摘要：Well designed and targeted animal breeding programs allow a sustainable genetic improvement of livestock with increases in animal productivity of 1-2% per annum. Over time, massive improvements have been achieved, e.g. in dairy and pig and poultry production systems, now resulting in higher production that requires much fewer input of resources. Although reproductive and genomic technologies contribute nowadays to increases in rates of genetic improvement, the key to successful breeding programs lies in a strong focus on simple and well-defined breeding objectives, effective investment in trait measurement, a clear understanding of the structure of the breeding program, and efficient systems for genetic evaluation, selection and mating of elite animals. The dissemination of the genetics of selected animals to the wider population also needs consideration, requiring commercial farmers or smallholders to have the means to have access to improved genetics as well as an understanding of the value of using improved bulls. Definition of the breeding objectives as well as evaluation of genetic merit needs to be based on the local environment. Compared with other interventions to improve productivity and stability, genetic improvement is a critical and cost-effective approach as genetic gains are permanent and cumulative.
