Seidel explores prospects of using sexed semen in beef cattleWritten by Gayle Smith
As ranchers look for ways to manage their herds more efficiently, Colorado State University’s George Seidel, Jr. experiments with using sexed semen in beef cattle. While the dairy industry has made wide use of sexing calves, Seidel sees promise in the beef industry, as well.
“Sexed semen is a genetic trait, but it is complicated, slow and expensive,” he says. “But, with the right equipment, it can be above 90 percent accurate.”
However, one instrument used in the procedure can cost $500,000. Also, only fresh semen can be used.
“Semen can not be collected at the farm, frozen, sent to a lab, unfrozen, sorted for sex, refrozen and sent back to the farm,” Seidel explains. “It just doesn’t work that way.”
In fact, the biggest problem with sexing semen is fertility, but it is an area being rapidly addressed by technology, he says.
Using sexed semen
With sexed semen, Seidel says any type of estrus synchronization scheme can be used, but cattle need to be bred on detected heat.
“We tend to breed once a day 12 to 14 hours after detected heat,” he says. “Fixed artificial insemination (AI) is not recommended for sexed semen, but people do it anyway. If we are going to use sexed semen with fixed time AI, put patches on the cows and breed those that aren’t tripped the following day or we will have a real wreck,” he explains.
In vitro fertilization with sexed semen is also becoming more popular because fewer sperm are needed for fertilization. Seidel says a technician can collect ovocytes from the cow on the farm, put the eggs into an incubator operated on batteries and ship the incubator by FedEx to a lab. Technicians there can fertilize the eggs with fresh semen and ship the fertilized eggs back to the farm to be implanted into donor cows.
Seidel sees a real need for sexed semen in the future of beef cattle.
“Right now we breed our herd and get half maternal traits and half paternal traits,” he says. “There isn't one kind of cattle that fits everything.”
“On the paternal side, steer calves will sell for more than heifer calves because they weigh more and gain better, which makes them worth more,” he says. “The key is being able to breed part of the herd for female replacements and breed the rest of the herd for a terminal cross.”
As technology improves, Seidel hopes other management concerns will improve, too. Currently sexed semen is an extra $15 to $20 over traditional AI semen.
Herd management is also key.
“Using sexed semen only works when things are done well. It requires good management, nutrition, semen, heat detection and a well-trained technician. Management of fertility is vital for success,” he says.
Way of thinking
As everyone talks about how agriculture is going to feed an increasing world population, Seidel and a small group of research partners are looking at ways to more efficiently produce beef from birth to slaughter and every point in between.
“While there is a lot of thinking outside the box, we need a foundation for thinking inside the box, first,” he says. “We already AI heifers, but we may need to start AIing more cows with the cost of bulls.”
“We also need to look at vaccination programs, crossbreeding and animal identification, and how to do these things right before thinking outside the box,” he continues.
Seidel believes in leaving the bulls with his cows until the cows are pregnancy checked in the fall.
“An experienced veterinarian can stage the pregnancies, and ultrasound is a tool that can help with that,” he says. “I sell all my late calvers. They may fit into someone else’s calving program really well,” he says.
In his own beef operation, heifers are also the key.
“I keep back about 50 percent more replacement heifers than I need and sell the biggest, prettiest five percent of those because although they will make nice big cows, they are not the most profitable in my operation,” he explains.
Seidel also bypasses traditional management tactics like reproductive tract scoring, ovulation synchronization programs and pelvic measurements of heifers.
“Ovulation synchronization programs push heifers toward puberty whether they are ready or not,” he says. “I let nature decide if that heifer is going to get pregnant or not. I don’t pelvic measure because some heifers with a small pelvis grow a bigger one later and some with a bigger pelvis have problems anyway, so I don’t feel it is of much help in my own operation.”