Métodos de Sexaje y su Repercusión sobre la Producción en Bovinos de Leche.

Abstract

This technical study presents the sitometry flow method, which is the only methodof bovine semen sexing. It is based on DNA content which differs between X and Y chromosomes in sperm. Sperm is marked with a fluorescent vital dye (Hoechst). The sperm with the X chromosome emit stronger signal than those who have a Y chromosome. The fluorescence emitted by a single spermatozoon is detected by cytometry flow. The device has a laser beam, which excites the fluororhore thus emitting light. Two sensor arranged at a 90º angle measure the fluorescence. One of the sensors, facing directly the sperm, determines DNA content. Female sperm X contain more DNA and, and consequently, a higher reflectivity than male sperm Y. the information is sent to a computer for data analysis which helps separate the male and female into 2 separate populations through an electric field. The use of sexed semen did not affect milk production and did not produce genetic damage. There is 90% efficiency of calves born that will be female. However, the use of sexed semen will cause reduced fertility and it is only recommended with first-calf heifers.