Hmmm...I give them too much grain according to what (I "read") everyone else seems to give them. That's why I didn't chime in on your post until you re-posted :wink:
I have had goats (PB Nubians) for 4 years, but only milking for 2 years. During the summer months, my girls
in milk are in what I consider the best "goat pasture" ever. They have an amazing choice of pine, fir, maple, alder saplings, ferns, etc., etc.... They each
still get at least 5-6 cups of grain 2x/day,
while I'm milking 2x/day. At kidding time, and for a few weeks after kidding, they get a very nicely filled 2 quart scoop each (2X/day). I feel that this is A LOT of grain, according to what I'm reading that everyone else seems to be doing. It really depends on the doe. Some of them hold weight better than others. I have 2 does that give the same amount of milk per day, yet one seems to require more grain. Why? They are all so different! I think that's why this was a difficult question to answer. Oh, and none of my girls are "over-conditioned"! At least not the goats! Now, the breeder sows are another story...
The 1 year-old wether I sold this year was still getting 1 cup grain 2X/day. They didn't have good pasture at the moment, I was questioning the quality of the hay I had, and it made him really happy.

Oh, and he wasn't "fat" in the least ~ also never had "UC" problems...
2 YR. old buck: 2-3 cups/ 2X day in winter, 1-2 cups 2X day in summer.
Current pen of 3 bucklings: 2 PB Nubian ( 4 & 5 month olds), 1 PB Boer (6 month old), share a FULL 2-quart scoop of grain 1x/day.
All the goats have free-choice minerals, and the "in milk" girls each get about 1/4 cup of Black Oil Sunflower Seeds/day.
I think that "required" grain has a lot to do with pasture/hay quality for part of the year, but for those of us in the more extreme climate zones, it just makes sense that any creature will require more calories/fat/protein intake during extreme temperatures. I know I do! :greengrin:
Sorry to make this so long, but have to add (since we're talking about Nubians): That's with the does putting out 3/4-1 gallon per day. Lots of butterfat!!! :wink: