The Weekly Livestock Reporter

Is Sexed Sperm A Reality For The Livestock Industry? You Bet!

Sexing Technologies, located between College Station and Navasota, is soon to become the first licensed facility in the United States to offer this long-awaited service. Sexing Technologies will be the only Texas firm licensed by XY Inc. of Fort Collins, Colorado, for the production of pre-sexed sperm for both cattle and horses.

Sexed sperm is the result of an intense purification process in which the sperm are sex-sorted into X bearing chromosome (female) and Y bearing chromosome (male) populations. These highly purified subpopulations are then frozen for future use in artificial breeding to predetermine the gender selection of the offspring. The sorting procedure does not involve genetic modification in any way‹it merely separates the male- and female-producing sperm. “Predetermined sex in offspring is something the livestock industry has wanted for many years,” said Maurice Rosenstein, president of Sexing Technologies and a veteran cattle producer. “I have always thought that artificial insemination (AI) is much more economical than maintaining bulls.”

Dr. Larry Boleman, Associate Department Head for Extension at Texas A&M University, says, “When sexed semen is available, it will offer producers a great advantage in planning their marketing prior to conception. If a producer needs more replacement heifers, bulls or more steer calves, what better way than developing an early strategy for the upcoming market.”

Sexing Technologies is offering sexed sperm services along with complete custom bull collection at Genetic Resources International (GRI). The recent expansion of GRI, owned by Rosenstein and partner, Juan Moreno, along with the acquisition of the sexed sperm licenses for both bovine and equine, make this one of the most exciting developments ever in the livestock industry.

“ We have just completed a 12,000-square-foot, state-of-the-art building that will house both operations,” said Moreno. “GRI will be the only facility in Texas capable of collecting bulls year-round in a climate-controlled environment.” At complete expansion, GRI will be able to house 36 bulls in the controlled environment. The bulls are maintained in 65-67 degrees with 47 percent humidity.

At GRI, customers will have the option to have the sperm sorted or frozen conventionally. “The cost of sexed sperm,” says Rosenstein, “will be very minimal in comparison to the financial return you will receive for your investment.” GRI and Sexing Technologies will also offer semen sales for their customers and on bulls owned by the company.

The world¹s first sex-selected calf using frozen sexed semen and AI was born in 1999, but it took many years of collaborated research to birth that calf.

Threats of a nuclear war in the ‘60s triggered the first research in this area. The government feared sterilization in the U.S. population if a war of this nature would come to pass. This original research was intended for use in humans.

However, it wasn¹t until the late ‘70s and early ‘80s that researchers seriously started trying to control the sex of animal offspring by technology. “Dr. Larry Johnson of the United States Department of Agriculture (USDA) developed the technology of staining sperm,” said Mike Evans of Sexing Technologies. Evans, who has more than 25 years of flow cytometry experience, worked closely with Dr. Johnson at XY Inc. on instrument development. “Dr. Johnson also modified a standard flow cytometer to accommodate the analysis of stained sperm by adding forward angle fluorescence (DNA content) and side angle fluorescence (orientation of the sperm within the stream) detection,” said Evans. “This allows the optimal signal detection for sexing sperm.” The flow cytometer can evaluate sperm at speeds exceeding 30,0000 per second and then sort them based on criteria setup using a powerful computer system. Depending on the quality of the sample, sort speeds can be in excess of 5,000 per sex per second. At this rate 10-14 million per hour can be achieved.

Flow cytometry is the measurement of cells as they flow by a detector. It was designed to analyze and sort a variety of cell types in fluid suspension. Flow cytometers use focused laser light to illuminate cells as they pass the laser beam, one at a time, in a fine fluid stream. Light scattered by the cells and light emitted by fluorescent dyes attached to cells of interest are analyzed by detectors and processed by a computer. Cells may be distinguished and selected on the basis of size and shape, as well as by the presence of many different molecules inside and on the surface of the cells.

Dr. Mervyn Jacobson, CEO and President of XY Inc., has been a driving force in the research, development and commercialization of sex-selection techniques. XY Inc. was formed in 1996 to initially offer gender selection to the United States dairy industry by way of sorting sperm. Today, XY Inc. has expanded its mission and is now the global leader in sex selection for all relevant non-human mammals, including cows, horses, pigs, endangered species and more. XY Inc. carries the master license in control of all sperm sorting in non-human mammals worldwide using technologies developed by USDA, Colorado State University (CSU) and Cytomation, a company that develops advanced flow cytometers.

For years a major concern in gender selection was the capability of obtaining enough sorted sperm from an ejaculate to make it a cost effective procedure. Although the speed and accuracy of the flow cytometer was becoming better and better, studies at CSU would help bring it all together.

“ Researchers at CSU were arguing that to get a cow pregnant you only need one sperm,” said Jacobson. “Their theory was that if it only took one sperm, then why use such an excess of sperm (20 million) as the textbooks indicate. They started experimenting with low-dose insemination and it worked.”

Another advantage to the sorting process, which also assists in the success of the low-dose theory, is that a normal ejaculation is made up of X and Y sperm and a certain percentage of damaged, dead or dying sperm. When the sperm is sorted it also eliminates that which is not usable, making the remaining sperm more viable. “We are even experimenting to see whether two million is perhaps unnecessarily high,” said Jacobson. “We have trials going on to see whether we can even optimize the system with one million sperm.”

Already, thousands of successful and healthy pregnancies have been achieved in cattle worldwide using sperm-sexing methods combined with AI. “However, there will be an increase in efficiency as we go along,” says Jacobson. “It’s very important to understand that this is an ongoing process of improving, refining and perfecting.” Today’s success rate is 93 percent gender accurate. “We are getting closer and closer to 100 percent, but we will never promise 100 percent because nothing in science is predictable and perfect,” said Jacobson.

With the recent acquisition of the equine license, Rosenstein and Moreno are ecstatic about the possibilities in the horse industry. The equine service will not be available until next breeding season, but the plans are already in the development stages. Like cattle, the horses will be bred with low-dose insemination. This procedure has already proven successful across the United States using 50 million sperm versus the recommended 500 million for an insemination.

“ An amazing 60 percent of the foals born today are from AI‹with the exclusion of Thoroughbreds,” said Rosenstein. “The impact of sex-selected gender in the equine industry will be enormous.”

The stallions will be collected and the sperm will be shipped immediately to Sexing Technologies, where it will be sorted and sent to the destination of the mare to be bred. The life of a stallion’s fresh, pre-sort ejaculation is approximately 18 hours. Post-sort is about eight to 10 hours.

The world¹s first sex-selected foal was produced in 1998 by XY. Since then, they have experimented and produced several offspring using different combinations of fresh-shipped sperm, frozen and thawed sperm, and low-dose insemination. This year the world¹s first foal, First Lady, was produced from the first sex-selected filly by sperm from the first sex-selected colt. First Lady was conceived using 17 million sperm‹just three percent of the recognized “standard” dosage used with AI in horses.

An extensively trained and educated staff forms the backbone of Sexing Technologies and GRI. “We strive to keep ourselves and our clients surrounded by people who are the best in the business,” said Moreno.
Sexing Technologies has already made exciting advances in the livestock industry. But is there more in store for the progressive partnership?

Rosenstein and Moreno just completed the purchase of the first and only legal license in the United States to identify the markers for tenderness and marbling by DNA testing. This process has been available to cattlemen, but testing has been done outside of the United States. Now, cattlemen will be able to achieve the same results using the same technology here in the states.

Sexing Technologies and GRI have made a major breakthrough for the genetic advancement of the bovine and equine industries. Now, it¹s up to the producers to take it to the next level and reap the rewards that have come from years and years of research and experiments.