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Abstract
One-hundred and five virgin Holstein heifers were sampled pre-breeding for circulating AMH concentration and transrectal ultrasonography was performed to determine AFC and cyclicity status. Post-calving, heifers were sampled at 5-20 days in milk for AMH. At 45-60 days in milk, two-hundred and fifty-two primiparous and multiparous were enrolled and all animals were sampled for AMH concentration and transrectal ultrasonography was performed. Animals were assigned to an estrous detection or TAI breeding protocol and grouped based on pre-breeding circulating AMH. AMH was positively correlated with AFC, lactation number, age and milk-weight on sampling and breeding day (P<0.0001). Conception risk to first service in cows and heifers was not impacted by breeding protocol or AMH category (P>0.05). Older, greater lactation animals were more likely to cycle and be bred on an estrous detection protocol (P<0.01). Heifers maintained their AMH categorization post-calving and pre-breeding but dropped in AMH post-calving (P<0.0001).