1. An experimental study has been made of the effects of heat, light, air, enzymes and bacteria on carotene destruction, when green fodder is dried and stored as hay.
2. Carotene in green fodders can be destroyed by autoclaving or other forms of heating in the presence of air. The extent of destruction depends upon the period of heating.
3. Carotene is not destroyed if green plants are dried in a vacuum.
4. Atmospheric oxygen plays the predominant part in the destruction of carotene; and heat, light and moisture are merely accelerating agents. The destruction of carotene during storage is due mainly to a slow spontaneous oxidation of the pigment in plant material.
5. The utility in India of grass drying or hay making with the specific object of providing vitamin A supplements is questionable, because of the carotene destruction during storage under prevailing temperature and climatic conditions.