Effect of pre-slaughter handling on the behaviour and blood composition of beef cattle

Abstract

The pre-slaughter handling, behaviour and blood composition of beef cattle at slaughter was studied in a commercial slaughterhouse. The main problems identified were the routine use of driving instruments and delays caused by stoppages in the slaughter line. The plasma concentration of cortisol at the time of slaughter was positively correlated with the time spent standing still and with the time spent in the pre-stun pen. The plasma activity of creatine kinase was positively correlated with the time spent in the race, but no correlations between creatine kinase and physical activity in the race were found. The plasma concentration of glucose was positively correlated with the time spent trotting and the number of times that struggling occurred. The proportions of cattle struggling, vocalizing and defaecating were greatest when they were confined in the race and pre-stun pen. Cattle kept overnight in the lairage had a greater concentration of free fatty acids at the time of slaughter than those slaughtered on the day of arrival. There were no other significant differences in either the blood compositon or the handling and behaviour of cattle kept overnight in the lairage, compared with those slaughtered on the day of arrival. Some of the handling problems observed were caused by incorrect design of the handling facilities. There should be some means of removing cattle from a race if delays are encountered and some means of handling the cattle in the race other than by using an electrical goad. The optimal dimensions of races and passageways to prevent crowding and turning around should be assessed at the design stage. Non-slip floors are essential.