As in the case of Human diet a higher percent of Fiber content is required for Horses also to keep its normal function of the digestive system . The normal requirement of roughage in the case of a horse is determined in relation to its body weight. Ideally speaking a horse should get 1.5 percent to 2 percent of its body weight as roughage in a day. But ideal situations are rare and as such it should be ensured that the animal gets roughage at least a minimum of one percent of its Body weight.
Roughages are the vital component of the diet of a horse that includes Hay and Pastures also. It is the source of the digestive energy, protein and a small percentage of Vitamins and Minerals. The total requirement of food per day for an average animal is estimated at around 3 percent of the body weight of the animal . However the suggested percentage cannot be applied without consideration of a few basic facts. The feed need be adjusted based on the grain content in the food , the stage of growth of the animal, lactation and the volume of work besides the expected body condition.
As already explained the term Roughage means high content fiber feed with an expected minimum fiber content of not less than 18 percent in crude form. Though hay and pasture the normal roughage there are many other alternate feed that can be effectively used to replaced the above two .
It is quite normal for the Horse owners to compromise on the hay and pastures supply in the daily feed of the horse during the period of severe drought when they become too expensive. In such situations they may either be replaced completely or their quantity curtailed. It is in this context the relevance of grains with moderate levels of fiber content comes into picture. It is expected that such alternate feed contain eleven to fifteen percent of fiber. It should be born in mind that such low fiber content cannot replace the hay and pasture s completely but the amount of hay can be reduced successfully. The change in the feed may not be done immediately rather gradually. One need ensure that the Horse gets at least one percent of its body weight Roughage per day the remaining portion being filled by the required quantity of moderate fiber feeds.
Though it has been stated earlier that a horse ideally requires one to two percent of their body weight as roughage in the daily feed the same cannot be applied uniform for all type of Horses. As per the standard prescribed by the Nutrient requirement of Horses a normal mature idle horse may require roughage of 1.5 to 2 percent of its body weight. In the case of working horses though this depends on the intensity of work on an average this can be taken as one to two percent. The mare either in late gestation or lactation may be taken as work horse for the purpose of feed content, while weanling and yearling requires comparatively lesser quantity of roughage say one to 1.5 percent.
Having seen the importance of the roughage in the feed of a horse let us discuss some of the alternate feed that can either partially or fully replace for the hay and pastures. The alfalfa hay is a good supplement for the hay and the pastures in this category as it contains higher protein and calcium and as such less quantity would suffice. The grass hay and the Bermuda grass hay are also complete supplements for the normal hay and pastures. While Millet hay has less nutrient value when compared to other grass hays. This has a laxative effect when exclusively fed as roughage.
Among other feed substitutes for roughage in full , sorghum grass is not recommended because of its bad effect on the health of the animals leading to neurological problems. The other major supplements are haylage,oat hay,straw,beet pulp, soy hulls, alfalfa hay,bermudagrass hay and millet hay etc. that can be successfully used as a roughage substitute. Besides the above there are other sources of moderate fiber feeds that can be used as partial substitute for hay and pastures in the horse feed like rice bran wheat bran oats etc. High hay diet is however not recommended for race horses for weight is a concern for them.