Effect of biological treatments by cellulolytic bacteria on chemical composition and cell wall constituents of some roughages

Abstract

This paper considers the separation of five strains of cellulolytic bacteria (Cellulomonas sp., Acetobacter sp., Thermonospora sp., Ruminococcus sp. and Bacillus sp.) from rumen liquor of Baladi goats and evaluation of these bacteria by electrophoresis method. Then these bacteria were used as biological treatments of silage to study the changes that occur on chemical composition and cell wall constituents of three roughages. Silages were made from three roughages (corn stalks, bagasse and rice straw) and incubation for two months. The additive ( additive/ DM,w/w)contained water 200%, urea 3%,molasses 4%, formic acid 0.03%, acetic acid 0. 5% and one of the cellulolytic bacteria at the rate of 2 liters/ ton. Results indicated that using cellulolytic bacteria caused marked increase in crude pro tein from average 1.98%to 15.16% and decrease crude fiber from average 52.6% to 38.1% in all roughages compared with the untreated roughages. All treatments significantly decreased NDF, ADF and ADL. It was concluded that the five strains of bacteria were different significant and all strains secretes cellulase enzymes according to the electrophoresis method. In addition, the biological treatments by Cellulomonas sp. and Ruminococcus sp. were succeeded more with bagasse and corn stalks while Thermonospora sp. and Bacillus sp. succeeded more with rice straw. However, the biological treatments of corn stalks, bagasse and rice straw silage improved its chemical composition and cell wall structure.