Effect of Various Tropical Roughages on Rumen Ecology and Digestibility of Beef Cattle

Siwaporn Paengkoum, Metha Wanapat, Chalong Wachirapakorn, Ngarmnit Nontaso


Four-fistulated, castrated male crossbred cattle were randomly allocated to a 4 x 4 Latin square design. The treatments were: T1) urea-treated (5%) rice straw (UTS); T2) cassava hay (CH); T3) fresh cassava foliage (FCF); T4) UTS: FCF (1: 1 dry matter basis). Faecal and feed samples were collected during the last seven days of each period and analyzed for DM, Ash, CP, NDF ADF and acid-insoluble ash (AIA). Rumen fluid and blood samples were collected on the last day of each period at 0, 2 and 4 h-post feeding and then analyzed for microorganisms (total viable and cellulolytic bacteria), NH3-N, volatile fatty acid (VFA) and blood urea-nitrogen (BUN). The results revealed that total viable and cellulolytic bacterial population were enhanced (P < 0.05) with UTS as the roughage source. Animals fed with FCF had a higher rumen propionate production (P < 0.05) with a lower cellulolytic bacteria count. In addition, roughage intake and total DM intake were highest by using UTS (2.2 and 2.5 %BW, respectively) as the roughage source (P < 0.05). Organic matter intakes were similar among among UTS, CH and UTS: FCF treatments (8.0, 6.8 and 8.7 kg/d, respectively). Digestion coefficients of DM and OM were similar among treatments. However CP digestion coefficients were similar among CH, FCF and UTS: FCF treatments, but were higher (P < 0.05) in CH than in UTS. It was also observed that feeding FCF as a full-feed resulted in anorexia and ataxia as well as frequent urination. Therefore FCF should only be fed fresh as part of the feed or should be fed wilted. Hence, combined use of FCF and UTS as well as CH and FCF were recommended.

Key Words: Cassava hay; Cassava foliage; Urea-treated rice straw; Rumen ecology

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