Production and economic comparison of milking F1 Holstein × Gir cows with and without the stimulus of the calf

F1 Holstein × Gir cows were allocated to two treatments as they calved: C− (53) were milked without their calves (bucket-fed four kg milk/day) and C+ (52) were milked with the stimulus of the calf for approximately 60 days and without the calf thereafter. Milk yield, composition, somatic cell count and milk sucked by the calf were recorded monthly and cow body weight and condition bimonthly. Times spent in milking and related activities were periodically recorded. Analyses of (co)variance were performed by least squares or maximum likelihood (repeated observations) and discrete variables were analysed by chi-square. The milked out milk means in C+ and C− were, respectively, 2383 ± 176 and 2184 ± 176 kg and the milk consumed by the calves 268 ± 75 and 195 ± 88 kg. The concentrations of protein, fat, lactose and solids in the milked out milk were not significantly different between treatments (P > 0.05) but C+ cows had longer lactations than C− cows (251 ± 12 and 216 ± 12 days). No significant differences were found between treatments in somatic cell count, calf mortality and morbidity, 2-month calf weight, cow weight and body condition score, calving to first oestrus and calving to conception intervals. The additional time needed to milk with the calf in C+ was similar to the time spent on artificial feeding in C− (3.8 and 3.6 min/calf/day). Saleable milk was 410 kg higher in C+ than in C−, resulting in a US$33.5/lactation/cow superiority in gross margin.