نوع مقاله : مقاله کامل علمی - پژوهشی
نویسندگان
1 گروه تکثیر و پرورش دانشگاه علوم کشاورزی و منابع طبیعی گرگان
2 عضو هیئت علمی گروه شیلات دانشگاه علوم کشاورزی و منابع طبیعی گرگان
3 هیات علمی دانشگاه گرگان
4 موسسه تحقیقات علوم شیلاتی کشور
5 هیات علمی
چکیده
کلیدواژهها
موضوعات
عنوان مقاله [English]
نویسندگان [English]
The current research aimed at assessing the effects of different levels of Thymol on blood, feeding and survival factors in Oncorhinchus mykiss against Yersinia ruckeri. In this order, three experimental treatments including control (fed with commercial food), first treatment (commercial food with 0.5 % Thymol) and second treatment (commercial food with 1% Thymol) were used with three replications for each treatment using a completely randomized design. Then, fish were fed for 7 weeks using associated diets. Then, in order to assess fish endurance, different treatments were challenged using Yersinia ruckeri. Ultimately, the measures were compared between different groups. The result showed that different levels of Thymol had no significant effect on survival rate of Oncorhinchus mykiss (p>0.05). Regarding blood indices before the challenge, we found that the 0.5% Thymol had no significant effect, however, the 1% Thymol treatment showed significant difference (p<0.05) which caused an increase in the amount of hemoglobin and the mean corpuscular hemoglobin concentration Measuring blood indices after the challenge, however, showed no significant different. The comparison of growth indices between different Thymol treatments showed that the 0.5 %Thymol had significant effect on final weight, weight gain, special growth rate, protein yield ratio and food conversion factor compare to the control and 1% Thymol treatments. The result from current study showed that Thymol stimulates growth and improves nutritional conditions in rainbow trout.
کلیدواژهها [English]