Evaluation of crosses of Holstein, Jersey or Brown Swiss sires x Holstein-Friesian/Gir dams. 3. Lifetime performance and economic evaluation

RESUMO

Lifetime dairy production, reproduction and growth traits of 75 females sired by Holstein, Jersey or Brown Swiss bulls and Holstein-Friesian x Gir dams of 1/2 to 3/4 Holstein-Friesian fractions were compared. The animals were in a single herd under the same management. Milk, fat and protein yields, concentrates fed, reproduction, and weights were recorded throughout the lifetime of the cows. The data were analyzed by least squares techniques under models including the fixed effects of breed of sire, Bos taurus fraction and year of birth. Herd lifes for Holstein, Jersey and Brown Swiss crosses were 6.006 +/- 0.812, 8.129 +/- 0.863 and 7.247 +/- 0.777 years. Milk yields per day of herd life were 7.150 +/- 0.266, 6.757 +/- 0.282 and 6.249 +/- 0.254 kg. Weights of cull cows sold were 458 +/- 15, 415 +/- 15 and 457 +/- 13 kg. Based on these and on previously reported results of the same experiment, intakes of roughage and pasture were estimated from energy requirements. Lifetime expenditures on concentrates, roughages, pastures, milking, reproduction, and heifer rearing were calculated based on mean performance of each breed of sire, as well as on receipts from animals and milk sold (the latter with four sets of prices of protein, fat and carrier). The conclusion was that in systems of artificial female calf rearing and male calf wastage, the Jersey crosses appear to offer important economic benefits to farmers, which would be even greater if payment on milk protein and fat becomes effective