A tough summer and fall are turning into a tough winter for Ozarks ranchers, as tight and expensive feed supplies have left many cows in poor condition for rebreeding. According to Dave Patterson, University of Missouri Professor of Animal Science, the optimum body condition score for cows heading into calving season would be 5-7, particularly for younger cows. “They’ve got the added requirements for their own growth, plus maintenance, plus lactation,” Patterson told Ozarks Farm & Neighbor. “It puts an extra strain on those cows in terms covering all those bases and still being able to get back into condition for rebreeding.”
Patterson said it’s harder to put condition onto cows after calving than before, because they’ll turn any extra supplementation or feed they receive into milk. “If they’re in that condition score 4 or under range, then you’re really behind the eight-ball if you wait until calving to try to get it on,” he said. “It’s going to take the thinner females longer to resume cyclicity following calving.”
If cows lose significant weight after calving, they may not be able to rebreed for a very long time; they can even return to an anestrous, or noncycling state. “The way people need to think about things relative to prioritization of nutrient intake is that reproduction’s pretty low on the totem pole,” said Patterson. However, to boost fertility in a cow that is just a little too thin, estrous synchronization may be the answer. “The progestin based protocols for cows and feeder based protocols are very, very effective in terms of jump starting non-cycling cows,” said Patterson, but added, “What we don’t want people to do is to think of them as a crutch for overcoming problems in body condition. You can take cows that are perhaps borderline and jump start those but if the cows are extremely, extremely thin, that’s not going to do the trick.”
Dr. Tom Troxel, University of Arkansas beef cattle specialist and associate Animal Science Department head, said the body condition on cattle is not as good as it has been in the past. “We’ve not had the quantity and the quality of hay that we’re used to having,” Troxel told OFN.
Troxel recommended that cattle producers have their hay tested for nutrient content; armed with that knowledge, they can develop a least-cost ration to make up for any deficiencies. Although supplements aren’t cheap, they can help bridge the nutrition gap. “Things like corn, hominy, rice bran and some other byproduct feeds are available that can bring up the energy level to maintain body condition and maintain production in their cows,” Troxel said.
At this point, it’s too late to build up cows with low body condition scores prior to calving, so the goal is to maintain the body condition that they have. “Most of the time when cows calve they’ll lose a body condition score, and that’s what you’re trying to prevent,” said Troxel in reference to the standard 1-9 scoring method, with 1 being emaciated and 9 being obese. “Hopefully with the nice winter rains that we’ve had, we’ll get some cool season grasses growing in March, and we’ll get improved body condition,” he said.
When cows calve and start to lactate, their nutrient energy requirements rise 36 percent; if they don’t receive supplements, they’ll be using more energy than they take in. That’s detrimental to both milk production and rebreeding; it can even threaten the herd. “If the cows have been on the negative energy balance for a long period of time, when it comes time to calve they just won’t have the energy,” warned Troxel. “Cows could potentially just give up and lay down, and not calve.”
The combination of poor body condition and wet weather also increases the threat of scours to newborn calves. “When cows calve in poor body condition, they produce less colostrum and a lesser concentration of colostrum,” concluded Troxel. “That means that calf will not be as protected as they would normally.”
