The işnvestigation of the possibility of using red California earthworm (Eisenia fetida) meal as a alternative protein source in rainbow trout (Oncorhynchus mykiss) diet

This study was carried out to determine the effect of earthworm meal usage on growth performance and body composition in fry rainbow trout feed. The fry rainbow trout (5.05±03.61g) were fed at 2.5% live weight for 90 days with four different experimental diets, namely earthworm meal 0 % (SU0 control group), earthworm meal 10 % (SU10), 20 % (SU20) and 30 % (SU30). At the end of the study, SU30 group reached the highest mean live weight with 259.40%, followed by SU20, SU10 and control SU0 (211.17 %, 182.76 %, 113.68 %, respectively). The difference between the SU30 group and the other groups was statistically significant in terms of live weight gain, specific growth rate, feed conversion ratio and protein efficiency ratio (P <0.05). In this study, it was determined that the condition factor (CF) and hepatosomatic index (HSI) were positively affected by the addition of the earthworm meal in the ration and the viscerosomatic index (VSI) value was not affected. Additionally, earthworm meal did not cause a statistically significant change in meat quality. As a result, considering the growth performance measurement criteria, it was determined that the use of 30 % earthworm meal in the rations of fry rainbow trout could increase fish growth significantly.