Somkid Promma and Damrat Chatreewong

pp. 765 - 770

Abstract

      An experiment was conducted to evaluate the dry matter disappearance and potential degradability of urea-treated rice straw (UTS). Five kg of non-glutinous rice straw (RS) was chopped and treated with urea solution and kept in a double sheet polyethylene bag. The ratio of RS to water was 1:1. The urea
concentration was 4, 5 and 6% by weight of RS and the duration of treatment was 7, 14 and 21 days. There were 9 treatment combinations with 3 replications. The dry and ground UTS were weighted into nylon bags and incubated in 3 fistulated cows. The dry matter disappearance was detected at different incubation times.
       The result showed that CP content of UTS was higher than RS and the amount increased with the increasing level of urea. The longer treatment duration caused depletion in CP content. Nitrogen was lost as ammonia when UTS was dried, which led to the lower CP than fresh UTS. The duration of treating of 7, 14
and 21 days caused no-significant difference in potential degradability (71.61±2.59, 72.38±2.80 and 72.70±2.44%, respectively, P> 0.05), but 6% UTS has higher potential degradability than 4 % UTS (74.24±0.53 and 69.84±1.03%, respectively, P< 0.05)