Artificial Insemination Program in Cattle

Abstract

Artificial insemination is a key technique to increase reproductive efficiency and the genetic improvement in cattle. The first report of artificial insemination has been dated to more than 220 years ago; after that, many studies have been published, and this biotechnology is widely used in domestic animals. Despite the advances of embryo transfer programs in vivo and in vitro in cattle, artificial insemination still represents the main form of assisted reproduction in many herds, being one of the lowest cost strategies to improve genetic merit in the farms. Artificial insemination has many advantages compared to natural breeding, such as health benefits, e.g. control of infectious diseases; genetic improvement, e.g. use of genetically improved bulls; reproductive management improvements; and more stringent control of the zootechnical and economic features of the herd, e.g. standardized management and animals.In addition, we highlight the main advances related to the use of artificial insemination in cattle, such as the development of other reproductive biotechniques, such as timed artificial insemination and resynchronization of estrus or ovulation. In addition, the sexed semen has evolved satisfactorily with promising results both in insemination and in embryo production. An important advance in artificial insemination is related to the hormonal control of the estrous cycle that allows the elaboration of highly efficient protocols for the synchronization of estrus and ovulation. The hormonal protocols have contributed to the dissemination of the artificial insemination by allowing the insemination of many females in a short period of time. Based on many studies evaluating timed artificial insemination protocols and early and accurate pregnancy diagnosis techniques, it was also possible to establish estrus and ovulation resynchronization strategies, which have greatly contributed to economic profitability. Finally, here we review many strategies associated with manipulation of the dominant follicle, estrus behavioral and antral follicle count have been elaborated and they represent an important progress to improve the use of timed artificial insemination in cattle. Therefore, this chapter aims to present the main advances of artificial insemination and timed artificial insemination, highlighting the technical parameters, advantages, and influencing factors, and to discuss practical and current strategies for the improvement of the herd via artificial insemination programs.