Heterosis in animal breeding is referred to as hybrid vigor. It is a phenomenon where the offspring of two different breeds or strains of animals show improved performance or characteristics compared to their parents. This occurs because the offspring inherit different versions of genes from each parent, resulting in new combinations of genes that can lead to superior traits such as growth rate, disease resistance, and reproductive performance.
Hybrid vigor is commonly observed in crossbred animals such as beef cattle, dairy cattle, pigs, and chickens. It is an important aspect of animal breeding because it can increase the productivity and profitability of livestock production by producing animals with improved performance and quality traits.