They just said anything that has B1 in it- nothing in particular. They had MVF feet and fertility at tupping and then went onto MVF extra energy, both of which have it in. They didnt need treating for CCN but the lambs grazing that field in October did, the vet just said to keep an eye on the ewes and give them a lick bucket. Will look into blousing thank you, they are being mineral drenched next week (will finish the bottle first before blousing and check out the drench named above, thank you)