Dairy production and reproduction by crosses of Holstein, Jersey or Brown Swiss sires with Holstein-Friesian/Gir dams.

The performance was compared of cows sired by Holstein, Jersey or Brown Swiss bulls out of Holstein-Friesian x Gir dams of 1/2 to 3/4 Holstein-Friesian content. The animals were kept in a single herd under the same management. The data were analysed by least-squares techniques under a model that included the fixed effects of breed of sire. Bos taurus fraction of the dam, parity, year and season of calving, and a random cow effect. Based on 480 observations, the milk yields per lactation for the Holstein, Jersey and Brown Swiss sired groups were 2,821 +/- 163, 2,320 +/- 61 and 2,418 +/- 119 kg, respectively. The corresponding means for fat yield per lactation were 96.9 +/- 6.6, 86.8 +/- 2.5 and 92.8 +/- 4.8 kg; for protein yield per lactation were 85.3 +/- 5.1, 71.3+/-1.9 and 76.3 +/- 3.7 kg; for lactation length, 339 +/- 18, 283 +/- 7 and 313 +/- 14 days for fat percentage. 3.37 +/- 0.10, 3.73 +/- 0.04 and 3.77 +/- 0.07%; and for protein percentage, 3.02 +/- 0.05, 3.10 +/- 0.02 and 3.16 +/- 0.04%. The respective calving intervals were 487 +/- 24, 408 +/- 11 and 461 +/- 245 days. The yields of milk and protein per day of calving interval were similar in the Jersey and Holstein sired groups, while the former had higher yields of fat, implying that production economics might favour the smaller Jersey crosses in production systems in which the males were not reared. Crossing with Brown Swiss did not improve performance over the Holstein sired crosses.