Vongsamphanh et al., 2004. Livest. Res. Rural Dev., 16 (8)

In the first experiment, a local and an introduced cassava variety (Rayong72; RY72) from Thailand) were studied to determine the effects on yields and chemical composition during three harvests (at 3, 5 and 7 months after planting). Dry matter (DM) and protein yields of cassava variety RY72 at each harvest were higher than the local variety. Condensed tannin was 3.3 to 3.4 and 3.5 to 3.8 %, in RY72 and local variety, respectively. In the second experiment, the effect of level of cassava hay supplementation on rumen parameters, digestibility and rice straw intake in growing native cattle was studied. Four, 2-year-old rumen fistulated bulls were randomly assigned to a 4 x 4 Latin square design to receive four dietary treatments: 0, 200, 400 or 600 g/day of cassava hay during periods of 28 days. The basal diet was ad libitum rice straw and 200 g/day of a rumen supplement (5% urea; 95% rice bran ).Each feeding period consisted of 7 days adaptation, 14 days for rice straw intake measurement and was followed by a 7 days collection period of feed, rumen fluid, blood and fecal samples. Ruminal NH3-N and blood urea nitrogen were not affected by level of cassava hay in the diet. Bacterial and fungal zoospore populations were increased while protozoal population was decreased as a result of cassava hay supplementation. Digestion coefficients particularly those of DM, OM, and CP were increased by cassava hay supplementation. It is concluded that cassava hay supplementation improves intake of rice straw, rumen ecology, and digestibility in native cattle.