Answer provided by Robin Rastani, Ph.D., Dairy Tech Specialist at MSC (Milk Specialties Company).
Q: Corn prices are coming down again, but the lesson from earlier this year is to be creative and find alternatives to corn when it’s economically feasible. Can we use corn gluten feed and sugar with organic acids to replace some of the corn in the ration?
A: Creativity and flexibility in ration formulation can provide exciting results.
Let’s evaluate your situation by looking at two key areas:
- Cows do not have a requirement for starch. Instead, they have a requirement for fermentable carbohydrates, including starch, soluble fiber, and sugar. The cow uses the rapidly fermentable carbohydrates to provide energy to rumen microbes, which consequently helps optimize the conversion of feed into volatile fatty acids and amino acids.
- It’s important to match up carbohydrate and protein sources so that they have relatively similar rates of rumen degradation. For example, grass silage contains a high proportion of soluble protein, which degrades very quickly in the rumen, so a sugar source would be a good synergistic match due to its quick rate of rumen degradation. Cows should have a mixture of carbohydrate sources in the diet that have varying rates of degradation, just as they have a mixture of protein sources in the diet with varying rates of degradation.
Corn gluten feed, like most by-products, is greater in protein (24 vs. 9 percent) and lower in fermentable carbohydrate (32.5 vs. 77.1 percent) relative to corn. However, it is similar in total fat compared with corn (15 vs. 18 grams for corn gluten feed and corn). If corn gluten feed is available for a lower cost on an energy basis than corn, it makes sense to buy or book it.
Since corn gluten feed is lower in fermentable carbohydrate than corn, additional fermentable carbohydrate must be added to the ration. This is where the sugars come in. They can increase fermentable carbohydrate and provide that rapidly available carbohydrate that the cow needs.
A commercially available sugar source with organic acids can help. These organic acids help feed the microbes in the rumen, and aid in the conversion of lactic acid (which causes acidosis) to volatile fatty acids. As a result, rumen pH is maintained and the cow has more energy available for milk production.