عنوان مقاله [English]
To carry out this study, 3000 Rainbow troutFry’s (2-3gr) were sampled and divided into three trails (A, B and C) with 3 repeats in each trail (300 Fry’s in each repeat). Group A includes 3% diatomite, group B includes 2% diatomite and group C was without any additive matter. 30 Fry’s were selected randomly every 20 days one time and growth factors and survival rates were compared with each other. Fry’s were stored in 1m3 fiberglass tanks and then handled to concrete ponds. Results of growth factors and survival rates showed no significant differences in each group (P>0.05), but results of carcass chemical analysis showed a significant different in these groups (P<0.05), so that fat percentage in B group (0.87%) was lower than A (1.05%) and C (1.86%) group. An adverse relationship was observed between liver and muscle fat percentage in groups A and B. there was a significant difference in fat among each group, so that in B group was 7%, in a group was 6.28% and in C group was 4.67%. Muscle protein in C (18.47%) group was more than B (18.28%) and A (18.11%) groups. there was no significant difference between C group with A and B group in protein percentage. Basis on these results, the Diatomite has a noticeable effect on fat percentage of fish ration and carcass (liver and muscle) and it can be used for regulating of them.