Weaning, feeding trials and research continue at SARECWritten by Christy Hemken
On hand to discuss them were UW State Beef Extension Specialist Steve Paisley and UW Ruminant Nutrition Professor Bret Hess.
One study, led in part by UW Beef Extension Specialist Scott Lake, looks at 90 early-weaning Angus-sired calves and giving them a higher plane of nutrition to try to enhance marbling and take better advantage of the genetic advantage the animal has to marble, especially in the period of time from 150 to 250 days old.
Paisley noted that early weaning does pose a higher cost to the producer. “We early weaned the calves with the idea of quickly working them up to a 50 percent grain diet, and at this point they’re doing well,” he said, adding that after they’re up to the desired plane of nutrition 20 of them will go back out to graze crop residue. “We want to know if we can build some marbling potential in early, then get the economic gains later on.”
The early-weaned calves will be compared to those weaned at UW herd’s normal late October or early November time frame.
The calves had arrived at SAREC the week before the late-July field day, with an average weight of 325 pounds. The herd base is an Angus-Gelbvieh cross, with some South Devon, although Paisley said UW is transitioning to more of an Angus base.
Currently the calves receive a 70 percent alfalfa/30 percent grass coarse chop hay combination, and Paisley said they’re bumping up their corn content as quickly as possible. “I’ve been amazed at how they’re slicking the bunk, and they’re ahead of us as far as getting them on feed.”
The center just finished up a study involving 41 head of steers for a year and a half. “We were feeding camelina meal, which is a pretty high protein and has quite a bit of fat, to the cows 60 days prior to calving,” said Paisley. “The background research shows feeding a pre-calving supplement for 60 days has a lot of benefits and we were curious about the impact the pre-calving supplement has on a calf’s performance all the way through the feedlot.”
The camelina meal was compared to other rations containing safflower and corn/soybean meal, and Paisely said once the data came back there wasn’t much to report. “All the groups performed similarly and had similar feed efficiencies, but we were hoping to see some impact there. There are Nebraska studies that have shown a response, but we didn’t capture it.”
Last winter 100 head of bulls went through a feed efficiency bull test for 70 days in the center’s GrowSafe feeding system. Paisley said they expect the system to fill again soon with new tests. “Our goal is to essentially keep the unit as full as we can,” he said. “Because we’re a research center we have a responsibility for research first, but then to accommodate anybody and make the facility available.”
The GrowSafe system has been used to gather information on residual feed intake (RFI). “In our experiments we try to find the bulls that gain similar to the rest of the group but consume less feed,” said Paisley. “There are other ways to measure RFI, with individual stalls or gate systems, but they’re all very labor-intensive. With the GrowSafe system we can go through and fill them up like we would normally feed. It’s a lot less labor and a lot better information.”
He said the center hopes to eventually expand and put in at least another 10 feeders. “That’s in the plans, and part of the motivation for keeping this full all the time,” he said.
Two studies led by Hess have taken place at SAREC over the last two years, one collaborative project evaluating season of calving and another analyzing the effects of protein supplement during gestation.
In the season of calving project, the calves were evaluated for the development of a mild level of diabetes and overeating resulting in obesity. “We had two groups of cattle that grazed the same pasture at the same time, but their time in gestation was different,” said Hess. “We were able to evaluate an earlier and later plane of nutrition.”
In the second study cows were divided into three groups. One group was fed a plane of nutrition comparable to a good year on the range, another group was fed the equivalent of 70 percent of that, which equates a bad year on the range. The last group was fed the same 70 percent ration, but to it was added a protein supplement. “We were separating out the effects of protein and energy,” said Hess.
Hess said because of the GrowSafe system they were able to collect some data they would have been unable to otherwise. “What we found was the calves that were undernourished as developing fetuses had a feed efficiency index that was worse. This system allowed us to get data we wouldn’t have been able to capture before.”
Hess said it’s been determined that effects that impact offspring later in life in regard to feed efficiency come about during the first trimester, when organs develop, and carcass quality is affected in the second and third trimester when skeletal muscles develop.
The university is also just beginning the preliminary stages of research involving Quiet Wean nose tags in a commercial herd this fall.