Alfalfa (Medicago sativa L.) is often referred to as the “Queen of Forages” due to its relatively good digestibility, high protein, and ability to readily fix nitrogen. As a result of fixing nitrogen, the protein produced by alfalfa should have a high economic return in dairy systems because minimal outside inputs are required to produce it (i.e., no expensive nitrogen-based fertilizers).

However, this assumes that the dairy cow can efficiently capture the protein produced by alfalfa. Vegetative proteins of forages like alfalfa are rapidly degraded in the rumen of dairy cows and are not efficiently utilized to capture all of their potential nutritional and economic value. Protein fragments (partially degraded protein molecules) are even less efficiently utilized . . . resulting in a need for additional protein additives in the diet . . . resulting in additional nitrogen waste in manure. It is critical that a large amount of the forage protein is preserved as “true protein” as it goes into the dairy diet. This becomes a challenge in the more humid U.S. agricultural producing regions that ensile alfalfa forage.

Why? Because during the ensiling process, plant proteases are released and they begin degrading the vegetative proteins even before they are fed. This is one reason ensiling practices emphasize the need to rapidly decrease silage pH to a point that it limits protease activity and stops protein degradation. Variable and changing environmental conditions often lead to the production of less than optimal silage; protein degradation may be as high as 70 to 75% of the true protein.

Why red clover?