[Womble]

We've been using Chronogest sponges with our sheep for a few years now, in an attempt to synchronise their ovulation and hence lead to a smaller spread of lambing dates. These are literally marshmallow-sized sponges with a string attached, which you insert into the sheep's vagina (am I even typing these words? what would my Mother think?). Then after two weeks, you pull on the string to remove the sponge, and ovulation happens about 36-48 hours later.


Apart from one year when they didn't seem to work very well, this has been a great success, with us usually managing to lamb within a 3 day period, perhaps with some returners during another 3 day period a couple of weeks later.  (It's worth saying that because we're tupping in the autumn and lambing at Easter, we don't inject with "PMSG", because the ewes should be ovulating anyway - we're just messing about with the timing of that).


Anyway, we used CIDRs for the first time this year. They're an alternative to sponges, and look like small Y-shaped tampons:





You fold up the Y-shaped bits to get the CIDR into an applicator. Then put the applicator in and push a plunger which releases the CIDR. At this point it becomes a Y again, with the arms helping to hold the CIDR in place.

The CIDR is then removed after 12 days [Note, not 14 as with sponges], by pulling on the plastic tab which sticks out of the sheep's back end.


Some thoughts:

• The CIDRs were easier to load into the applicator than sponges, and the applicator was easier to insert and use with the sheep.
• Removal was also easier than with sponges and seemed to bother the ewes less.
• There was no gush of fluid on removal like you get with a sponge, so maybe this is healthier for the ewe?
• The instructions say that 1 in 10 CIDRs may be lost by the sheep. We only have 13 ewes, so not a big enough sample size to tell, but all worked fine.
• We put the tup in 22 hours after CIDR removal. Five out of the 13 ewes were immediately receptive, with the rest all being covered by the tup within 36 hours. We're taking a risk this year and only leaving the tup in for one cycle, so we now know that lambing will all be done and dusted over a long weekend next year (this is important when we both work full time).
• Note that CIDRs have slightly different timings to sponges - they're in for 12 days, then tups go in the next day.
• CIDRs are a bit more expensive at around £3.75 each, compared with sponges at around £3.00 each.

Overall, we'd use either product again, but the CIDRs definitely win out on ease of use.

Hope that's helpful. If you have any experience of either product, do please add to the discussion below 

[Rosemary]

Great post, [member=2128]Womble[/member]   

[SallyintNorth]

Really interesting [member=2128]Womble[/member], thanks for taking the time to write that up. 

Please update in April when you know the final results! 

[Anke]

Yes I have been using CIDR's now for three years with my goats - both for AI and for natural (but planned) matings. The only problem I have encountered is that the goats (or their pen mates more likely) manage to pull the CIDR's out, and you find them lying in the straw (good to know that a) they are not inside the goat and b) they have not ben eaten...).


I can definitely recommend them for planned breeding.

[Womble]

The only problem I have encountered is that the goats (or their pen mates more likely) manage to pull the CIDR's out

Yes, I can see how that might happen, particularly with goats. If you had one animal who made a hobby out of CIDR pulling, you'd be in big trouble. I read a forum post where somebody said they snip off the wee ball on the end of the pull chord for that reason, [member=3211]Anke[/member] - so maybe that's something you could try? I don't think sponges would be vulnerable in that respect, but they can still fail in other ways (e.g. string pulls through, sponge falls out, string and sponge gets stuck inside).

Please update in April when you know the final results!

Will do. But since we had an experienced tup who wasn't paying any attention to ewes not cycling, if it does go wrong now, it won't have been the CIDRs fault anyway, hence why I decided not to wait until Easter to report back.

[SallyintNorth]

Will do. But since we had an experienced tup who wasn't paying any attention to ewes not cycling, if it does go wrong now, it won't have been the CIDRs fault anyway, hence why I decided not to wait until Easter to report back.

I know what you are saying, but as a biologist, I'd say the device and the hormones can potentially have a huge effect on ovulation, fertilisation, implantation - and every stage beyond.  So I'd still be interested in the end results  

[Anke]

I know what you are saying, but as a biologist, I'd say the device and the hormones can potentially have a huge effect on ovulation, fertilisation, implantation - and every stage beyond.  So I'd still be interested in the end results

I have not experienced any unusual results, especially not if you only use CIDR's and then mate naturally, but even with using PMSG for AI I only once had quads, twins still the usual outcome. The laprascopic AI pre-procedure schedule did change this year, and now involves Estrumate as well as PMSG, so we will see if that changes things. Mine will be scanned next week, another goatkeeper has just scanned and out of three AI-ed, one did not take (very old semen) and two are in kid with twins. She also used the same schedule for a natural mating and the goats are scanned for triplets, again totally normal for Anglo Nubians.


The only advice I would give to anyone planning on mating their sheep over a weekend - scan (if possible), pen them up individually in good time - as in a few days before and be there 24/7 - mis-mothering is a serious problem in that situation - I have been there...

[Womble]

Patience, Sally! I'll let you know in about 145 days time! 

Honestly, I don't think a sample size of 13 is enough to judge much on anyway, but in seven years of using sponges, we've not had any issues, and the CIDRs are very similar to the sponges in the way they work (though I think the active ingredient may be slightly different because it's progestorone, rather than flugestone acetate).

We are aware that we're messing with nature here, and everybody needs to weigh that up for themselves. In our case we both work full time and my new job involves a lot of travelling. This means that knowing that lambing will be done within a few days is worth a great deal to us, and even the risk of some 'empties' that would otherwise have caught second cycle (that's the big risk here - if the boy wasn't working, we won't find out until scanning).

That's an interesting point about mis-mothering, but we lamb outdoors if the weather is ok and I have to say we haven't ever seen it except in one case where a first timer rejected one of her lambs and it decided to go and take its chances with Grandma. In that case Granny had scanned with a single and had a water bag hanging out of her bum, so we just let them get on with it! 

That's a good point actually - another big advantage for smallholders is that having the whole flock lambing at once allows more opportunity for "twinning on" triplets or rejected lambs onto ewes which have had singles. If we've scanned in advance and know who to twin onto, we do a "wet twinning" during the birth of the ewe's own lamb, which has a high success rate. In the days before we sponged and scanned, we rarely managed to do this because there were only 1 or 2 lambing on any given day.

[Anke]

That's an interesting point about mis-mothering, but we lamb outdoors if the weather is ok and I have to say we haven't ever seen it except in one case where a first timer rejected one of her lambs and it decided to go and take its chances with Grandma. In that case Granny had scanned with a single and had a water bag hanging out of her bum, so we just let them get on with it! 

Well they are only so many "favoured" spots in my field where my Shetlands like to lamb, if they all start at once, there will be mismothering going on, unless you are there to sort it straight away. That is my experience, and one of the reasons why I stopped using sponges/CIDR's in the sheep, even though I really appreciated a short lambing season. Especially if all the lambs look the same...

[Womble]

[member=3211]Anke[/member] - there might be another consideration here with Shetlands.  When we had the Manx Loaghtans, we didn't go anywhere near them when lambing...... they were so wild, we couldn't even if we wanted to!     Equally they never actually needed help.


We used to catch the lambs when new born to iodine their navels, and then prayed we'd be able to catch them again in time for their first heptavac. Most of them even got a second dose a month later but I will confess, not all . So if I still had Manxs, I don't think I'd be sponging anyway - I'd just buy a good pair of binoculars and let them get on with it over whatever time period they fancied!