evaluation of graded level of Silkworm pupae () oil on methane production, fermentation characteristics, and protozoal populations.

Aim: The present study was undertaken to evaluate the effect of variable levels of silkworm pupae oil and roughage: concentrate ratio on methane production, fermentation characteristics, and rumen protozoa population.

Materials And Methods: gas production study (24 h) was performed with graded levels of silkworm pupae oil, namely, 0.5, 1, 2, 4, and 5% of the basal diet and four variable dietary regimes consisting roughage and concentrate in different proportions (70:30, 60:40, 50:50, and 40:60). At the end of incubation, gas samples were analyzed for methane, while fermented rumen liquor was used for protozoa enumeration. A separate set of incubations was carried out for the determination of dry matter digestibility.

Results: Results from the studies revealed no adverse impact of the silkworm pupae oil supplementation up to 2% level on total gas production. However, supplementation beyond 2% has shown a reduction in total gas production. Incubation with variable levels (0.5-5%) of silkworm pupae oil with different dietary regimes indicated negligible (3-5%) to a substantial reduction (25-30%) on methane production. A graded decrement in methane production was recorded with increasing levels of silkworm pupae oil. Similarly, the protozoal populations were decreased from 10 to 51.5% with graded levels of silkworm pupae oil in different dietary regimes as studies did not reveal any significant (p>0.05) variation between 2 and 4% of oil supplementation.

Conclusion: The silkworm pupae oil supplementation at 2% level decreases methane production by 12-15% without any adverse impact on feed fermentation. Oil supplementation may have a more pronounced effect on methane reduction if added to high roughage diet at conditions. However, , studies in ruminants are warranted to confirm the methane reduction with silkworm pupae oil supplementation.