CIDR OVIS is a new product on the market aimed at fertility control in sheep. Roland Millar talks us through the benefits…

Synchronising ewes for a tighter lambing period or to allow sheep to lamb early in the season can have many benefits. A short lambing period will reduce labour costs and allow for better control and management of routine procedures such as vaccinating, worming and selecting lambs for the market or slaughter. Lambing earlier in the year and achieving good growth rates in lambs will allow more lambs to be sold in the early spring market when prices are higher than later in the summer. This, however, will require a higher level of feeding late in the winter and more housing space in the case of adverse weather which is likely if lambing is early. The products used to synchronise ewes in this way are regularly used in the pedigree world for AI and ET work but can also have major cost benefits for the commercial farm.

What is CIDR OVIS?

CIDR OVIS is a progesterone containing device placed vaginally in the ewe and can be used to induce and synchronise oestrus in both cycling and non-cycling ewes. The device is easily inserted using a specific applicator and left in place for 12 days with an injection of eCG when removed. Up to 96.5% of animals treated using this protocol will come into oestrus with most ewes showing signs of heat 1 – 2 days after removal of the device. The breeding season can be brought forward by about 4 to 6 weeks using progesterone implants. Other programmes using melatonin implants can advance the breeding season by a maximum of two months.

CIDR OVIS Fertility Control for Sheep

Following synchronisation of ewes, rams should only be introduced at a ratio of 1:10 after removal of the CIDR OVIS. Rams should then be re-introduced at 16 days after removal of the device to mate ewes that have not held to the synchronised heat. Only mature rams that have had a full breeding soundness exam should be used and they should be in a body condition score of 3.5 – 4. This needs to be checked at least two months before the mating period and ensuring rams are disease free so as to allow for adequate sperm production and maturation. Ewes should be in body condition score 2.5 – 3 and on a rising plane of nutrition for the three weeks before introduction of rams.