Abstract

Dairy farm profitability can be increased through the use of superior cows in the lactating herd. Genetic superiority is determined by additive genetic effects and heterosis (present in crossbred animals). Profitability is the difference between income (sale of milk, bobby and salvage animals) and costs (related to the number of cows in the herd and the land area farmed). At comparable production, bigger cows consume more feed reducing their profitability per unit feed consumed. Previous studies have identified the high productivity of first-cross cows comprising Holstein- Friesian (F) and Jersey (J) breeds. In a self-replacing herd, first-cross (F1) animals will not be continuously available unless some straightbred animals are maintained. One approach for exploiting heterosis in a self-replacing herd, is to make use of rotational crossbreeding. This paper reports profitabilities of some rotational crossbreeding programs in comparison to farming straightbred dairy animals. A model was used to estimate on an annual basis, the nutritional, biological and economic performance of whole herds consuming 12,000 kg dry matter per ha. Expected performances for straight- and cross-bred cows comprising F, J and Ayrshire (A) breeds, were obtained using estimates of breed and heterosis effects derived from Livestock Improvement

N, Lopez-Villalobos, and DJ Garrick

Proceedings of the New Zealand Society of Animal Production, Volume 56, , 216-220, 1996