STUDIES OF ENTERIC PATHOGENS AND GAMMA-GLOBULIN LEVELS OF NEONATAL CALVES IN SWEDEN

Faecal and blood samples were taken from 10-30% of calves, 36 hours to 14 days old, in 47 dairy herds in different regions of Sweden from Se ptember 1987 to October 1988 (Olsson et al. 1993). Faecal samples from 279 calves were analysed for the presence of Escherichia coli (K99+), rotavirus and Cryptosporidium sp. Twenty (7.2%) of these samples were from diarrhoeic calves. An ELISA was developed and used for the rotav irus analysis. E. coli K99+ was detected in 11.5%, Cryptosporidium sp. in 6.1% and rotavirus in 5.4% of the faecal samples. The presence of rotavirus alone and the combination rotavirus and E. coli (K99+) was f ound to be associated with diarrhoea (p<0.001 and p<0.01 respectively) . Blood samples from 327 calves were analysed for the level of total p rotein and gamma-globulin. In 43 of these samples (13%) gamma-globulin did not separate from the beta2-region by electrophoresis. The mean t otal protein concentration was 53.6 g/l in calves free from diarrhoea. The mean gamma-globulin concentration, adjusted to 7 days age was 5.9 g/l. The 20 diarrhoeic calves had lower levels of both total protein and gamma-globulin, compared with calves without diarrhoea, but the di fference was not significant. One litre more of colostrum at the first feed increased the level of total protein of the calves' sera by 1.4 g/l (p = 0.05). Calves born between May and September had a 2.0 g/l hi gher (p<0.001) serum concentration of gamma-globulin than calves born between October and April.