Leading artificial breeding organisation, Semex Pty Ltd, will introduce sexed semen to its Australian catalogue in time for the spring breeding season.

Sexed semen from a number of popular Holstein and Jersey sires within the Semex catalogue will be available within weeks. They include Gillette Final Cut, Deslacs Milk Star, Bofran Lucky Star, Bridon Remake Comerica, Pine Haven Senior and Hollylane Lilibet’s Legacy.

Semex Pty Ltd General Manager, Jim Conroy, said sexed semen was the greatest technological advance he’d witnessed in the artificial breeding industry over the past 35 years.

“Breeders now have a proven and cost-effective means to quickly expand their herd, increase its rate of genetic improvement or disseminate desirable bloodlines,” he said.

“In simple terms, this technology will allow breeders to increase the percentage of females born each generation. The days of hoping for a heifer but ending up with the disappointment of a bull calf are over.”

Mr Conroy said the new technology would underpin further growth in the Australian market. “Combined with the international appeal of Semex genetics, this unique technology will add even more value and depth to our catalogue,” he said.

“Obviously, sexed semen will be more expensive that the conventional product, reflecting its significantly higher production costs, but just about every dairy farmer in Australia would value the benefit of being able to breed more heifers.”

Mr Conroy said extensive testing throughout North America had shown that the use of sexed semen routinely produced about 90 percent heifer calves. “As with all biological processes, this can vary according to a number of factors beyond our control,” he said.

“Likewise, it is acknowledged that all semen sexing techniques result in lower conception rates. For this reason, sexed semen should be used only in maiden heifers. It is not recommended for use in embryo transfer programs.”

Semex Pty Ltd is the exclusive Australian distributor of livestock genetics marketed by the Semex Alliance, the world’s largest artificial breeding organisation.

A partnership of four of the largest farmer-owned artificial breeding organisations in Canada, the Semex Alliance markets livestock genetics in more than 80 countries throughout the world.

The Semex Alliance acquired a world-wide licence for XY® sexing technology, which was developed by the U.S. Department of Agriculture in conjunction with DakoCytomation, about two years ago.

Developed over the past decade, the process sorts sperm into X and Y-bearing populations using a flow cytometer. Sperm is stained with a harmless fluorescent dye and then illuminated by a laser beam as it flows past a detector in a fine stream.

A computer then analyses, processes and sorts individual cells on the basis of their size, shape and the presence of certain molecules within them. In cattle, the X chromosome contains about four percent more DNA than the Y chromosome.

XY sexing technology, which is claimed to be faster, more accurate and safer than other sex selection techniques, is already being used under commercial licence in the UK, Canada, USA, Mexico, Argentina, Brazil and China.   

Best Practices Guide

As everyone has read, sexed semen is a delicate product that must be used carefully and appropriately to achieve success. This includes proper handling and usage at all stages of production and at all points of transfer.

Semex's Director - Production and Quality Control, Tom Kroetsch recommends the following as Steps for the Successful Use of Sexed Semen:

Have Reasonable Expectations

It is critical to remember that sex-sorted semen is intended for use in virgin heifers. Field trials using sex-sorted frozen semen have demonstrated that sexed semen used on virgin heifers results in a fertility rate of up to 80% of conventional semen used in the same herd.

To maximize your chances for success focus on two key areas:

1. Selection And Care of Heifers To Be Bred

Only virgin heifers that are well-managed, well grown and in moderate or better body condition are suitable to receive thawed sexed semen.

Efforts must be made to reduce stress; suitable group size in a familiar surroundings combined with a consistent feed plan, will contribute to your success.

2. Use Proper AI Technique

Frozen sex-sorted semen is unique in many ways and although strict quality control remains a big part of the process, it must be remembered that:

Therefore, proper AI procedures are more critical and if done properly can contribute even more towards your success.

Handling Sex-Sorted Semen

Thawing Sex-Sorted Semen

Inseminating With Sex-Sorted Semen