Ask livestock geneticist Holly Neibergs why the dairy cattle fertility rate is dropping, and she'll tell you "that's a good question."
But it is one that will be answered, she hopes, with new research under a $3 million USDA grant for researchers from several universities to investigate.
"I think part of the problem we are seeing a drop in dairy cow fertility is that the animals are being asked to do a lot," she says. "They are asked to produce milk, have a great immune system, and high fertility. I think that breeding for these traits some will be stronger than others."
In other words, she explains, dairymen may be paying for their high milk production with lower fertility.
In the 1980s the conception rate of an average cow was 50%. Today, make that 35%.
What happened to the cow conception is the topic of a new study at Washington State University where scientists like Neibergs are working under a $3 million USDA grant to use advanced genomics to reverse the trend challenging the state's dairy industry.
"Besides feed cost, infertility is one of the most costly issues for the dairy industry," says Tom Spencer, who holds the university's Baxter Endowed Chair in Beef Cattle Research in the WSU Department of Animal Sciences.
"In general, there has been a 1% per year decline in fertility."
In infertile animal has to be culled from the herd, a high cost factor to the producer who must replace the animal.
Fertility is a complex polygenic trait, he explains, so it is harder to select for than other traits when conducting animal breeding. "If we can identify and isolate the multiple genes responsible for fertility, we may be able to tell earlier what cows are going to be fertile – maybe as early as at birth."
The USDA National Institute for Food and Agriculture has invested $3 million in this effort. Infertility is considered one of the biggest barriers to global competitiveness for American dairy farmers. The five-year grant, announced in early March, includes scientists from WSU, the University of Idaho and University of Florida.
The research component will begin focusing on identifying genetic markers for fertility in dairy heifers and cows. Spencer and WSU Neibergs, as well as Joe Dalton from the Department of Animal and Veterinary Science of UI, will work with select dairy producers in the Northwest to collect cattle DNA and blood samples and identify which genes are associated with fertility.
"Our hypothesis is that dairy cow fertility can be increased through genetic selection for maternal fertility.