JWSS - Journal of Water and Soil Science

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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.

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Three levels of urea (0, 0.5 and 0.75% on fresh weight basis) were added to whole corn plants to investigate their effects on the chemical composition, and digestibility in 16 Ghezel male lambs using a completely randomized design. Rumen degradability and nutritive values were also evaluated.

 pH, total nitrogen and ammonia-N concentration of silages increased (P<0.05) with the addition of urea. Total nitrogen apparent digestibility was higher (P<0.05) with the urea addition. Nitrogen balance in ruminal fluid increased (P<0.05) with the addition of 0.5% urea. pH and ammonia-N concentration increased (P<0.05) with the addition of urea until 1.5 hr post feeding. Blood serum urea nitrogen concentration was higher (P<0.05) with the addition of urea until 6 hr post feeding. Potential degradability of dry matter and organic matter was higher at 0.5% urea level. Average daily gain increased with the urea addition and was highest (212.88 gr) at 0.75% urea. Subcutaneous fat depth was significantly (P<0.0l) lower for the sheep fed with 0.5% urea-treated silage as compared to other treatments. The results indicated that feed efficiency may be improved by urea addition and that the addition of urea (0.5% on fresh weight basis) may be recommended in order to increase the feeding value of whole corn plants.

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This experiment was carried out to study the effects of Lactic Acid Bacteria (LAB) and urea on chemical composition, nutritive value and rumen fermentation characteristics of whole-crop barley. In a completely randomized design with cross over arrangement, 4 Suffolk male lambs were used. Whole-crop barley was either treated with LAB solution (35% dry matter) at the rate of 2 L/ton herbage fresh weight or urea (55% dry matter) at the rate of 40 Kg/ton dry matter herbage and ensiled for 60 days. Low dry matter silages had lower pH and higher residual water soluble carbohydrates, ammonia-N, lactic acid and ethanol and higher lactate:acetate ratios. LAB resulted in higher lactic acid content and lactate:acetate ratios. DM (P<0.001), OM (P<0.01), NDF (P<0.05), ADF (P<0.01) and total nitrogen (TN) digestibility increased with additives. Mean rumen ammonia-N concentration and pH significantly (P<0.05) increased with urea-treated silages. Rumen propionate concentration was significantly (P<0.01) higher with LAB-treated silages than with urea-treated ones. The results indicated that the addition of LAB at the rate of 2 L/ton fresh weight to whole-crop barley at 35% dry matter enhanced fermentation and nutritive value.