Systemic and local anti-Mullerian hormone reflects differences in the reproduction potential of Zebu and European type cattle

• AMH values measured and compared in two cattle subspecies, Zebu and European type, as well as crossbred animals.
• Plasma, follicular concentration and granulosa mRNA transcript levels of AMH checked for correlation with reproductive parameters: antral follicle count, ovarian diameter, number of oocytes, cleavage and blastocyst rate.
• Values of AMH greater in Zebu compared to European type cattle and correlated to AFC and oocyte number.
• Where investigated, the crossbred animals were more similar to their maternal Zebu counterparts.
• Granulosa AMHR2 RNA levels significantly different between high and low oocyte producing ovaries in European type cattle.

This study was conducted to evaluate plasma anti-Mullerian hormone (Pl AMH), follicular fluid AMH (FF AMH) and granulosa cell AMH transcript (GC AMH) levels and their relationships with reproductive parameters in two cattle subspecies, Bos taurus indicus (Zebu), and Bos taurus taurus (European type cattle). Two-dimensional ultrasound examination and serum collection were performed on Zebu, European type and crossbreed cows to determine antral follicle count (AFC), ovary diameter (OD) and Pl AMH concentration. Slaughterhouse ovaries for Zebu and European type cattle were collected to determine FF AMH concentrations, GC AMH RNA levels, AFC, oocyte number, cleavage and blastocyst rate. Additionally GC AMH receptor 2 (AMHR2) RNA level was measured for European type cattle. Relationship between AMH and reproductive parameters was found to be significantly greater in Zebu compared to European cattle. Average Pl AMH mean ± SE for Zebu and European cattle was 0.77 ± 0.09 and 0.33 ± 0.24 ng/ml respectively (p = 0.01), whereas average antral FF AMH mean ± SE for Zebu and European cattle was 4934.3 ± 568.5 and 2977.9 ± 214.1 ng/ml respectively (p < 0.05). This is the first published report of FF and GC AMH in Zebu cattle. Levels of GC AMHR2 RNA in European cattle were correlated to oocyte number (p = 0.01). Crossbred animals were found more similar to their maternal Zebu counterparts with respect to their Pl AMH to AFC and OD relationships. These results demonstrate that AMH reflects differences between reproduction potential of the two cattle subspecies therefore can potentially be used as a reproductive marker. Furthermore these results reinforce the importance of separately considering the genetic backgrounds of animals when collecting or interpreting bovine AMH data for reproductive performance.