Crude propolis as an immunostimulating agent in broiler feed during the first stage

Resumo

The experiment herein was conducted to evaluate the efficacy of supplementing a broiler diet with crude propolis on the animals’ immune response (humeral and cellular), lymphoid organ weight and hematological profile. One hundred sixty-eight male broilers raised in metabolic cages until 21 days of age were used in the experiments. The birds were randomly distributed in an experimental design with six treatments that consisted of different crude propolis doses (0, 100, 200, 300, 400 and 500 ppm); the experimental unit was repeated seven times with four birds each. Including crude propolis in the food did not affect (P<0.05) the relative weights of the thymus, spleen and cloacal bursa or serum antibody production against Newcastle disease. The macrophage phagocytic activities were quadratic (P<0.05) in accordance with the level of crude propolis; the lowest activity observed corresponded to a 350.72 ppm dose of crude propolis. Moreover, when each crude propolis dose was compared with the control group, the birds fed 100 ppm and 500 ppm of crude propolis had higher levels of phagocytic activity (P<0.05) and a greater number of red blood cells phagocytized per macrophage (P<0.05), respectively. No change in nitric oxide production was observed (P>0.05). The interdigital reaction to the phytohemagglutinin displayed quadratic behavior as a function of time and crude propolis dose. Using the adjusted equation, the 275.45 ppm crude propolis dose and 39.35 hours produced the lowest and highest reaction values. Inclusion of 100 ppm crude propolis in the broiler feed was an effective immunostimulatory agent for cell-mediated responses.