Sexual stimulation as a luteolytic inductor in beef heifers
| Autor: | Rodolfo Ungerfeld, María Victoria Felipez, Tomas J. Acosta |
|---|---|
| Rok vydání: | 2019 |
| Předmět: |
Male
Ovulation Luteolytic Effects Luteolysis Ovary Biology Luteal phase Sexual Behavior Animal 03 medical and health sciences 0302 clinical medicine Animal science Estrus Food Animals Corpus Luteum medicine Animals Sexual stimulation Small Animals Estrous cycle 030219 obstetrics & reproductive medicine Equine Minimum distance 0402 animal and dairy science 04 agricultural and veterinary sciences 040201 dairy & animal science Breed medicine.anatomical_structure Cattle Female Animal Science and Zoology Corpus luteum |
| Zdroj: | Theriogenology. 132:83-87 |
| ISSN: | 0093-691X |
| Popis: | The objective was to determine if the introduction of androgenized steers or females in oestrus has luteolytic effects during the advanced luteal phase (Day 12–13 of the cycle, Day of ovulation = Day 0) in heifers by analysing the changes in corpus luteum (CL) size and perfused area together with progesterone (P4) secretion. Experiment 1 (EXP1) was carried out in May (autumn) with 12 Angus and Angus X Hereford heifers and experiment 2 (EXP2) in September (spring) with 20 heifers of the same breed. Procedures for both experiments were the same. Firstly, oestrus was synchronized in heifers, then, transrectal colour doppler ultrasonography was performed daily from Day 10 to Day 12 of the cycle in all animals. On Day 12 in the afternoon, animals were allocated to two experimental groups (control and biostimulated) and maintained separated (minimum distance: 1000 m) until the end of each experiment. In EXP1, two androgenized steers were introduced into the biostimulated group (BAS) and compared with unstimulated control group (CON1). In EXP2, 20 animals were separated into control group (CON2) and biostimulated group (BHE), in which 4 oestrous heifers were introduced on Day 12 in the afternoon, and 4 more on day 13. The oestrous heifers were injected with 2 mg i.m. of oestradiol benzoate every 12 h until the end of the experiment to maintain the receptiveness. In both experiments, from Day 13 until the day on which detectable luteal blood flow (irrigation) disappeared, colour doppler ultrasonography was performed every 12 h in both groups. Blood samples were collected from all heifers every 12 h from Day 10 to the day in which irrigation disappeared. In EXP1 there was no effect of treatment on CL volume. The BAS had less CL’s perfused area than controls 0.09 ± 0.02 cm2 vs 0.16 ± 0.02 cm2, respectively (p = 0.015), less percentage of perfused area (2.4 ± 0.4% vs 4.2 ± 0.4%; p = 0,011), and lower progesterone (P4) concentration than CON1 (2.7 ± 1.0 ng/mL vs 5.8 ± 0.9 ng/mL respectively; p = 0.046). On Day 14.5 of the cycle, the BAS tended to have a lower concentration of P4 than the CON1 (p = 0.06) and on Days 15.5, 16, 16.5, 17, 17.5, 19.5 the P4 concentration was lower in BAS than in CON1 (p |
| Databáze: | OpenAIRE |
| Externí odkaz: |
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