Wild gaur feed mainly on grasses, herbs, shrubs and trees, with high preference for leaves. In Goa, finer and fresh grass was preferred to coarse grasses, though Strobilanthes species ixiocephalus and callosus were the most preferred food. Gaur spent 63% of their daily time feeding. Peak feeding activity was observed in the morning between 6:30 and 8:30 am and in the evening between 5:30 and 6:45 pm. During the hottest hours of the day, 1:30 to 3:30 pm, they rest in the shade of big trees.[5]
Gaur graze and browse on a wider variety of plants than any other ungulate species of India, with a preference for the upper portions of plants, such as leaf blades, stems, seeds and flowers of grass species.[6] Food preference varies by season, with more grass and herb species consumed in monsoon than tree species. In winter, no food type is dominant, but in summer, more tree species are eaten than grasses and shrubs.
Gaur consume the bark of teak (Tectona grandis) and cashew (Anacardium occidentale) in the summer season, perhaps due to an insufficiency of green grass in summer. Gaur are also known to feed on the bark of other tree species, including Adina cordifolia , Holarrhena antidysentrica and Wendlandia natoniana. Gaur may debark due to shortage of preferred food, a shortage of minerals and trace elements needed for their nutrition, or for maintaining an optimum fiber/protein ratio for proper digestion of food and better assimilation of nutrients. Gaur may turn to available browse species and fibrous teak bark in summer as green grass and herbaceous resources dry up. High concentrations of calcium (22400 ppm) and phosphorus (400 ppm) have been reported in teak bark, so consumption of teak bark may help animals to satisfy both mineral and other food needs.