Utilizing sexed semen can increase productivity in beef cattle operations
Artificial insemination and embryo transfer programs are one way to have access to the best genetics. By adding sexed semen into the equation, producers have an array of options to improve the genetics within their herd.
During a recent University of Nebraska-Lincoln (UNL) Beefwatch podcast, Texas A&M’s Dr. Cliff Lamb dives in to discuss how to utilize sexed semen to its fullest potential.
Genetics and biosecurity
The ability to freeze a bull’s semen and ship it all over the world has made a tremendous impact on the beef industry’s genetics.
“First, we started by collecting a bull and distributing semen,” shares Lamb. “The progress from before we could freeze and ship chilled semen, to where we are today has probably enhanced genetic progress almost more than any other single technology.”
In the U.S., only 10 to 12 percent of beef cattle females are inseminated, which does not seem great like a great amount, but this practice has given a lot of access to genetics.
“Not only do we see an improvement in genetics, but we can do it in a fairly herd health safe way. When semen is shipped, producers can stay away from many of the transmittable diseases,” notes Lamb.
Use of technology
“In the last 30 years, the understanding of how to separate male and female sperm has had a huge impact on the industries,” Lamb shares.
According to Lamb, the only way to sex semen is through flow cytometry. This method can distinguish the size between male and female sperm, as female-bearing sperm tends to be greater in size.
Lamb explains the sperm is put under an extreme amount of pressure, making each one into a droplet, which is measured in size using laser technology and given a dye. The female sperm is larger in size, giving it more of a charge coming through the machine which separate it from male-bearing sperm.
“Under conventional semen, there is generally a 50/50 mix of Y (male) or X (female) sperm, but when we sex the semen, we end up with greater than 90 percent accuracy of getting the desired sex,” explains Lamb.
Sexing the semen also gives the producer a cleaner sample of sperm. In conventional semen, there can be other cells present. These unwanted cells get cleaned out in the processing procedure before sexing.
Applying sexed semen in timed AI
According to Lamb, current technology allows producers to breed their genetically superior animals to sexed semen to create heifer calves. These heifers enter into the herd, providing desired genetics.
This does not mean the producer has to select all their females to be sexed semen. Sexed semen tends to be more expensive than conventional semen, but can also result in a five to 10 percent lower pregnancy rate.
“Sexed semen must be timed with ovulation more closely than how producers would time with conventional semen,” Lamb says, explaining sexed semen is more grouped than convention semen, which limits the capacity to spread.
With timed artificial insemination (AI), synchronizing ovulation of the females is key to getting the best results for sexed semen. Lamb shares this means females will need to be worked more often to benefit from the use of sexed semen.
“We’ve started utilizing a pre-synchronization program, like one would see in a dairy,” he says. “We run heifers through the chute an extra time, a week before we typically would if we weren’t using sexed semen.”
He continues, “This allows us to pre-synchronize the heifers so they’re all at a more concentrated time of ovulation than the current systems of conventional semen.”
There is a lot of time put into economic analyses on sexed semen, so producers can break down their options and determine which will benefit them most. In the past three years, Lamb has worked on a project involving sexed semen, where 3,000 heifers were bred on 25 different operations.
“We used their actual data to come up with a model to determine some of the key things producers need to understand if they’re considering using sexed semen,” says Lamb, noting this model allows producers to decide if adding sexed semen into their program will hold value.
Lamb explains producers need to have a good idea on the expected premium for the desired sex. In addition, they need to know the size of the herd, anticipated weaning weights and the difference in weaning weights between desired and undesired sexes. Ultimately, sexed semen is more expensive, as producers are paying for the technology.
“If producers are selecting to create females over conventional semen, we realized the premium, or the perceived premium of the heifer, would have to be $154 more per heifer than if she had a male of the same sex,” states Lamb.
Each herd and management system are different, but creating this model has provided more information for producers to use in deciding if sexed semen will benefit their operation.
Delcy Graham is a corresponding writer for the Wyoming Livestock Roundup. Send comments on this article to firstname.lastname@example.org