Consequences of eight consecutive applications of equine chorionic gonadotropin on ovarian follicle development and ovulation in bos indicus cows
ABSTRACT: The equine chorionic gonadotropin (eCG) is a glycoprotein produced in mare endometrial calices. In bovine, it is used in estrus synchronization protocols. However, studies have shown that it is potentially immunogenic and its effect can decrease after repetitive use. This study aimed to ev...
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| Format: | Article |
| Language: | English |
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Universidade Federal de Santa Maria
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| Series: | Ciência Rural |
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| Online Access: | http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-84782016001102018&lng=en&tlng=en |
| _version_ | 1818672717497368576 |
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| author | Bhárbara Delboni Stuhr Isaac Santos Gil Tracy Ferreira Lacerda Mauricio Gomes Favoreto Bárbara Loureiro |
| author_facet | Bhárbara Delboni Stuhr Isaac Santos Gil Tracy Ferreira Lacerda Mauricio Gomes Favoreto Bárbara Loureiro |
| author_sort | Bhárbara Delboni Stuhr |
| collection | DOAJ |
| description | ABSTRACT: The equine chorionic gonadotropin (eCG) is a glycoprotein produced in mare endometrial calices. In bovine, it is used in estrus synchronization protocols. However, studies have shown that it is potentially immunogenic and its effect can decrease after repetitive use. This study aimed to evaluate antral follicle dynamics, corpus luteum (CL) and ovulation rate in bos indicus cows submitted to an estrus synchronization protocol in association with eCG for eight times consecutively. Ten cyclical, multiparous, and pasture raised beef cows were divided into two groups: control group (n=5) and eCG group (n=5). In 30 day interval, all animals were synchronized with the same estrogen/progesterone based protocol, totalizing 8 re-synchronizations. Cows in the treatment group received 300IU eCG 48 hours prior to the presumable ovulation. Ultrassound examinations were performed on Day 4 of the protocol (approximately 1.5 days after follicle recruitment) to count antral follicles, on Day 10, to count antral follicles and to measure size of the largest follicle and on Day 18 to measure the diameter of the CL. No difference (P>0.05) between follicular growth and size of the pre-ovulatory follicle was reported between groups. Cows treated with eCG had a larger (P<0.05) CL and increased (P<0.05) ovulation rate (18mm and 92%, respectively) when compared with control group (14.1mm and 80%, respectively). Furthermore, consecutive treatments did not affect CL nor ovulation rates. In conclusion, eCG treatment increased CL size and ovulation rate even after 8 consecutive treatments. |
| first_indexed | 2024-12-17T07:44:20Z |
| format | Article |
| id | doaj.art-651bf16b46934874a20d6408cd764274 |
| institution | Directory Open Access Journal |
| issn | 1678-4596 |
| language | English |
| last_indexed | 2024-12-17T07:44:20Z |
| publisher | Universidade Federal de Santa Maria |
| record_format | Article |
| series | Ciência Rural |
| spelling | doaj.art-651bf16b46934874a20d6408cd7642742022-12-21T21:58:04ZengUniversidade Federal de Santa MariaCiência Rural1678-459646112018202310.1590/0103-8478cr20160091S0103-84782016001102018Consequences of eight consecutive applications of equine chorionic gonadotropin on ovarian follicle development and ovulation in bos indicus cowsBhárbara Delboni StuhrIsaac Santos GilTracy Ferreira LacerdaMauricio Gomes FavoretoBárbara LoureiroABSTRACT: The equine chorionic gonadotropin (eCG) is a glycoprotein produced in mare endometrial calices. In bovine, it is used in estrus synchronization protocols. However, studies have shown that it is potentially immunogenic and its effect can decrease after repetitive use. This study aimed to evaluate antral follicle dynamics, corpus luteum (CL) and ovulation rate in bos indicus cows submitted to an estrus synchronization protocol in association with eCG for eight times consecutively. Ten cyclical, multiparous, and pasture raised beef cows were divided into two groups: control group (n=5) and eCG group (n=5). In 30 day interval, all animals were synchronized with the same estrogen/progesterone based protocol, totalizing 8 re-synchronizations. Cows in the treatment group received 300IU eCG 48 hours prior to the presumable ovulation. Ultrassound examinations were performed on Day 4 of the protocol (approximately 1.5 days after follicle recruitment) to count antral follicles, on Day 10, to count antral follicles and to measure size of the largest follicle and on Day 18 to measure the diameter of the CL. No difference (P>0.05) between follicular growth and size of the pre-ovulatory follicle was reported between groups. Cows treated with eCG had a larger (P<0.05) CL and increased (P<0.05) ovulation rate (18mm and 92%, respectively) when compared with control group (14.1mm and 80%, respectively). Furthermore, consecutive treatments did not affect CL nor ovulation rates. In conclusion, eCG treatment increased CL size and ovulation rate even after 8 consecutive treatments.http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-84782016001102018&lng=en&tlng=encorpus luteumeCGfertilityimmunityFTAI |
| spellingShingle | Bhárbara Delboni Stuhr Isaac Santos Gil Tracy Ferreira Lacerda Mauricio Gomes Favoreto Bárbara Loureiro Consequences of eight consecutive applications of equine chorionic gonadotropin on ovarian follicle development and ovulation in bos indicus cows Ciência Rural corpus luteum eCG fertility immunity FTAI |
| title | Consequences of eight consecutive applications of equine chorionic gonadotropin on ovarian follicle development and ovulation in bos indicus cows |
| title_full | Consequences of eight consecutive applications of equine chorionic gonadotropin on ovarian follicle development and ovulation in bos indicus cows |
| title_fullStr | Consequences of eight consecutive applications of equine chorionic gonadotropin on ovarian follicle development and ovulation in bos indicus cows |
| title_full_unstemmed | Consequences of eight consecutive applications of equine chorionic gonadotropin on ovarian follicle development and ovulation in bos indicus cows |
| title_short | Consequences of eight consecutive applications of equine chorionic gonadotropin on ovarian follicle development and ovulation in bos indicus cows |
| title_sort | consequences of eight consecutive applications of equine chorionic gonadotropin on ovarian follicle development and ovulation in bos indicus cows |
| topic | corpus luteum eCG fertility immunity FTAI |
| url | http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-84782016001102018&lng=en&tlng=en |
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