A COMPARISON OF 10 RICE-STRAW VARIETIES GROWN AT 2 DIFFERENT ALTITUDES DURING A WET AND A DRY SEASON, USING THE IN-VITRO CUMULATIVE GAS-PRODUCTION TECHNIQUE

In vitro cumulative gas production was used to evaluate a series of ri ce straws for their fermentability. The straws comprised ten different varieties which had been grown at two locations (higher and lower alt itudes), during two seasons (wet and dry). Curves were fitted, and the resulting parameters, DM loss and gas yield, were tested for signific ant differences by an analysis of variance using the Tukey test, Signi ficant differences between the parameters of the fitted curves were fo und between the offered and refused straw, the material grown at diffe rent altitudes, the material from the wet and dry seasons, and between varieties. Significant interactions were found between the environmen tal factors and cultivar, for the offered and refused feeds.