http://mgdas.com/2010/07/cow-dung-facts-and-statistics/ D ung available from one fully grown cow/ bull is around 5.4 tonnes per annum. so dry dung will be around 54. x 0.30 = 1620 kg per annum. This is equivalent to 712 kg of dry wood. This amount of wood comes from 6 large trees. So by keeping one old cow or bull alive we protect 6 large trees per annum from felling. Around beginning of 20th century states where cow slaughter was banned only cow dung cakes were used for pryre to give agni samskar to dead bodies as per vedic custom. So that much forest was saved as that many tree were not cut. A tree has great value when it is alive. It decreases pollution, maintains rain cycle, turns CO2 into O2 etc etc. It also provieds shade, fruits, flowers. Also as forest were cut down to provide fuel we saw that many medicinal herbs easily available in forests were lost because of deforestation. By killing of one old bull we deplete co...