RESUMEN
The aim of the present study was to evaluate the effect rosemary (Rosmarinus officinalis L.) powder (RP) and vitamin E (VE) at different levels on humoral immunity of broilers during a 42-day production cycle. A total of 270 1-day-old male chicks were assigned to nine groups with three replicates of ten birds each, and diets were supplemented with 0, 0.5, or 1.0% RP and 0, 100, or 200 mg/kg VE, respectively. Commercial-inactivated vaccines against avian influenza (AI) and Newcastle disease (ND) viruses, and living infectious bronchitis virus (IBV) vaccine were administered by spray method. Sheep red blood cells (SRBC) were administered subcutaneously. Blood samples were collected from birds 1 week after each vaccination to determine antibody titers. At the 42nd day, blood samples were also assessed for globulin level, and lymphoid tissues (thymus, spleen, and bursa) were weighed. Neither antibody titers against viruses nor lymphoid tissues weight were affected by RP and/or VE (P > 0.05) treatments. However, broilers supplemented with 0 mg/kg of VE had lower antibody titers against SRBC than those fed 100 mg/kg of VE (P < 0.05) at the 24th day. A significant RP × VE interaction effect (P < 0.05) on plasma globulin level was observed. The findings of our study suggest that dietary RP and VE additives can interact and modulate the humoral immunity of broilers, but not sufficiently to improve antibody titers against specific virus during a 42-day production cycle.
Asunto(s)
Pollos/inmunología , Dieta/veterinaria , Inmunidad Humoral/efectos de los fármacos , Rosmarinus/química , Vitamina E/farmacología , Animales , Proteínas Sanguíneas , Suplementos Dietéticos , Virus de la Bronquitis Infecciosa , Masculino , Virus de la Enfermedad de Newcastle , Ovinos , Vitamina E/químicaRESUMEN
The aim of the present study was to evaluate the effect of rosemary (Rosmarinus officinalis L.) powder and vitamin E, as feed additives combined at different levels, on oxidative stability of broiler meat up to 14th day after chilling. A total of 270 1-day-old male chicks of Ross 308 strain were randomly assigned to nine dietary groups with three replicates having 10 birds each. Diets were supplemented with 0, 0.5, or 1.0% of rosemary (R) powder and 0, 100, or 200 mg/kg of vitamin E (alpha-tocopherol acetate; VitE) according to the following treatments: T1 - control basal diet (0R + 0VitE); T2 - 0R + 100VitE; T3 - 0R + 200VitE; T4 - 0.5R + 0VitE; T5 - 0.5R + 100VitE; T6 - 0.5R + 200VitE; T7 - 1.0R + 0VitE; T8 - 1.0R + 100VitE; and T9 - 1.0R + 200VitE. At day 42, two birds of each replicate were slaughtered and the length and weight of cecum was recorded. Carcasses and their economically valuable parts were also weighted and broiler breast refrigerated at 4°C for 14 days. At day 0, 4, 7, and 14 of storage the malondialdehyde (MDA) content of breast meat was evaluated. After 4 days of storage, meat MDA contents of the T5 (0.43 mg/kg) and T9 (0.41 mg/kg) were lower than control group (T1: 0.55 mg/kg; p < .05). On day 7, groups supplemented with rosemary or VitE alone showed similar MDA contents (p > .05) than control. On day 14, lower (p < .05) MDA contents than T1 were observed in all groups except for broilers fed diet supplemented only with vitamin E. No effects were observed between treatments on the relative weight of the several carcass traits, however, VitE influenced (p < .05) the weight and size of cecum. Based on our findings, the combination of rosemary powder and vitamin E at different levels in diet is useful to limit the lipid oxidation of chilled chicken meat.