Iodine for mating
/The trace element status of ewes pretup affects:
Ovulation rate
Implantation and survival of embryos
Health of the newborn lamb.
Iodine is an essential trace element required to make the thyroid hormones which control the metabolism and temperature of the ewe and is required for bone, brain and wool development of foetuses. A very iodine deficient ewe may abort in late gestation or at full term, while a live lamb deficient in iodine frequently will have an enlarged thyroid gland, and may be born small or weak and have little or no wool. These lambs are very susceptible to starvation/exposure. Farms that benefit from iodine supplementation frequently report similar scanning rates but improved lamb survivability.
Iodine deficiency may be a primary deficiency where the diet lacks iodine (eg some pastures and most winter root crops), or more commonly in NZ, a secondary deficiency, where plants producing goitrogens such as clover or brassica crops are fed which prevent the thyroid gland from utilising the iodine in the diet.
There are two main methods of supplementation:
Oral drenches eg LSD-short acting. Given pre-tup, 8 & 4 weeks pre-lamb
Iodised oil injections eg Flexidine. Single injection of 1.5ml 3-4 weeks pre-tup. Increases iodine status for up to 200 days, label claim is to supply sufficient iodine for one year.
Flexidine is our most popular iodine supplementation method due to its length of action and easy administration. It is usually given at the same time as CampyVax4. A 1% increase in lamb survival easily justifies the cost and time to use it.
If you miss the boat pre-tup it can be used up to two months before lambing, and at weaning.
If you’re on the fence about Flexidine or other iodine supplementation call into your local Veterinary Centre clinic and discuss your specific farming system with one of the team.
