REVIEW ARTICLE Towards saving freshwater: halophytes as unconventional feedstuffs in livestock feed: a review Mohamed E. Abd El-Hack 1 & Dalia H. Samak 2 & Ahmed E. Noreldin 3 & Muhammad Arif 4 & Hilal S. Yaqoob 5 & Ayman A. Swelum 5,6 Received: 13 January 2018 /Accepted: 16 April 2018 /Published online: 26 April 2018 # Springer-Verlag GmbH Germany, part of Springer Nature 2018 Abstract Water represents 71% of all earth area and about 97% of this water is salty water. So, only 3% of the overall world water quantity is freshwater. Human can benefit only from 1% of this water and the remaining 2% freeze at both poles of earth. Therefore, it is important to preserve the freshwater through increasing the plants consuming salty water. The future prosperity of feed resources in arid and semi-arid countries depends on economic use of alternative resources that have been marginalized for long periods of time, such as halophytic plants, which are one such potential future resource. Halophyte plants can grow in high salinity water and soil and to some extent during drought. The growth of these plants depends on the contact of the salted water with plant roots as in semi-desert saline water, mangrove swamps, marshes, and seashores. Halophyte plants need high levels of sodium chloride in the soil water for growth, and the soil water must also contain high levels of salts, as sodium hydroxide or magnesium sulfate. There are many uses for halophyte plants, including feed for animals, vegetables, drugs, sand dune stabilizers, wind shelter, soil cover, wetland cultivation, laundry detergents, and paper production. This paper will focus on the use of halophytes as a feed additive for animals. In spite of the good nutritional value of halophytes, some anti-nutritional factors as nitrates, nitrite complexes, tannins, glycosides, phenolic compounds, saponins, oxalates, and alkaloids may be present in some of them. The presence of such anti-nutritional agents makes halophytes unpalatable to animals, which tends to reduce feed intake and nutrient use. Therefore, the negative effects of these plants on animal performance are the only objection against using halophytes in animal feed diets. This review article highlights the beneficial impact of con- sidering halophytes in animal feeding on saving freshwater and illustrates its nutritive value for livestock from different aspects. Keywords Halophytes . Livestock . Feed . Production . Histology, nitrogen pollution Responsible editor: Philippe Garrigues * Mohamed E. Abd El-Hack m.ezzat@zu.edu.eg; dr.mohamed.e.abdalhaq@gmail.com Dalia H. Samak dalia_samak@vetmed.dmu.edu.eg Ahmed E. Noreldin nourislam2010@yahoo.com Muhammad Arif dr.arif.uca@gmail.com Hilal S. Yaqoob hyaqoob@ksu.edu.sa Ayman A. Swelum aswelum@ksu.edu.sa 1 Department of Poultry, Faculty of Agriculture, Zagazig University, Zagazig 44511, Egypt 2 Department of Veterinary Forensic Medicine and Toxicology, Faculty of Veterinary Medicine, Damanhour University, Damanhour, Egypt 3 Department of Histology and Cytology, Faculty of Veterinary Medicine, Damanhour University, Damanhour, Egypt 4 Department of Animal Sciences, University College of Agriculture, University of Sargodha, Sargodha 40100, Pakistan 5 Department of Animal Production, College of Food and Agriculture Sciences, King Saud University, P.O. Box 2460, Riyadh 11451, Saudi Arabia 6 Department of Theriogenology, Faculty of Veterinary Medicine, Zagazig University, Zagazig 44511, Egypt Environmental Science and Pollution Research (2018) 25:14397–14406 https://doi.org/10.1007/s11356-018-2052-9