A method for manufacturing liquid feed for animals by using high-temperature and high-pressure water is provided to obtain excellent liquid feed by hydrolyzing protein. A method for manufacturing liquid feed for animals by using high-temperature and high-pressure water comprises: holding protein and water in a liquid/solid ratio of 5:1~100:1 at 150~260°C under 0.4~30MPa for 5~180min. The protein comprises at least one selected from food waste, agricultural and marine product waste, stock farm waste, and organic waste. In the manufacturing method, 0.001~0.05mass parts of egg shell is added to the protein and water, per 1mass part of the protein.
