Comparing somatic cell counts, production and milking durations of dairy cows when milked at two automatic cup-removal flow-rate thresholds

Abstract

The present study evaluated the effect of two automatic cup remover (ACR) flow-rate threshold settings (0.2 and 0.4 kg/min) on somatic cell count (SCC), clinical mastitis (CM), milk production and milking duration for cows milked twice daily. In a crossover design, 161 cows were assigned to one of two groups and milked with an ACR set at either 0.2 kg/min (Group 1, n = 81) or 0.4 kg/min (Group 2, n = 80) for a 3-week period from peak lactation. Following a 1-week transition period at a milk-flow threshold setting of 0.3 kg/min for both groups, there was a further 3-week treatment period where Group 1 was milked with an ACR set at 0.4 kg/min and Group 2 set at 0.2 kg/min. The milk-flow threshold setting did not affect SCC (P > 0.05). Clinical mastitis was detected in 3% of cows, and was not more prevalent when cows were milked to a flow rate of 0.4 kg/min. Post-milking strip yields were larger when thresholds were set at 0.4 kg/min than those with 0.2 kg/min (P < 0.05). Average fat yield was not affected by treatment (P > 0.05), but average daily milk, MS and protein yields were lower (P < 0.05) for the 0.4 kg/min setting, equating to a 1% difference in production. Milking duration was reduced by 11% (P < 0.001) when cups were removed at flow rates of 0.4 kg/min, compared with 0.2 kg/min. Increasing the milk flow-rate threshold for cluster removal can reduce milking time without affecting milk quality, but may result in a minor reduction in MS production.