Performance and egg quality parameters of laying hens submitted to different rearing densities

Abstract

This study aimed to evaluate the effect of different rearing densities during brooding (0 to 2 weeks) and growth (3 to 15 weeks) on performance and egg quality of laying hens (Hy-line W-36) during production phase (18 to 42 weeks). In the brooding phase, a total of 3250 day-old chicks were allocated in wire cages, distributed in a completely randomized design composed of 5 treatments (63.57; 66.38; 69.44; 72.80 and 76.50 cm²/bird) with 10 replications each. At the beginning of the growth phase, floor space in each treatment was increased. Therefore, a total of 750 birds were selected from the original treatments, which represented 237.57, 265.52, 300.92, 347.22, and 410.35 cm²/bird. At the end of the growing phase, 390 pullets were transferred to production facilities and distributed, according to their original treatment, in conventional cages with 430.76 cm²/bird (13 birds/cage). For this phase, only 6 replications per treatment were adopted. Experimental data were subjected to analysis of variance and, in the case of significant differences, means were analyzed using polynomial regression test. Body weight, weight gain and uniformity were compared during the brooding and growth phases. First-egg weight, age at first egg, age at 50% daily production, weights of egg, albumen, yolk and shell, egg mass, yolk diameter, yolk height, yolk index, albumen height, percentages of shell, albumen and yolk, shell thickness, Haugh unit, and egg specific gravity were analyzed during the production stage. In conclusion, raising pullets on 63.57 cm2/bird (71 birds/cage) does not affect chicks’ performance during the brooding phase. However, for the growth phase, the recommendation is to provide 410.35 cm2/bird, which corresponded to 11 birds/cage in this research. For the production period, the recommendation is to utilize pullets raised on 265.52 cm2/bird, which corresponded to 17 birds/cage on this research.