Control Strategies for Prevention of Undesirable Traits in Cattle - Review

Cattle genome sequencing has a major impact on livestock breeding and provides useful information in the field biotechnology that can ultimately lead to the development of several techniques for early molecular diagnosis. These developments within molecular genetics have made possible the rapid and effective detection of lethal or mutant alleles associated with a disease-specific phenotype by DNA isolation followed by in vitro amplification techniques and enzymatic restriction. DNA tests are currently in use for the detection of heterozygotes and diagnosis of genetic diseases such as bovine leukocyte adhesion deficiency (BLAD), deficiency of uridine monophosphate synthase (DUMPS) and bovine citrullinemia. These genetic defects are autosomal recessive disorders which were widespread trough advanced reproductive technologies, including artificial insemination and multiple ovulation embryo transfer, as result of selection focused on desirable traits carried by elite bulls with high genetic merit. In order to prevent the risk of dissemination of inherited defects in dairy herds and to decrease the economic losses all bulls have to be tested, although the prevalence of the above mentioned recessive alleles is low. Therefore, it is advisable to use molecular markers to assess bovine health and to implement such programs for the purpose of monitoring hereditary diseases in cattle.