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New Mexico State University

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NMSU Animal Nutritionist Works to Improve Cattle Reproduction

LAS CRUCES -- It sounds like a rancher's nightmare. Corralling range cattle every other day and taking two hours to feed them supplements individually. Or, having to split up cattle that all get the same supplement on several different pastures. These are just two of the strange, time- consuming ranching practices that scientists with New Mexico State University's Agricultural Experiment Station must put up with in order to get good research information.


Mark Petersen, an animal nutritionist, follows these practices in his research to find a protein supplement that will improve reproductive efficiency in range beef cows.

"So we can feel confident about making recommendations to ranchers in the state, we often do things ranchers wouldn't do," said Mark Petersen, an animal nutritionist.

But in the end, Petersen hopes following strict feeding practices and repeating experiments will result in solid information for New Mexico's ranchers. "When we look at the current situation of low cattle prices, high feed prices and a lack of forage on the range due to low rainfall, a low-cost, effective supplement is very important," he said.

Currently, ranchers may feed cattle cubes of cottonseed meal or a combination of cottonseed meal and grain. "These supplements have been effective, but we want to find something better and less expensive than what is traditionally used," Petersen said.

In one recent study, he found that 80 percent of the two-year-old cows fed a combination of cottonseed meal, blood meal and feather meal got pregnant in the first 21 days of the fall breeding season. That was about a 20-percent improvement over other supplements tested, he said.

"The idea is the sooner the cows get pregnant, the larger their calves will be next year and the sooner those calves will reproduce," Petersen explained.

He is getting ready to test the supplement again to see if the results can be duplicated. In another study, Dean Hawkins, a reproductive physiologist, found that the same supplement increased the number of yearling heifers that got pregnant.

"We've had two experiments where we saw improvement and that's encouraging," he said. "In the end, we'd like the opportunity to work with ranchers to adapt our research to a practical situation."

Ranchers across the state got a chance to learn about this research and other studies being conducted by scientists with NMSU's animal and range sciences department through the Cattle Growers' Short Course held Mar. 28-29 in Las Cruces.

As part of the short course, NMSU published about 60 research briefs covering everything from range management to cattle reproduction, physiology and nutrition. In addition, the briefs include several studies about sheep production.

"The short course, which has been offered since the 1940s, gives ranchers and others the opportunity to get up to date on what's going on at NMSU," said Ron Parker, head of the animal resources department with NMSU's Cooperative Extension Service.

Petersen said the short course offers a chance for researchers and ranchers to exchange ideas. "We publish the proceedings so people can see what we're doing," he said. "We do hope that they'll give us a call to try to find out how to adapt any research results that look interesting to them."

As a researcher, Petersen said he also learns from farmers and ranchers. "They give us ideas about research that we usually end up doing."