Feeding effect of cholesterol in the diet on sex hormones concentrations and the gonads' growth of yearling common carp [Cyprinus carpio]

ABSTRACT

There are some evidences that cholesterol can affect fish reproductive system. In this study the effect of high diet cholesterol on fish sex hormones and gonads weight was investigated. A randomized experiment was conducted on 90 immature common carp. The fishes were divided into three groups with three replicates each [control, 0.5% cholesterol diet, and 1% cholesterol diet]. After one-month feeding, progesterone, estrogen and testosterone were measured. The level of progesterone in control group, 0.5% cholesterol and 1% cholesterol diet were 1.83 +/- 0.42, 2.45 +/- 0.38 and 2.62 +/- 0.52 ng/ml, respectively. Also the level of estrogen in control group, 0.5% and 1% cholesterol diet were 3670.34 +/- 186.26, 3791.20 +/- 98.48, and 3836.78 +/- 81.74 pg/ml, respectively., while those of testosterone levels were 1.75 +/- 0.319, 2.09 +/- 0.425, and 2.25 +/- 0.321 ng/ml, respectively. The highest and the lowest body weight and gonad weight were observed in fish fed% 1 cholesterol and the control, respectively. The results showed positive effects of cholesterol on sexual hormones, the 0.5% cholesterol diet and the 1% cholesterol diet did not show any significant difference in the sexual hormones levels. The results indicated that the effect of cholesterol on the these sex hormones, gonad weight, body length and body weight was significant [p<0.01]. We can conclude that diets of 0.5% cholesterol can be used to increase the amount of sexual hormones in common carp