No matter what, there is almost always a group of cows that don’t conceive on the first attempt. They are inseminated, but within a month or two, they have either required another insemination or unexpectedly turn up open. What is going on?

Reproductive management is a game of averages. Different strategies for getting pregnancy established in dairy cows encompass a range of targets for timing artificial insemination (A.I.). Some are precise, aiming for the ideal timing. Others are broader and simply aim for an acceptable average. Most approaches result in pregnancies, but in some cases there remains opportunity for improvement and economical gain.

Reproduction is a fascinating story. The story begins with the supply of oocytes that are present from before birth on both ovaries.

Open cows that aren't cycling normally can hamper successful reproduction. This article, the first in a series on cyclicity, defines the terms “anovulation” and “anestrus.”