With caution and a little nutrition common sense, producers and nutritionists can formulate good diets with no or little alfalfa in them and maintain milk production.
That’s the conclusion that Noah Litherland, University of Minnesota Extension dairy nutritionist, came up with using model predictions.
He’s constantly been asked by Midwestern producers, some of whom lost alfalfa to winterkill this year, “How do we feed cows without alfalfa?”
So Litherland replaced the region’s standard total mixed ration ingredient of 16 lbs of alfalfa dry matter per cow per day with corn silage, then with feed byproducts, and finally with mixed-grass silage.
The higher corn silage diet had lower crude protein content, lower soluble protein, higher neutral detergent fiber, much higher starch and lower calcium. But the model predicted cow performance would be “surprisingly similar” to the alfalfa diet.
With the byproduct diet, ingredients such as cottonseed and soybean hulls cost more per cow per day than alfalfa, and “we were unable to affordably match the nutrient profile of the alfalfa diet with byproducts.” Even so, the predicted cow performance was comparable to the alfalfa diet.
The mixed-grass-silage ration cost less than the alfalfa diet and was still “acceptable,” offering good effective fiber.
In Minnesota, Litherland says, “we’re certainly seeing more grass because of the alfalfa winterkill. People were looking for a quick stand just to fill the gaps from a nutrition standpoint.”
In another study comparing the fiber digestibility of good-quality orchardgrass hay to alfalfa, Litherland says, “we were able to see that grass hay performed equally, if not better in some instances, than alfalfa.
“Three factors are going to play a pretty big role in some unique diets,” he says. They are the genetics offered in silage-specific corn hybrids, the Shredlage harvesting technique that offers long chop length and high silage corn digestibility and doing a good job of processing silage corn conventionally.
Along with effective fiber, make sure any new diet contains the right amount of two other vital nutrients that alfalfa supplies – calcium and soluble protein, he warns.
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