@conference {41276,
	title = {Effect of premating iodine supplementation of ewes fed pasture or a brassica crop prelambing},
	booktitle = {Proceedings of the New Zealand Society of Animal Production},
	volume = {61},
	year = {2001},
	month = {Jan},
	pages = {164-167},
	publisher = {New Zealand Society of Animal Production},
	organization = {New Zealand Society of Animal Production},
	address = {Christchurch},
	abstract = {On two sheep farms with different winter feeding systems, namely pasture only (farm A) or pasture then swedes or swedes/turnips/kale for 6 to 8 weeks prelambing (farm B), 700 ewes/farm were randomly assigned to 2 groups of 350 animals to assess animal performance. About 5 weeks premating, one group was injected with 390 mg iodine (as Flexidine iodised oil) intramuscularly. Iodine supplementation increased and maintained serum and milk I concentrations for at least 210 days ({\textmu}g/L; farm A, serum 43 v 65; milk 72 v 197. Farm B, serum 29 v 45; milk 26 v 132), but did not affect potential lambing percentage at scanning, perinatal mortality, or lambing percent (farm A, 140 v 150\%; farm B, 138 v 130\%). On farm A no goitre was observed among the 77 lambs postmortemed, regardless of I treatment of the ewes. On farm B goitre was observed in 85\% of the 34 lambs postmortemed from untreated ewes, but not among the 36 lambs from treated ewes. In the following year, the trial was repeated with 50 ewes/group to monitor changes in I status, and the treatment significantly increased serum I over time but had no consistent effect on serum T4 and T3 concentrations. Supplementing ewes premating with long-acting injectable I prevented goitre in newborn lambs from ewes fed swedes or swedes/turnips/kale as a winter supplement. },
	issn = {1176-5283},
	author = {Grace ND and Knowles SO and Sinclair GR}
}
