Relationships between infection with caprine arthritis encephalitis virus,intramammary bacterial infection and somatic cell counts in dairy goats

Somatic cell counts, the bacteriological condition of the milk and antibodi es against caprine arthritis encephalitis virus (CAEV) were measured monthl y throughout lactation in 121 lactating goats of the Murcia-Granada breed i n four commercial dairy goat herds. The prevalence of bacterial intramammar y infection was 5.6 per cent and the prevalence of CAEV infection was 20.6 per cent. An analysis of variance revealed a significant effect of herd, in tramammary infection and the interaction between intramammary infection and CAEV on the somatic cell count In udder halves free of intramammary infect ion, the somatic cell counts were significantly lower in seronegative goats than in seropositive goats(P<0.05). but the difference was not significant in udder halves persistently infected by bacteria. There was a significant increase in somatic cell counts due to bacterial intramammary infection (P <0.01) in the seronegative goats, but this effect was not present in the se ropositive animals.