The effects of adding poor quality ground hay to the concentrate mixture for dairy cows

The use of ground roughage in the dairy concentrate mixture is common practice in many parts of Tennessee. A visit to local feed mills in Middle Tennessee during the winter will show the magnitude of this practice. A few of the dairymen use only small quantities of good quality hay to mix with the grain, but many of them use larger amounts of poor quality hay. Molasses are usually added to make the mixture more palatable. This mixture is then fed, not as a roughage, but as a concentrate mixture to the dairy cows.

Owners of many of the higher producing herds in these areas of Tennessee do not use any ground hay but feed an all grain concentrate mixture. The use of poor quality ground hay seems to be more prevalent among, although not confined to, relatively small producers of manufacturing milk with lower producing cows. On many of these farms the roughage that is fed long is of a poor quality also. Thus, a cow is getting low-quality roughage and a concentrate mixture made up"largely of the same low quality roughage.

Some of the reasons given by the farmers for using ground hay in the concentrate mixture are that feed costs are lowered and needed bulk is added to the concentrate mixture. Work by Moore, Huffman and Plum (12) has shown that the bulk of the concentrate mixture is not as important as believed formerly. It is probably true that feed costs are lowered but is milk production lowered? If so, how much? Is the composition of milk affected? Also, are there other effects that should be expected?

In an effort to obtain answers to these questions, a study was conducted to determine the effects of adding poor quality ground hay to the concentrate mixture for dairy cows.