The Ovulatory Response To Human Chorionic Gonadotropin Administration On Day 4 Post Timed Artificial Insemination Improved Fertility In Repeat Breeder Cows
| Autor: | G. Yilmazbas-Mecitoglu, Ahmet Gümen, Ebru Karakaya-Bilen, Rabia Cakircali, Abdulkadir Keskin, Baris Guner |
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| Přispěvatelé: | Veteriner Fakültesi |
| Rok vydání: | 2021 |
| Předmět: |
endocrine system
medicine.medical_treatment media_common.quotation_subject hCG Fertility Human chorionic gonadotropin Andrology 03 medical and health sciences 0302 clinical medicine medicine reproductive and urinary physiology media_common Repeat Breeding 030219 obstetrics & reproductive medicine General Veterinary business.industry Artificial insemination 0402 animal and dairy science 04 agricultural and veterinary sciences 040201 dairy & animal science Post TAI Cattle business Administration (government) hormones hormone substitutes and hormone antagonists Repeat breeder |
| Popis: | Güner, Barış (Balikesir Author) This study focused on determining the success of inducing endogenous progesterone source (by formation of accessory corpus luteum) by human chorionic gonadotropin (hCG) administration on day 4 post timed artificial insemination (TAI) and on evaluating the effect of the day of hCG administration (day 4 or 5 post TAI) on pregnancy rates in repeat breeder cows according to their responses to hCG administrations. Non-pregnant cyclic lactating Holstein dairy cows with more than three services despite no clinical reproductive abnormalities were enrolled in the study. All cows (n = 192) received the Ovsynch protocol (GnRH-7d-PGF(2 alpha)-56h-GnRH-16/18h-TAI) and hCG administration (1500 IU, i.m.) was performed in group hCG4 (n = 64) on day 4 and in group hCG5 (n = 68) on day 5 post TAI. The control group (CON, n = 60) did not receive any hCG treatment. The responses (ovulation rate) to hCG (similar to 64%) were similar on days 4 and 5 post TAI. Pregnancy per AI (P/AI) at 31 days was similar among the groups (48.3% in CON, 48.4% in hCG4, and 42.6% in hCG5). Regardless of the day of the treatment (hCG4 + hCG5), the cows had an ovulatory response to hCG (54.1%), and a greater P/AI (P = 0.007) at 31 days than those without a response (29.8%). The administration of hCG on either day 4 or 5 post TAI did not increase overall pregnancy rates, however, the ovulatory response to the post TAI hCG administration on day 4 improved fertility in repeat breeder cows. Further studies are needed with a larger number of animals to reveal this potentiallly beneficial effect. University of Bursa Uludag, Scientific Research Projects Council KUAP(V)-2019/1 |
| Databáze: | OpenAIRE |
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