CIDR 1.38g Vaginal Delivery System for Cattle Uses For the control of the oestrous cycle in cycling cows and heifers, including: - Synchronisation of oestrus in groups of animals. - Synchronisation of donor and recipient animals for embryo transfer. To be used in combination with prostaglandin F2α or analogue. Use as recommended normally results in oestrus 48-96 hours after device removal with the majority of animals showing oestrus within 48-72 hours.