This set was referred to as both the 'Down on the Farm' and 'Farm Animals' Play Sets #5927. Released 2009-2010, this set included a Donkey, Cow, Running Calf, Chicken, Dwarf Goat, Farmer Doll, and 4 Fence Pieces. On the 2010 Retired List.
The Brown Donkeys from the Visiting Vet Clinic, Country Vet, Emergency Animal Rescue, Down on the Farm and Farm Animals Play Sets all appear to be basically the same color and pattern. With the amount of sets released, there are subtle variations, but these variations tend to appear in multiple sets.