The effect of thyroxine hormone in the early stages of growth on the growth indices of Rainbow trout (Oncorhynchus myksis)

Kiapour, Fatemeh; Hajimoradlou, Abdolmajid; Ghorbani, Rasoul; Hajibeglou, Ali

doi:10.22069/japu.2023.21492.1793

The effect of thyroxine hormone in the early stages of growth on the growth indices of Rainbow trout (Oncorhynchus myksis)

Document Type : scientific research article

Authors

¹ Department of Fisheries, Gorgan University of Agricultural Science and Natural Resources, Gorgan, Iran.

² Professor, Dept of Fisheries, Gorgan University of Agricultural Sciences and Natural Resources, Gorgan, Iran

³ Professor, Dept of Fisheries, Gorgan University of Agricultural Sciences and Natural Resources, Gorgan, Iran. E-mail: : rasulghorbani@gmail.com

⁴ Faculty member of fisheries, Agricultural and Natural and Natural Resources of Gorgan University

10.22069/japu.2023.21492.1793

Abstract

This study was conducted with the aim of investigating the effect of different levels of thyroxine hormone in rearing water and diet on growth factors in the early stages of growth of rainbow trout. The experiment was carried out in three stages: hatched eggs until complete hatching, hatched larvae until active feeding, and active feeding until weighing about 1 gram of fry fish. In each stage, the experiment was performed in three concentrations of thyroxine solution (0.03, 0.06 and 0.09 mg/liter) along with the control group (without thyroxine hormone) with 3 repetitions. Thyroxine was added to water in the first and second stages and to food in the third stage. At the end of the third stage, growth indicators were examined. The results showed that the highest final weight and length in treatment 9 were 1.53±0.04 and 5.85±0.31 cm respectively. The percentage of body weight gain and specific growth factors showed a significant difference compared to other treatments (p<0.05) and were 872.45±18.32 and 5.05±0.04, respectively. The highest food conversion rate and obesity rate in the control group were 0.78±0.004 and 1.14±0.07 respectively. According to the present study, thyroxine hormone has led to positive effects on growth factors in rainbow trout fry.

Keywords