اثر باکتری Cellulomonas uda بر تخمیر و ترکیب شیمیایی ذرت علوفه ای

Whole corn plant was ensiled in 70 gr minisilos for 60 days to evaluate the effects of addition of two levels of Cellulomonas uda bacteria (0, 1.2×105 and 2.4×105 cfu per gr of fresh forage) on fermentation and chemical composition of silage. The experiment was arranged as a completely randomized design. The silos were opened after 3 and 6 days of fermentation. The criteria measured included dry matter (DM), pH, organic matter, water soluble carbohydrates, crude protein, cell wall (NDF), acid detergent fiber (ADF), hemicellulose, cellulose, and ammonia-N contents. Both levels of bacteria significantly decreased the pH of silages after 3 days (P<0.05). The final pH of silage with the higher level of bacteria was significantly lower, indicative of a greater fermentation of cellulose in this silage. Addition of bacteria resulted in a non-significant increase in the level of final residual water soluble carbohydrates. Final silage ammonia-N concentration was less than 0.8% of dry matter in all silages and was not affected by bacterial treatment. The ADF content was decreased by 11.9% in the silage containing the lower level of bacteria and by 1.8% in the silage which contained the higher level of bacteria. The NDF content increased in the control silage and that with the lower level of bacteria but decreased by 3.6 gr Kg DM-1 in the silage with the higher bacterial level. Hemicellulose contents increased in all silages but cellulose contents decreased by 9.38% (control), 17.37% (low bacteria) and 12.49% (high bacteria) in the control and bacteria-treated silages, respectively. The results indicated that the addition of 12×105 cfu Cellulomonas uda per gr of whole fresh corn plant was effective in increasing residual water soluble carbohydrates, reducing NDF and hydrolyzing cellulose of whole corn plant.