Purdue University Agricultural Experiment Station Lafayette, Indiana
Mimeo DH-72
THE FEEDING VALUE OF OAT SILAGE FOR MILKING COWS
F. A. Martz, C. H. Noller and D. L. Hill
Dairy Department
Although oat silage has been made and fed by many farmers and experiment stations, the results, in general, have been disappointing. The failures can be attributed, at least in part, to a lack of a quality silage which requires that the plant be harvested in a high nutritive state and preserved by a good fermentation. Although the value of the plant cannot be increased by ensiling, the fermentation must be controlled to produce a palatable silage and to save more of the forage nutrients. A poor fermentation produces an unpalatable silage which is unacceptable to the cow and disliked by people working around it.
Good quality oat silages have been made using the wilt method or the direct-cut method with a preservative. The poor results using the direct-cut method have usually been associated with the failure to use a preservative. A low quality silage is not relished by the cow, so the failure of most oat silages is primarily a lack of intake. It has been indicated that a lack of voluntary intake is in a large measure responsible for the low milk yield from forages. To improve silage quality and to increase intake, the use of preservatives such as molasses, grain concentrates or sodium metabisulfite has been recommended.
Oats, which are usually used for grain on dairy farms, may be pastured or harvested for hay or silage. Oats make an excellent nurse crop for new seedings of legumes and grasses. Earlier removal of the oat forage conserves moisture in the soil and gives the legume or grass seeding a better opportunity for growth than it would have if the oats were permitted to mature.
The quality of silage is affected by its chemical composition and it is here that the oat silages have sometimes fallen short. Many reports indicate that a forage crop of higher protein content can be obtained by harvesting the crop while it is in the early stages of growth and, particularly, before it is fully mature.
The question of composition has practical importance owing to the fact that farmers frequently ensile a green cereal crop and are disappointed to find that the silage Produced is very low in protein. The reason is that following the early stages of growth there is a fairly rapid and continuous fall in the percentage of crude protein in the plant and too many times the crop is cut after the decrease in crude protein has occurred.
Because of the considerable differences of opinion among people making oat silage, and also because of the many poor results reported, it was evident that there was a need for more information about oat silage. Therefore, an experiment was conducted at Purdue University with milking cows to compare the palatability and feeding value of grass-legume silage with oats cut for silage at three stages of maturity.