You can pull sponges between 8 and 12 days if the ewes are already cycling ( after september to october depending on breed). If you've say 20 ewes & 1 tup, pull 10 on day 8 & put with tup then pull the rest on day 10 & add to the first group. Lambing will be over in a week. I've got clients who lamb their flocks in batches of 150 this way..... But make sure you will have enough pens & man power. Most of my small hobby flocks also do this & just take a few days off work.