RELATIONSHIP BETWEEN FORAGE QUALITY AND DAIRY-CATTLE PRODUCTION

The effect of forage quality on animal production is observed routinel y in the field by farmers and nutritionists when switching from one fo rage or ''batch'' of forage to another. When production decreases, die tary adjustments sometimes reduce or eliminate the differences in prod uction. However, altering supplementation strategy will not always all ow one forage to achieve the same level of production as another. Whil e it is clear that differences in ruminal degradation of forage compon ents affect energy intake, absorbed protein and subsequent production, it has been difficult to assess their relationship quantitatively. Th is is because of the many interactions among forages, other dietary co mponents, rumen microbes and animals that determine animal production. While many feeding studies have compared forages of different quality , few have tried to supplement each forage optimally. This has resulte d in conflicting information in the literature. Since so many factors are involved in these interactions, virtually no two studies are alike . It is extremely difficult to conduct trials in which forages vary on ly in the forage quality factors of interest. Therefore, nearly all tr ials in the literature are confounded when one tries to evaluate the i mportance of specific factors.