The invention discloses animal feed which comprises the following components in parts by weight: 30-60 parts of ensilage, 10-25 parts of carrot, 3-20 parts of alkali grass, 5-20 parts of corn, 1-10 parts of acidified corn, 1-10 parts of wheat bran, 1-10 parts of wheat middling, 0.1-1 part of salt, 1-8 parts of extruded soybean, 1-8 parts of bean pulp, 1-8 parts of cottonseed cake, 0.1-0.8 part of bone meal, 0.1-1 part of fish meal, 1-10 parts of mineral premix, 0.1-0.5 part of microecologics and 0.1-1 part of rumen by-pass amino acid. The feed formula is reasonably matched, the rumen environment of the dairy cattle is regulated, the nutritive value of various components in the feed is fully exerted, the beneficial effects of improving the feed utilization rate, regulating the rumen function of the dairy cattle, improving the total milk production and lactoprotein content of dairy cows and relieving heat stress of cows are achieved, the animal feed is suitable for developing green and healthy cultivation, and pollution-free ruminant products are produced.