In case it's helpful, here's a summary I wrote elsewhere of our experience sponging for the first time:
It’s approaching the time of year to make plans for tupping and a question that has come up in some posts is about sponging. What is it, why do it, and how to go about it?
So prompted by a comment earlier today I thought I would share our experiences from last year. This is by no means the only stuff worth knowing, but hopefully it is useful and others with more practice can add to these points.
Chronogest (
http://www.noahcompendium.co.uk/?id=-454454) are a hormone-soaked sponge roughly the size and shape of a marshmallow (but definitely don’t try eating one!), with some strings attached a bit like a tampon. They are used to synchronise ovulation in sheep and therefore give more predictable lambing dates, generally over a shorter period. This can be extremely useful to us smallholders as the alternative – a lambing spread over many weeks – can be difficult to manage.
They are inserted vaginally using a plastic tube applicator and left in place for two weeks. Once removed the ewe will come into season in around 48 hours. We found the applicator had some rough bits from the moulding process so I used some fine sandpaper to file these off to avoid any unintended injuries to the ewes. Loading the sponges into the applicator involves compressing them and popping them in one end and then using a plunger to push them to the opening at the other end. Keep your finger over the end when doing this otherwise they have an awkward habit of just whizzing out before you know it. Amusing once perhaps but annoying when the tenth one flies out onto the grass in front of you.
When putting them in it is critical to use lots of lubricant and proceed slowly. Using your finger to feel the angle the ewe’s vagina takes from the vulva can help you with positioning the applicator and stops you pushing it against the wall of the vagina. If I recall correctly it was slightly upwards rather than parallel to the spine. A rotating motion on the applicator also seemed to help it go in more easily.
In between ewes it makes sense to rinse the applicator and your hands in a bucket of hot water and appropriate cleaner to reduce the risk of infection. As it is likely to be a cold day this can also be a welcome relief for your fingers.
When it comes to removal day then you simply locate the strings and pull slowly and firmly and the sponge will pop out. Beware of splashback – it will not smell pleasant and the sponges will have absorbed quite a bit of fluid! I have seen others say you have to be really careful about dogs as they apparently love them and having them removed from their stomachs is not an inexpensive exercise.
We attempted to sponge 13 Hebrideans last year – a mixture of 1 and 2 crop ewes and seven shearlings. There wasn’t a noticeable difference in difficulty putting them in or removing them. When it came to the sponging days one shearling resolutely refused to be penned, so we only sponged 12. By the time of removal we found one, the first we’d put in, had fallen out along the way – probably as it hadn’t gone far enough in. In the rest we staggered removal by doing four per day. This meant that by day three, when the first four should have been coming into season we could put the whole group in with the tup knowing that he could start with those four and then another four would come into season the next day and the day after that.
This is important because the tup has to work harder to cover more ewes per day than he would do in a traditional system. A common tup:ewe ratio used there is 1:50, but as the ewe’s cycles are 17 days this means he only has to cover 3 per day on average. When sponging the maximum ratio is 1:8 or 1:10. Perhaps even lower if the ewes and/or tup are not experienced. As it turned out for us 12/13 were pregnant in the first cycle and just one ran over to the second. But as this was a sponged ewe as soon as we’d passed the due dates for a first cycle pregnancy we knew she would be second cycle and what date that should mean. This allowed us to plan company in the lambing shed for her and to reduce the days we needed to continue doing night time checks.
Sponging meant that each of us could book two weeks off work – both there in week 1 and then one each in weeks 2 and 3 – and cover the whole likely lambing period, even allowing for some second cycle ewes. With both of us around in the first week we could manage the busy days where the majority of the flock would be delivering. Eight lambed within three days and ten within 5 days – just the one that refused to be penned, the one whose sponge fell out and the second-cycle ewe did not lamb in that short window.
The sponges come in packs of 25 but our vet was willing to sell them to us individually. They were roughly £3 + VAT each and the applicator was a one-off £10 expense. The only other stuff we needed was gloves and lubricant – which we all have anyway.
So if you want, or need, a more predictable and time-limited lambing then sponging is definitely the way to go.