Milking Performance and Udder Health of Cows Milked Robotically and Conventionally

Abstract

Milking performance and measures of udder health were followed on two groups of about 50 cows milked either robotically or in a conventional parlor for a period of 30 weeks. Mastitis indicators were also compared. The following measurements of milking performance were recorded at every milking: milk yield, machine-on time, and electrical conductivity of udder-composite milk. Measures of udder health recorded weekly were somatic cell count of udder-composite milk and California Mastitis Test score by quarter. The robotically milked cows produced 0.5 kg (1 lb) more milk per day and averaged five minutes more milking time per day than the parlor milked cows. As a result of the greater machine-on time, the average milk flow rate of the robotically milked cows was 0.5 kg/min (1.2 lb/min) slower than the parlor milked cows. The geometric mean SCC of the robotically milked cows (158,000 cells/ml) was significantly different than for the parlor milked cows (100,000 cells/ml). There was no difference between the treatment groups in the new infection rate at either the cow or quarter level. Electrical conductivity of udder-composite milk, CMT score and udder- composite somatic cell count were correlated, although the correlation coefficient was low.