Organic Manure as Rearing Substrates for Red Worms (<i>Eisenia fetida</i>): Effects on Chemical Composition and Growth Performance

Abstract

Red worms (<i>Eisenia fetida</i>) can convert biowaste and by-products into body mass and become high in protein and lipid content. However, the type of growth media used affects both larval body composition and growth performance. Using recycled organic materials from chicken manure (CM), cow dung manure (CDM) and rabbit manure (RM), the present study evaluated the production of red worms that could be used as a substitute protein source for fish meals. Two experiments were conducted, the first experiment tested the compatibility of each organic manure when mixed with soil separately, whereas the second experiment combined the three organic manures with a fixed amount of soil. The study was conducted for 60 days. The findings showed that red worms reared on 100 % CM had a significantly higher body weight (19.27 ± 0.9 g) followed by those reared on 100 % CDM and 75% RM, whereas red worms reared on 100 % RM had the lowest body weight (4.9 ± 0.1 g). A combination of 20% CM + 40% CDM + 20% RM + 20% Soil supported significantly higher body weight of red worms (24.9 ± 1.1 g), while the lowest value of body weight (5.1 ± 0.2 g) was in a combination of 20% CM + 0% CDM + 60% RM + 20% Soil). Furthermore, the results revealed that red worms reared on 100 % CDM without soil as waste substrate had the highest crude protein (73.28% DM) compared to red worms reared on other types of substrates. The study suggests the potential of reusing organic manure such as chicken and cow dung manure at different inclusion levels in the production of red worms.