Profitabilities of some mating systems for dairy herds in New Zealand

The aim of this study was to evaluate the profitability of dairy herds unde r three mating systems involving the Holstein-Friesian, Jersey, and Ayrshir e breeds. Mating systems were straight breeding and rotational crossbreedin g using two or three breeds. A deterministic model was developed to simulat e the nutritional, biological, and economic performance of dairy herds unde r New Zealand conditions. Expected performances per cow were obtained using estimates of breed group and heterosis effects, age effects, and age distr ibution in the herd. Requirements for dry matter in feed were estimated per cow for maintenance, lactation, pregnancy, and growth of the replacements. Stocking rate was calculated by assuming 12,000 kg of dry matter utilized annually per hectare. Productivity per hectare was calculated as performanc e per cow multiplied by stocking rate. Profitability was the difference bet ween income (sale of milk and salvage value of animals) and costs (related to the number of cows in the herd and the land area farmed). Under current market values for milk and meat, all of the rotational crossbred herds show ed superior profitability to the straightbred herds (Holstein-Friesian x Je rsey, NZ$505/ha; Holstein-Friesian x Jersey x Ayrshire NZ$493/ha; Jersey x Ayrshire, NZ$466/ha; Holstein-Friesian x Ayrshire, NZ$430/ha; Jersey, NZ$43 0/ha; Holstein-Friesian, NZ$398/ha; and Ayrshire, NZ$338/ha). Changes in th e value for fat relative to protein affected profitability more significant ly in herds using the Jersey breed, and changes in the value for meat affec ted profitability more significantly in herds using the Holstein-Friesian a nd Ayrshire breeds. Results suggested that, under New Zealand conditions, t he use of rotational crossbreeding systems could increase profitability of dairy herds under the conceivable market conditions.