Cow, if you eat, hot will become of you
In Hinduism, the cow is considered a very sacred and revered creature, so much so that those who follow this belief also tend to follow a strictly vegetarian diet. Though in communities where those who follow this practice are mixed with those who do not, it is often useful to have a more simplified or at least practical justification for this practice. Particularly in the case of providing a more explanation to and between naïve and curious children, a biological reason that reinforces the religious reason are two forces which combine to be very persuading. The biological explanation is as follows: because it is very humid in India, meat in general, which conveniently for this belief system includes that of cows, very often goes rancid. Should one proceed to eat this bacteria infested meat, one will become sick with a fever. Thus, this little superstition is a perfect compliment to the Hindu belief, simply a different means to the same end.
The informant did mention he began to hear this more frequently when he moved from India to the United States, where the eating of cow was much more prevalent. In an environment where a childs practices at home are very different from those he or she experiences elsewhere in his daily life, the fear of sickness evoked by this superstition would quickly eliminate much of the initial curiosity by the child to indulge in what the activities that surround him.