Anti-Mullerian Hormone and Follicle Counts as Predictors of Superovulatory Response and Embryo Production in Beef Cattle
Since the development of cattle
superovulation and non-surgical embryo recovery in the 1970s, the
unpredictability and variability of the superovulatory response has remained a
major obstacle.
Anti-Mullerian
hormone (AMH) is a glycoprotein that is expressed in granulosa cells of growing
follicles. It has been
classified as a good predictive marker of the ovarian response to follicular
stimulation for oocyte retrieval and in
vitro embryo production, as well as an endocrine marker that could help
predict superovulatory responses of cows.
This study
evaluated Anti-Mullerian hormone (AMH) and/or follicle counts as predictors of
subsequent superovulatory response and embryo production in 79 beef cows.
Before superovulation, 3 to 5 mm follicles presented on the ovaries of donor
cows were counted, and blood was collected for measure of serum AMH.
Across cows, serum
AMH ranged from 0.013 to 0.898 ng/mL, with a mean of 0.293 ng/mL. The
distribution of both AMH concentrations and follicle counts were divided into
quartiles (AMH Q1 through Q4, with Q1 the lowest and Q4 the highest) for
analysis. Donor cows in AMH Q4 had a greater (P < 0.001) number of 3 to 5 mm
follicles at the start of superovulation than did donors in either Q1 or Q2. At
embryo collection, cows in AMH Q3 and 4 had more (P < 0.001) palpable
corpora lutea (CL) than cows in AMH Q1. The mean number of embryos recovered
from donor cows in AMH Q4 was greater (P < 0.001) than those recovered from
cows in either AMH Q1 or Q2, but similar to that of AMH Q3. Analysis indicated
that AMH was positively correlated (P < 0.001) with mean follicles (r =
0.458), CL (r = 0.452) and embryos recovered (r = 0.430). Donor cows with
higher follicle counts (F Q3 and 4) at the start of superovulation had more (P
< 0.001) palpable CL at embryo collection than donor cows in F Q1 or 2. More
(P < 0.001) embryos were recovered from cows with the highest follicle
counts (F Q4) as compared with cows having lower (F Q1 and 2) follicle counts.
Results confirm
that relative AMH concentration was positively correlated with number of small
antral follicles in the ovaries of cows; both AMH measure and antral follicle
counts might be used to predict subsequent superovulatory response in beef
cows.
Article by Keith Center, et al, from USA.
Full access: http://mrw.so/2ocqnI
Image by Alister Anderson, from
Flickr-cc.
评论
发表评论