Two of the most commonly fed and easily accessible protein sources for dairy rations are canola meal and corn dried distillers grains with solubles (DDGS). The two ingredients are often fed together in a single ration, but little is known about how they should be fed together, and at what ratio milk production is maximized.
Researchers at the University of California, Davis spent two years studying just that. In the first year, the researchers studied what the optimal ratio of canola meal to DDGS was for milk production in lactating dairy cows. The study, “Determining the optimal ratio of canola meal to corn distillers dried grain protein as the primary supplemental protein for high-producing dairy cows,” looked at both crude protein levels in the ration as well as what was making up that crude protein.
All rations were 17 percent crude protein, broken out as follows for each of the four study rations:
Over the 28-day study, it was determined that the 13.5 percent canola meal (67 percent of crude protein) ration maximized milk production. Full study results can be found here.
After the first study, the research team decided to take their research another step. Their second study, The optimal ratio of canola meal and dried distillers grain proteins in high-producing Holstein cow diets, continued to look at milk production, but also took into account dairy cow health indicators such as body condition score (BCS), as well as market indicators such as milk fat and protein levels.
At the end of the study, it was determined that feeding canola meal at a rate of 60 percent of crude protein (12 percent of the total ration of dry matter) and 40 percent DDGS was the optimal ratio of canola meal and DDGS. In fact, at these levels, milk production averaged 104 pounds per day per cow. Also recorded during the study at the 60 percent inclusion rate was an optimal BCS increase of 0.034 of a unit over 28 days for this group of high-producing cows. The full research abstract can be viewed here.
Canola meal and DDGS are both parts of the modern dairy cow diet, and are easily accessible to dairy producers around the country. Using both protein sources together, at the right level, can provide economical results.