Vermi-modification of ruminant excreta using Eisenia fetida

Present investigation aims on the vermicomposting of the excreta of different ruminants to convert it into manure employing earthworm species, Eisenia fetida. A total of 11 feedstocks (FS₁-FS₁₁) with different ratios were prepared from the excreta of different ruminants, viz., sheep, cow, buffalo, and goat. Semi-composted feedstocks were fed to E. fetida for 90 days under laboratory conditions. Vermicomposting enhanced the nutrient contents of ruminant excreta and converted it into odor-free and homogenous vermicompost. The growth of E. fetida was significant in all the feedstocks, but largest biomass gain was achieved in buffalo excreta followed by [sheep + buffalo] > [goat + buffalo] and [cow + buffalo] feedstocks. Highest fecundity (782 ± 23.3) was also recorded in buffalo excreta followed by [goat + buffalo] excreta feedstock (484.6 ± 15.7). In vermicomposted feedstocks, total organic carbon and organic matter was lesser, while NPK and heavy metals were higher as compared to raw feedstocks. C/N ratios of vermicomposts ranged from 15.37 to 38.56, which indicate a good level of maturity and stabilization of feedstocks.