Nonorganic milk can contain small traces of pesticides. Since milk is a staple food for children, this is cause for concern. Organic milk is more pure. Organic dairies give their cows feed made from grain grown without chemical fertilizers or pesticides. Growth hormone isn't allowed. Dairy animals are not given antibiotics, which could get into the milk. Widespread use of antibiotics also increases the possibility of antibiotic-resistant bacteria developing in the future. U.S. Department of Agriculture standards say organic dairy cows must graze in a pasture for at least 120 days a year [source: Skrzycki]. The avoidance of pesticides and fertilizers in the feed and in the pasture lessens the impact of the herd on the environment. Remember, too, to look for organics in products made from milk such as yogurt, ice cream, butter and cheese.