- Decline in dairy cow fertility leads to "major" production losses.
- Genetic selection mainly has focused on production traits.
- Identifying markers for fertility can improve genomic selection programs.
FERTILITY in dairy cattle is normally considered a result of multiple environmental factors, but more recently, scientists have determined that there may be a greater genetic connection than once thought, according to Texas A&M AgriLife Research ruminant animal health scientist Pablo Pinedo.
In order to search for genetic markers for fertility, Pinedo has lead a collaborative effort to develop a study that involves seven universities and 12 scientists.
The project brings together experts in dairy cattle reproduction, genetic selection, bioinformatics, dairy extension and education from institutions across the country, Pinedo said.
The project, "Genomic Selection for Improved Fertility of Dairy Cows with Emphasis on Cyclicity & Pregnancy," has been awarded $2.98 million for 60 months from the U.S. Department of Agriculture through the National Institute of Food & Agriculture's 2012 Agriculture & Food Research Initiative-Food Security program.
"Fertility is a critical component of efficient dairy production," Pinedo said. "Failure to attain and maintain a timely pregnancy is a major reason for production loss in dairy herds. Consequences of low fertility include a reduced percentage of cows at the early stages of lactation, increases in insemination costs, premature culling and delayed genetic progress.
"The decline in fertility of dairy cows has been a concern for the dairy industry and has motivated profuse research in the last decades," he said. "Multiple variables have been identified as contributing factors to this condition."
Development and implementation of the genetic selection of dairy cattle has been the major method to improve productivity per animal; however, the selection emphasis has been focused on production traits and only more recently on reproduction and health traits, Pinedo said.
"Current molecular technologies provide the opportunity for exploring genetic variation related to fertility," Pinedo said. "Identification of genomic markers associated with fertility will contribute to the improvement of existing genomic selection programs, leading to enhanced productivity."
The study will involve collecting DNA from cows at dairies in five states, together with establishing phenotypes for multiple fertility traits, he said. Researchers will be looking at variables such as time from calving to conception, embryo mortality and uterine health to determine if some areas in the genome are different in the so-called high- and low-fertility cow populations.
In addition to AgriLife Research, the Texas A&M University College of Veterinary Medicine & Biomedical Sciences, University of Florida, University of Wisconsin-Madison, Cornell University, University of Minnesota, University of Illinois and The Ohio State University will be involved.
The group of researchers will integrate a project that combines research, education and extension and involves an advisory panel with dairy farmers, USDA investigators and dairy consultants, Pinedo said.
Educational course modules will be developed at the participating universities, as well as web-based presentations.
Key concepts on traditional and genomic selection practices for the dairy industry and findings from this study will also be disseminated through two institutes: The Dairy Summer Institute at Cornell's College of Veterinary Medicine and the Southern Great Plains Dairy Consortium Summer Teaching Institute in Clovis, N.M.