Transgenic crops (TCs) have potentially higher yield and quality as compared to their traditional relatives. Cultivation of these crops will lead to less use of chemical pesticides. In addition to its use as food resources, TCs “such as soybeans, canola, cotton, corn and potatoes” are currently being used for livestock feeding. About 90 percent of transgenic soybeans as well as 70 percent of transgenic corns have been assigned to the livestock sector so that, it can be said that TCs constitute a significant part of the fodder needed for livestock feeding. Researches have shown that chemical contents of transgenic crops are same as non-transgenic crops in terms of their chemical composition and amino acid content. Moreover, so far, no allergic property has been reported for TCs. Surveys have also shown that the compounds, digestibility, feed value and safety aspects of TCs were quite substantial equivalence with non-transgenic crops. The present study is an overview of concerns about the use of TCs for livestock feeding.