Assessment of urea and/or lime treatment on rice straw quality using in vitro gas fermentation technique

Abstract

An experiment was conducted to investigate the effectiveness of urea (NH 2) 2CO and calcium hydroxide [Ca(OH) 2] treatment of straw using a 4X4 factorial arrangement in a completely randomized design. Chopped rice straw was treated with mixtures of urea (0-3 g kg -1 dry matter) and calcium hydroxide [Ca(OH) 2] (0, 0.5, 1 and 1.5 g kg -11 dry matter) by dissolving in 100 mL water g 2 straw and ensiled in a plastic box at room temperature for 14 days. Ensiled rice straws were examined for chemical composition and in in vitro gas production. Rumen fluid was collected from two ruminally fistulated native crossbred beef cattle with an average body weight of 230 kg. During the incubations, gas production was recorded at 1, 2, 4, 6, 8, 10, 12, 18, 24, 30, 36, 42, 48, 54, 60, 72 and 96 h after incubation. All gas production volume collected were linearly increased as fermentation time interval proceeded from 0-96 h after incubation. Gas volume from insoluble fraction were significantly altered (p<0.05) by urea level as fermentation time increased while there were no effects by lime treatment. Ammonia nitrogen (NH 3-N) concentration were increased when increasing urea level. The highest NH 3-N was found in 3% urea-treatment (p<0.05) while there were no significant differences in calcium hydroxide treatments under in vitro gas production technique. © Medwell Journals, 2012.