Department of Animal Science, College of Agriculture, G. B. Pant University of Agriculture and Technology, Pantnagar-263145, India
Online published on 29 December, 2011.
Nine samples of rice straw of varieties Pusa-33, Kasturi, UPR-79-123, Manhar, UPR-79-11, Sarju-52, IR-8, IR-24 and Type 3 grown under uniform agronomical and soil conditions were dried, ground (2mm) and analysed for proximate principals, cell wall constituents and pH besides evaluation of zero and 48 hr in sacco disappearance of various estimates. In sacco DM digestibility differed significantly (P<0.01) with a range of 56.19% in Kasturi to 63.59% in Pusa-33 giving a genetic variability of 7.4 units. NDF digestibility was lowest (63.63%) in UPR-79-11 and highest (72.06%) in Pusa-33 with a genetic difference of 8.5 units. The ADF and hemicellulose digestibilities also differed significantly (P<0.01). The zero hour disappearance (solubility r = -0.75°) and hemicellulose digestibility (r=- 0.81”) were significantly negatively correlated with rumen fluid pH as achieved by feeding different diets. The AIA of NDF of (undigested straw, NDF and DM digestibiities and in sacco solubility were positively (P< 0.01 or P< 0.05) affected by the pH of the straw. A highly positive correlation (P< 0.01) was found between hot water solubility and ND soluble contents of straw. The DMD was dependent (r = 0.84**) on NDF digestibility. The cell wall contents of straw can be estimated with help of hot water extraction of straw.
