Plasma anti-Mullerian hormone concentration as a predictive endocrine marker for selection of donor lambs to improve success in juvenile in vitro embryo transfer programs

The use of juvenile in vitro embryo transfer (JIVET) is limited by variation between prepubertal lambs in ovarian response to exogenous gonadotrophins. In cattle, anti-Mullerian hormone (AMH) is a predictive endocrine marker of antral follicle count. In this study we measured plasma AMH concentrations in lambs at 3 and 5 weeks of age and determined associations between AMH concentrations and ovarian response to gonadotrophins and in vitro blastocyst production at 6-8 weeks of age in a JIVET program. At 5 weeks, AMH (n = 38) was positively correlated with surface antral follicle count (r = 0.87, P < 0.001), blastocysts produced (r = 0.92, P < 0.001) and blastocysts produced as a proportion of oocytes collected (r = 0.44, P < 0.01) or cleaved (r = 0.43, P < 0.01). Similar associations were observed between AMH at 3 weeks (n = 30) and follicle number (r = 0.70, P < 0.05) and blastocysts produced (r = 0.87, P < 0.05). Lambs with high (>2.2 ng mL(-1)) compared with medium (0.4-2.2 ng mL(-1)) and low (<0.4 ng mL(-1)) AMH at 5 weeks had more antral follicles (mean (+/- s.e.m.) 118.7 +/- 13.9 vs 68.2 +/- 8.1 and 30.4 +/- 12.3 respectively; P < 0.05) and more blastocysts produced (mean (+/- s.e.m.) 54.9 +/- 6.9 vs 18.9 +/- 4.0 and 7.5 +/- 6.1 respectively; P < 0.05). These results suggest that AMH concentration at 5 weeks of age can be used to select donor lambs which enhance the success of JIVET programs.