lactates, lipids, proteins, colloidal osmotic pressure, cortisol, ACTH, T3, TSH, osmolality etc.) of cattle were investigated. The experimental animals, crossbreed (Brahman, Afrikander and Hereford) heifers and oxen obtained from Kanhym Estates, Middelburg, were unaccustomed to handling. One group of animals was subjected to the stress of sampling with restraint, a second group was sampled with restraint after transportation and a third group had blood taken after slaughter at the Kanhym abattoir at Balfour. Control blood samples were obtained from Friesland dairy cows accustomed to handling and blood sampling and from crossbreed oxen unaware of the sampling procedure. Both control and experiment groups were studied in the same season. (April and May, 1984). Results were analysed and compared statistically. The blood cortisol, ACTH, lactates and glucose were significantly higher in the experimental groups than in the control group. Cortisol and ACTH values were significantly higher, and the lactate and glucose values significantly lower in the group subjected to the stress of sampling with restraint than in the other two experimental groups. Therefore, if the variables measured are an assessment of stress and change because of stress, then the animals investigated experienced stress. In addition, cattle unaccustomed to handling perceive the slaughtering process as less stressful than blood sampling in a crush (based on cortisol and ACTH results).