Increased number of large non-atretic follicles and co-dominance effects account for high litter sizes in Bonga sheep
| Autor: | Aberra Melesse, Muluken Zeleke, Cristian Porcu, Aynalem Haile, Zelalem Abate, Joram M. Mwacharo, Tesfaye Getachew, Mariem Rouatbi, Mourad Rekik, Asrat Tera Dolebo, Barbara Rischkowsky |
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| Rok vydání: | 2019 |
| Předmět: |
Litter (animal)
Ovulation Litter Size media_common.quotation_subject Biology 03 medical and health sciences Animal science Estrus Ovarian Follicle Follicular phase Dominance (ecology) Animals 030304 developmental biology media_common Estrous cycle 0303 health sciences Sheep Estradiol 0402 animal and dairy science 04 agricultural and veterinary sciences General Medicine 040201 dairy & animal science Female General Agricultural and Biological Sciences Plasma estradiol |
| Zdroj: | Animal science journal = Nihon chikusan GakkaihoREFERENCES. 91(1) |
| ISSN: | 1740-0929 |
| Popis: | To understand the ovarian basis for prolificacy of Bonga sheep, a total of 31 ewes were selected based on litter size (LS) records and divided into two groups: High Prolificacy (HP) (n = 20) with LS ≥ 2 and Low Prolificacy (LP) (n = 11) with LS = 1. At a synchronized estrus, follicular dynamics were determined using transrectal ultrasonography. Plasma estradiol concentrations were also monitored. In total 27 ewes were observed in estrus being 9/11 LP (82%) and 18/20 HP (90%). On the day of estrus (day 0), the mean number of large follicles was higher (p < .05) in HP (1.78 ± 0.19) than in LP (1.0 ± 0.28) ewes. Prior to estrus, more (p < .05) medium follicles were visible for HP compared to LP ewes. Plasma estradiol concentrations were higher in HP compared to LP ewes (18.91 ± 0.41 vs. 14.51 ± 0.65 pg/ml; p < .05) and similarly was ovulation number (2.3 ± 0.15 vs. 1.28 ± 0. 14; p < .05). Higher ovulation rates and litter size in Bonga sheep are evidenced by the previous presence of more large follicles and the existence of co-dominance effects as most likely medium follicles are selected to ovulate. |
| Databáze: | OpenAIRE |
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