I know this is an old thread, but I wanted to update it with our experience from this year:
Firstly I didn't use an applicator this year, as I've always found it a bit of a faff. Instead, I just wore surgical gloves and poked the sponges up as far as my index finger would reach. Despite the nagging feeling that this was a little more intimate than I was really comfortable with when it comes to sheep, it was considerably quicker, worked absolutely fine and I think was less likely to hurt the sheep. I'll definitely be doing it that way from now on.
Regarding timings, this is the official advice from the leaflet:
"Oestrus usually occurs 36 to 72 hours after sponge withdrawal, but occasionally may be evident as early as 24 hours after removal. However, rams must not be introduced earlier than 48 hours following sponge removal. Otherwise they will repeatedly serve the same ewes, depleting their semen reserves prior to the main group coming into season."
However, following advice from a farmer friend, we introduced the tup earlier this year and watched to see what happened. This is for a flock of twelve ewes running with a mature and experienced tup:
Four stood for him and were served at 30 hours. I then separated them and went to bed.
Five more were served at 37 hours.
We then raddled the tup and left them to it. The remaining three were served at 42, 44 and 48 hours respectively. He also didn't re-cover any of the ones served at 30 hours, which suggests he either knew he'd already been there, or they were already off heat(?).
What I don't know is what would have happened if we'd left it until 48 hours to introduce him. Would the early girls still have been interested, or would we have missed them? Any thoughts folks?