Barney & Friends: E-I-E-I-O (Season 4, Episode 20) 

Barney and his friends go to Grammy Johannson's farm to learn about farm animals, working together and getting some milk for their peanut butter sandwich snack.
Thanks to Matthew Pollard and Jeffrey (mario555227) for their copies.
Episode (c) Lyons Partnership, L.P. / Hit Entertainment / 9Story