The experiment was carried out at the Poultry Farm, Faculty
of Agriculture, Fayoum University (middle Egypt). This study aims to
show the effect of dietary malic acid (MA) supplementation as a growth
promoter on Japanese quail performance, carcass characteristics,
intestinal villi and pH, bacteria enumeration, some blood parameters and
digestibility coefficients. A total number of 360 unsexed one day-old
Japanese quail chicks (Coturnix coturnix japonica) were equally divided
into four groups of six replicates each. Two starter-grower corn-soybean
meal (C-SBM) basal diets were formulated to contain 24 % CP and
2900 kcal ME /kg diet and 22 % CP and 2750 kcal ME /kg diet,
respectively. Also, two layer C-SBM basal diets were formulated to
contain 20 % CP and 2900 kcal ME /kg diet and 18 % CP and 2750 kcal
ME /kg diet, respectively. Each of the four basal diets was either
unsupplemented or supplemented with 0.15% (1.5 kg/ton) dietary malic
acid. Therefore, four experimental treatments were used in both startinggrowing and laying periods. Each chick group fed one of the four
experimental diets. At 35 days of age, a slaughter test was performed to
determine carcass traits, edible giblets, lymphoid organs and intestinal
villi, microflora count and pH. Blood samples were taken and assayed to
determine some serum blood parameters. Digestibility trials were
conducted to determine nutrients digestibility for starter-grower
experimental diets. At laying period, egg number, weight, mass and
production rate as well as feed intake and feed conversion were
recorded. At the end of the 90-day period, egg samples were taken and
broken out to determine internal egg quality and analysis. From
nutritional of view, it was observed that using malic acid at a level of
0.15% (1.5 kg/ton) in Japanese quail diets containing sub-optimal
energy and protein levels helped in reducing microflara count,
particularly pathogens and in turn, improved quail performance and
immunity. However, using MA at a level of 0.15% (1.5 kg/ton) in
Japanese quail diets containing optimal energy and protein levels caused
an increase in egg mass and a decrease in feed intake.