Studies On Various Treatment Conditions Affecting Urea-Ammoniated Rice Straw In Ghana

ABSTRACT

Four experiments were undertaken to evaluate the effect of various treatment conditions on the  nutritive value of urea-ammoniated rice straw. Experiment 1 was carried out to determine the optimum conditions necessary fo r ammoniating rice straw with urea. The factors investigated included urea concentration (3 .5 , 4.0, 6.5 and 8.0% W/w), treatment period (7, 14 and 21 days) and moisture le v e l (40, 50 and 60%), in a 4 x 3 x 3 fa c to r ia l experiment. Samples were analysed to ta l Nitrogen content, neutral detergent fibre (PDF), acid detergent fib r e (ADF) and in vitro organic matter digestible (IVOMD). Results showed that the optimum urea concentration, treatment period and moisture le v e l ware 6.5%, 21 days and 40% respectively. In Experiment 2, the optimum conditions obtained in Experiment 1 was used to treat rice straw which was then stored in different n t types of s ilo (earthern p it, cane basket and cement culvert) to determine the best silo to use. The earthen pit was found to be the best among the silo s with its contents having an N content of 1.75% and IVOMD 52.65. Straw from the basket and cu lvert had 1.55% and 1.10% N and 50.03 and t 43.21 IVOMD respectively. The in situ rate of ruminal dry matter (DM) I , disappearance (DMD) (3-72h) and extent of DM disappearance (72h) investigated in Experiment 3 indicated that urea X ammoniated straw was more fermentable In the rumen of sheep compared with untreated rice straw. The rate and extent o f DMD was found to be 0.48%/hr and 44.64% fo r untreated ric e straw and 0.74%/hr and 58.97% fo r ammoniated rice straw. Urea treatment sig n ifica n tly increased straw intake but did not prevent sheep freight loss in Experiment 4. Straw ensiled with urea fo r 21d and fed to sheep with l i t t l e supplementation can supply maintenance needs of ruminants during the dry season.