Abstract
The aim of this study was to assess the effects of melatonin on the in vitro maturation and fertilization of sheep oocytes, and on the in vitro culture of the embryos. Oocytes from sheep ovaries collected at the slaughterhouse were divided into four groups, two of which were treated with either 10E5 M (M5) or 10E6 M (M6) melatonin, while the other two groups served as untreated controls (C5 and C6). After in vitro fertilization with fresh ram semen, the embryos produced in each group were divided into two sets, one cultured with melatonin (M5M, C5M, M6M and C6M), and the other without melatonin (M5C, C5C, M6C, and C6C). A melatonin concentration of 10E6 M increased maturation rate (82.5% vs. 73.7% for M6 and C6, respectively; P < 0.05) and tended to improve cleavage rate 36 hours after in vitro fertilization (79.4% vs. 72.6% for M6 and C6, respectively, P = 0.08). A higher melatonin concentration (10E5 M) did not have significant effects on those parameters. Blastocyst rates on day 8 did not differ significantly among groups.
Highlights
The use of melatonin implants to improve reproduction in sheep is widely spread in some Mediterranean countries
The objective of this study was to evaluate the effects of two different melatonin concentrations on the in vitro maturation and fertilization of oocytes from sheep ovaries collected at the slaughterhouse, and on the in vitro culture of the embryos
Those oocytes were randomly assigned either to one of two melatonin-treatment groups [10–5 M (M5) or 10–6 M (M6)] or to one of two untreated groups [C5 and C6]. and transferred into a maturation medium that contained bicarbonate-buffered TCM-199, supplemented with 10% (v/v) oestrus sheep serum, 10 μg mL–1 each of follicle-stimulating hormone (FSH) and luteinizing hormone (LH), 100 μM of cysteamine, 0.3 mM of sodium piruvate, 100 IU mL–1 of penicillin G, and 100 μg mL–1 of streptomycin sulphate, covered with mineral oil, and incubated for 24 h at 39°C under 5% CO2 and a saturated humidity
Summary
The use of melatonin implants to improve reproduction in sheep is widely spread in some Mediterranean countries. Melatonin is used widely to advance the breeding season in sheep and is an effective method of inducing oestrous cycles, increasing lambing rates and prolificacy during the seasonal anoestrous (Haresign et al, 1990; Haresign, 1992; Abecia et al, 2007). Those effects are associated with an improvement in ovulation rate (Zúñiga et al, 2002), luteal function (Durotoye et al, 1997; Abecia et al, 2002) and embryo viability (Forcada et al, 2006). For a summary of the effects of exogenous melatonin on the ovary and early embryos in ewes, see Abecia et al (2008)
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
