Size and number of corpora lutea and serum progesterone concentrations when administering two doses of eCG in an estrous synchronization treatment regimen for dairy cattle
| Autor: | M. Vojgani, H. Mahdavi-Roshan, Amir Niasari-Naslaji, D. Nikjou |
|---|---|
| Rok vydání: | 2020 |
| Předmět: |
Ovulation
Serum progesterone Dinoprost Chorionic Gonadotropin Cloprostenol Andrology Gonadotropin-Releasing Hormone 03 medical and health sciences Follicle 0302 clinical medicine Endocrinology Food Animals Corpus Luteum Medicine Animals cardiovascular diseases Dairy cattle Progesterone 030219 obstetrics & reproductive medicine Treatment regimen business.industry 0402 animal and dairy science Estrus synchronization 04 agricultural and veterinary sciences General Medicine 040201 dairy & animal science Animal Science and Zoology Cattle Female Ultrasonography business Estrus Synchronization |
| Zdroj: | Animal reproduction science. 222 |
| ISSN: | 1873-2232 |
| Popis: | There was investigation of whether there were ovulations from co-dominant follicles following eCG administration. In all experiments, there was GnRH injection and CIDR insertion on day 0 (D0), CIDR withdrawal on D8, and cloprostenol administration on D8 (Exp. I and II) or D7 and D8 (Exp. III). Females in the control group were not administered any further treatment. Females in other group(s) were treated with eCG (500 IU) on Day 2 in Exp. I, Day 2 (eCG-2) or 8 (eCG-8) in Exp. II and Day 2 (eCG-2) or Days 2 and 6 (eCG-2-6) in Exp. III. Ovaries were examined using ultrasonography. In Experiments I and II, females had follicle emergence on Day 2. At the time of CIDR removal, more eCG-treated heifers (8/9; Exp. I) and cows (5/6; eCG-2; Exp. II) had co-dominant follicles compared to those in the control group (P 0.05). Occurrence of ovulations from co-dominant for individual cows was minimal. In Experiment III, the time period from CIDR removal to estrus in cows treated with eCG-2 (68 ± 13 h) was longer compared to cows in the control (37±2 h) and eCG-2-6-treated group (38 ± 5 h; P 0.05). There was a greater proportion of heifers having ovulations and thus greater progesterone concentration in the eCG-2-6 than eCG-2 group (P 0.05). Administering eCG twice 4 days apart with the initial administration being two days after GnRH administration, at the time of follicle wave emergence, could induce growth of and ovulation from co-dominant follicles and enhance progesterone production in cattle. |
| Databáze: | OpenAIRE |
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