Grass Hay 1 bale per week per donkey (healthy pasture will reduce dependence on baled hay May-August)
$4.00 to $7.00 per bale (average $5) =$260
Dewormer (1 time a year?) = $10
Annual Vaccination (Spring?) = $25 to $50
Farrier 4 times per year @$$35-$50 = $180
Mineral supplement = $100
Fly Spray = $20
Carrots = $25 
Total $640 per donkey
Other Start up costs
Lead Rope $15
Muck rake $12
Fly Mask $15
Brushes $20
Hoof Pick $4
Water Tank $70
Feed Bunk $78