Twin calves born to ranch cows are a mixed blessing. They bring extra profit to the rancher, but require extra work during an already busy time of the year.
Twins result in lower birth weights and more pounds of weaned calves. What rancher doesn’t want a good calf crop especially with the high cattle prices the industry has been experiencing?
On the Gill Ranch in Lucile, we kept 49 head of Hereford, black-baldy cross replacement heifers to calve out in February. Out of those, we had four sets of twins.
Three sets of twins were born on their own without complications. The fourth set we had to assist; the first calf was pulled out normal, the second calf came out backwards.
Only one set of twins was a freemartin. The other three sets were matching bull calves.
The first set was born to a Hereford cow, the other three sets were produced by black cows. These replacement heifers were artificially inseminated to different bulls.
Genetics are responsible for some twinning. Twinning is both heritable from the bull side as well as the cow side.
“We definitely have some cattle lines heavy to twinning. We also breed to some bulls that have twinning in their pedigree,” stated Marty Gill, certified animal nutritionist, Performix Nutrition Systems.
Gill oversees the ranch replacement program where the first calf heifers are synchronized and artificially inseminated, being bred to high genetic bulls with low calving ease scores.
One of the most effective tools available to cattle producers to improve productivity and profitability of their cattle operations is artificial insemination (AI). This procedure has been utilized by the cow-calf industry for more than 50 years.
“It’s factual that artificial insemination places the eggs closer to the fertilization area in a heifer, promoting more chances of twins,” Gill said.
Ranchers need to prepare for an early calving season if twins are suspected. Gestation length of twins is from one to two weeks shorter than for single calves.
Estimates of the percentage of beef cattle that produce twins vary depending on breed and genetics.
Beef cattle are not usually high milk producers. Twins require extra milk to help them grow and round out. A ranch cow can sustain two calves for a while with supplemental help such as milk replacer being fed to the calves as well. This creates another daily chore for the rancher to mix and feed milk bottles to the twin calves.
Range cattle are not necessarily used to barn facilities or being confined in the corral for several days. This sometimes causes the cow to get stirred up and not want to mother her calf or calves. It can also be dangerous for the rancher when a cow is uncooperative.
If the cow was left amongst the herd with her twin calves, most likely she would take the stronger, more aggressive twin and orphan the other.
Cows nursing twins require more energy intake to maintain their body condition. Body condition scoring (BCS) is a useful management tool ranchers can use to determine the nutritional needs of their beef cows. A cow is expected to be in optimal body condition (BCS 5-7) before calving.
Body condition scores are numbers one to nine used to estimate energy reserves in the form of fat and muscle of beef cows; a score of one being extremely thin and nine being very obese.
Research has also indicated a strong link between the body condition of a cow and her reproductive performance. “Good nutrition is a vital link to having fertile cattle,” said Gill.
Cows nursing twins will take longer to recycle to rebreed for the next year’s calf crop. Ranchers try to breed their cows to calve in a reasonable time frame. This produces a uniform calf crop that is more appealing to market buyers.
Most twin calves are fraternal twins, not identical.
Freemartinism is recognized as one of the most severe forms of sexual abnormality among cattle. This causes infertility in female cattle born as a twin to a male. A rancher wants to guard against keeping a heifer twin that had a bull mate as the majority of these heifers are unable to produce a calf.
According to science, the sex of a calf is determined on the bull side.
Grafting a twin calf is often the best decision. Grafting is a process that entails helping a cow who lost her own calf through birthing difficulties or other causes to accept another calf as her own.
One way to graft a calf is to skin some hide off the dead calf and tie onto the adopted calf. This leads the mother cow into believing it is her calf through smell. Once the adopted calf is accepted by the new mother and has suckled her, the hide can be taken off.
When you have a good cow that is mothering both her calves, it is hard to split them up. Generally taking the more aggressive calf to graft is the best, leaving the weaker calf on his real mother.
There is a lot of factual science regarding twinning and artificial insemination, although Mother Nature still prevails.
Shelley Neal is a resident of Lucile.