Heifer Or Bull — You Decide: More Commercial Cattleman Exploring Sexed Semen To Add Value To Calf Crop
for Tri-State Livestock News
Despite the price tag and lower conception rates, the popularity of using sexed semen in dairy and seedstock operations has grown in recent years. Now, thanks to advancements in accuracy and conception rates, commercial cow-calf producers are seeing it as a viable option to add value to their calf crop.
For Brent Mason, of Mason & Knox Ranch located in Frankfort, South Dakota the dollars and cents of using sexed semen in his commercial cow-calf and heifer development program just makes economic sense.
“We want to breed for replacement heifers, and with sexed semen, we can take our standout maternal cows and breed them for heifers,” said Mason. “Then we can take our lower maternal cows and breed them with male semen and have feeder steers to sell. It’s been quite beneficial in our heifer development program to be able to consistently breed for heifer calves that have lower birth weights and better maternal traits.”
Sexed semen is created using a flow cytometer. Sperm cells are sorted based on differences in DNA content between X- and Y- chromosome-bearing sperm cells. Despite successfully being able to sort and freeze the sperm, the current technology has been plagued with issues of reduced viability and overall quality when thawing.
In an effort to improve sexed semen options for cattlemen, Mason & Knox Ranch has been involved in ongoing sexed semen studies with the University of Missouri (UM). In the most recent trial, UM evaluated 851 heifers at four locations, including Mason’s ranch, comparing fixed-time artificial insemination (FTAI) with conventional semen verses SexedULTRA sex-sorted semen.
Developed by ST Genetics of Navasota, Texas, SexedUltra is the latest advancement in sexed semen technology. According to the UM researchers, “Pregnancy rates to AI following detected estrus are improved with SexedULTRA semen compared to sex-sorted semen produced using the previous generation XY technology. The improved speed and reduced sperm cell loss associated with the new technology facilitates use of higher sperm cell numbers per unit, above 2 million cells per unit concentration that has become standards for units of sex-sorted semen produced using the XY technology.”
“We’ve been AI’ing for 32 years on our operation, and we currently AI all of our cows and offer two cycles of AI breeding to our heifers,” said Mason, who put 500 heifers on the trial. “When we were approached to do this study, we were very interested in seeing how well our heifers would do on trial. I thought that there would probably be a big difference with conception rates between the conventional and sexed semen, but I was very pleased with how it turned out. In the last group of 100 head we pregnancy tested through ultrasound, there was a half percent difference between the sexed semen and conventional semen.”
SexedULTRA had not yet been tested for FTAI, and researches wanted to look at efficacy rates following a 14-day CIDR-PG protocol using two of ST Genetics bull battery — Deer Valley Night Watchman and Gardiner Angus Ranch Predictor. Researchers recorded the pregnancy rates and discovered there was very little difference between heifers that received SexedULTRA semen at AI (52%; 218/422) and conventional semen at AI (60%; 257/429) and no difference in total pregnancy rate (89%) at the end of the 60 day breeding season.
“We were very pleased with how well SexedULTRA performed in the trial,” said Aaron Arnett, ST Genetics director of beef genetics. “We are seeing huge improvements in conception rates over the previous versions of sexed semen technology. Our goal has been to determine how to make a product that is just about as fertile as conventional semen, and I think we are about there. This could be a potential game changer in the beef industry, and I think we are going to see more producers taking a second look at artificial insemination.”
ST Genetics offers two outlets for producers to take advantage of sexed-semen technologies. First, the company has a bull lineup representing the industry’s major breeds with conventional and sexed semen, both male and female, available for sale at http://www.stgen.com. Second, the company can sort and freeze semen on a rancher’s own bull.
“We have a bull lineup with sorted semen that has four million cells per straw, and producers can choose which sex they want on most all of the bulls in our lineup,” said Arnett. “We also have the option for custom collection of bulls, and any bull stud in the country can overnight ejaculates to ST Genetics and have that bull gender sorted.”
Sexed-semen that is accurate, viable and affordable is opening up opportunities. Producers can expect to spend $10-20 more per straw than the typical conventional semen, but Arnett says the return on investment is worth considering the larger price tag.
“It’s important to remember the potential return on investment,” said Arnett. “Even with today’s challenging market conditions, steer calves typically bring over $100 more per head than their heifer mates at weaning due to advantages in weight and price received per pound.”
Embryologist Brett Tostenson works at Trans Ova Genetics at Yackley Ranches in Onida, South Dakota, where he sees both commercial and seedstock producers take advantage of sexed semen technology.
“Sexed semen is becoming more popular for commercial producers who are selling large groups of heifers,” said Tostenson. “We have a client who will AI 800-1,000 heifers using sexed heifer semen and sells these females in the commercial market. His clients like to know there is a high likelihood of a heifer pregnancy, and there’s a 95-95 percent accuracy rate for the correct sex using this sorted semen.”
Tostenson said the ability for his clients, whether using in AI’ing a group of heifers or placing embryos in a donor cow, to consistently raise high-quality progeny is a valuable tool to advance the industry.
“The pros of this technology is consistency in the next generation,” he said. “It’s a beautiful thing if that’s what you want, but there’s always the risk of giving up genetic diversity and having a calf crop that doesn’t work, too. Producers must weigh the associated risks as they make that choice.”
At Trans Ova, the price for semen sorting and freezing fresh ejaculates varies depending on the concentration of the straw. . It’s generally accepted that the higher the concentration, the better chances of conception. At two million sperm per straw, the price range is $35-50. For three million, the price is $50-70. For five million, the cost is $80-120. The price goes down based on the volume of straws ordered
“We see clients sell sexed-semen for $250-2,500, so there’s definitely a market for this product and people willing to pay for a specific gender for a specific bull,” said Tostenson.
At Riverview Dairy in Morris, Minn., sexed semen technology is an important tool used to produce both heifers and bulls.
“We use sexed semen on both the cows and heifers, and our conception rate is 30 percent for the cows and 45 percent for the heifers,” said Conrad Spangler, DVM, on-staff veterinarian at Riverview Dairy. “We use Limousin sexed semen in our program to raise feeder steers since Jersey bull calves have very little value as feedlot animals. A Jersey-Limousin cross can go through our calf system and into a feedlot and do very well.”
At other times in the cows’ cycles, sexed semen for Jersey heifers is used to raise replacement heifers. Riverview Dairy has utilized sexed semen since 2011.
“We are able to reduce the number of jersey bull calves that we would otherwise get with conventional semen, so that’s a big value to us,” he said. “We get the best of both worlds this way and are able to raise high-quality Jersey heifers and Limousin-cross steers. The quality of the sexed semen has improved greatly in the last five years, so I think the popularity of this technology will only continue to grow.”
Mason added, “If we can keep the conception rate within 5-8 percent of conventional semen, it will be very beneficial to the commercial cattleman. At that rate, I think this technology is very user-friendly and very attractive to a producer wanting to add value to their herd.”