From what I have heard and read, a doe produces a certain amount of milk, regardless of the litter size. As a result, the litter as a whole gains weight at about the same rate; how fast each kit grows depends on the number of kits in the litter. People who have the numbers to work with say that the ideal litter size for meat production is about 6 kits, so I have that number in mind when the fostering issue comes up. Obviously, for something small like my Dwarfs, 6 would be a real stretch, so I adjust my expectations according to the size of the breed, but the idea is that a moderate sized litter is actually better for the kits than either a large one or a small one.
Given the experience of the does you have, I'd have done exactly what you have done - leave the situation alone at first and monitor the kits closely, only making adjustments if they seemed not to be doing well. 10 is doable, but it is a big litter.
The first-time mom is, of course, a bit of a wild card. You can't be sure how much messing about she will tolerate; while I have had plenty of does that needed my "help" to get into the swing of things, I have had a couple that started off sorta OK, but abandoned their litters because of my interference. A first time mother usually has a very limited milk supply for the first couple of days; it doesn't really come in until about day 3. That's one of the great things about a doe with at least one kindling behind her (even if the litter was lost); her milk supply is better than a first-time doe from day 1. The best I can say with this doe is to make sure the kits have good opportunities to nurse and cross your fingers; while you may lose some, the rest should really pick up the pace in the next day or so.
Congrats on the litters, and wishing you good luck!
