Effects of human chorionic gonadotropin treatment after artificial inseminations on conception rate with the first follicular wave dominant follicle in the ovary ipsilateral to the corpus luteum in lactating dairy cows
| Autor: | Mitsunori Kayano, Ryotaro Miura, Motozumi Matsui, Nobu Matsumoto, Shingo Haneda, Taiki Izumi |
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| Jazyk: | angličtina |
| Rok vydání: | 2018 |
| Předmět: |
0301 basic medicine
endocrine system Pregnancy Rate medicine.medical_treatment Ovary First follicular wave dominant follicle Chorionic Gonadotropin Human chorionic gonadotropin Andrology 03 medical and health sciences Corpus luteum Ovarian Follicle Pregnancy Follicular phase Conception rate medicine Human chorionic gonadotropin (hCG) Animals Lactation Insemination Artificial medicine.diagnostic_test business.industry Artificial insemination Cow 0402 animal and dairy science 04 agricultural and veterinary sciences medicine.disease 040201 dairy & animal science Dominant follicle 030104 developmental biology medicine.anatomical_structure Fertilization Transrectal ultrasonography Animal Science and Zoology Original Article Cattle Female business Estrus Synchronization |
| Zdroj: | The Journal of Reproduction and Development |
| ISSN: | 1348-4400 0916-8818 |
| Popis: | We examined the effect of human chorionic gonadotropin (hCG) treatment 5 days after artificial insemination (AI) on conception rate when the first-wave dominant follicle (DF) in the ovaries was either ipsilateral or contralateral to the corpus luteum (CL) in lactating dairy cows. 577 cows from 4 dairy farms were divided into the following two groups 5 days after AI using transrectal ultrasonography: (1) the ipsilateral group (IG; n = 348), in which the DF was ipsilateral to the CL, and (2) the contralateral group (CG; n = 229), in which the DF was contralateral to the CL. IG and CG were further subdivided into two groups: non-treatment groups, which received no treatment (IG, n = 220; CG, n = 128), and hCG treatment group, that was administrated 1500 IU hCG 5 days after AI (IG, n = 143; CG, n = 86). Pregnancy was diagnosed by rectal palpation or transrectal ultrasonography from 53 to 67 days after AI. Conception rate was significantly (P < 0.01) higher in the hCG treatment group of IG (40.6%) than in the non-treatment group of IG (21.4%); however, there was no difference in the non-treatment (51.7%) and hCG treatment (43.0%) groups of CG. Parity, farm, days in milk at AI, interaction between the farm and hCG treatment and interaction between the farm and location of the first-wave DF and CL did not affect conception rate. Our results suggest that conception rate can be improved by administrating hCG only to cows with the first wave DF ipsilateral to the CL. |
| Databáze: | OpenAIRE |
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