Valorization of Cow Urine and Dung: A Model Biorefinery

Cow is one of the most common livestock of Indian farmers. Small farm households are strongly dependent on livestock for income as it contributes nearly 16% of their total earnings. As much as two-thirds of rural community depends on livestock for their livelihood. Farmers in India maintain a hybrid farming system, that is, a combination of crop cultivation and livestock, which are complementary to each other. Traditionally, the output of one enterprise is the input of another enterprise. Recent research suggests that in addition to milk, urine and dung obtained from cow are valuable resources of bioactive compounds, which can be converted into value-added products. In this review, we provide an outline for the physicochemical composition and valorization of cow urine and dung. They are utilized in agriculture as a pesticide, manure, and acts as a soil rejuvenator. Cow dung is used for bio energy production by fermentation and gasification. Medicinal and cosmetic products are prepared following ayurvedic formulations described in ‘Panchagavya’. Cow dung ash is used as adsorbent, construction material, mosquito repellent and electrolyte. A case study of manufacturing unit producing arrays of products from cow urine and dung is also presented.