Untitled Essay Research Paper Mac Winslow

Untitled Essay, Research Paper

Mac Winslow

Twinning in Cattle

Due to the continual fluctuation of the cattle market cattle producers

have been searching for ways to improve their production and increase their profits any

way possible. For years genetic engineers have been working hard on improving economic

efficiency in cattle. It is their hope that through genetic research they can improve the

yield and the income of cattle producers around the world. Research has shown that

twinning is one way that farmers can increase their yield . Twinning has a significant

influence on producers as well as people who are involved in all realms of agriculture.

The reason for this large impact at this time is the fact that the occurrences are

limited. However, many producers have a vision that twinning can be more than a once in a

blue moon occurrence. These producers see twinning as a way to dramatically increase their

yield per calving season. Producers will increase their income due to more weight per year

per cow. It is necessary ;however, that the producer be well educated on ho

w to handle twinning, in order for it to be successful for them.

Many agencies see twinning as an economic move upward. The American

Breeder Service has made efforts to produce semen as well as embryos with high predicted

breeding values available to producers. They have been recorded based on

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twinning probabilities and ovulation rates. A large amount of work on twinning has also

been done by the Meat and Animal Research Center. Since the early eighties, they have

located cattle with a high frequency of twinning and been forming a breeding foundation

based on this characteristic. “We believe the time has come to make some of these

unique genetic resources available to the beef industry through artificial insemination

and embryo transfer” (Gregory 23). An extensive amount of research has been done

using embryo transfer in cattle. In one study recipients were implanted with either a

single embryo, two embryo in one uterine horn, or one embryo in each uterine horn. It is

also possible to split embryos using a micro manipulator and implant each half to produce

identical twins. On the average about 16% of the cows implanted with two embryos produced

twins. When two embryos were implanted, and one was placed in each horn, conception rates

were comparable with the prior method, however the twinning rate wa

s much higher when the embryos were in separate horns (73% vs. 45%). For the most part,

when one embryo was split in an attempt to produce identical twins, only one of the

offspring survived birth (Davis 302).

Many producers see twinning as a possible

advancement in economic prosperity for themselves. Scientists have increased the

possibility of successful twinning through extensive genetic research. They now also able

to inform the producer of twins through the use of proper palpation techniques as well as

ultrasound. Blood can be analyzed in labs to determine fetal weight gain. In addition

nutritious feeds and technology that aids in calf survival have made the possibility of

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high twinning success rates closer to being reality. These factors enable the genetic

possibilities to be an asset to producers (Gregory 23-24).

“Increased frequency of twinning should increase efficiency of

beef production” (Davis 301). Results from twinning are very appealing to a farmer

who can use one brood cow to produce two calves per year. Reports show that beef cattle

can wean a higher total weight per cow. A twin’s average daily gain depends on the

environment as well as genetics (Cady 950-956). Single born calves are reported to have

birth weights of 25% more than a twin calf. Over time, however, the twin calves approach

the weight of the single calves. At weaning the weight gap decreases to only about 15%.

Despite this seemingly large difference in weaning weights, it should be realized that

there are two calves to sell from a set of twins as compares to one from a single birth.

In addition to their size, twin calves consume less rations of fees than their

counterparts. From these conditions, promise for economical stimulus is easily seen,

especially in beef cattle (Cundiff 3133-3135).

Despite all of these draw backs, work is being done to help twinning

become profitable, instead of problem causing. A gene has been researched that causes

twinning in cows. This gene could be selected for through expected progeny difference

scores just like someone might select for birth weight. This gene would not only make the

offspring of the bull more likely to have twins, but it would also help her to be maternal

to both of the offspring instead of nurturing one of them and abandoning to other one.

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“At the present, selection for more twin births in dairy cattle

results in deleterious effects on the dams” (

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