Abstract
This study aimed to evaluate the effects of mineral sources and rosemary oil levels in the diet of commercial layers on the qualitative and quantitative characteristics of the waste generated. Manure was obtained from 288 commercial laying hens of the HyLine Brown lineage (semi-heavy layers) at 30 weeks of age over a period of 112 d (four cycles of 28 d). A completely randomized design was used with a 2×3 factorial scheme with repeated measures over time (16 repetitions), with two mineral sources (inorganic and organic) and three levels of rosemary oil (0, 100, and 200 mg kg-1). The waste was collected weekly, weighed, and the calculations of waste production, residue coefficient (RC) were performed. Also analyses of total solids (TS), volatile solids (VS), pH, macro-, and micro-minerals were performed. Mineral sources affect the quality characteristics of the manure. The amount of rosemary oil affected the quantitative and qualitative characteristics of the waste generated. It was concluded that diets containing organic minerals resulted in waste with less polluting power, as it had a lower TS, pH, total N, and total P values. Rosemary oil increased manure production in natural matter (NM) and increased the TS and VS values in the manure layer, causing a greater environmental impact.
Keywords:
additives; organic mineral; residue; Rosmarinus officinalis