Are There Unique Features of Alfalfa Hay in a Dairy Ration?

Alfalfa hay is, or should, be highly valued as a dairy cattle feed due to its relatively high (for a forage) crude protein (CP) level which has a low rumen soluble fraction and a relatively high rumen escape fraction which contains a high level of the key amino acid lysine. It should also be valued for its high level of rapidly rumen digested pectin which has a high cation exchange capacity (CEC), as well as for its high levels of nutritionally important minerals. However, perhaps most importantly, alfalfa hay is, or should, be valued for its relatively low (for a forage) structural fiber (NDF) level which is relatively rapidly rumen fermented, has a high CEC and stimulates ruminative chewing and salivation. These characteristics, taken together, mean that alfalfa hay added to a dairy diet at 10 to 20% of dry matter (DM) tends to increase the nutritional value of the entire diet. Yet because all contemporary ration formulation software programs fail to describe many of these key characteristics, alfalfa hay is undervalued to varying degrees by these programs. However dairy nutritional professionals know this to be the case and frequently ‘force’ alfalfa hay into a diet when their computer programs tell them that it is economically unwise to do so, thereby increasing the real fiscal value of alfalfa hay.