The sale prices are highest in the fall so we target 8+ month old lambs for the late fall; we also want to use the lambs in our annual sheepdog trial on our farm at the end of Sept. This means we breed all the ewes in the fall right after our trial. We typically leave the rams in for 6 weeks which means our lambs are born within 6 weeks after 5 months gestation.
We have a breed of sheep that are very good mothers and rarely need help to deliver. I check in the morning when I get up for work (between 4am-5am), my wife checks throughout the day, and one of us checks before bed. Over 90% of the lambs will need no special attention. We record births (and losses) by ewe ID and then ear tag lambs in groups recoding the lamb ID with the ewe ID. We record lambing issues so that we can cull ewes that are not productive enough, have milk production issues, or not good mothers (can only count to 2 when they have 3).
We want ewes that deliver 2 large lambs on their own, raise those lambs without any help on hay & some grain in the winter and grass (when it's growing), and lambs that require little deworming. So we select for those genetics in our ewes and cull ewes that don't meet these requirements. As our flock gets closer to these ideals we have less work during lambing time.