Some effects of different rearing systems on health, cleanliness and injury in calves.

Abstract

Abstract A study was made of the effect of different calf-rearing systems on the incidence of disease, dirtiness and injury in: A. suckler cows with calves at pasture; B. home-reared calves, early weaned and (i) bucket-fed in individual pens or (ii) teat-fed in groups; C. bought-in calves, bucket-fed and early weaned; D. bought-in calves reared for veal and (i) bucket-fed in individual crates or (ii) teatfed in groups. Veal calves in crates tended to be very caked with faeces around the legs and hindquarters which they were unable to groom from about eight weeks of age. Veal calves in straw yards were generally far dirtier overall than any other group. In general calves were free from external injuries. However, 20% of veal calves in crates had abrased, bruised or swollen knees; 3% of knee injuries in this group were diagnosed as serious. Mortality rates in all groups were extremely low compared to previous surveys. Records of treatments for infectious disease revealed that 50% of conditions were diagnosed as respiratory diseases and 30% as septicaemia or enteric disease. Three times as many farmers rearing bought-in calves had to treat animals for disease than those rearing calves on their farm of birth. The proportion of calves requiring treatment on affected farms was the same for home-reared and bought-in animals suggesting that the reason less homereared calves fall sick is that they escape infection entirely. Treatments for enteric disease were almost all given to unweaned animals, thus the only groups requiring treatment after six weeks of age were veal calves. For early-weaned calves arrangements involving individual pens and bucket feeding, or teat feeding calves in groups were equally successful. The proportion of group-housed veal calves treated for enteric disease in the first two weeks on the unit was higher than for any other group. The proportion of farms requiring to treat bought-in calves for respiratory disease was five to six times greater than for home-reared calves. The peak incidence of respiratory disease occurred when calves were six to eight weeks of age; i.e. several weeks after arrival of bought-in calves at the rearing unit. This supports the contention that respiratory disease in calves needs not only the presence of specific pathogens but some predisposing environmental stress.