Isolation and characterization of anaerobic bacteria with fiber degradation potential from faeces of Boselaphus tragocamelus grazing on semi arid Indian conditions.

Hindgut of wild ruminants harbours diversified anaerobic bacteria with promising fiber degrading ability. Fibrolytic enzyme activity is strongly influenced by diet and host species which till date remains unexplored for harnessing their optimum benefits. The present study was conducted to isolate and characterize fiber degrading anaerobic bacteria from faeces of wild blue bull (Boselaphus tragocamelus) inhabiting in semiarid regions. A total of 167 isolates were obtained from 85 faecal samples using M-10 medium, on the basis of clear zones formed on Congo red plates 20 isolates were selected and designated as NLG1-20 for microscopic and biochemical characterization. Further, molecular confirmation was done by PCR analysis with universal 16S rDNA primers. All isolates were obligatory anaerobes except, NLG4, NLG19 and NLG20. Majority of the sugars tested were utilized by most of the isolates except arabinose. Fibrolytic enzyme activities revealed that NLG1 had highest endoglucanase activity, NLG13 had highest exoglucanase activity while NLG8 showed maximum xylanase activity. In case of FPase assay, highest and lowest values were observed in isolate NLG11 (8.96 U/mL) and NLG8 (5.58 U/mL), respectively. Phylogenetic analysis of the isolates revealed a highly diverse group of microbes mainly belonging to the family Paenibacillaceae which have not been previously characterized in ruminants for fiber degradation. Therefore, results obtained in the present study indicated that the screened isolates showed promising fiber degrading potential in terms of filter paper assay and fibrolytic enzyme activity which can be explored further for improving lignocellulose digestibility in ruminants as an additive.

Effect of complete feed block with tree leaves rich in hydrolysable and condensed tannins on nutrient utilization, rumen fermentation and growth performance of lambs.

Thirty lambs (Avishaan genotype, 10 weeks old, 14.0 ± 0.2 kg live weight) were randomly assigned into three equal treatment groups to study the effect of complete feed blocks (CFB; concentrate and roughage at 70:30 ratio) with three different tanniniferous tree leaves on intake and utilization of nutrients, rumen fermentation, microbial protein synthesis and growth performance. The treatments were T1 (Control), CFB1 with Vigna sinensis hay; T2, CFB2 with Acacia nilotica leaves rich in hydrolysable tannins (HT); and T3, CFB3 with Ziziphus nummularia leaves rich in condensed tannins (CT). The three CFBs were fed ad libitum to the respective groups of lambs for a period of 12 weeks. There was lower (p < .05) intake of dry matter (DM), total carbohydrates (TCHO) and fibre components in T2 compared with T1 and T3. However, the digestibility of nutrients except crude protein (CP) was higher in T2. Diet had no effect (p > .05) on the LW gain in lambs. Amongst the three groups, T3 showed enhanced N utilization with a comparable microbial protein synthesis, the lowest being in T2. The T2 group of lambs had higher propionate and lower non-glucogenic: glucogenic short-chain fatty acids ratio. It may be concluded that tanniniferous tree leaves at 30% of total mixed ration can meet the requirement of nutrients for desired post-weaning growth.