By Ron Johnson, Dairy Editor
Reprinted from Agri-View
February 14, 2002, Page C-1, Volume 28, Number 7
Is your herd's ration balanced? Read your cows' feedback to find out, said Tom Weaver, Darlington, a director of KOW Consulting Association and a certified crop advisor and dairy nutritionist.
Weaver spoke last week at the 10th Annual GrassWorks Conference in Stevens Point. He explained that if all is well with a ration, a cow will let you know. Conversely, if something is wrong with a ration, she will let a trained observer know that, too.
Among the signs that a ration is fine are these:
- A cow chews her cud regularly.
- She has perky ears, a shiny coat and bright eyes.
- She sports a big belly.
Eight to 12 hours of cud chewing a day is normal, Weaver said. "She should chew her cud about as long as she spends grazing," he compared.
Cud chewing produces saliva—on the order of 40 gallons a day. That saliva helps recycle nitrogen in her system and also acts as a buffer in her stomachs.
One gallon of cow saliva is equal to 1.5 ounces of sodium bicarbonate, Weaver said. That means, he added, "Grazing cows don't get acidosis."
And what prompts a cow to chew her cud? Plenty of fiber in her ration.
A healthy, productive dairy cow should not look like she's attending Weight Watchers. A big belly indicates that she is taking in an adequate amount of feed, Weaver said.
He advocated this simple test. Stand behind a cow and see if her belly sticks out on both sides. She should not appear straight-sided—or flat—when viewed from the back.
At least a couple of things, Weaver noted, can hurt feed intake: poor paddock condition and an empty feedbunk. To improve paddock condition for the inevitable "summer slump," he advised planting some sort of summer annual.
Of course, heat stress can also lower feed intake, as well as inhibiting reproduction. He advocated forming a contingency plan soon for dealing with heat stress. "Do you guys have a plan?" Weaver asked. One person in the audience replied, "Winter."
Since winter doesn't last forever, Weaver suggested rigging up a stretch of shade cloth in a pasture. True, that will cost something and take a bit of time, and the cows might start a mudhole under and around the cloth, but Weaver contended that it's better than dealing with cows that won't breed back because of hot weather. He drew a distinction between "low inputs" and "zero inputs" and asked the graziers to critique themselves on whether they had crossed the line.
He told the group that the feed at this time of year greatly affects cow performance once they open the gates in the spring and begin grazing again. Weaver contended that a winter feeding program should set the stage for "as slight and smooth a transition into new grass as possible."
Weaver pointed out that pasture grass fits the parameters of top-quality forage. It's a true green color; it hasn't been fermented at all; it has a soft texture; and it has a pleasant odor.
Corn silage, on the other hand, which makes up a good portion of a typical winter ration, falls into the "poor quality" forage category. Thus, he likened switching from feeding corn silage to fresh pasture to "jumping across the Grand Canyon."
Try growing some brown midrib sorghum-Sudangrass, he suggested, and feeding that in the winter. Or maybe feed a bit of dry grain at noon, making sure you cut back on grain at the other feedings.
A grain mix can also help prepare cows for the high-protein forage that awaits them in a couple of months. Such a mix might include ground shelled corn, ground high-oil ear corn, ground oats, beet pulp or citrus pulp, fish meal, molasses, and extra minerals to match what's in your pastures' grasses. Top it all off with free-choice salt and a free-choice buffer and the cows will adjust much more easily to all the fresh grass they care to eat.
Weaver also explored another topic: a dairy cow's biological requirements.
As an example, he reminded the graziers that there is more than one way to meet those requirements. Using water as an example, he pointed out at least three ways to provide it: Carry water to the cows in five-gallon buckets; set up a tank and let the cows walk to the water; and remove fences and let the cows walk to a creek or pond. All those options can work, he said, but they are not all equal in terms of efficiency.
Besides water, a dairy cow's biological requirements include feed that is palatable and digestible and that contains enough energy, protein, minerals and vitamins, the nutritionist said.
Then he asked, "What should the lifespan of a cow be? What does a cow require in her diet to be healthy and productive?"
Weaver asserted that a cow in a freestall barn is really no different from a cow on pasture, and blamed part of the typical culling rate of 33 percent on a violation of cows' biological requirements. Part of the reason for high culling rates, he said, is the so-called "hot" ration that's heavy on grain.
He presented this notion: "You can balance a ration with anything plus supplements," then asked, "Is this real?"
"What does a balanced ration look like in a cow?" Weaver queried. "Look beyond numerical values. If the cow doesn't agree, the ration's not balanced."
