Stabilization with sulfuric acid of the crude protein in urea-treated rice straw

Promma, S.; Tasaki, I.; Cheva-Isarakul, B.; Indratula, T.

doi:1994.7.4.481

Article

Ruminant Nutrition and Forage Utilization

Asian-Australasian Journal of Animal Sciences 1994;7(4): 481-486.
https://doi.org/10.5713/ajas.1994.481 Published online December 1, 1994.

Stabilization with sulfuric acid of the crude protein in urea-treated rice straw

S. Promma, I. Tasaki, B. Cheva-Isarakul, T. Indratula

Abstract

The effect of neutralization of urea-treated rice straw with sulfuric acid was investigated. Long-cut (15-20 cm) and short-cut (2-3 cm) rice straw were treated with 6% urea for 21 days, and the treated straw was mixed with an acid-molasses solution to neutralize free ammonia and kept airtightly in a plastic bag for 24 hours. The neutralized and non-neutralized straw were dried and subjected to chemical analysis and in vitro dry matter (DM) digestibility determination. The in vitro DM digestibility as well as crude protein (CP) content were remarkably improved by neutralization. Short-cutting of the straw before treatment gave a better result than the long-cut samples. Neutralization with sulfuric acid also affected the chemical composition and increased sulfur content of samples. The CP thus fixed by neutralization was proven to be kept stable for 3 months, and in vitro DM digestibility was not affected by the storing period.

Keywords: Urea-treated Rice Straw; Neutralization; Protein Content