| To investigate the effects of long-term Fenvalerate (Fen) exposure on reproduction physiology in male chicken,(1)10weeks old cockerels feeded on0.1,1.0and10mg·kg-1Fen till32w.(2)16weeks old cockerels feeded on10mg·kg-1Fen till35w, then the semen from each male was inseminated into normal healthy hens and bred first generation (Fl) We investigated the effects of Fen on gonadal development and reproductive physiology in male chicken and their offspring.1The effects of Fen exposure on gonadal development and reproductive physiology in puberty cockerels.(1) Gonadal developmentCockerels in pubertal were treated with0.1,1.0and10mg·kg-1Fen for22weeks, the relative testis weight, testicular tissue structure and the development of the secondary sexual characters in male chicken did not change obviously.(2) Sperm quality0.1,1.0and10mg·kg-1Fen significant decrease the sperm progress (P<0.05), but there were no significant differences among the three treatment groups.10mg·kg-1Fen significantly increased the sperm abnormality (P<0.05). The sperm abnormality of10mg·kg-1Fen treatment was significantly higher than other treatments (0.1,1.0mg·kg-1Fen) and control (P<0.05), but no statistic difference was found among the control,0.1and1.0mg·kg-1Fen.(3) Testosterone and estradiolAs the age increasing, the level of testosterone (T) in serum was increased. At the age of20weeks, the level of serum T in the group of10mg·kg-1Fen was significantly highter than the other groups (P<0.05). At the age of30weeks, serum T in the group of10 mg·kg-1Fen was significantly higher than the control (P<0.05), but no statistic difference was found among the treatment groups.With the age increasing, the level of serum estradiol (E2) was decreased. But at the age of20and30weeks, serum E2in groups of1.0mg·kg-1Fen and10mg·kg-1Fen were significantly higher than0.1mg·kg-1Fen and the control (P<0.05).(4) Testis steroid hormone biosynthetic enzymes0.1mg·kg-1Fen significant increased testicular17β-HSD mRNA expression (P<0.05), while1.0and10.0mg·kg-1Fen didn’t influence17β-HSD mRNA expression significantly.1.0and10.0mg·kg-1Fen significantly decreased testicular3β-HSD mRNA expression (P<0.05), but0.1mg·kg-1Fen had no statistic influence on3p-HSD mRNA expression. Testicular aromatase mRNA expression was no altered by0.1,1.0and10.0mg·kg-1Fen treatment.10mg·kg-1Fen treatment significantly increased testicular3β-HSD activity (P<0.05), significantly decreased testicular17β-HSD and aromatase activity (P<0.05).0.1mg·kg-1Fen and1.0mg·kg-1Fen did not influence testicular3β-HSD,17β-HSD and aromatase activity.2The effects of Fen exposure on the gonadal development and reproductive physiology in early adult cockerels and their male offspring.(1) The effects of Fen on the gonadal development and reproductive physiology in FO generation16weeks old cockerels feeded on10mg·kg-1Fen till35w, the relative testis weight and the development of the secondary sexual characters in male chicken were not different from the control. Ho were, the area of seminiferous tubules and germinal epithelium in Fen-treated chicken testes were significant lower than the control (P<0.05). Besides, Fen significantly decreased the sperm progress and the sperm motility (P<0.05), and significantly increased the spermic abnormality (P<0.01). There was no statistic difference in sperm counts and semen volume between Fen-treatment and the control.The results of female mate choice trial showed that the frequency of crowing and copulation in treatment group, as well as the residence time which the hen spent in the outside of the treatment group compartment were significantly lower than the control (P<0.05).10mg·kg-1Fen significantly increased the level of serum E2(P<0.05), but did not alter serum T level significant. Fen had little effect on17β-HSD and aromatase, but significantly increased the activity of3β-HSD in testes(P<0.05).(2) The effects of paternal Fen exposure on gonadal development and reproductive physiology in male offspring.Paternal Fen exposure didn’t cause significant influence on the growth of comb and wattle, whereas significantly decreased the growth of supr from16w to32w in F1cockerels (P<0.05). Paternal Fen exposure didn’t cause significantly influence on the relative testis weight, but significantly increased the area of seminiferous tubules and germinal epithelium in F1cockerels. Paternal Fen exposure significantly increased the sperm progress and the motility in F1cockerels (P<0.05).In female mate choice trial, the results showed that paternal Fen exposure did not influence the frequence of crows, wingflaps and waltzes, but significantly decreased the residence time that hen spent in the inside of the treatment group compartment (P<0.05). Paternal Fen exposure significantly increased the level of serum E2in Fl cockerels (P<0.05), but did not influence the level of serum T.Paternal Fen exposure did not affect testicular3β-HSD,17β-HSD and aromatase mRNA in Fl cockerels, but obviously increased F1testis3β-HSD activity (P<0.05), significantly decreased F1testis17β-HSD activity (P<0.05). In F1cockerels, no statistic difference of testicular aromatase activity were found between the F1of paternal Fen-treated and the control.All above suggested that,(1) Fen, as an endocrine disruptor, may influence the sythesis and secrtion of testis steroid hormones in dose and age dependent manner of cockerels.(2) Long term exposure to low dose Fen have adverse effect on the spermgenerous and sexual behavior in cockerels.(3) Paternal Fen exposure has adverse influence on the development of gonad and function in male offspring. |
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