Usually the female is between 800 and 1200 grams, but 600 sounds reasonable too...
For unknown reasons, females in this size range will frequently go off feed during the breeding season. They're too small to be bred, however.
I don't know why your friend would suggest removing the scent of breeding from a female that hasn't been bred.
They usually start eating again around the same time the breeders do. My yearlings did this to me this past season, and they're back on feed now.