Well my tups get the same as my ewes and have done for all the years ive been sheep farming , which is very many. Ive never had any issues but then then only get them for the month there with the ewes.and i always feed ewe rolls 16% . The ewes always have a energy lick with them at tupping , then again month b4 lambing , All the ewes are in the heptavec p system . Once in lamb they get turned away till 6 weeks b4 lambing on next doors dairy farm they do well on cow grass
.The only issue with high mag buckets is if you get one or two ewes that gorge on them which may be an issue u shouldnt need hi mag buckets unless you have an is with low levels of magnesium in your land . Just watch your tup when hes with the ewes if your feeding they can sometimes be a bit full of them selves and may be give u a dap in the back of the legs , but a sharp crack across the nose soon sorts it . I dont think there are any rules carved in stone when feeding livestock, its all about your farm ,and what your systems are. what grass you have , what the nutritive value of your hay/haylage is , what its DM is ( dry matter) and its CP ( crude protein) its always worth having an analasis done on it could save you apacket . Feeding is alot about common sense i think, keep an eye on your ewes a good indication of how they are doing is if they play, this may seem weird but my shearlings are like little lambs , they skip about like lambs playing in the spring , even though there in lamb , this is always a good sign there doing and healthy its a scream to watch on a sunny morning .