I agree, bag size is not always an indicator. Maybe she's thoroughly milked out by the calves in the pics. But still, her bag's small because she's young. Judging by her bag, I would guess she produces about two, maybe three gallons a day. A calf needs a minimum of one gallon a day to do well, or supplemented with grain and/or hay.
Our milk cows have large bags. Jenny, our highest producer, is a six year old Jersey. She gives 6-8 gallons a day. Her udder at milking time is about 18 inches wide, 24 inches long, and 18 inches deep (I feel so weird describing her... um... dimensions, LOL). Her teats do not drag in the mud at all, in fact far from it, and she gets along just fine. Dairy cows are bred to have well shaped udders that can handle the large size. Unlike beef cows, who usually get long and floppy, and not very well contained or connected...
Our milk cows have large bags. Jenny, our highest producer, is a six year old Jersey. She gives 6-8 gallons a day. Her udder at milking time is about 18 inches wide, 24 inches long, and 18 inches deep (I feel so weird describing her... um... dimensions, LOL). Her teats do not drag in the mud at all, in fact far from it, and she gets along just fine. Dairy cows are bred to have well shaped udders that can handle the large size. Unlike beef cows, who usually get long and floppy, and not very well contained or connected...