Effect of ovulatory follicle size on bovine pregnancy associated glycoproteins in beef cattle
No Thumbnail Available
Authors
Meeting name
Sponsors
Date
Journal Title
Format
Thesis
Subject
Abstract
The GnRH-induced ovulation of small dominant follicles was associated with reduced pregnancy rates and late embryonic/fetal survival around the time of embryo-uterine attachment. PAGs are secreted by binucleated trophoblast cells into the maternal circulation and have been used to monitor placental function and embryo/fetal mortality. The overall objective was to examine the relationship between ovulatory follicle size and circulating concentrations of bPAG. Postpartum cows were treated with the CO-Synch protocol and timed artificial insemination and classified into one of four groups based on the size of the follicle induced to ovulate at GnRH-2. There was an effect of treatment on pregnancy rates at d 30 post insemination with pregnancy rate being higher following GnRH-induced ovulation of 14 to 15 mm compared to 12 to 13 mm follicles. The first increase in bPAG occurred on d 24. There was an effect of day on bPAG but no effect of ovulatory follicle size or ovulatory follicle size by day interaction from d 20 to 60. Furthermore, there was an effect of month on bPAG but no effect of treatment or treatment by month interaction from 3 months of gestation to calving. In summary, there was no effect of ovulatory follicle size on serum concentrations of bPAG in pregnant cows.
Table of Contents
DOI
PubMed ID
Degree
M.S.
Thesis Department
Rights
OpenAccess.
License
This work is licensed under a Creative Commons Attribution-NonCommercial-NoDerivs 3.0 License.