Factors which affect blood variables of slaughtered cattle.

Blood was obtained at an abattoir from 4 groups of cattle. The first group was slaughtered in a conventional way, the second and third were subjected to shechita slaughter with or without the application of the captive bolt immediately after the cutting of the throat, and the fourth group of cattle was subjected to a period of recumbency prior to conventional slaughter. Blood samples were analysed for concentrations of catecholamines, cortisol, glucose, lactate and total lipids. The haematocrit and osmolarity was also determined. There were no major differences in the blood variables of cattle subjected to conventional slaughter and those of cattle which had been subjected to a period of recumbency prior to conventional slaughter. Plasma catecholamine concentrations in cattle subjected to shechita slaughter without the application of a stun, were significantly elevated when compared to any of the other groups. It was concluded that postural changes have very little effect on the blood variables, but that the application of a stun after the throat has been cut in shechita slaughter abolishes the increases in blood variables associated with shechita in the absence of stunning.

Effect of a 72 hour fast on physiological stress indicators in feedlot cattle.

Feedlot oxen (n = 15) were herded and subjected to venepuncture on a daily basis for 2 weeks. Plasma glucose, lactate, free fatty acids, total lipids, total protein, cortisol, catecholamines, osmolarity and haematocrit were compared between Days 1 and 14. Plasma glucose concentration and haematocrit decreased significantly while total plasma lipid and free fatty acid concentrations increased significantly over the 14 d. Thereafter, food was withdrawn for 72 h from the experimental group (n = 10) and the same blood variables were compared in the control and the experimental groups. Plasma free fatty acid concentrations rose, while glucose concentrations declined in the experimental group during the fasting period. It is concluded that food deprivation for 72 h in cattle cannot be regarded as a major stressor.