When I weaned my now 8 year old mare from her dam, they were only seperated for about 2 months, but there were also extenuating circumstances. I was at a boarding facility, they had an empty pen when I first started the weaning process, but then they got a new boarder with a new weanling; that weanling had no manners and was spoiled rotten, and she ran my filly through the fence. So, as soon as Hayley was 2 months past weanling, she went back in with her dam and my gelding; she was always independent and mom didn't have much milk in the first place, so she never did try to nurse on her mom after we put them back together. The last two I weaned, were fine. I pulled the colt's dam out of the foal pasture and left the colt in with the other mare and foal; when the filly was ready to wean, I pulled her dam out of the pasture; there was little to no screaming or worrying. I sold the one mare and the other wasn't pastured with her daughter again until this summer (filly is 2), just happened to have an extra pasture, so kept the youngsters seperate from the other horses to be able to give them more/different feed than the adult horses.