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21 results on '"Avdi Melpomeni"'

1. Sources of variation and genetic profile of spontaneous, out-of-season ovulatory activity in the Chios sheep

Author

Kouttos Athanasios, Banos Georgios, Avdi Melpomeni, Bodin Loys, and Chemineau Philippe

Subjects
reproduction, genetic parameter, sheep, ovulatory activity, Animal culture, SF1-1100, Genetics, QH426-470
Abstract

Abstract Organising the breeding plan of a seasonally breeding species, such as sheep, presents a challenge to farmers and the industry as a whole, since both economical and biological considerations need to be carefully balanced. Understanding the breeding activity of individual animals becomes a prerequisite for a successful breeding program. This study set out to investigate the sources of variation and the genetic profile of the spontaneous, out-of-season ovulatory activity of ewes of the Chios dairy sheep breed in Greece. The definition of the trait was based on blood progesterone levels, measured before exposing the ewes to rams, which marks the onset of the usual breeding season. Data were 707 records, taken over two consecutive years, of 435 ewes kept at the Agricultural Research Station of Chalkidiki in northern Greece. When all available pedigree was included, the total number of animals involved was 1068. On average, 29% of all ewes exhibited spontaneous, out-of-season ovulatory activity, with no substantial variation between the years. Significant sources of systematic variation were the ewe age and live weight, and the month of previous lambing. Older, heavier ewes, that had lambed early the previous autumn, exhibited more frequent activity. Heritability estimates were 0.216 (± 0.084) with a linear and 0.291 with a threshold model. The latter better accounts for the categorical nature of the trait. The linear model repeatability was 0.230 (± 0.095). The results obtained in this study support the notion that spontaneous out-of-season ovulatory activity can be considered in the development of a breeding plan for the Chios sheep breed.

Published
2003
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4. Effects of different reproduction management protocols on the reproduction efficiency of three indigenous Greek sheep breeds.

Author

Symeon, George K., Giantsis, Ioannis A., and Avdi, Melpomeni

Subjects
SHEEP breeds, REPRODUCTION, PROSTAGLANDINS, GONADOTROPIN releasing hormone, ANIMAL breeds
Abstract

The aim of this study was to evaluate the effects of two different methods of controlling ovine reproduction (ram effect and a combination of eco-friendly substances) in three Greek indigenous sheep breeds, namely Florina, Karagouniko, and Chios. 180 ewes, aged 2–3 years old, were used, equally divided between the three Greek sheep breeds. Each breed was divided in two equal experimental groups: In group ECO (combination of eco-friendly substances), a dose of Gonadotropin-releasing hormone (GnRH) was administered at day 0, followed by an intramuscular injection of prostaglandin seven days later and another dose of GnRH at day 9. In group ME, sexually active males were introduced to the females that have been isolated for 3 months. The experiment was conducted in three consecutive years: 2020, 2021, and 2022. Average estrus expression and fecundity in all three examined breeds was comparable, with the exemption of Florina ewes treated with the ecofriendly substances in the first year, a result that could be attributed to the strong seasonal pattern in estrus expression of the Florina breed. The average length to estrus expression in days was significantly lower in the eco-friendly method than the procedure using male effect and the prolificacy was higher for the Chios sheep than the Florina and the Karagouniko breeds. Overall, both methods for the induction and synchronization of estrus (male effect and PGF2a administration) could be used in sheep reproduction with promising results. Nevertheless, the male effect seems to be more efficient in indigenous breeds with long anestrus periods. [ABSTRACT FROM AUTHOR]

Published
2024
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6. The Association of MTNR1A Gene Alleles with the Response to Estrus Induction Treatments in Improved and Non-Improved Greek Indigenous Sheep Breeds †.

Author

Antonopoulou, Danai, Giantsis, Ioannis A., Symeon, George K., and Avdi, Melpomeni

Subjects
ESTRUS, SHEEP breeds, SHEEP breeding, ALLELES, ANIMAL breeds, ANIMAL breeding, GENETIC variation
Abstract

Seasonality in sheep reproduction and related limitations make milk production challenging throughout the year. In the present study, we investigated the response to estrus induction treatments in three indigenous breeds, Florina, Chios, and Karagouniko, as well as the melatonin receptor 1A gene variants in relation to this response. The three distinct synchronization methods were A: intravaginal sponges, B: GNRH use, and C: male effect. In group A, fertility was 85%, and Florina ewes expressed estrus at 90% in July. Ewes from Karagouniko and Chios had fecundity rates of 95% and 99%, respectively, and 100% estrus expression. The Florina ewes in group B expressed estrus at a percentage of 60%, with a fecundity rate of 57%, the Karagouniko ewes at a percentage of 65%, with a fecundity rate of 54%, and the Chios breed animals at a percentage of 87%, with a fecundity rate of 85%. Twenty to twenty-five days after ram induction, 68% of the Florina breed in group C showed signs of estrus, compared to 84% and 94% of Karagouniko and Chios breeds, respectively. In both Florina and Karagouniko breeds, all treatments showed a substantial difference in the frequency of the four identified SNPs in the MTNR1A gene between ewes who expressed estrus and ewes who did not. The genetic improvement based on the alleles analyzed in the current study is expected to decrease seasonality rates in indigenous sheep breeds. [ABSTRACT FROM AUTHOR]

Published
2024
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14. FLOCK - REPROD non hormonal insemination protocols for goats

Author

Grizelj, Juraj, Bruni, Guido, Avdi, Melpomeni, Barbas, João Pedro, Boissard, Karine, Branca, Andrea, Cavaco-Goncalves, Sandra, Epifani, Gian Paolo, Špoljarić, Branimira, Fatet, Alice, Freret, Sandrine, Lopez - Sebastian, Antonio, Coloma, Miguel Angel, Mascarenhas, Ramiro, Zamfirescu, Stela, Boue, Pascal, Pellicer, Maria Teresa, Marantidis, Apostolos, and Vince, Silvijo

Subjects
No hormonal protocols, hormone free, artificial insemination, goats, male effect, photoperiodic treatments
Abstract

Project developed innovative solutions to supply the hormone-free goat’s milk all year round. FLOCK-REPROD, supported by 7th Framework Program, proposed solutions that require no hormonal treatment and allow control of seasonality and application of artificial insemination (AI). In this manner, FLOCK-REPROD will help breeders produce more milk and provide an alternative way to meet EU legal requirements which restricts the use of hormones. Researchers developed new progestagen-free AI protocols (PG1, PG2, HF) involving procedures based on male effect and light treatments to induce and synchronize ovulations in any season. FLOCK-REPROD protocols exclude the use of progestagens. PG1 and PG2 are based on either 1 or 2 injections of prostaglandin (not subjected to residues constraints). The HF protocol is hormone-free, and can thus be applied in organic farms. New AI protocols have been tested in field conditions. Best results were obtained with HF (58% pregnancy, similar to classical hormonal treatment HT) followed by PG2 (54%) and PG1 (45%). Main problem for implementation of PG1 and HF protocols was high variability of fertility results depending on farms. New AI protocols were less efficient in terms of working time and costs of inputs, in comparison to the HT. PG1 was the most time-consuming protocol followed by HF and PG2. HF appeared to be the most expensive protocol whereas PG2 was cheaper than PG1. Increased workload and higher costs generated by new AI protocols were mainly due to number of supplementary bucks needed to carry out male effect (higher feed costs, time-consuming bucks’ handling).

Published
2014

15. FLOCK-REPROD nehormonski protokoli za umjetno osjemenjivanje koza

Author

Grizelj, Juraj, Bruni, Guido, Avdi, Melpomeni, Barbas, João Pedro, Boissard, Karine, Branca, Andrea, Cavaco-Goncalves, Sandra, Epifani, Gian Paolo, Špoljarić, Branimira, Fatet, Alice, Freret, Sandrine, Lopez - Sebastian, Antonio, Coloma, Miguel Angel, Mascarenhas, Ramiro, Zamfirescu, Stela, Boue, Pascal, Folnožić, Ivan, Pellicer, Maria Teresa, Marantidis, Apostolos, and Vince, Silvijo

Subjects
nehormonski protokoli, hormone free, umjetno osjemenjivanje, koze, utjecaj mužjaka, svjetlosni režimi
Abstract

Projekt je razvio inovativna rješenja za proizvodnju hormone free kozjeg mlijeka tijekom cijele godine. FLOCK-REPROD (Hormone free non-seasonal or seasonal goat reproduction for a sustainable European goat-milk market), uz potporu 7. okvirnog programa, iznosi nehormonska rješenja koja omogućuju kontrolu sezonosti uz primjenu umjetnog osjemenjivanja (UO). Na taj način FLOCK-REPROD pomaže uzgajivačima proizvesti više mlijeka i osigurava alternativni put koji je u skladu sa zakonskom regulativom EU koja ograničava uporabu hormona. Razvijeni su novi progestagen free UO protokoli (PG1, PG1, HF) koji uključuju postupke temeljene na učinku mužjaka i svjetlosnim režimima u svrhu indukcije i sinkronizacije ovulacije tijekom cijele godine. PG1 i PG2 temelje se na jednoj ili dvije injekcije prostaglandina (nisu podvrgnute rezidualnim ograničenjima). HF protokol je hormone free te može biti primijenjen i na organskim uzgojima. Novi protokoli UO testirani su u terenskim uvjetima. Najbolji su rezultati dobiveni s HF (58 % gravidnosti, slično klasičnom hormonskom protokolu HT), a zatim s PG2 (54 %) te PG1 (45 %). Osnovni problem za implementaciju protokola PG1 i HF jest visoka varijabilnost plodnosti među farmama. Novi protokoli UO manje su učinkoviti glede utrošenih radnih sati i ulaznih troškova u usporedbi s HT. PG1 je protokol koji zahtijeva najveći utrošak vremena, a nakon njega to su HF i PG2. HF se pokazao najskupljim protokolom, dok je PG2 jeftiniji od PG1. Veći radni angažman i viši troškovi koje stvaraju novi UO protokoli nastaju najviše zbog potrebe za dodatnim brojem jarčeva nužnih za provođenje utjecaja mužjaka (veći troškovi hranidbe, utrošak vremena za baratanje mužjacima).

Published
2014

16. FLOCK-REPROD protocoles non hormonaux d'insemination des chevres

Author

Grizelj, Juraj, Bruni, Guido, Avdi, Melpomeni, Barbas, João Pedro, Boissard, Karine, Branca, Andrea, Cavaco - Goncalves, Sandra, Epifani, Gian Paolo, Špoljarić, Branimira, Fatet, Alice, Freret, Sandrine, Lopez-Sebastian, Antonio, Coloma, Miguel Angel, Mascarenhas, Ramiro, Zamfirescu, Stela, Boue, Pascal, Pellicer, Maria Teresa, Marantidis, Apostolos, and Vince, Silvijo

Subjects
protocoles non hormonaux, sans hormones, l'insemination artificielle, chevres effet male, traitements lumineux
Abstract

Le projet a développé des solutions innovantes pour fournir du lait de la chèvre sans hormones toute au long de l'année. FLOCK-REPROD, soutenu par 7eme Programme Cadre, proposées les solutions qui ne nécessitent pas le traitement hormonal et permettent le contrôle de la saisonnalité et de l'application de l'insémination artificielle (IA). De cette manière, FLOCK-REPROD aidera les éleveurs produisent plus de lait et de fournir un moyen alternatif de répondre aux exigences légales de l'UE qui restreint l'utilisation d'hormones. Les chercheurs ont élaborés de nouveaux protocoles d’AI sans utilisation de gestagens (PG1, PG2, HF) impliquant des procédures basées sur l'effet mâle et traitements lumineuses pour induire et synchroniser des ovulations en toute saison d’année. Protocoles FLOCK-REPROD excluent l'utilisation de gestagens. PG1 et PG2 sont basés sur 1 ou 2 injections de prostaglandine (pas encore soumis à des contraintes de résidus). Le protocole HF est sans hormone, et peut donc être appliquée dans des fermes organiques. De nouveaux protocoles d'IA ont été testés dans des conditions de terrain. Les meilleurs résultats ont été obtenus avec du protocole HF (58% de gestations, similaire au protocole hormonal classique HT), suivie par PG2 (54%) et PG1 (45%). Le problème principal pour la mise en œuvre de protocoles de PG1 et HF était grande variabilité des résultats de fertilité en fonction de fermes. De nouveaux protocoles d'IA étaient moins efficaces en termes de temps de travail et des coûts des données, par rapport à la HT. PG1 est le protocole le plus prenant de temps, suivie d'HF et PG2. HF semblait être le protocole le plus cher alors que PG2 était moins cher que PG1. Charge de travail accrue et des coûts plus élevés générés par de nouveaux protocoles d'IA étaient principalement en raison du nombre de boucs supplémentaires nécessaires pour mener l’effet mâle (coûts plus élevés des alimentations, prenant du temps pour la manipulation avec les boucs).

Published
2014

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