Tryptophan feed for dairy cattle, preparation method of tryptophan feed and application of tryptophan

The invention relates to a tryptophan feed for dairy cattle, a preparation method of the tryptophan feed, a method for increasing the content of melatonin in cow milk and application of tryptophan inthe increase of the content of the melatonin in the cow milk of the dairy cattle. The principle of the tryptophan feed is that tryptophan is a precusor substance for synthesizing the melatonin, so that free tryptophan in blood can enter the brain through blood brain barriers and can be converted into the melatonin under the action of enzyme. 本发明涉及种奶牛用色氨酸饲料、饲料的制造方法、提高牛乳的褪黑激素含量的方法以及色氨酸作为提高奶牛牛乳褪黑激素含量的应用。本发明的原理在于：因为色氨酸是合成褪黑激素的前体物质，血液中游离的色氨酸可以通过血脑屏障进入大脑，在酶的作用下转变为褪黑激素。