Soybean meal is currently the nearly universal protein source for calf starter grain formulations in the U.S.
But if you could tame some of the wilier aspects of distillers grain, it too can pack a powerful protein punch. Dr. Billy Brown, Assistant Professor at Kansas State University specializing in dairy cattle nutrition, discussed that possibility on a recent episode of The Dairy Nutrition Blackbelt podcast.
“One of the fascinating aspects of the ethanol industry today is that they’re getting really aggressive about trying to add value to the co-products they’re producing,” Brown noted. “It’s not just a bi-product. They’re doing a great job of trying to add value to those products that could realistically do great things for us in the dairy industry.”
Brown and his colleague recently conducted a preweaned calf study evaluating a specialty distillers grain product called “ProtomaxTM, manufactured by ICM, Inc.
The researcher noted there has been very little published literature summarizing research utilizing distillers grain as a protein source in calf starters. He said the few studies that have been performed showed relatively poor performance for calves fed distillers grains, in terms of calf growth and average daily gain (ADG).
“The high fiber content of the corn bran in distillers grains is probably a little bit more difficult for those calves to digest in that early life period,” Brown stated.
But thanks to a fractionation process that removes the corn brand, Protomax is more easily digested by preweaned calves. And, unlike earlier renditions of distillers grain, this product is dried without the solubles and fiber fractions.
The result is a highly digestible, low-fiber feedstuff that rivals soybean meal in protein content at about 50% crude protein. Brown said the manufacturers are also enhancing the product by fermenting yeast bodies, condensing the products of fermentation, and adding them back into the finished high-protein distillers grain.
Brown and his colleagues recently conducted a study comparing a starter grain formulation containing the new product to traditional calf starter using soybean meal as the protein source.
“We kind of expected some negative results as a part of including this high-protein corn product in the diet,” shared Brown. “We actually saw the opposite. Calves on the high-protein corn product grew more, had greater average daily gain, and tended to have more dry-matter intake, but there was no evidence of difference in feed efficiency.”
Even more encouraging were the results of actual digestibility. “To our surprise, the calves on the high-protein corn product actually had greater apparent total tract digestibility and crude protein digestibility,” he shared.
Brown noted that, compared to previous studies of distillers grains in preweaned calf diets, the Kansas State researchers were mindful of amino acid balancing. They used the CNCPS model to meet estimated lysine and methionine requirements using rumen-protected supplements for those potentially limiting amino acids.
And the financial bottom line? Encouraging as well. The cost of the distillers grain-based ration was about $5.00/ton less than the traditional soybean meal-based ration. Even including the cost of the amino acid supplements, the net cost was about 6 cents/calf/day lower for the distillers ration.
While acknowledging this study is an initial foray into a whole new possibility for preweaned calf rations, Brown is encouraged by the results.
“We know that calves that gain more weight in the preweaning period have greater lifetime milk production,” he noted. “A lot of that comes from the milk feeding program, but if we can also help accomplish that with the grain feeding program – even carrying into the post-weaning period for a month or so – that’s a really positive benefit for that calf long-term down the road.”
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