Recent approaches in forage evaluation

Abstract

For forage quality evaluation, three methods, chemical, in vitro and in vivo are commonly employed. Chemical methods, even following the newer techniques of partitioning plant cells (cell contents and cell wall constituents) are not adequate for forage evaluation. Efforts need to be directed in establishing relationship between cell wall components and their digestibility both in vitro and in vivo. The efficient in vitro system which has high correlation with the in vivo digestibility reflects all the known and unknown factors limiting the availability of forage to the ruminant system. A number of relationships have been proposed which may be helpful to animal and plant scientists for predicting dry matter digestibility of Indian forages. The plant breeders' genetic stock can be screened at the early stage of development when the number of strains are large and the amount of plant material available small. These equations are slightly different from those established for forages in temperate zones and therefore, can be used for screening forages in our country. For a better estimation of nutritive value of forages, however, the in vitro and in vivo digestibility are obviously to be preferred. It is suggested that more work in this area needs to be done to develop easier methods applicable under various agro-climatic conditions.