Harvest Moon 64 Mining & Cow Chart

3 Cows - 10,300 from Mine
 -3 Trips - 3,434 g per
  -7 Moon Ore
 -4 Trips - 2,575 g per
  -5 Moon Ore
 -5 Trips - 2,060 g per
  -6 Iron, 3 Moon Ore [9]
  -4 Iron, 4 Moon Ore [8]

4 Cows - 16,300 from Mine
 -3 Trips - 5,434 g per
  -5 Blue, 4 Moon Ore [9]
  -7 Blue, 1 Moon Ore, 4 Coins [8]
   (All Blue if no coins).
 -4 Trips - 4,075 g per
  -8 Moon Ore, 1 Iron [9]
  -7 Moon Ore, 1 Blue [8]
 -5 Trips - 3,260 g per
  -6 Moon Ore, 3 Iron [9]
  -7 Moon Ore [8]

5 Cows - 20,800 from Mine
 -3 Trips - 6,934 g per
  - 9 Pontata Roots [9]
  - 6 Pontata Roots, 2 Rare Medals [8]
 -4 Trips - 5,200 g per
  - 6 Moon Ore, 2 Blue, 1 Root [9]
  - 4 Moon Ore, 4 Roots [8]
 -5 Trips - 4,160 g per
  - 9 Moon Ore [9]
  - 7 Moon Ore, 1 Blue [8]

6 Cows - 26,800 from Mine
 -3 Trips - 8,934 g per
  -9 Rare Medals [8's Impossible]
 -4 Trips - 6,700 g per
  - 5 Blue, 4 Roots [9]
  - 5 Roots, 1 Blue, 2 Rare Medals [8]
 -5 Trips - 5,360 g per
  - 5 Moon Ore, 3 Blue, 1 Root [9]
  - 4 Roots, 3 Moon Ore, 1 Blue [8]

Iron - 100 g
Moon ore - 500 g
Blue Stone - 700 g
Pontana Root - 800 g
Rare Metal - 1,000 g

72,000 for Extensions, 43 grass, Chicken, Berry.

3 Cows - Start buying on Winter 20 to be safe:
20 Days of 3 Large Milks
28 Days of 2 Larges, 1 Gold

4 Cows - Start buying on Spring 18 to be safe:
15 Days of 4 Large Milks
17 Days of 3 Larges, 1 Gold

5 Cows - Start Buying on Spring 18 to be safe:
12 Days of 5 Large Milks
10 Days of 4 Larges, 1 Gold

6 Cows - Start buying on Spring 18 to be safe:
10 Days of 6 Large Milks
4 Days of 5 Larges, 1 Gold

1 cow  - 0 mine  - 60 milk days to 60 - 86 days for money - 51:05
2 cows - 1 mine  - 30 milk days to 60 - 48 days for money - 54:40
3 cows - 1 mine  - 20 milk days to 60 - 28 days for money - 44:30
4 cows - 2 mines - 15 milk days to 60 - 17 days for money - 43:20
5 cows - 3 mines - 12 milk days to 60 - 10 days for money - 46:20
6 cows - 3 mines - 10 milk days to 60 - 4 days for money  - 43:00
7 cows - 4 mines - 9 milk days to 60  - 0 days for money  - 44:50
8 cows - 5 mines - 8 milk days to 60  - 0 days for money  - 50:40