Capacidad de las praderas para llenar los requisitos de energía y proteína de herbívoros

Abstract

The energy value of forage is being studied from new angles since it has been discovered that ruminants absorb energy producing substances directly from the rumen, in the form of short chain fatty acids. Little is known yet about the influence of different pastures to change the fatty acid metabolism of the rumen. However work done so far with stabled animals indicates that it is rather easy to influence the formation of these intermediate metabolites by changes in the diet. The forage consumed by grazing animals is of greater nutritional value than it was formerly thought. This is due to the ability of the grazing animal to select the feed he takes. The selection more than compensates for the loss in energy due to grazing, provided the animal is given a good chance to select. Overgrazing results in very little selection chance. Knowing these principles of selection by the grazing animal it is not surprising to know that recent experiments show that reasonable good pastures are quite capable of meeting all the nutritional needs of bovines. This is particularly true in the case of protein for the growing animal. For milk production, the grazing cow on reasonably good pastures should be able to meet all requirements of maintenance and up to 9 Kg of 4% milk for large cows and up to 11 Kg of milk for small cows.