CIDR Sheep and Goat The Zoetis (formerly Pfizer) CIDR Sheep and Goat Device treatment programs represent a convenient and effective method for both synchronising and inducing oestrus in production animals. Using only naturally occurring progesterone, these unique treatment programs take control of the oestrous cycle by mimicking normal physiological events.CIDR Sheep and Goat Devices contain the natural hormone progesterone. Intravaginally placed CIDRs release progesterone at a controlled rate into the blood stream.Progesterone is given to sheep or goats as an implant. One form available is the CIDR sheep/goat insert, which achieves synchrony by lengthening the oestrus cycle while it remains implanted. It releases progesterone, which is the same as the natural hormone produced by the corpeus luteum on the ovary between Day 7?17 of the normal cycle.The CIDR (pronounced ‘cedar’) sheep/goat insert is a Controlled Internal Drug Release device, which when inserted into the vagina of the ewe or nanny, delivers progesterone at a controlled rate into the animal’s bloodstream.An applicator is needed to use the CIDR and is purchased separately.The CIDR sheep/goat insert consists of a plastic core coated with silicon that contains progesterone. The progesterone is absorbed through the vaginal wall and the implant acts as a substitute corpeus luteum. Other hormones may be administered at the time of insertion or on its removal to increase conception rate and oestrus response.When the implant is removed the progesterone level in the bloodstream drops quickly. This results in another egg developing and normal signs of oestrus behaviour are shown.The progesterone implants have the advantage over prostaglandins in that they will not cause abortions if they are used on pregnant animals (in fact they may have the opposite effect and may be able to help sustain some early pregnancies) and are also still effective if used on sheep or goats that have just been in season. Progesterone treatment can be used to stimulate the hormonal system of sheep or goats that are not cycling (anoestrus).The benefits of using the CIDR sheep/goat insert include:AI programs can be completed in only a few daysbetter use of labour resources by spending less time on heat detectionmore accurate oestrus detectionfewer non-pregnant animals at the end of the breeding periodimproved rates of genetic gain through better use of AI and ETenhanced fertility in embryo transfer recipient.