Ratio of digestible lysine to arginine in Japanese laying quails

Abstract

The objective of this study was to evaluate the existence of an interaction between lysine and arginine, and to determine their optimal ratio in the diets of Japanese laying quails. We used 480 quails with an initial mean weight of 180 g at 140 days of age. The quails were distributed in the experimental units in a completely randomized (3 × 2) factorial design, with three levels of digestible lysine (1.083, 1.183, 1.283%) and two levels of digestible arginine (1.472 and 1.580%). There were six treatments, with 10 replicates each, for a total of 60 experimental units. Rations, leftovers, and dead animals were weighed in order to calculate and adjust performance parameters. The variables analyzed were: daily diet consumption (DDC), laying rate (LR), average egg weight (AEW), egg mass (EM), feed conversion per egg mass and dozen eggs (FCEM and FCDE, respectively), weights of yolk, eggshell, and albumen (YW, ESW, and AW, respectively), relative yolk, eggshell, and albumen weights (RYW, RESW, and RAW, respectively), Haugh unit (HU), and marketable egg percentage (ME). There was no interaction (P > 0.05) between the levels of digestible lysine and arginine on the parameters analyzed; independently, these parameters were not affected by lysine and arginine levels. In conclusion, the optimal ratio of lysine and arginine in the diet of laying quails was 1.36: 1.00, which was the lowest used in the present study.