1 Department of Biochemistry, Vitagene and Health Research Centre, Bristol, BS4 2RS, UK. psurai@feedfood.co.uk.
2 Department of Hygiene and Poultry Sciences, Moscow State Academy of Veterinary Medicine and Biotechnology Named After K. I. Skryabin, Moscow, 109472, Russia. psurai@feedfood.co.uk.
3 Department of Biochemistry and Physiology, Saint-Petersburg State University of Veterinary Medicine, St. Petersburg, 196084, Russia. psurai@feedfood.co.uk.
4 Department of Animal Nutrition, Faculty of Agricultural and Environmental Sciences, Szent Istvan University, Gödöllo, 2103, Hungary. psurai@feedfood.co.uk.