Stocktake Sale on now: wide range of books at up to 70% off!
Register      Login
Animal Production Science Animal Production Science Society
Food, fibre and pharmaceuticals from animals
RESEARCH ARTICLE

Effects of melatonin implants on reproductive performance in sheep: a systematic review and meta-analysis

Ender Uzabacı https://orcid.org/0000-0002-9634-0055 A * and Hakan Ustuner https://orcid.org/0000-0002-4341-5842 B
+ Author Affiliations
- Author Affiliations

A Department of Biometrics, Faculty of Veterinary Medicine, Bursa Uludag University, Bursa, Türkiye.

B Department of Animal Science, Faculty of Veterinary Medicine, Bursa Uludag University, Bursa, Türkiye.

* Correspondence to: euzabaci@gmail.com

Handling Editor: Gry Boe-Hansen

Animal Production Science 64, AN23109 https://doi.org/10.1071/AN23109
Submitted: 20 March 2023  Accepted: 8 April 2024  Published: 13 May 2024

© 2024 The Author(s) (or their employer(s)). Published by CSIRO Publishing

Abstract

Context

Sheep are seasonal breeding animals. Different reproduction systems exist to enhance productivity in non-breeding season. One of the methods used in enhancing reproductive performance in sheep breeding is melatonin administration.

Aim

This study aimed to evaluate the impact of melatonin application on reproductive performance in sheep by meta-analysis according to different factors.

Methods

To find eligible studies, PubMed and Web of Science databases were searched. Twenty studies published between 1991 and 2021 were included in the meta-analysis. The effect sizes of pregnancy rate, lambing rate and litter size were calculated according to breeds, production characteristics (dairy-meat breeds) and season (breeding–non-breeding). The study estimated the risk ratio for pregnancy and lambing rates, and standardized mean difference for litter size as effect size.

Key results

The melatonin hormone increases the pregnancy rate by 1.07 times and the lambing rate by 1.36 times. The effect size (risk ratio) of the Rasa Aragonesa breed (1.15) for pregnancy rate and the Merino breed (1.65) for lambing rate was higher than the Sarda breed.

Conclusions

The positive effect of melatonin was found to be higher in the non-breeding season than in the breeding season for the three reproductive performance traits examined.

Implications

This study is a comprehensive research study examining the effect of melatonin application in sheep according to different factors.

Keywords: breeding season, effect size, heterogeneity, melatonin, meta-analysis, publication bias, reproductive performance, sheep.

References

Abecia JA, Palacín I, Forcada F, Valares JA (2006) The effect of melatonin treatment on the ovarian response of ewes to the ram effect. Domestic Animal Endocrinology 31, 52-62.
| Crossref | Google Scholar | PubMed |

Arrebola FA, Abecia JA, Forcada F, Garcia A, Martí RA, Mesa O (2009) Effects of annual rainfall and farm on lamb production after treatment with melatonin implants in Merino sheep: a 4-year study. New Zealand Veterinary Journal 57, 141-145.
| Crossref | Google Scholar | PubMed |

Brzezinski A, Vangel MG, Wurtman RJ, Norrie G, Zhdanova I, Ben-Shushan A, Ford I (2005) Effects of exogenous melatonin on sleep: a meta-analysis. Sleep Medicine Reviews 9, 41-50.
| Crossref | Google Scholar | PubMed |

Buscemi N, Vandermeer B, Hooton N, Pandya R, Tjosvold L, Hartling L, Vohra S, Klassen TP, Baker G (2006) Efficacy and safety of exogenous melatonin for secondary sleep disorders and sleep disorders accompanying sleep restriction: meta-analysis. BMJ 332, 385-393.
| Crossref | Google Scholar | PubMed |

Carcangiu V, Mura MC, Bini PP, Vacca GM, Daga C, Luridiana S (2012) Can advance of first lambing induced by melatonin implants influence the next lambing time in Sarda breed sheep? Canadian Journal of Animal Science 92, 67-71.
| Crossref | Google Scholar |

Cevik M, Yilmazer C, Kocyigit A (2017) Effects of melatonin implantation on the fertility potentials of Kivircik and Charollais ewes and rams during the non-breeding season. Polish Journal of Veterinary Sciences 20, 501-506.
| Crossref | Google Scholar | PubMed |

Cosso G, Mura MC, Pulinas L, Curone G, Vigo D, Carcangiu V, Luridiana S (2021) Effects of melatonin treatment on milk traits, reproductive performance and immune response in Sarda dairy sheep. Italian Journal of Animal Science 20, 632-639.
| Crossref | Google Scholar |

El-Mokadem MY, Nour El-Din ANM, Ramadan TA, Taha TA, Samak MA, Sharaby MA, Rashad AM (2020) Greater concentrations of IGF-1 are associated with increasing pregnancy rate in melatonin implanted anestrous Barki ewes. Animal Reproduction Science 219, 106542.
| Crossref | Google Scholar | PubMed |

Forcada F, Abecia JA, Lozano JM, Ferrer LM, Lacasta D (1999) The effects on reproductive performance in the short and medium term of the combined use of exogenous melatonin and progestagen pessaries in ewes with a short seasonal anoestrous period. Veterinary Research Communications 23, 257-263.
| Crossref | Google Scholar | PubMed |

Forcada F, Abecia JA, Zúñiga O, Lozano JM (2002) Variation in the ability of melatonin implants inserted at two different times after the winter solstice to restore reproductive activity in reduced seasonality ewes. Australian Journal of Agricultural Research 53, 167-173.
| Crossref | Google Scholar |

Gavojdian D, Cziszter LT, Pacala N, Sauer M (2013) Productive and reproductive performance of Dorper and its crossbreds under a Romanian semi-intensive management system. South African Journal of Animal Science 43, 219-228.
| Crossref | Google Scholar |

Gómez JD, Balasch S, Gómez LD, Martino A, Fernández N (2006) A comparison between intravaginal progestagen and melatonin implant treatments on the reproductive efficiency of ewes. Small Ruminant Research 66, 156-163.
| Crossref | Google Scholar |

Haresign W (1992) The effect of implantation of lowland ewes with melatonin on the time of mating and reproductive performance. Animal Science Journal 54, 31-39.
| Crossref | Google Scholar |

Haresign W, Peters AR, Staples LD (1990) The effect of melatonin implants on breeding activity and litter size in commercial sheep flocks in the UK. Animal Science 50, 111-121.
| Crossref | Google Scholar |

Kleemann DO, Kelly JM, Arney LJ, Farley IL, Tilbrook AJ, Walker SK (2014) Positive effects of melatonin treatment on the reproductive performance of young border leicester rams mated to merino ewes in spring: preliminary observations. Reproduction in Domestic Animals 49, 894-898.
| Crossref | Google Scholar | PubMed |

Laliotis V, Vosniakou A, Zafrakas A, Lymberopoulos A, Alifakiotis T (1998) The effect of melatonin on lambing and litter size in milking ewes after advancing the breeding season with progestagen and PMSG followed by artificial insemination. Small Ruminant Research 31, 79-81.
| Crossref | Google Scholar |

Lopez Sebastian A, Inskeep EK (1991) Response of ewes of mediterranean sheep breeds to subcutaneous implants of melatonin. Livestock Production Science 27, 177-184.
| Crossref | Google Scholar |

Luridiana S, Mura MC, Daga C, Farci F, Di Stefano MV, Zidda F, Carcangiu V (2015) Melatonin treatment in spring and reproductive recovery in sheep with different body condition score and age. Animal Reproduction Science 160, 68-73.
| Crossref | Google Scholar | PubMed |

Moher D, Liberati A, Tetzlaff J, Altman DG, The PRISMA Group (2009) Preferred reporting items for systematic reviews and meta-analyses: the PRISMA statement. PLoS Medicine 6, e1000097.
| Crossref | Google Scholar |

Mura MC, Luridiana S, Farci F, Veronica M, Di Stefano MV, Daga C, Pulinas L, Starič J, Carcangiu V (2017) Melatonin treatment in winter and spring and reproductive recovery in Sarda breed sheep. Animal Reproduction Science 185, 104-108.
| Crossref | Google Scholar | PubMed |

Mura MC, Luridiana S, Pulinas L, Bizzarri D, Cosso G, Carcangiu V (2019) Melatonin treatment and male replacement every week on the reproductive performance in Sarda sheep breed. Theriogenology 135, 80-84.
| Crossref | Google Scholar | PubMed |

Palacin I, Forcada F, Abecia JA (2011) Meta-analysis of the efficacy of melatonin implants for improving reproductive performance in sheep. Spanish Journal of Agricultural Research 9, 730-743.
| Crossref | Google Scholar |

Papachristoforou C, Koumas A, Photiou C (2007) Initiation of the breeding season in ewe lambs and goat kids with melatonin implants. Small Ruminant Research 73, 122-126.
| Crossref | Google Scholar |

Scott PR, Sargison ND, Macrae AI, Gough MR (2009) Melatonin treatment prior to the normal breeding season increases fetal number in United Kingdom sheep flocks. The Veterinary Journal 182, 198-202.
| Crossref | Google Scholar | PubMed |

Song Y, Wu H, Wang X, Haire A, Zhang X, Zhang J, Wu Y, Lian Z, Fu J, Liu G, Wusiman A (2019) Melatonin improves the efficiency of super-ovulation and timed artificial insemination in sheep. PeerJ 7, e6750.
| Crossref | Google Scholar | PubMed |

Staples LD, McPhee S, Kennaway DJ, Williams AH (1992) The influence of exogenous melatonin on the seasonal patterns of ovulation and oestrus in sheep. Animal Reproduction Science 30, 185-223.
| Crossref | Google Scholar |

Staric J, Pulinas L, Di Stefano MV, Mura MC, Luridiana S, Bini PP, Carcangiu V (2019) Reproductive activity in sheep with different lambing period treated with melatonin in April. Journal of Central European Agriculture 20, 62-67.
| Crossref | Google Scholar |

Stellflug JN, Rodriguez F, Lavoie VA, Glimp HA (1994) Influence of simulated photoperiod alteration and induced estrus on reproductive performance of spring-born Columbia and Targhee ewe lambs. Journal of Animal Science 72, 29-33.
| Crossref | Google Scholar | PubMed |

Tempest WM, Boaz TG (1973) The seasonality of reproductive performance of Merino sheep in Britain. Animal Science Journal 17, 33-41.
| Crossref | Google Scholar |

Uslu BA, Mis L, Gulyuz F, Comba B, Ucar O, Tasal I, Comba A, Kosal V, Sendag S, Wehrend A (2017) Is there a relationship between serum minerals (Ca, Mg) and trace elements (Cu, Fe, Mn, Zn) at mating on pregnancy rates in fat-tailed Morkaraman sheep? Indian Journal of Animal Research 51, 256-262.
| Crossref | Google Scholar |

Vázquez MI, Forcada F, Casao A, Sosa C, Palacín I, Abecia JA (2009) Effects of melatonin and undernutrition on the viability of ovine embryos during anestrus and the breeding season. Animal Reproduction Science 112, 83-94.
| Crossref | Google Scholar | PubMed |