Published online by Cambridge University Press: 01 June 2009
Tests over a 2-year period of milk from an Ayrshire herd showed that there was a greater incidence of low S.N.F. samples from milk with a high cell count compared with samples from that of a low cell count.
While a wide variation in S.N.F. was found at any particular cell count level, there was a broad correlation between cell count and S.N.F., the average S.N.F. for cows in the same lactation being lower for those animals with high cell counts in the milk.
It is suggested that a cell count > 100,000/ml. in bulk milk should be regarded as significant.
Bacteriological examination of the high cell count samples showed that in a large proportion of cases no typical mastitis-producing organism could be isolated.
The authors wish to thank their colleagues in the Bacteriology, Chemistry and Veterinary Investigation Departments for assistance in this work.