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.

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Image by Alister Anderson, from Flickr-cc.