Effects of different levels of dietary thyme (Thymus vulgaris) oil on growth of carp (Cyprinus carpio L.) fry

In this research, it was targetted to determine the effects of different levels of dietary thyme (Thymus vulgaris) oil, 0, 0.5, 1,0 and 1.5%, on growth of the carp (Cyprinus carpio) fry (initial average live weights of 0.88±0.36 g). The trial was carried out in 12 tanks for 84 days in 3 replicates. At the end of the study, growth parameters, feed conversion ratios, survival rates, proximate compositions, and liver and small intestine histology of the groups were compared. The highest mean live weight was obtained from the group fed with 0.5% thyme oil supplement (6.93±2.23) and the lowest live weight gain was observed in the 1.5% group (6.46±2.56) (p<0.05). There was no significant difference between the groups in terms of feed conversion and survival rates (p> 0.05). The fact that the proximate analyzes did not differ between the groups and that the liver and small intestine tissues in all groups were found in normal morphology revealed that thyme oil did not adversely affect the health status of the carp at the rates used in the research. However, it was suggested that it would be advisable to use low doses when combined with growth performance results.