Comparative studies on the gammaglobulin level in sera of market calves in relation to their health.

Blood samples from 3901 calves, marketed by the intermediary of a local society of the Swedish Farmers Meat-Marketing Association during the course of one year, were examined with respect to gammaglobulin levels. The age of the majority of the calves varied between 10 and 21 days. Information concerning the health of the calves and symptoms of illness within four weeks of the sale were obtained from the purchasers. Calves which died were necropsied and subjected to bacteriological, parasitological and in certain cases to virological examinations. A description is given of the immunodiffusion technique applied. Sixteen % of the healthy calves had a- and hypogammaglobulin- aemia. A significantly greater mortality risk could be observed in sick calves with low gammaglobulin levels in their serum. When healthy and necropsied calves were compared, the mortality risk was thrice as great in the two groups which had the lowest gammaglobulin levels compared with the others. No significant correlation was obtained between the gammaglobulin level and morbidity risk. Nor were there any differences with regard to the gammaglobulin level between “sporadic” cases of sickness and “herd disease” cases. The most common symptom of illness in the calves was diarrhoea. No significant correlation between a low gammaglobulin level and diarrhoea could be demonstrated. The causes of death most common in order of frequency were gastroenteritis, septicaemia and pneumonia. Seventy-five % of the calves which died of septicaemia had hypogammaglobulinaemia. There was no relationship between the age of the calves and the gammaglobulin level. There was, however, a very strong correlation between low weight of the calves and a high frequency of hypogammaglobulinaemia. There was also a significantly statistical correlation between the season of the year when the calves were born and their serum gammaglobulin level.