外源褪黑激素对水貂血清主要生殖激素年周期变化的影响

为探究埋植外源褪黑激素(MLT)对水貂血清主要生殖激素年周期变化的影响,实验选用4月龄雌貂和雄貂各72只,分为A、B、C、D组,A组(雌貂)和C组(雄貂)不做任何处理,B组(雌貂)和D组(雄貂)于2018年7月7日至2019年7月7日埋植外源MLT.实验期间,每隔30 d每组随机选取3只水貂,心脏采血并分离血清,共12...

Melatonin implantation affected annual changes of main reproductive hormones in mink serum

The purpose of this experiment was to explore the effects of the implanted exogenous melatonin(MLT) on the annual changes of main reproductive hormones in mink serum.A total of 72 female and 72 male minks at 4 months old were randomly divided into four groups:Group A(female) and Group C(male) without any treatment as controls, Group B(female) and Group D(male) were implanted with exogenous MLT from July 7, 2018 to July 7, 2019.During the implantation period, three minks in each group were randomly selected to collect cardiac blood and separate serum samples for every 30 days, resulting in 12 sample collections.The Enzyme-linked immunosorbent assay(ELISA) was used to determine the contents of the main reproductive hormones in the collected sera.The results showed that (1) in Group A, the contents of gonadotropin-releasing hormone(GnRH), prolactin(PRL), and progesterone(P) were at higher levels in January than those in other time.The levels of PRL and P showed a small peak in June and July, respectively.Follicle stimulating hormone(FSH) and luteinizing hormone(LH) first decreased and then increased in autumn and winter and reached a high level in December.In spring and summer, FSH showed a gradual downward trend, while LH decreased at first and then increased.Estradiol(E2) gradually increased in autumn and winter and reached a high level in January, followed by a gradual decrease and fluctuated trends in spring and summer. (2) In Group B, in comparison with Group A, GnRH significantly increased in October(P ≤ 0.05) and January(P ≤ 0.01);PRL decreased in January, February, and June(P ≤ 0.05);P increased in October and June(P ≤ 0.05);FSH increased(P ≤ 0.01) in October, but decreased in both January and February(P ≤ 0.05);and LH significantly increased in March(P ≤ 0.05).(3) The testosterone(T) in Group C increased to the highest level only in January, while in Group D decreased in January(P ≤ 0.01).In summary, the exogenous MLT can increase the content of GnRH, reduce the concentrations of PRL, P and T in January, and induce FSH and LH to reach the peak in October and E2 to peak in November.Implantation of MLT resulted in inconsistent estrus periods between male and female minks, therefore this protocol is not suitable for mink breeding.