in recent years, sexed semen has been commercially available. due to its lower fertility and higher price compared to conventional semen, economic evaluation should be undertaken before recommending the technology to dairy producers in each country. the objectives of the present study were to evaluate the advantages and disadvantages of the sexed semen usage at farm level in economic conditions...

Service-sire conception rate (SCR), a phenotypic fertility evaluation based on conventional (nonsexed) inseminations from parities 1 through 5, was implemented for the United States in August 2008. The SCR model contains the categorical fixed effects of parity for lactations 1 to 5; state-year-month of insemination group; 6 standardized milk yield groups; service number for inseminations 1 to 7...

Dairy farmers and others have been discussing the use of enriched X-bearing semen (sexed semen) for many years (Seidel and Garner, 2002). Sexing bovine semen is possible because X-sperm have 3.8% more DNA than Y-sperm. This difference can be identified with a flow cytometer by staining the sperm with a fluorescent dye that binds to the DNA. The technique is reasonably accurate (10% error rate) ...

Use of sexed semen in conjunction with in vitro embryo production is a potentially efficient means of obtaining offspring of predetermined sex. For thousands of years, livestock owners have desired a methodology to predetermine the sex of offspring for their herds. The ability to sort individual sperm cells into viable X- and Y-chromosome-bearing fractions made producers' sex selection dreams r...

the objective of the current study was to examine the extent of variation of genetic improvement in dam of dams genetic pathway after insemination of heifers with sex sorted semen. for this purpose three different sexed semen based strategies were examined including 1: continuous use of sex sorted semen (strategy cs), 2: use of sex sorted semen for the first and the second inseminations and use...

The methodologies used for cytometric sorting of fresh spermatozoa never allowed a clear resolution of sexual chromosomes of frozen-thawed semen. To devise a novel method for the production of bovine predefined sexed embryos using frozen-thawed semen, sorting efficiency of different protocols was studied using a new quantitative real-time PCR method to verify the purity of sexed semen. To this ...

AI is commercially applied worldwide to breed pigs, yielding fertility outcomes similar to those of natural mating. However, it is not fully efficient, as only liquid-stored semen is used, with a single boar inseminating about 2000 sows yearly. The use of liquid semen, moreover, constrains international trade and slows genetic improvement. Research efforts, reviewed hereby, are underway to reve...

Insemination at the uterotubal junction is a practical technique that can be used to decrease the number of spermatozoa used per insemination. Video endoscopic insemination allows one to visualize the uterotubal papilla during the insemination and provide higher pregnancy rates than a flexible AI catheter. Further studies are needed to determine if a consistent technique can be developed for de...