COW FERTILITY, SOIL HEALTH, AND COW EFFICIENCY HOT TOPICS AT CATTLEMEN’S COLLEGE

Here’s a peek at some of the hot topics featured at the Cattlemen’s College, the production seminars offered at the 2017 Cattle Industry Convention.

Cow fertility: This is one of the left-behind traits of the cattle industry, says Megan Rolf, an animal breeding professor at Kansas State University. While many cattle traits, such as daily gain and muscle quality, have benefited greatly from research, fertility traits like pregnancy rate and calving percentage have stayed fairly stagnant over many years. “What we need to do is find out how to get more cow pregnancies early in the breeding season, and then maintain more of them to term,” says Rolf.

With a growing database of genomic information on animals, she and colleagues at other colleges have a project that will use the power of data and computers to plan matings of cows and bulls to eliminate some that could have a lethal ending because of a recessive gene trait. That would enhance fertility – more cows that get bred stay bred. The cattle breed associations control most of this genetic data and will impact how soon this system makes its way to your ranch.

Soil health: Ranchers have probably spent less time studying their soils than crop farmers, but that may be changing – and it should. Steven Shafer represents a relatively new organization called the Soil Health Institute. He says that pasturelands behave a little like cover crops where there is something growing and covering the soil all the time. It’s been proven that this helps the soil retain water, carbon, and nutrients such as nitrogen. 

His colleague, Dennis Chessman from the NRCS, says there’s new evidence of the value of rotational grazing (vs. continuous) for rainwater infiltration. One test shows that in continuous grazing, it takes an inch of rainwater about 100 minutes to infiltrate the soil. In rotational grazing, because of enhanced soil structure, it only takes five minutes to infiltrate. “What happens above ground affects below ground,” says Chessman.

Genomics and animal health: A group of animal geneticists from around the country is conducting a study to find if there is a genetic connection to bovine respiratory disease (BRD), the biggest disease scourge to the beef industry. Alison Van Eenennaam of the University of California-Davis tells beef producers that 1.4% of feedlot cattle die before harvest, many of them of BRD. “That number hasn’t changed in 30 years,” she says. 

She thinks that finding a genetic solution – breeding for animals that have resistance to BRD – would be far superior and cheaper than treating with antibiotics, especially in light of consumer demands. Researchers developed objective measures of when an animal has BRD: rectal temperature, nasal discharge, cough, eye drainage, and head disposition. When they identify an animal with BRD, they find a penmate that is healthy and compare the pair’s genome. 

After doing that on thousands of animals at two cooperating feedlots, they see some patterns of certain genes and gene clusters that may predict which animals will get sick. They can correlate that back to specific bulls – some tend to sire BRD-resistant calves. 

“The heritability of BRD susceptibility is about 20%, so it’s 80% environmental,” Van Eenennaam says. “It’s not a bulletproof predictor, but you could breed cattle that are just a little less likely to get sick.” 

One encouraging fact is that the dairy industry has had some success using genetics to reduce mastitis, she says, as has the pork industry with PRRS. If we’re lucky, the genes that predict BRD susceptibility might be the same genes that also help on other diseases, and lead to faster-gaining cattle.

Cow efficiency: Dave Lalman, beef cattle Extension specialist at Oklahoma State University, says that when it comes to beef cow efficiency, we may be going after the wrong things. For instance, he says, some producers want to select cows that have greater milk production on the grounds that it will lead to higher weaning weights. But, he says, you can select cows for more milk than your environment actually can support. For instance, he says, average milk production of a beef cow might be about 17 pounds per day. You could emphasize selection on that trait and increase it to 30 pounds, but if your pastures won’t support that much production anyway, it won’t do anything for calf performance. 

“More milk is usually not the answer to more efficiency,” Lalman says.

Neither is bigger cows. He points to a study that says for every 100 pounds of cow weight, it costs you $40 extra per year to maintain her. But in terms of calf weaning weight, a 100-pound bigger cow gets somewhere between 4 and 15 pounds more calf weaning weight. 

“For the bigger cow, you spend $40 a year to get 15 pounds more calf, at most,” he says. “That doesn’t work.” Rather, he says, maybe you should go for a more moderate cow size that is easier and cheaper to maintain, and work on weaning weights in areas that are more economic.