Milk prostaglandins and electrical conductivity in bovine mastitis

Prostaglandin (PG) levels in milk samples from healthy and mastitic cows were determined by radioimmunoassay. In composite milk the PG levels were rather high both in healthy and mastitic samples, and the only significant difference was in thromboxane B2 (TXB). In quarter milk samples classified according to the degree of mastitis by use of somatic cell counts, PGE2 was 40, PGF2 alpha 15, and TXB2 44 per cent higher respectively in affected samples. PG levels were in good correlation with somatic cell counts (r = 0.63-0.68, p less than 0.01) and electrical conductivity (r = 0.36-0.52, p less than 0.01), two established criteria for diagnosis of mastitis. PGE2 also correlated with protein, TXB2 with fat content. PGF 2 alpha was in a negative correlation with milk yield. The good correlation of PGs with somatic cell counts and electrical conductivity suggests that PGs might be used as markers of mastitic inflammation.