Níveis de zinco complexado a aminoácidos na dieta de poedeiras comerciais em fase de cria: indicadores de bem-estar animal

Abstract

The present study aimed to evaluate the effects of inclusion levels of zinc complexed to amino acids in the diet of commercial laying hens in the brooding phase, on welfare indicators related to bone development, feathering and tegument. A total of 648 Dekalb White chicks were used, from 1 to 35 days of age. The birds were housed in cages with the density recommended by the manual and distributed in a completely randomized design, consisting of 6 treatments, of 6 replicates and 18 birds per experimental unit, totaling 36 experimental units. The treatments consisted of a diet formulated with corn and soybean supplemented with 18, 30, 42, 54, 66 and 78 mg/kg of amino acid-complexed zinc, respectively. Water was provided ad libitum and the ration adjusted weekly according to the needs of the birds and the lineage manual. Welfare indicators were adapted and evaluated based on the Welfare Quality protocol for laying hens during the first 6 weeks of life. Amino acid-complexed zinc supplementation did not influence welfare indicators when aspects such as injury to the keel, skin, crest and foot pad, as well as plumage cover, deficiency and damage to the plumage in the brooding phase were observed.