Rumen Manipulation to Increase the Efficient Use of Local Feed Resources and Productivity of Ruminants in the Tropics

Local feed resources, particularly low-quality roughages and agricultural crop-residues, are of prime importance for ruminants raised in the tropics. These feeds exhibit close relationships with rumen ecology, microbes and rumen fermentation patterns. A number of dietary factors could influence rumen fermentation especially the basal roughage source, its physical form and fermentation end-products. Diurnal fermentation patterns in ruminants fed on rice straw were consistently maintained in terms of pH and temperature, but for for NH3-N or VFAs. Manipulating rumen fermentation through treatment of roughage and strategic supplementation with high quality feed block, tannin-containing plants, especially cassava hay and other local feed resources, could improve rumen efficiency by maintaining higher pH, optinum NH3-N and increasing microbial protein synthesis and essential VFAs, and thus enhance ruminant productivity in the tropics. However, further research on the specific roles of these feeds in rumen fermentation and practical applications both by farmers and industries, is warranted.