ABSTRACT Two trials were carried out to evaluate the effect of groups of organic minerals with different chemical characteristics on the performance, egg quality, biometry of digestive organs, and bone quality of laying hens in the first and second laying cycles. In the first cycle, 180 layers at 72 weeks were used in a completely randomized design (CRD) with four treatments and five replicates with nine birds each. In the second cycle, 216 layers at 94 weeks of age were used in a CRD with four treatments and six replicates with nine birds each. Birds were fed the following diets: treatment 1 - basal diet (inorganic minerals); treatment 2 - basal diet + amino acid chelated minerals (Cu, Fe, Mn, and Zn) + selenium yeast; treatment 3 - basal diet + mineral-amino acid complex (Mn, Zn, and Cu); and treatment 4 - basal diet + metal chelate (Mn, Zn, and Cu) + methionine hydroxy analogue. The following performance variables were evaluated: feed intake (g/bird/day), egg production (%), egg weight (g), egg mass (g/bird/day), conversion per mass (kg/kg), and conversion per dozen eggs (kg/dz). In the egg, the percentages of albumen, yolk, and shell; eggshell thickness (mm); and specific gravity (g/cm3) were determined. The relative weights (%) of the proventriculus, gizzard, liver, pancreas, and intestines were also measured. Lastly, in the tibiae, the weight (g), length (mm), resistance (kgf/cm2), deformity (mm), Seedor index (mg/mm), and mineral matter content (g/kg) were measured. The variables were not influenced by the groups of organic minerals used. Groups of organic minerals with different chemical characteristics can be used in layer diets without affecting their performance, egg quality, digestive organs, or bone quality.

RESUMO Neste experimento objetivou-se de avaliar o desempenho, qualidade dos ovos e qualidade óssea das poedeiras comerciais leves em 2° ciclo de produção, submetidas às dietas contendo minerais orgânicos e inorgânicos e duas granulometrias do calcário. Foram utilizadas 216 aves, com peso médio de 1,527 ± 0,092 kg, distribuídas em um delineamento inteiramente casualizado em um esquema fatorial 2 × 2 (duas fontes de minerais e duas granulometrias do calcário), com seis repetições. Foram empregados quatro tratamentos a seguir: T1 = minerais inorgânicos + 100% de calcário fino; T2 = minerais inorgânicos + 50% de calcário fino + 50% de calcário grosso; T3 = minerais orgânicos + 100% de calcário fino e T4 = minerais orgânicos + 50% de calcário fino + 50 % de calcário grosso. Não houve interação significativa entre os fatores estudados para nenhuma variável. A produção de ovos, massa de ovo, resistência e deformidade óssea foram melhores com a suplementação orgânica. O peso da casca, percentagem da casca e a gravidade específica foram melhores nos tratamentos com a associação do calcário fino + grosso. Concluiu-se que suplementação mineral orgânica melhora o desempenho com base na produção de ovos e massa dos ovos. A utilização da associação do calcário fino com o de maior granulometria melhora a qualidade externa dos ovos. A utilização de minerais orgânicos melhora a qualidade óssea das aves, em 2° ciclo produtivo.

SUMMARY The aim of this experiment was to evaluate the performance, egg quality, and bone quality of commercial white-egg layer hens in the second production cycle fed diets containing organic and inorganic minerals and two limestone particle sizes. A total of 215 birds with an average weight of 1.527 ± 0.092 kg were distributed in a completely randomized design in a 2 × 2 factorial arrangement (two mineral sources and two limestone particle sizes) with six replicates. The following four treatments were tested: T1 = inorganic minerals + 100% fine limestone; T2 = inorganic minerals + 50% fine limestone + 50% coarse limestone; T3 = organic minerals + 100% fine limestone; and T4 = organic minerals+ 50% fine limestone + 50% coarse limestone. No significant interaction occurred between the studied factors for any variable. Egg production, egg mass, bone resistance and bone deformity were higher with organic supplementation. Eggshell weight, percentage of eggshell, and specific gravity were higher in the treatments with the fine+coarse limestone association. In conclusion, organic mineral supplementation improves the performance based on egg production and egg mass. The association between fine and larger-sized limestone improves the external quality of eggs. The use of organic minerals improves the bone quality of birds in the second production cycle.