I vaccinate all my breeding stock when I give the ewes their booster (Heptavac). If the ram was in for two cycles or more I'd think seriously about keeping the barreners, particularly one suffering from persistent lameness, unless you want pet sheep. At lambing minus 6 weeks I start feeding 50g per ewe twice a day then increase to 100g twice a day at minus 5 weeks. I then split them when they get their booster at minus 4 weeks and feed them according to how many lambs and/or their condition. All this is very dependent on breed, age, condition, weather, shelter, quality of grass and feed (I use 18% protein), spread of lambing dates ..... Getting it right is one of the most delicate taks of shepherding.