Focusing on fertility: AAA presents cutting-edge research on fertility haplotypes
During the 137th American Angus Association’s (AAA) annual meeting, held on Nov. 8-9 in Kansas City, Mo., several speakers presented on two of the association’s current focuses – fertility and longevity.
AAA’s “Focusing on Fertility” panel discussion included University of Wisconsin-Madison’s Department of Animal Scientist Professor and Chair Kent Weigel, the Holstein Association’s Executive Director of Research and Development Tom Lawlor and Angus Genetics, Inc.’s (AGI) Director of Genetic and Genomic Programs Kelli Retallick.
“Reproductive function has really been a priority for individuals at AGI, those involved with AAA and Angus breeders around the nation,” Retallick stated at the event. “As we gain a genomic database of the size and scale AAA members have committed to, we have the opportunity to identify haplotypes affecting different traits, including fertility.”
In an antecedent Angus TV webinar, dated Oct. 27, Retallick noted, “Getting cows pregnant is one of the main drivers of economic sustainability in the beef industry. In fact, in 2018, the Beef Site reported a loss of $1.6 billion in revenue due to infertility.”
“Because we know fertility is of the utmost importance to our Angus breeders, we went a step further in our research to understand haplotypes affecting fertility in Angus herds,” she continued.
Understanding haplotypes
During the October webinar, Retallick was joined by AGI’s Research Geneticist Dr. Duc Lu, who has spent several years looking into haplotype patterns in the AAA’s genomic database.
“A haplotype is a string of consecutive alleles – a minimum of two and a maximum of the length of the chromosome – on the same DNA strand and tend to be inherited together,” Lu explained. “If a haplotype is identical, it is considered homozygous in that particular region, and if the haplotypes on each DNA strand are different, they are considered heterozygous.”
Lu noted he found a handful of haplotypes in the database, which behave similarly to the recessive mode of inheritance. He further noted these haplotypes occur at a range of different frequencies, from around one to five percent in the population.
Haplotypes versus genetic conditions
Retallick noted there are a few glaring differences between haplotypes and genetic conditions.
“Genetic conditions involve an individual genetic mutation. This may be a specific insertion, deletion or change in variation of the genes,” she explained. “Another difference we have identified is genetic mutations occur at much higher frequencies, around 15 percent.”
Additionally, Retallick explained many genetic conditions are lethal, therefore they have a greater financial impact on cowherds.
“Lu’s research basically identifies a haplotype pattern associated with a phenotype. He isn’t identifying a causative mutation,” she stated.
Future opportunity for Angus breeders
While AGI and AAA are still in the thick of their haplotype research, Retallick noted the end goal is to ultimately provide a new breeding management tool for Angus breeders.
“There are a few things we hope to accomplish as we move forward,” she said. “First, we want to leverage this unique information for our Angus breeders.”
“A lot of other beef breeds and individuals in the industry aren’t in the position to do this,” Retallick explained. “Because AAA members have been so great about buying into new technology and genomic testing, we are able to leverage the Angus genotype database and address this issue before the frequency gets even higher.”
“Next, we need to identify haplotype regions of interest with real phenotypic data, and the type of data we are looking at is currently focused on fertility,” she added. “We also need to make all of this information available to our breeders so they can make breeding decisions around these nuances in the population, which will ultimately decrease the frequency of identified haplotypes.”
In order to accomplish these things, Retallick noted AGI and AAA need the continued help of Angus breeders.
“While I appreciate the fact our members have sent in over 100,000 records of heifer pregnancy, it isn’t powerful enough for us to track these patterns in the overall population,” she said. “We need members to continue sending us complete and detailed breeding records.”
Hannah Bugas is the managing editor of the Wyoming Livestock Roundup. Send comments on this article to roundup@wylr.net.
