HAYS, Kan. – It’s always been done this way, right? Calves are weaned in the fall. But drought conditions in the Plains states prompted some beef producers to wean calves earlier than usual in recent years, which may have been surprisingly beneficial, according to recent Kansas State University studies.
“The conventional weaning time has always been in the fall, when calves are around 180 to 210 days old, but there was no substantial research to show that that was necessarily the best time,” said John Jaeger, beef scientist with K-State Research and Extension, based in Hays. There were probably many factors at play over the years, including bringing cows home from summer pasture, fitting weaning into crop harvest, fall school activities and more.
“We wondered if, rather than putting growth on calves at the expense of cows, it might be better to wean them earlier. If the calves fared well, it might give the cow more time to recover from calving and lactating and improve her own body condition before going into winter,” Jaeger said.
This may be an especially important time to look at such management options, he said, as producers are planning to expand herds after cutting back several years due to drought and the resulting lack of forage.
The cattle industry in Kansas generated $7.88 billion in cash receipts during 2012, and ranked sixth nationally in the number of beef cows at 1.33 million head as of Jan. 1, 2013, according to Kansas Agricultural Statistics.
Jaeger, along with K-State Research and Extension beef science colleagues K.C. Olson, who is based in Manhattan and Justin Waggoner, based in Garden City, conducted two studies – one in 2007 and another in 2012, to determine the effect of earlier-than-usual weaning on the calves.
Calves gain, cows benefit
The studies found that calves weaned at 120 to 160 days at an average of 360 pounds gained as much weight and were just as healthy as calves that were weaned later. It also indicated that the health risks and death loss were no different in early-weaned calves than in those weaned at the more conventional ages of 180 to 210 days.
“Previous studies by other researchers have shown that early weaning reduces grazing pressure,” Jaeger said, adding that a calf weighing 450 pounds at 120 days of age eats about 6.8 pounds of forage per day. So, for every 30 days that a calf is weaned early, there should be one week of additional grazing for the cow.
Early weaning also decreases the cow’s nutritional requirements. The studies showed that for every 30 days that a calf is weaned early, there will be another three additional days of grazing for the cow. Cows enter fall and winter in better body condition, which trims the amount of winter supplementation needed and decreased cow maintenance costs. If the increased body condition is maintained through the winter and calving and to breeding, there is potential for improved conception rates the following summer.
Over the years, there’s been a tendency to think that calves were not capable of using concentrated feed at a younger age, Jaeger said. Coupled with worries about calf stress, health risks, and heat – a complicating problem in July, August and September – has often kept producers from weaning earlier.
Optimum age still undetermined
Through this and other research, however, scientists know that calves can be weaned as early as 90 days, Jaeger said, but added that an optimum age for a beef production system has not been established.
“The optimum age in response to drought conditions is usually dictated by the severity of the drought and forage availability,” he said. “I usually advise producers interested in early weaning to wean when calves average 120 days of age. Most progressive producers have a 60-day breeding season, so calves weaned at an average of 120 days of age will range from 90 to 150 days of age.”
The studies indicated that the younger calves need feed that is highly palatable, meaning that it tastes good to them, and relatively high in nutrient density to offset the fact that they don’t eat as much as older calves do. They also found that feed moisture content of 20 to 30 percent is optimum.
“Familiar feeds may not have the nutrient density that you’ll need if you wean calves early,” Olson said. Just like humans sorting their most and least favorite foods on a plate, calves will sort their diet ingredients, so the size of the particles matters.
“Newly-weaned calves require management, regardless of the age at weaning. Producers should have a management plan and follow it,” said Jaeger, who provided tips for producers based on the studies.
• Place an additional water tank and feed bunk in the pen with the calves.
• Remove floating covers from automatic water troughs.
• Pen calves based on their body size. Limit the weight range within a pen to no more than 50 pounds less or more than the average weight in the pen.
• Make sure each calf has at least 12 inches of linear bunk space.
• Make sure the feed bunk and water supply can be easily accessed by the calves.
• Consider air flow – especially in hot weather. Too little shade promotes crowding.
A follow-up study is currently under way, in which the researchers weaned calves from their mothers at between 120 and 160 days, with an average of 127 days, and split them into two groups. Half of the calves were left to graze on pasture and the other half were placed in a feedlot. At the end of 60 days in the separate environments, the weaned calves will be put back together as a group, fed a common ration up to market weight. In that way, the team will be able to evaluate how grass-fed calves fared in comparison to those fed a high-concentrate diet. Those data will be available in 2014.