もみ殼と稲わらの栄養価改善に対するアンモニア処理の条件

Abstract

In search of the optimal process conditions of ammonia treatment for rice hulls and straw at the shorter duration and lower temperature possible without the use of special and expensive equipment in the field, the combined effects of ammonia concentration, temperature and duration were determined on the chemical composition and in vitro digestibility. Rice hulls were treated with 2.5, 5.0 and 10.0% of ammonia (by wt) for 15, 30 and 60 days at 25°C, or with 1.0, 2.5 and 5.0% of ammonia for 5 and 10 days at 45°C. Nitrogen contents and in vitro dry matter disappearance (IVDMD) of the ammoniated rice hulls (ARH) were increased with the increment of ammonia concentration at both the temperatures of 25 and 45°C. Duration of treatment (30 and 60 days) affected only the nitrogen content at the 5 and 10% ammonia treatment. The highest nitrogen recovery was observed in the ARH treated with 2.5% ammonia. Increased values of IVDMD in the ARH treated at 45°C for 5 days with 2.5 or 5.0% of ammonia were markedly superior to that treated at 25°C for more than 15 days with the corresponding levels of ammonia. Chemical composition and IVDMD of the rice straw (ARS) treated by more than 2.5% of ammonia at 45°C were nearly equivalent to that observed in the ARS treated for a long term at ambient temperatures. These results suggested that the ammoniated products, which was improved to have a considerable amount of the nutritive value as roughage for ruminants, are prepared by the 2.5% of ammonia concentration in only 5 days where the temperature is maintained at about 45°C in the field. fect of ammonia concentration, temperature and duration on the chemical composition and IVDMD of the rice hulls and straw, and to suggest optimal treatment conditions which are to be accepted as the short period treatment without special and expensive equipment in the field.