Grass silage for beef cattle /

In recent years, great interest has developed in preserving meadow crops as silage rather than as hay.This interest has arisen from an increasing apprecia- tion of the importance of high-quality roughage in the winter feed of all classes of cattle and from the difficulty of making good hay in unfavorable weather.New developments in harvesting machinery have reduced the cost and the dif- ficulty of handling heavy, green material.The term 'grass silage' is generally used for the product obtained from green forage crops that have fermented in silos.It is often called hay-crop silage because most of the forage crops ensiled would otherwise be harvested as dry hay.Grass silage may contain legumes or grasses, or both in almost any ratio.More specific terms such as alfalfa silage and alfalfa-molasses silage are sometimes used to in- dicate the particular material ensiled or the method of preservation.'Grass silage' is also used for silages made from cereal crops, peas, vetches, soybeans, or a mixture of these crops.In this publication 'grass silage' is used for a mixture of grass and one or more legumes. NUTRITIVE VALUE OF GRASS SILAGEGrass silage varies widely in feed value.For example, it may vary from about 70 to 84 per cent in moisture content, depending on the forage mixture, the stage of maturity, and the weather when the crop was ensiled.This means that cattle may get roughly 1.5 times as much dry matter per pound of feed from a silage with 70 per cent moisture as from one with 80 per cent.A moisture content of about 74 per cent is best for producing palatable, good-quality silage.Cattle that feed on such silage will take in enough dry matter.The protein content of grass silage, on a dry basis, may vary from about 8 to 19 per cent, depending on the forage mixture and the stage of maturity at which it was ensiled.Generally, silages high in legumes contain more protein than those high in grass.Cutting at an immature stage yields a silage higher in protein than cutting at greater maturity.Grass silage is lower in net energy and digestible nutrients than well-eared corn silage because of the considerable amount of grain in the latter.It is slightly lower in digestible nutrients than well-cured hay from the same forage.However, these differences in favor of corn silage and hay may be offset by the higher protein content of grass silage.Grass silage is high in carotene and, when forming part or all of the roughage ration, will provide for the vitamin A needs of all classes of beef cattle.On the other hand, grass silage is low in vitamin D, especially if the silage is made with- out wilting the material after cutting.Hence, a vitamin D supplement may be advisable if animals are wintered indoors.