Tesis
Métodos de Sexaje y su Repercusión sobre la Producción en Bovinos de Leche.
Fecha
2012-04-20Registro en:
Carrasco Cando, Ángela Magali. (2012). Métodos de Sexaje y su Repercusión sobre la Producción en Bovinos de Leche. Escuela Superior Politécnica de Chimborazo. Riobamba.
Autor
Carrasco Cando, Ángela Magali
Resumen
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.