Effects of Low-Protein Diets Supplemented with Essential Amino Acids on Growth Performance, Meat Quality, and Nitrogen Retention in Growing Japanese Quails

One experiment was carried out to investigate the effect of low crude protein (CP) diets supplemented with crystalline essential amino acids (EAAs) on growth performance, meat quality, and nitrogen retention in Japanese quails reared from ۱ to ۳۵ days of age. A total of ۸۴۰ unsexed one-day-old quail chicks were used in a completely randomized design consisting of seven treatments with six replicates and ۲۰ birds in each. In addition to the control diet, two negative control diets were also adjusted to contain ۱۰ and ۲۰% lower CP than the control (LP۱۰ and LP۲۰ diets, respectively). The EAAs/CP ratio was similar to that of the control diet. Also, four rations supplemented with amino acids were formulated to contain ۱۰% (LP۱۰+EAAs۱۰ and LP۲۰+EAAs۱۰) or ۲۰% (LP۱۰+EAAs۲۰ and LP۲۰+EAAs۲۰) higher EAAs than LP۱۰ and LP۲۰. Crude protein digestibility was determined using the total collection method at ۲۱ and ۳۵ d of age. After slaughtering at ۲۱ and ۳۵ d of age, whole-breast meats were dissected out to determine meat quality indices. During ۱ - ۲۱d of age, ۱۰ or ۲۰% reduction in CP significantly decreased body weight gain and increased feed conversion ratio; however, amino acid supplementation significantly improved body weight gain and feed conversion ratio (P < ۰.۰۵). During ۱- ۳۵ d of age, reduction of CP to ۲۰% led to decreased body weight gain in EAAs supplemented and un-supplemented diets. Dietary treatments did not have any significant effect on the breast meat quality variables except for pH. At ۳۵d of age, ۲۰% reduction in dietary CP significantly reduced nitrogen retention percentage. Overall, a ۱۰% reduction in dietary CP without EAAs supplementation had no adverse effect on the growth performance of Japanese quails during the ۱ to ۳۵d of age.

Keywords:

Meat pH , Performance , Cooking loss , Japanese quail , Meat water holding capacity