Effective embryo production from Holstein cows treated with gonadotropin-releasing hormone during early lactation.

The low efficiency of embryo production in Holstein cows during early lactation presents many challenges for animal production. To improve its efficiency, the outcomes of single GnRH injections 48 hours before each of three cycles of ovum pick up (OPU; weeks 2, 4, and 6) were compared with three cycles of unstimulated OPU (controls; weeks 1, 3, and 5) in 35 Holstein cows during 6 weeks of early lactation (40-80 days postpartum). More total follicle numbers (19.