Embryo sexing in cattle : review

Predetermination of sex is of commercial importance since economic value of each livestock species is different for different sex. Embryo sexing enables the producers to run a fewer recipient female and thus quickly increase the size of their herd. The widespread use of embryo transfer technology has created an alternative approach in controlling the sex of offspring. The methods used can be grouped under two main categories: invasive and non-invasive. The latter is generally considered optimal, since embryonic integrity is maintained and the capacity for normal development should be optimized. Non-invasive sexing, however, is not as accurate as invasive techniques and recent advances in DNA probing have minimized the losses in embryonic viability inherent in all invasive techniques. With recent progress in molecular biology, more rapid and reliable embryo sexing techniques are being evolved like PCR (Polymerase Chain Reaction) and fluorescent in-situ hybridization (FISH). A routine method of embryo sexing must include an accurate sexing procedure and survival of embryos. Sexing methods must also be easy to use and inexpensive to operate. The dairy industry eagerly awaits the perfection of this scientific advancement. The sexing of embryo is likely to find a widespread application in embryo transfer industry in near future.