Eutrophication phosphate into water is slow, hence the difficulty of reversing the effects of eutrophication. However, numerous literature report that nitrogen is the primary limiting nutrient for the accumulation of algal biomass. The sources of these excess phosphates are phosphates in detergent, industrial/domestic run-offs, and fertilizers. With the phasing out of phosphate-containing detergents in the 1970s, industrial/domestic run-off and agriculture have emerged as the dominant contributors to eutrophication. Cultural eutrophication is the process that speeds up natural eutrophication because of human activity. Due to clearing of land and building of towns and cities, land runoff is accelerated and more nutrients such
Natural growth promoter and quebracho ("Schinopsis lorentzii", condensed tannins) extracts, are effective to reduce and control infection. Moreover are considered a natural alternative to AGPs due to the difficulty of bacteria to develop resistance against the diverse range of molecules that contain these plant compounds. Animal feeds contain varying levels of indigestible nutrients and undesired components such as fiber, phytate or proteins with antigenic effects. Different feed enzymes such as, carbohydrases, phytases or proteases, can be included in feeds to improve the utilization of energy and nutrients or to degrade several undesired components. Moreover, some enzymes (e.g. amylases, lipases) can be added to