Impact of gonadotropin-releasing hormone administration at the time of artificial insemination on conception risk and its association with estrous expression
ABSTRACT: Cows with reduced estrous expression have compromised fertility. The aim of this study was to determine whether the administration of GnRH at the time of artificial insemination (AI) would affect ovulation rates and the fertility of animals expressing estrous behavior of lesser intensity....
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| Format: | Article |
| Language: | English |
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Elsevier
2022-02-01
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| Series: | Journal of Dairy Science |
| Subjects: | |
| Online Access: | http://www.sciencedirect.com/science/article/pii/S0022030221010286 |
| _version_ | 1811228414857707520 |
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| author | Tracy A. Burnett Augusto M.L. Madureira Janet W. Bauer Ronaldo L.A. Cerri |
| author_facet | Tracy A. Burnett Augusto M.L. Madureira Janet W. Bauer Ronaldo L.A. Cerri |
| author_sort | Tracy A. Burnett |
| collection | DOAJ |
| description | ABSTRACT: Cows with reduced estrous expression have compromised fertility. The aim of this study was to determine whether the administration of GnRH at the time of artificial insemination (AI) would affect ovulation rates and the fertility of animals expressing estrous behavior of lesser intensity. Cows were enrolled at the time of estrus from 3 farms (n = 2,607 estrus events; farm A: 1,507, farm B: 429, farm C: 671) and randomly assigned to receive GnRH at AI or not (control). The intensity of estrous expression, monitored through leg-mounted activity monitors, was determined using the maximum activity during estrus; estrous expression was categorized as greater or lower relative to the farm median. On farm A, cows were assessed at alert, and 24 h, 48 h, and 7 d post-alert for ovulation using ultrasonography. Pregnancy per AI was confirmed at 35 ± 7 d post-estrus for cows that were inseminated. Differences between treatments were tested using the GLIMMIX procedure of SAS. Treatment with GnRH at the time of AI increased pregnancy per AI (41.3 ± 1.6 vs. 35.7 ± 1.7%). An interaction between treatment and estrous expression on pregnancy per AI was found. Control cows with greater estrous expression had greater pregnancy per AI than those with lesser expression, whereas GnRH administration increased pregnancy per AI for cows with lesser estrous expression but not those with greater expression (GnRH, greater intensity: 43.5 ± 2.1; GnRH, lesser intensity: 37.8 ± 2.2; control, greater intensity: 42.6 ± 2.2; control, lesser intensity: 31.0 ± 2.2%). A higher proportion of cows with greater estrous expression that were administered GnRH at AI were found to ovulate by 48 h and 7 d post-estrus; however, ovulation of cows with lesser estrous expression was unaffected by GnRH administration. In conclusion, fertility of cows with reduced estrous expression may be increased using GnRH at the time of AI; however, increased ovulation rates do not seem to be the direct mechanism behind this relationship. |
| first_indexed | 2024-04-12T09:57:36Z |
| format | Article |
| id | doaj.art-74d3fed0e8e24aadbc9b59231e787f6d |
| institution | Directory Open Access Journal |
| issn | 0022-0302 |
| language | English |
| last_indexed | 2024-04-12T09:57:36Z |
| publishDate | 2022-02-01 |
| publisher | Elsevier |
| record_format | Article |
| series | Journal of Dairy Science |
| spelling | doaj.art-74d3fed0e8e24aadbc9b59231e787f6d2022-12-22T03:37:38ZengElsevierJournal of Dairy Science0022-03022022-02-01105217431753Impact of gonadotropin-releasing hormone administration at the time of artificial insemination on conception risk and its association with estrous expressionTracy A. Burnett0Augusto M.L. Madureira1Janet W. Bauer2Ronaldo L.A. Cerri3Faculty of Land and Food Systems, University of British Columbia, Vancouver V6T 1Z4, CanadaFaculty of Land and Food Systems, University of British Columbia, Vancouver V6T 1Z4, CanadaFaculty of Land and Food Systems, University of British Columbia, Vancouver V6T 1Z4, CanadaCorresponding author; Faculty of Land and Food Systems, University of British Columbia, Vancouver V6T 1Z4, CanadaABSTRACT: Cows with reduced estrous expression have compromised fertility. The aim of this study was to determine whether the administration of GnRH at the time of artificial insemination (AI) would affect ovulation rates and the fertility of animals expressing estrous behavior of lesser intensity. Cows were enrolled at the time of estrus from 3 farms (n = 2,607 estrus events; farm A: 1,507, farm B: 429, farm C: 671) and randomly assigned to receive GnRH at AI or not (control). The intensity of estrous expression, monitored through leg-mounted activity monitors, was determined using the maximum activity during estrus; estrous expression was categorized as greater or lower relative to the farm median. On farm A, cows were assessed at alert, and 24 h, 48 h, and 7 d post-alert for ovulation using ultrasonography. Pregnancy per AI was confirmed at 35 ± 7 d post-estrus for cows that were inseminated. Differences between treatments were tested using the GLIMMIX procedure of SAS. Treatment with GnRH at the time of AI increased pregnancy per AI (41.3 ± 1.6 vs. 35.7 ± 1.7%). An interaction between treatment and estrous expression on pregnancy per AI was found. Control cows with greater estrous expression had greater pregnancy per AI than those with lesser expression, whereas GnRH administration increased pregnancy per AI for cows with lesser estrous expression but not those with greater expression (GnRH, greater intensity: 43.5 ± 2.1; GnRH, lesser intensity: 37.8 ± 2.2; control, greater intensity: 42.6 ± 2.2; control, lesser intensity: 31.0 ± 2.2%). A higher proportion of cows with greater estrous expression that were administered GnRH at AI were found to ovulate by 48 h and 7 d post-estrus; however, ovulation of cows with lesser estrous expression was unaffected by GnRH administration. In conclusion, fertility of cows with reduced estrous expression may be increased using GnRH at the time of AI; however, increased ovulation rates do not seem to be the direct mechanism behind this relationship.http://www.sciencedirect.com/science/article/pii/S0022030221010286estrous expressionfertilitygonadotropin-releasing hormone |
| spellingShingle | Tracy A. Burnett Augusto M.L. Madureira Janet W. Bauer Ronaldo L.A. Cerri Impact of gonadotropin-releasing hormone administration at the time of artificial insemination on conception risk and its association with estrous expression Journal of Dairy Science estrous expression fertility gonadotropin-releasing hormone |
| title | Impact of gonadotropin-releasing hormone administration at the time of artificial insemination on conception risk and its association with estrous expression |
| title_full | Impact of gonadotropin-releasing hormone administration at the time of artificial insemination on conception risk and its association with estrous expression |
| title_fullStr | Impact of gonadotropin-releasing hormone administration at the time of artificial insemination on conception risk and its association with estrous expression |
| title_full_unstemmed | Impact of gonadotropin-releasing hormone administration at the time of artificial insemination on conception risk and its association with estrous expression |
| title_short | Impact of gonadotropin-releasing hormone administration at the time of artificial insemination on conception risk and its association with estrous expression |
| title_sort | impact of gonadotropin releasing hormone administration at the time of artificial insemination on conception risk and its association with estrous expression |
| topic | estrous expression fertility gonadotropin-releasing hormone |
| url | http://www.sciencedirect.com/science/article/pii/S0022030221010286 |
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