Relationship between the timing of the first postpartum ovulation and antral follicle counts in Holstein cows
| Autor: | Koichiro Ueda, Tomoyuki Masaki, Min Bo, Masashi Nagano, Yojiro Yanagawa, Kenichiro Sakaguchi, Eri Furukawa |
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| Rok vydání: | 2019 |
| Předmět: |
0301 basic medicine
Anti-Mullerian Hormone Ovulation Antral follicle count Time Factors Pregnancy Rate medicine.medical_treatment media_common.quotation_subject Cell Count Estrous Cycle Biology lcsh:Gynecology and obstetrics 03 medical and health sciences 0302 clinical medicine Animal science Ovarian Follicle Pregnancy Follicular phase medicine Animals Ovarian reserve lcsh:RG1-991 media_common Ultrasonography Estrous cycle 030219 obstetrics & reproductive medicine Artificial insemination Research fungi Body Weight Postpartum Period First postpartum ovulation Obstetrics and Gynecology food and beverages respiratory system Antral follicle Hormones Pregnancy rate 030104 developmental biology Milk Oncology Cattle Female Luteinizing hormone |
| Zdroj: | Journal of Ovarian Research Journal of Ovarian Research, Vol 13, Iss 1, Pp 1-9 (2020) |
| ISSN: | 1757-2215 |
| Popis: | Background The timing of the first postpartum ovulation is an important factor affecting the timing of estrous resumption in dairy cows. The first postpartum ovulation is delayed in cows producing large amounts of milk with an intensive negative energy balance. The antral follicle count (AFC) and serum anti-Müllerian hormone concentrations are known to be indicators of the ovarian reserve, which is the number and quality of follicles left in a pair of ovaries and known as an indicator of female fertility. Cows with higher AFC have been proven to show higher pregnancy rate and shorter calving to conception intervals; however, the relationship between the timing of the first postpartum ovulation and ovarian reserve remains unclear. Therefore, this study examined the relationships between postpartum follicular dynamics, the ovarian cycle, nutritional status, and ovarian reserve. Methods Transrectal ultrasonography was conducted from calving to 70–120 days in milk (DIM) in 26 cows to monitor AFC, follicular dynamics and the ovarian cycle. Body weight (BW) and milk yield were used as indicators of nutritional status. Results The first postpartum ovulation was significantly later in cows with low AFC ( Conclusions The first postpartum ovulation was significantly earlier in cows with high AFC than in those with low AFC. The assumed reason for this result was higher sensitivity to luteinizing hormone and larger androstenedione and estradiol production in follicles in high AFC cows. Therefore, cows with high AFC may be more fertile than those with low AFC while their milk production increase and BW decrease; it means they are in negative energy balance. (340/350 words) |
| Databáze: | OpenAIRE |
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