The impact of melatonin administration on the fertility performance and several relating parameters during the breeding season in the Arabi ewes

Abstract

A total of twenty-four healthy ewes aged between 2-3 years old and weighed about 35.09 kg of body weight were divided randomly into four groups (6 animals for each group). The first group included the non-treated control group, while the other three groups were subjected to various oral doses of melatonin 9 mg, 12 mg and 15 mg/head, respectively. All treatments were applied at 6 o'clock in the morning, to investigate the effect of treatment with melatonin during breeding season on reproductive performance and levels of some biochemical parameters in Arabi ewes from 1 May to 1 October 2017. Blood samples 7ml were collected after one hour of treatment and then monthly during the pregnancy months to determine the concentrations of biochemical parameters. After Postpartum, lambed ewes/lambs number, birth weight, placenta empty weight and cotyledon number were recorded. The results showed significant (P<0.05) improvement in reproductive performance (fertility percentage, twinning rate and the number of offspring) when ewes administrated melatonin at two doses (12 and 15 mg/ head). Also, melatonin administration caused significant (P<0.05) decrease in the concentrations of thyroxin, cortisol, and cholesterol. Conversely, there was a significant increase (P<0.05) in glucose concentration after 1 hour of treatment. The concentrations of thyroxin, cortisol, cholesterol, and vitamin C increased significantly (P<0.01) in early-gestation compared with mid and late-gestation, while the concentrations progesterone and glucose increased significantly (P<0.05) in midgestation compared with early and late-gestation. In conclusion, melatonin administration at doses 12 and 15 mg/ head improves ewe reproductive performance (fertility percentage, twinning rate and the number of born lambs). Additionally, the gestation stage has a negative effect on the concentrations of thyroxin, cholesterol and vitamin C.

The Role of Certain Specific Hormonal Treatments in Estrus Synchronization of Ewes: A mini Review

“…Treatment of ewes with melatonin improved the reproductive performance of domestic ewes by increasing the fertility rate and the number of additional pregnancies [67]. As Kassim et al [68] noted, Melatonin treatment at doses 12 and 15 mg/ head showed an increase in the percentage of fertility and twinning in ewes.…”

Administration of melatonin prior to modified synchronization protocol improves the productive and reproductive efficiency of Chinese crossbred buffaloes in low breeding season

“…The pregnancy rate results agreed with the earlier reports (16, 17, 42) when buffaloes were treated with melatonin, in injectable or slowrelease forms, during the low breeding season. Previous reports proved that melatonin administration improved fertility and fecundity in ewes (49)(50)(51). A higher percentage of pregnancy rates might be associated with an improvement in fertilization which is connected to the antioxidant capacity of melatonin (52).…”

The Efficiency of Melatonin Hormone Implantation in Suppressing the Estrus Cycle in Domesticated Queens (Felis catus)

“…However, melatonin synthesis involves the conversion of hydroxylated tryptophan to 5-hydroxytryptophan, which is then converted into serotonin. This process also controls ovarian activity in seasonal animals, such as cats (Al-Hamedawi T M et al, 2020;AL-Shammary and Al-Yasiri, 2023), with peak concentrations occurring during anestrus and interestrus (Kassim et al, 2019). Exogenous melatonin (administered orally or by injection) appears to suppress cats' estrus cycles.…”