Digestible arginine concentrations in the diet of Japanese quails

Abstract

The objective of this study was to evaluate the effect of different levels of arginine in the diet of Japanese quails and to determine which provides the best egg production indices. We used 400 birds with an initial average weight of 180 g at 140 days of age. These were distributed among experimental units in a randomized design. Five levels of digestible arginine were studied (1.148, 1.256, 1.364, 1.472, and 1.580%) in reference to a fixed level of digestible lysine (1.083%; for arginine to lysine ratios of 1.06, 1.16, 1.26, 1.36, and 1.46). Each treatment was replicated 10 times for a total of 50 experimental units, each with eight quails. Feed rations, leftovers, and dead animals were weighed to calculate and adjust performance parameters. The variables analyzed were: daily feed intake (DFI), egg laying rate (ER), average egg weight (EW), total egg mass (EM), feed conversion per egg mass and per dozen eggs (FCEM and FCDE), yolk, skin, and albumen weights (AYW, ASW and AAW), relative weights of yolk, albumen and shell (RYW, RAW and RSW), the Haugh unit (HU), and the percentage of eggs suitable for market (EP). The variables associated with performance and internal and external quality were not affected (P > 0.05) by different levels of arginine, except for EP, which decreased linearly (P = 0.009) with increasing arginine according to the equation: ? = -3.44x + 103.13, r² = 0.94. We conclude that the best concentration of arginine in quail diets is 1.148%, corresponding to an arginine to lysine ratio of 1.06.