Serum immune globulin status of purchased calves: an unreliable guide to viability and performance

The circulating immune globulin levels and weights of 40 bought-in calves were measured as the group was introduced into a commercial calf rearing enterprise. Records of growth rate and mortality were kept during the 11 to 12 weeks the group remained on the premises. This was repeated with five further batches. No relationship could be found between the recorded performance parameters of the calves and either the immune globulin content of their serum or their weight at purchase.