ABSTRACT
In the intestinal lumen, excess of oxides and sulfates interfere with the absorption of minerals due to competition from the same absorption site. Amino acids-mineral complexed (AACM) is intended to minimize these problems, which might be absorbed by different absorption sites. Then, a study including Zinc (Zn), Manganese (Mn) and Copper (Cu) from different sources was carried out to evaluate the performance, blood parameters and reproductive organs development of Brown Laying Hens. A total of 800 Lohmann Brown Lite were fed, from one-day-old to 182-days-old, Zn, Mn and Cu from different sources. Measurements were made from 105 to 182-days-old. The laying hens were distributed according to a completely randomized design with 20 replicates and 20 birds per experimental unit. The treatments consisted of a diet supplemented with 70, 70 and 8 mg/kg of Zn, Mn and Cu; respectively, from inorganic sources (IM). The second treatment contained 40, 40 and 2.75 mg/kg of Zn, Mn and Cu, respectively from IM plus 30, 30 and 5.25 mg/kg of Zn, Mn and Cu; respectively, from AACM sources. Performance and reproductive organs development (oviduct and ovary weight), tibia weight, liver weight, egg output and body weight, and blood variables were evaluated. Data were compared by Student's t-test (P < 0.05). Laying hens fed AACM reached 35% of egg output two days earlier and presented heavier tibia bone than the IM group. Those hens also presented greater oviduct weight, greater hematocrit and greater serum concentration of total leukocytes, erythrocytes, eosinophils, monocytes and the hormones T4 and FSH, than the hens fed IM. The supplementation of AACM in laying hens' diets since one-day-old improves the productive performance from the beginning of egg output to peak production, which is justified by better development of bones and oviduct, hormone production and immune system support.
