Treatment with hCG 4 or 6 days after TAI to improve pregnancy outcomes in repeat-breeding dairy cows
Autor: | Mufeed A. Alnimer, Ahmad I. Shamoun |
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Rok vydání: | 2015 |
Předmět: |
medicine.medical_specialty
Pregnancy Rate Dinoprost Buserelin Chorionic Gonadotropin Drug Administration Schedule Human chorionic gonadotropin Endocrinology Food Animals Pregnancy Blood plasma Animals Humans Medicine Pregnancy outcomes Insemination Artificial Progesterone Gynecology business.industry General Medicine medicine.disease Parity Cattle Female Animal Science and Zoology Seasons Estrus Synchronization business |
Zdroj: | Animal Reproduction Science. 157:63-70 |
ISSN: | 0378-4320 |
DOI: | 10.1016/j.anireprosci.2015.03.016 |
Popis: | A study was conducted to evaluate the effect of human chorionic gonadotropin (hCG) administration 4 or 6 days after timed AI (TAI) on P4 concentration and pregnancy outcomes in repeat breeding dairy cows. All cows were treated by Cosynch protocol before being assigned into 3 groups: CON (n = 139): did not receive hormonal treatments; D4 (n = 136): received 1500 IU hCG 4 days post TAI; and D6 (n = 131): received 1500 IU hCG 6 days post TAI. Plasma P4 concentration was evaluated on Day of hCG and 12 days post TAI. Pregnancies per AI (P/AI) on Day 45 were greater for D6 (38.9%) than CON (30.9%) groups. Pregnancy losses (PL) were lower for D6 (15.0%) and D4 (26.7%) than CON (37.7%) groups. Treatment by season revealed a greater P/AI and lower PL for D6 (30.3% and 18.2%) and D4 (33.3% and 31.0%) than CON (19.2% and 58.3%) groups during summer, while P/AI was greater for D6 (57.1%) than D4 (30.6%) and CON (37.9%) groups during winter. Treatment by parity indicated a greater P/AI for D4 (46.4%) and D6 (31.6%) than CON (15.8%) groups within primiparous cows. Pregnancy losses were lower for D6 (15.1%) than CON (36.5%) groups within multiparous cows while D4 tended to be lower (13.3%) than CON (50.0%) groups. Plasma P4 concentration on Day 12 post TAI was higher for treated than for CON groups. Applying hCG 6 days after TAI was beneficial in improving P/AI either in summer or winter as a result of reducing PL and increasing P4 concentration. |
Databáze: | OpenAIRE |
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