Yield and quality with different cutting regimes; digestibility and feeding value for sheep/goats of Desmanthus virgatus (L.) Willd.

Total herbage dry matter yield (t/ha/yr), significantly increased with lowering cutting heights (CH) and increasing cutting intervals (CI). Significant interaction of the two factors on regrowth yield was found showing in the wet season (WS), similar values among the CH's at 30 and 45 days CI becoming significantly higher with 30 cm CH compared to the other two CH's at 60 days CI. In the dry season (DS), yield was highest with 100 cm CH at 30 days, similar among the CH's at 45 days and lowest with 100 cm CH at 60 days CI. Regrowth yield was higher in the wet than dry season. Dry matter (DM) content of fresh herbage significantly increased while crude protein (CP) content decreased with longer CI's but were not affected by CH and the interaction of the two factors. While DM value increased significantly from the wet to dry season, CP value had the opposite response. Ash content was generally insensitive to varying CH's with the only exception being lower ash content (P 0.05) with the highest CH during the wet season. On the other hand, ash content tended to become higher (P 0.05) with longer CI, although non-significant differences were found between 45 and 60-day and 30 and 45-day CI's for the wet and dry seasons, respectively. In vitro DM digestibility (IVDMD) was significantly affected by CH, CI, and their interaction. IVDMD value did not significantly change from the wet to dry seasons. The falls in digestibility and CP values with longer CI's were accompanied by significant decrease in leaf proportion and noticeable increase in DM content of the harvested materials. Dry matter digestibility was found significantly higher with increasing levels of dietary desmanthus. Nitrogen retention was highest with pure desmanthus diet for the goats while for the sheep it was at the 1.6% BW desmanthus diet. Dry matter digestibility by total collection method (Y) could be predicted through the AIA indicators (X1) and in vitro DM digestibility (X2) values equations: Y