Effect of Physical and Chemical Treatments on Berseem Silage Quality, Nutritive Values, Rumen Fermentation and Blood Metabolites of Rams

Abstract

The object of this study was to investigate the effect of wilting, chopping and formic acid treatment on berseem silage quality besides determination of digestibility, rumen fermentation and blood metabolites of rams fed tested rations. Berseem forage (at 3 rd cut) was manually chopped at 2-3 cm of length and wilted for 0, 24 or 48 hr and thereafter ensiled with or without formic acid (0.5%) treatment in plastic barrels. At the same time, another quantity of un-chopped berseem forage was wilted for 24 hr and ensiled with or without formic acid treatment. Digestibility trials were conducted to evaluate the utilization of berseem silages using mature Ossimi rams. The results showed that DM of berseem silage increased by wilting to around 20% and 30% for 24 hr and 48 hr, respectively. The wilted silage for 24 hr and treated with formic acid (S4) had the lowest value of pH (being 3.87), the highest level of lactic acid (3.15%) the lowest level of acetic (1.57%) and butyric acids (0.0%) with Flieg's score 90. The lowest level of lactate and Flieg's score of quality, whilst the highest pH value was obtained in un-chopped berseem silage either treated or untreated with formic acid. Likewise, the highest count of lactobacilli, the lowest mold and clostridia were found in S4, which were positive correlated with fermentation parameters. Digestibility of DM, OM, CP, EE and CF was higher (P<0.01) in un-wilted than wilted silages, as well as, nutritive values had a similar trend. The intake of TDN, DCP and ME was higher (P<0.05) in wilted silage rations than un-wilted. Formic acid treatment improved (P<0.05) digestibility of most nutrients, whilst nutritive values did not differ significantly. The nutrients digestibility of un-chopped silage was lower than chopped silage except for CF and its fractions. The quality index (QI) value was (P<0.05) improved by wilting of silage. The lowest value of QI was found in un-chopped and unwilted silages. Rumen liquor parameters were not significantly affected by wilting or formic acid treatment, except for NH3-N and TVFA's which were higher in wilted than un-wilted silage. The highest (P<0.01) value of NH3-N and TVFA's was showed in wilted for 24 hr and treated silage. The pH, eNDF and NH3-N values were higher in un-chopped than chopped silage ration. Blood hemoglobin and hematocrite values, as well as plasma total protein and glucose (P<0.01) increased in wilted silage groups than un-wilted. Whereas, formic acid did not affect blood parameters. It could be concluded that, the lowest quality and digestibility was obtained with un-chopped silage either with or without formic acid treatment. Chopping and wilting berseem forage for 24 hr (about 20% DM) as pre-ensiled treatments with formic acid sprinkle produced the best quality silage and higher digestibility without any side effect on health of rams during the experimental period, which could be resulted in improvement growth performance of the animal.