بهناز عینی

In order to investigate effect of cutting on chemical composition and degradability parameters of sorghum silage an experiment was don. Sorghum forage was used from first and second cutting for ensiling. Ensiling was done in plastic buckets (2.5 kg weight) for 80 days. The result showed that dry matter, neutral and acid detergent fiber in silage of second cutting was higher (P

This experiment was conducted to investigate the effect of harvesting, addition of formic acid and ruminal fluid to sorghum silage on amount of gas production. Sorghum at the first and second harvesting (with 25 % DM) was treated with formic acid and rumen fluid and then was ensiled for 81 days. After opening and drying the samples, a sample was taken from each treatment and put it into gas production syringe. Gas production at 2, 4, 6, 8, 16, 24, 48, 72 and 96 hours of incubation were recorded. Results showed that for the second-cut silage gas production was lower and that coefficient b was higher as compared to the first-cut silage. In the second experiment, gas production for the silage treated with ruminal fluid was significantly lower than the control treatment and a higher b coefficient was also found for the formic acid treated silage. Organic matter digestibility (OMD) and metabolism energy (ME) were greater for the first-cut as compared to the second-cut silage. Treating the silage with ruminal fluid caused a significant decrease of OMD (45.73 % vs. 52.1 and 52.59 %), ME (6.72 MJ/kg DM vs. 7.7 and 7.75 MJ/kg DM) as compared with formic acid and control treatments.