Effect of acetic acid treating and autoclaving of bitter vetch on nutrients degradability, protozoa counts, metabolisable protein and CNCPS protein fractionation

The present study was evaluated the effects of acetic acid treating and autoclaving the bitter vetch (Vicia ervilia) on nutrients degradability, protozoa counts, some ruminal parameters, and metabolisable protein. Three Farahani permanent rumen-canulated sheep were used in a 3×3 Latin square design with 21-d periods. Three experimental treatments were; 1) raw bitter vetch, 2) chemical processed bitter vetch, and 3) physical processed bitter vetch. Treating bitter vetch with 8% acid acetic and its autoclaving (121 ˚C, 117 Kpa, 20 min) were considered as chemical, and physical processing, respectively. The incubation times for in situ experiment were 2, 4, 8, 16, 24 and 48 h. Metabolisable protein was estimated based on in situ data as well. The results cleared that both processing methods (i.e. chemical and physical) reduced the degradation of dry matter and protein in the rumen which physical treating was more effective in this reduction. However the processing methods did not change metabolisable protein content of treatments. The results of protein fractionation showed that autoclaving caused to reduce the A and B1 fractions and increased the slow degradable fractions (P<0.05). Ruminal ammonia nitrogen concentration was tended to be significant (P=0.06). The protozoa count increased in rumen fluid of sheep fed autoclaved bitter vetch. The results of the current study showed that both chemical (treating with acetic acid) and physical processing (autoclaving) transferred the protein degradation from the rumen into small intestine and the effect of physical treating (autoclave) was more relevant.