Cattle Breeds

Cattle Sex-sorted semen is sorted semen either to contain X or Y chromosome bearing sperms and the use of it would produce a desired sex i.e. male or female animal. In dairy sector preference is always given to a female calf and thus the use of X chromosome bearing sperms semen will be useful to produce maximum number of females.

Normal semen cells (spermatozoa) contain either X or Y-chromosomes and both these cells are present in a normal semen ejaculate or a semen straw. But ova released by female contains only X chromosomes. At the time of fertilization, if X chromosome from semen enters the ovum, then the resulting foetus will be a female (XX), and if Y chromosome enters the ovum then the resulting foetus will be a male (XY).

Therefore, in natural process there is an equal chance of getting male and female foetus. However, the advanced reproductive technology is able to separate spermatozoa bearing X or Y-chromosomes. Chromosomes are made up of DNA (De Oxyribo Nucleic Acid). X cells contain more quantity of DNA (3.8% more) than the Y-chromosomes. This difference in molecular weight is used to differentiate X and Y chromosome bearing spermatozoa. For separation of X and Y chromosomes, the technique used is Flow-Cytometry.  Flow cytometry is a laser based technology used for cell sorting. 

The main global player in semen sex sorting is Sexing Technologies (ST), USA . The sex sorting lab with its severe quality control, focusses on removal of dead, male sperm cells to ensure production of over 90% females – a unique aspect of this technology”, due to removal of the dead and unwanted sperms the sex-sorted semen will be highly viable and fertile.