Effects of gonadotropin-releasing hormone administration or a controlled internal drug-releasing insert after timed artificial insemination on pregnancy rates of dairy cows
Journal of Veterinary Science
; : 577-582, 2016.
Article
in En
| WPRIM
| ID: wpr-167759
Responsible library:
WPRO
ABSTRACT
This study investigated the effects of gonadotrophin-releasing hormone (GnRH) administration (Experiment 1) and a controlled internal drug-releasing (CIDR) insert (Experiment 2) after timed artificial insemination (TAI) on the pregnancy rates of dairy cows. In Experiment 1, 569 dairy cows that underwent TAI (day 0) following short-term synchronization with prostaglandin F(2α) were randomly allocated into two groups: no further treatment (control, n = 307) or injection of 100 µg of gonadorelin on day 5 (GnRH, n = 262). In Experiment 2, 279 dairy cows that underwent TAI (day 0) following Ovsynch were randomly allocated into two groups: no further treatment (control, n = 140) or CIDR insert treatment from days 3.5 to 18 (CIDR, n = 139). The probability of pregnancy following TAI did not differ between the GnRH (34.4%) and control (31.6%, p > 0.05) groups. However, the probability of pregnancy following TAI was higher (odds ratio: 1.74, p < 0.05) in the CIDR group (51.1%) than in the control group (39.3%). Overall, CIDR insert treatment at days 3.5 to 18 increased pregnancy rates relative to non-treated controls, whereas a single GnRH administration on day 5 did not affect the pregnancy outcomes of dairy cows.
Key words
Full text:
1
Index:
WPRIM
Main subject:
Pregnancy Outcome
/
Insemination, Artificial
/
Gonadotropin-Releasing Hormone
/
Pregnancy Rate
Limits:
Pregnancy
Language:
En
Journal:
Journal of Veterinary Science
Year:
2016
Type:
Article