The 2010 Winter Olympics were held this past February. I always enjoy watching the best athletes in the world compete. Whether they’re snow skiing, snow boarding, bobsledding or ice skating, they’re at the top of their form, having devoted many years of their life getting to where they’re at.
I consider the high-producing milk cow to be something of an athlete, as well. For dairy cows to perform well, they have to be at the top of their game. And being the domesticated animal that they are, cows depend on us to get them to that point.
The measure of performance excellence for a dairy cow is how much milk and components she produces during a lactation or a lifetime. The high-producing dairy cow is “in training” her entire life. While good genetics certainly plays a big part in deciding if a cow is going to be a winner, genetics is something that is set in the DNA on the day of conception and from that point on, there’s little we can do to alter it. Diet, environment and management have the most influence on whether a cow can ever “make it to the podium.”
Whether we like it or not, the economics of forced efficiencies is what has driven much of the large-herd commercial dairy industry in the U.S. over the past few decades. We’ve done a very commendable job of improving the productivity of our cows while, at the same time, many times overproducing our way into a cashflow crisis every few years.
In the process, in an effort to stay ahead of ever-increasing production costs, we’ve had to make our cows better producers. Now we find ourselves in the ironic situation that makes it nearly impossible to see our herd averages decline after realizing what’s possible. It’s sort of like having to go back to driving a Rambler after driving a BMW for a couple of years.
The private sector and academia have pumped millions of dollars into research directed towards improving the performance of the modern dairy cow. Today there is very little that we don’t know when it comes to their biology and physiology. Cows, being mammals, share many of the same metabolic requirements as pigs and horses or dogs and cats. But because they are ruminants, their diets require another level of sophistication. In order for a cow to perform her best throughout her lifetime, her rumen must be in tip-top shape.
It all starts when she’s a baby calf. She requires the best care of all before she is weaned. At that stage of their life they’re very susceptible to a multitude of pathogens that can either kill them or stunt their growth. We’ve all seen the young heifer that had a bad case of pneumonia while still a baby and her lungs are permanently scarred, preventing her from ever growing very well. Whether you’re milking Holsteins, Jerseys or Brown Swiss, heifers can be in the barn, milking before two years old, at which point they should be about 75 percent to 80 percent of their adult weight and height. There’s been plenty of research done on how much more a cow’s lifetime milk production will be if she can make it into the milk string between 22 and 24 months old.
A calf’s rumen is non-functioning when it is born. The rumen slowly starts to develop in a couple of weeks and calves can be weaned off of milk by 4 to 5 weeks of age and fed a diet that is still higher in protein and non-fiber carbohydrates. The goal here, of course, is to maximize daily gain throughout the two years it takes to get her freshened. By the time a calf is 6 months old, the rumen is fully functioning. From that point on, it’s all about the rumen.
In order for a cow to perform well and stay healthy, the rumen has to be functioning efficiently. And at the heart of rumen health are the rumen microbes. They are what are responsible for converting feedstuffs into energy and blood glucose. A cow without glucose is a cow that can’t perform.
When carbohydrates, both structural (neutral detergent fiber) and non-structural (sugars and starches), undergo microbial fermentation, they produce volatile fatty acids (VFA), which are the building blocks for glucose. The three primary VFAs are acetic, propionic and butyric acids. These VFAs provide most of the energy needs of the animal, with the rest of the energy coming from protein and dietary fat.
Just like the human athlete, a cow’s diet must be balanced with the correct types of feedstuffs to ensure that the rumen bugs are healthy and can proliferate so they can go about their job of fermenting feeds and making VFAs. Just as a human athlete training to ski the downhill wouldn’t dream of eating all junk food to maintain strength and endurance, the dairy cow needs highly digestible feedstuffs that maximize rumen efficiency.
And the “training regimen” must continue every day, even when the cow is in the dry pen. Even though milk production has ceased for a couple of months, the cow is still in need of a proper diet as a fetus grows inside of her and she’s preparing for the next lactation. We all know how quickly we get out of shape when we stop exercising or don’t eat correctly. The same thing holds true for our dairy cows. We can’t expect her to be at the top of her game on the day she freshens if she hasn’t been fed correctly while a dry cow. While feed intakes are greatly reduced during the dry period, the rumen must be prepped a few weeks before freshening so that the bugs are ready to “launch out of the gate” when they’re called upon to do so.
The dairy cows on all of our dairies represent a considerable investment and certainly in these tough economic times it’s easy to look at them as a liability rather than an asset. Most dairy farmers, however, will find themselves in a more favorable financial position if they keep their cows as productive as possible. PD
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John Hibma
- Nutritionist
- Email John Hibma