**4. Conclusion**

Whey is still considered a by-product with no economical value despite its biological properties and despite all the alternative uses that have been proposed. The uses of whey as a culture medium or as a beverage, as discussed here, are examples of how simple processes can contribute to the development of new products and at the same time to reduce environmental impact. We are intensifying production systems and genetically improving livestock to produce more milk; meanwhile, we are discarding 50% of the nutrients in milk as whey. This should be considered also as part of lack of animal welfare. We do not need to produce super cows, with all the metabolic stress that it causes to the animal; we need to rethink the systems of food elaboration.

 It is important to discuss the way we are producing food and the biological value of the food we want to consume. Environmental and production policies that favor the use of by-products are required. We need to break the paradigm of considering milk products as waste and develop new strategies for use.
