Uso de microminerais sob a forma de complexo orgÃnico em raÃÃes de frangas na fase de recria. / Use of trace minerals in the form of organic complex in diets of rearing pullets.

AUTOR(ES)
DATA DE PUBLICAÇÃO

2005

RESUMO

The experiment was carried out in the Section of Poultry Production of the Department of Animal Sciences at the Federal University of Lavras - UFLA, in Lavras, MG, Brasil. It was aimed to study the effects of mineral trace in the organic complex in diets of pullets in the rearing phase, on the performance and bone characteristics in the period of 7-16 weeks, as well as the peformance of the laying hens up to the 32nd week of age. The treatments consisted of the supplementation of mineral trace in the inorganic form (control treatment) and organic form with inclusion of 0.4% in the diet, that corresponds to the supplementary levels of 60, 80, 70, 10, 1 and 0.3 ppm of zinc, iron, manganese, copper, iodine and selenium respectively, and the reduction of the supplementation of mineral trace in the form organic complex with the inclusion levels in the diets: 0.35; 0.3; 0.25 and 0.2%. The diets were based on corn and soybean meal, balanced according to nutrient recommendations by Lohmann - LSL Strain Handbook (2002). A total of 648 pullets Lohmann - LSL, at 42 days old were used. Eighteen and sixteen birds were considered as experimental unit in the periods from 7 to 12 and 13 to 16 weeks of age, respectively,distributed in a completely randomized design with 6 treatments and 6 replicates. In the egg production phase a completely randomized design was used in split plot in time (4 periods of 21 days), with 6 replicates and 12 birds per plot, receiving the same diet, for evaluation of the effects of the applied treatments in the rearing phase of pullets. There were not significant differences (P>0,05), among the treatments for performance characteristics in the phase from 7 to 12 and 7 to 16 weeks. The uniformity was not influenced (P>0,05), in the 12th and 16th weeks of age of the birds. There was a linear reduction (P<0,05), of the porcentage of ashes in the tibias of the pullets at the 12th week with the reduction in the levels of addition of the organic supplement. However there was no significant difference for this characteristic (P>0,05) in the 16th and 32nd weeks. The percentage of zinc in tibias, as well as the weight, length, thickness and bone index of the tibia and femur and, the density of the femur were not influenced by any treatment (P>0,05), in the 12nd and 16th weeks, as well as characteristic performance and quality of the eggs in the period from 20 to 32 weeks. Under these conditions the organic source of mineral trace supplementation showed a comparative advantage relative to the inorganic source. The reduction in the levels of 30, 40, 35, 5, 0.5 and 0.15 ppm of zinc, iron, manganese, copper, iodine and selenium, respectively, is possible without affecting the performance and bone characteristics in the rearing of the pullets, or the performance and quality of the eggs up to the 32nd week of age.

ASSUNTO(S)

laying hens monogastric nutrition zootecnia nutriÃÃo de monogÃstrico podeira

ACESSO AO ARTIGO

Documentos Relacionados