Measurement of mastitis in first lactation heifers and third to fourth lactation cows

The influence of lactation stage on susceptibility to mastitis infection in Friesian dairy cows was investigated. The cattle studied included third to fourth lactation cows and both summer and autumn calving groups of heifers. No increase in vulnerability to invasion by mastitis pathogens in recently calved cattle was demonstrated. Analysis of raw milk samples using ATP bioluminescence produced variation in results, suggesting that further work to develop the technique is required.