Efeito do peso corporal de poedeiras na fase de pós-pico sobre o desempenho, qualidade dos ovos e indicadores de bem-estar

Abstract

The objective of this work was to evaluate the effect of body scores of laying hens in the post-peak phase on performance, egg quality and welfare indicators. We used 90 Dekalb White layers aged 60 to 72 weeks distributed in a completely randomized design in 3 treatments composed of different body weights of the birds (light, medium and heavy) with 6 replications of 5 birds each. Bird performance was evaluated through egg production (%), feed consumption (g), feed conversion (g/g) and egg mass (g). Egg quality was assessed using egg weight (g), yolk color, albumen height (mm), Haugh Unit, shell strength, yolk height and diameter (mm) and yolk index by an automatic analyzer. of eggs. Animal welfare was assessed using indicators from the Welfare Quality protocol for laying hens (keel injuries, skin injuries, crest injuries, foot pad injuries). The data obtained on the performance and quality variables of the eggs were subjected to analysis of variance, and when found to be significant, the Tukey test was performed at 5% significance. Well-being indicators were subjected to the chi-square test at 5% significance. Feed consumption for heavy birds was higher, followed by medium birds and lower for light birds. Heavier eggs were observed in medium and heavy birds compared to light ones. Medium birds had greater egg mass compared to heavy ones, not differing from light ones. Heavy birds showed worse conversion per egg mass compared to light and medium birds, which did not differ from each other. Medium and heavy birds produced heavier eggs when compared to light ones, despite having lighter eggs, birds with lower body weight produced eggs with heavier yolks. The albumen height was more pronounced in light and medium birds, the yolk index was higher in light birds while the yolk color was more pigmented in medium birds. Shell strength was worse in heavy birds. There was no significant effect of body weight on well-being indicators related to the skin, ridge and footpad. However, heavy birds had a higher frequency of keel fractures compared to light and medium birds. With this, it is concluded that the control of body weight and uniformity in batches of laying hens is necessary, especially in relation to the increase in weight of birds in relation to the standard, since the greatest losses to performance, egg quality and well-being of birds were observed in heavy birds.