A cow with a problem birth in 2015 will likely cost you money in 2016.
That’s according to Dr. Tom Troxel, associate head of the Department of Animal Science at the University of Arkansas. Troxel told Ozarks Farm & Neighbor calving difficulties (“dystocia”) trigger a sequence of events that affect the cow’s productivity. “The result of that means that cows generally take longer to rebreed,” he said. “If they conceive later in the breeding season this year, that means they’ll calve later in the calving season in 2016. If that occurs, and you’re in a controlled breeding and calving season, when that calf is weaned it will be younger in 2016, and the number one factor that affects the weight of a calf is its age…That will affect the gross income from that cow in 2016.”
One common cause of dystocia, heavy birth weights, can be avoided through sire selection. Troxel said heavy birth weights are most commonly manifested in first calf heifers, so heifers should be bred by bulls with favorable birth weight and calving ease EPDs. Other things that can cause calving problems are beyond the rancher’s control, among them an anomaly in the calf’s presentation. Troxel said, “Normally you want to see the two front legs with the nose in between them, but sometimes the presentation of that calf gets turned around and you might have a front leg that may be turned back.”
Whether you should keep a cow that’s had a difficult birth may depend on the degree of difficulty. Sometimes it’s so bad that the uterus can actually turn inside out. The veterinarian can sew it back into place; you can keep that cow until its calf is weaned, but generally after that she has to go to town. On the other hand, an unorthodox calf presentation is not necessarily a signal to cull the cow. Troxel said, “Generally speaking if a leg is turned back, through manipulating the calf and getting that leg turned back up the calf is delivered pretty smoothly. Those cows can rebreed and have a calf with normal positioning in the future.” Nobody knows, he added, what causes those unusual presentations.
Troxel also emphasized proper nutrition for the cow prior to calving. “Cows that are in good body condition and healthy have the ability to push properly,” he explained.” “When they lie down and give birth, they have the strength and stamina to expel that calf generally without as much problem as those that are thin. If you have a cow that’s thin, she’s weak and will get tired quickly when she pushes during the labor process. Those are problem cows that will have dystocia problems more often.”
Sometimes cows fail to get bred due to a genetic flaw. A team of animal scientists across the country are attempting to identify genetic traits that cause embryonic mortality. The project is getting resources from breed association and other industry groups. The research component is led by University of Missouri Professor of Genetics and Animal Science Dr. Jerry Taylor, who explained embryonic failure as a result of gene mutation is often not recognized, simply because there is no fetus that would signal a spontaneous abortion.
Of the 3 billion nucleotide base pairs sequenced from the genomes of cattle from various breeds, Taylor said about 10,000 have been identified that cause loss of function, but not all are lethal because the bull carries multiple copies of the gene. Once they’ve decided which are damaging to the viability of the animal, they’ll sample 10,000 commercial Angus heifers in Missouri’s Show-Me-Select heifer development program to see which of these genes never show up in two copies in living animals. In the future this information will be incorporated into EPDs, so producers can select bulls that will not contribute to the potential of embryo loss in their cows.
