Fetal Programming and Genetic Potential
contributed article by Dr. Vince Collison, Collison Embryo and Veterinary Services,
Rockwell City, Iowa
I was recently listening to a podcast that talked about the importance of fetal programming. Basically, it emphasized the importance of protein, vitamins, and trace mineral supplementation to the dam throughout gestation for the fetus. They talked about a trial they did, stating that calves from dams that were supplemented during the entire gestation had a 60-pound advantage at weaning versus the calves from control dams that were not supplemented through gestation.
I have written about this before in an article about epigenomics. I feel that fetal programming and epigenomics are different terms for the same thing. We often emphasize the importance of mineral and nutrition during the pre-calving time frame and throughout the breeding season, but we often feel that the cow can be floated along through gestation until the next calving season. This study emphasized the importance of meeting the needs for minerals, vitamins, and protein throughout gestation. Fetal programming (epigenetics) is a process that continues throughout the entire development of the fetus from conception until birth.
Recipe for Success
To make the most genetic improvements in our herds, we invest in the best genetics possible with the bulls, cows, semen, and embryos that we purchase. We spend a lot of effort planning the matings we will produce via ET or AI. We can also invest a lot of time in studying how EPDs will be improved by the way we breed our cattle. We also invest money in the genomic testing of our calves, looking for the best heifers to keep as replacements and as marketing tools for bull sales. All of these things are the genetic package that future offspring will inherit. To make the most of this genetic package is where fetal programming comes into play.
Impact of Nutrition
Fetal programming (epigenomics) is providing the environment to turn on the good genes in a positive way. The diet the cow consumes during gestation is an immediate way to impact the fetal environment. When nutritional needs are not being met in the gestating dam, good genes in the fetus are not being signaled to turn on, thus affecting the future calf’s ability to perform even when it has the genetic package we’ve worked hard to produce.
This can be the difference between a strong, viable, healthy calf produced in one herd versus a calf that is not as viable or healthy being produced in another herd with essentially the same genetics. If you keep your own replacement females, it is essential that you take advantage of and maximize fetal programming. These are the females that will be bigger at the time of breeding and have been shown to last in the herd longer.
Duration of Epigenetics
One thing that we need to keep in mind is that epigenetics can be affected during the entire life of the calf. So, what we do after birth will also make a difference in how the calf will express its genetic potential. Ensuring adequate colostrum intake in the initial few hours after birth is also key to maximizing genetic potential due to the health benefits and other nutritional factors.
Giving the calf the proper diet during its growth phase, sanitation, enough space for exercise, disease and parasite control all play a role in maximizing genetic expression. But when considering how we can maximize the epigenomic potential of a genetic package, realize the epigenome is probably most easily impacted in the early part of the life cycle and will be less impacted with age. Thus, we can probably make the biggest impact while the calf is still a fetus.
What we do after birth also is important, but you will not be able to make up for lack of fetal programming after a calf is born. In the study mentioned earlier, calves born from supplemented cows versus un-supplemented cows weaned off 60 pounds heavier and were all treated the same after being born.
Impact of Exercise
Besides nutrition, the other thing that can have a large influence is adequate exercise during the growth phase. In order to properly develop the skeleton and muscles of a calf, it needs to be able to get around and move. This requires space. For most producers this is not an issue as most calves will go to pasture, but if you are leaving pairs in a small lot or trying to raise them in a hoop building consider giving the calves a place where they can get the proper exercise to develop.
I always like to emphasize this point with a case I had years ago. I was the veterinarian for an emu farm and one day I was called out for baby chicks that were going down and unable to get up. On examination, the birds were crippled to the point where the patella was being pulled off to the side of the stifle joint. These chicks were on a good nutrition program but were being raised in a 1000-gallon water tank. Basically, the chicks’ bones were growing faster than their muscles and tendons from the lack of development due to restricted exercise.
In the wild these chicks would have been running large distances from the time they were hatched. Although I have never seen anything this extreme in calves, I do feel that there are growth advantages to calves raised out in the open versus in confined areas.
As far as the opportunities with fetal programming and epigenetics, we must remember there are these windows of time in the calf’s life cycle that can make a big difference if we do the right things. Once that window of time has passed by, it will be hard to make up for any lack of nutrition, etc. that could have had a positive impact on the epigenome.
learn more www.collisonembryoservices.com
Dr. Vince Collison is co-owner of Collison Embryo and Veterinary Services PAC
in Rockwell City, Iowa.
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