Head to Lon Lon Ranch in the middle of Hyrule Field after the story sequence with the princess is over. Go into the first door on your left to find Talon and a bunch of chickens. Throw all the chickens into the corner at the bottom of the stairs and talk to Talon. Win his game and you'll get a bottle of milk. The milk is kinda useful but the really useful thing is the bottle itself. Also, go to the horse corral and talk to Malon until she talks about a song her mother composed. Whip out your Ocarina and she'll teach you Epona's Song. Use Epona's Song on any cows you see for some free Milk. Now leave Lon Lon Ranch and head back to Kokiri Forest.
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