Writer: D'Lyn Ford
ARTESIA - Although New Mexico is among the nation's leaders in per-cow milk production, researchers hope that raising heifers on irrigated pastures could help the state's dairy producers save money and increase milk yields. New Mexico State University scientists are testing this idea with Holstein heifers at NMSU's Agricultural Science Center at Artesia.
"It is expensive to raise heifers because it takes two years before they produce their first calf," said Mike Looper, dairy specialist with NMSU's Cooperative Extension Service. "I see a lot of heifers being raised in a feedlot-style environment around the state or sent out of state to be developed. We want to try to bring production costs down so those heifers can be raised on pastures in New Mexico."
In Artesia, the researchers worked with a core group of 64 heifers which were grazed in pastures on four different grasses: Jose tall wheat grass, Jose tall wheat grass mixed with alfalfa, Klein grass and Klein grass mixed with alfalfa. The heifers were weighed monthly so researchers could look at average daily gain. Blood samples were also taken monthly to check urea protein and hormone levels. Before sending the heifers back to the dairy, researchers measured hip heights to check long bone growth.
Rene Flores, an NMSU graduate student in animal science, evaluated each of the grass mixtures monthly to determine protein, fiber and nutrient content. "We also measured the digestibility of these grasses and the dry matter production," he said. "Preliminary results show the heifers fed the alfalfa mixtures developed better than the ones fed strictly grass."
Dairy producers were pleased with the results from the test group of heifers, said Liz Hansen, a research technician who handled day-to-day operations. "The real plus to having them on pastures is the fitness of the heifers," she said. "They have stronger feet and legs, develop better bones, and muscle tone, and are leaner. They're not putting on those fat deposits which are the bane of a dairyman's existence."
The heifers raised at the science center gained an average of 1.75 lbs. per day, which Looper said is ideal. "Higher weight gains can be detrimental to their milk production," he said.
Looper says grazing the heifers on irrigated pastures could help dairy operators cope with increased scrutiny from the Environmental Protection Agency.
"The EPA doesn't like to see such large numbers of animals in such a confined area," he said. "They also want dry stock manure placed on additional land and want farmers to have an outlet for their wastewater. If the dairies purchase additional land, then develop it by planting grass-legume mixtures, they can have a place to get rid of waste, and develop better heifers."
Looper said with additional land, dairy producers can become crop producers, too. "Basically, we kill two birds with one stone," he said. "We implement a waste management plan and develop our heifers in-state at a much cheaper cost."
The researchers will continue to raise heifers at the science center and test different combinations of environmentally friendly grass-legume mixtures.
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