Three hundred and sixty quails were divided into six groups to evaluate the effect of dietary betaine on profiles of proteins and lipids, bioenergetics, peroxidation and quality of meat of Japanese quail fed diets containing three levels of metabolizable energy (ME) viz. optimum
(2900 kcal ME/kg), restricted (2800 kcal ME/kg) and low (2700 kcal ME/kg). Dietary betaine improved meat quality parameters viz. cooking loss, thawing loss and water-holding capacity of Japanese quail fed diets containing either restricted or low ME by enrichments of the meat with omega-3 fatty acids and reduction of lipids levels.