Acasalamento dirigido para aumentar a produção de animais geneticamente superiores e reduzir a variabilidade da progênie em bovinos

Abstract

A simulation study was carried out to apply and compare an alternative mating strategy for increasing the probability of producing outstanding animals and reducing progeny variability, with other conventional strategies. Fifty populations were simulated, each containing 4,800 dams, 160 sires and 4,800 calves. For each dam and sire, a random variable from a normal distribution was generated, mimicking an index composed by several expected progeny differences (EPD). The mating strategies considered were: (1) random mating (RM); (2) positive assortative mating (PA); (3) negative assortative mating (NA); (4) combined, PA (assortative mating) for 20% top dams, and NA (negative assortative mating) for the remaining 80% (C20); (5) combined, PA (positive assortative mating) for 50% top dams, and NA (negative assortative mating) for the remaining 50% (C50). After applying the mating program, the expected progeny indexes were computed and the strategies were compared based on these indexes. The alternative mating strategies, C20 and C50, show probability of producing outstanding animals as great as the positive assortative mating, and reduce the probability of producing extremely inferior animals. The negative assortative mating is very efficient in producing uniform progeny. © 2009 Sociedade Brasileira de Zootecnia.