Drinking a glass of warm milk is known to induce sleep. But a report which was released by Fox News stated that milk collected from "sleepy cows" are better in terms of inducing sleepiness as it has calming effects.

A study which was published in the Journal of Medicinal Food stated that sleepy cows, or cows being milked at night, possess high levels of tryptophan and melatonin in their bodies, which is then present in the liquid extracted from their udders. The study also added that milk acquired at night has 24 percent more tryptophan and 10 times more melanin than milk being extracted in the morning.

As per the Journal of Medicinal Food, both tryptophan and melatonin are responsible for reducing anxiety and is effective in inducing sleepiness. Both chemicals are normally taken separately if acquired from supplements but can both be found in a glass of milk from a sleepy cow. Melatonin is responsible for regulating the biorhythm in all animals. The studies also added that the effects of  a sleepy cow's milk on mice is similar to a dose of diazepam, which is a drug used to treat anxiety.

"Considering the fact that tryptophan and melatonin are abundant in night milk, it is possible that the sedative effect of night milk may be attributable to these substances," as stated in the journal.

Researchers from Sahmyook University in Seoul, South Korea were able to conclude that mice that were given a dose of night milk appeared to be more sluggish, fell asleep faster, and became less active than those that were given the usual milk.

As per The Guardian, a study was done by a German company Milchkristalle GmbH back in 2010 focused on "nocturnal milk." The company stated that "night milk crystals are rich in melatonin."

The company manager Tony Gnann told The Guardian that it is important to make sure that the conditions for the cows that produce nocturnal milk have to be right.

"Conditions for the cows have to be just right -- light in the day and very low light conditions at night,"

Director of the epilepsy and sleep division in Columbia University's neurology department, Carl Brazil, was first quite hesitant in taking the "nocturnal milk" into consideration, as per The Guardian. Brazil stated that the researchers were able to execute the study in a "pretty possible way."

Brazil even stated that the "theory is correct." This is in reference to the effects of tryptophan and melatonin in having sedative properties that helps individuals fall asleep faster.