The effect of different dietary and bed treatments on earthworm (Eisenia fetida) for aquaculture

This experiment conducted to evaluate the effect of different dietary and bed treatments on earthworm (Eisenia fetida) for aquaculture. Concurrent with initial proliferation of earthworms, a pilot experiment also performed. In pilot experiment that conducted to become familiar with specialty and requirements of Eisenia fetida earthworms, lasted 4 months. The pilot treatments were including: 1) cow manure with covering its surface(control group) , 2) cow manure (C.M.) without covering its surface, 3) C.M.+ 5% wind sand , 4) C.M. + 30% saw dust, 5) urban compost , 6) C.M. + 20% alfalfa meal , 7) C.M. + 20% wheat bran and 8) C.M. + 20% rice bran . After initial proliferation of earthworms and performing a pilot experiment, two trials designed. The first trial performed in outdoor environment, inside the plots dugged in the earh, with six treatments. The treatments were including : 1) cow manure(control group) , 2) cow manure (C.M.) with vertical ventilation, 3) C.M.+ 30% saw dust (S.D.) , 4) C.M. + 30% S.D. with vertical ventilation , 5) urban compost + 20% C.M. and 6) urban compost + 40% C.M. The experiment lasted 6 months. In the end of trial in every plot, from 4 points, sampling for number of mature and immature earthworms, cocoons and the weight of earthworms were measured. The second trial performed in greenhouse by using wooden boxes. In this trial the treatments were including: 1) C.M. as control group, 2) C.M. + 30% S.D. , 3) C.M. + 30% S.D. + 10% alfalfa meal, 4) C.M. + 30% S.D. + 10% wheat bran, 5) C.M. + 30% S.D. + 10% rice bran, 6) C.M. + 30% S.D. + 10% soil, 7) C.M. + 30% S.D. + 5% fine sand, 8) C.M. + 30% S.D. + 1% lime powder and 9) C.M. + 30% S.D. + 200 ppm ammonium nitrate. Every treatment performed in 3 replicates. The earthworms reared in controlled condition for moisture and temperature, for about 4 months. The pH of treatments measured monthly by paper pH meter and by method of solution extraction. In the end of trial the number of mature and immature worms, cocoons and the weight of earthworms in every box were measured and the average weight of every earthworm calculated. The results of pilot experiment showed that covering surface the bed is necessary for maintaining moisture and darkness for earthworms. In wind sand treatment, the bed had sticky and compacted statues and appeared that the earthworms moved and activated difficultly. The saw dust treatment had a wet- spongy environment and the earthworms distributed well in it and their size was larger than control. Urban compost treatment unlike its suitable pH (equal 8), hardly accepted by the earthworms and they stayed in the corner of bed for more than one month. The wheat bran and rice bran treatments, both had sticky texture at the begining but by spending time, their beds improved. The results of first trial showed the Eisenia fetida earthworms can survive and growth in outdoor environment even in cold season of winter. In this trial the highest total number of eartworms and cocoons and the total weight of earthworms was belong to control group, that had significant difference with the treatments C.M. + 30% S.D., urban compost + 20% C.M. and urban compost + 40% C.M. (p<0.05). The performing of ventilation in experimental treatments had not significant effect on the number of mature earthworms, total number of earthworms and their total weight compare to control group. The urban compost was not suitable for rearing Eisenia fetida, although addition of 20 and 40 % of cow manure could improve it for usage by the earthworms. The results of second trial showed that, addition of alfalfa powder, wheat bran, rice bran and lime powder to cow manure had not significant effect on the total number and total weight of earthworms compare to control group. The usage of soil in treatment C.M. + 30% S.D. + 10% soil caused significant decrease in number of mature earthworms compare to control group (p<0.05). The treatments including addition of saw dust and saw dust + fine sand to cow manure increased the number of mature earthworms, cocoons and total weight of earthworms compare to control group significantly (p<0.05) and treatment of ammonium nitrate caused significant increase in total weight of earthworms (p<0.05) .

Iranian Fisheries Science Research Institute

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