You have to inoculate the ferment properly, initially, then always inoculate with 10% of the previous batch. For a good lactic fermentation, start with sauerkraut juice as your inoculator. fermenting in the 60-70F range will do a lot to keep your ferment healthy (lower temps are fine, but too...
If someone ferments the feed, there is surely very abundant vitamin C even if none was present initially. Sauerkrauts have some ten times the vit.c of oranges.