The effects of inclusion levels of a phytogenic feed additive(PFA), characterized by menthol anethol and eugenol, on broiler growth performance, nutrient digestibility, biochemical biomarkers and total antioxidant cap...The effects of inclusion levels of a phytogenic feed additive(PFA), characterized by menthol anethol and eugenol, on broiler growth performance, nutrient digestibility, biochemical biomarkers and total antioxidant capacity(TAC) of plasma and meat, as well as on the relative expression of selected cytokines,were studied in a 42-d experiment. A total of 225 one-day-old male Cobb broiler chickens were assigned into 3 treatments, with 5 replicates of 15 chickens each. Chickens were fed maize-soybean meal basal diets following a 3 phase(i.e., starter, grower and finisher) feeding program. Depending on PFA inclusion level, treatments were: no PFA(PFA-0), PFA at 100 mg/kg(PFA-100) and PFA at 150 mg/kg(PFA-150).Feed and water were available ad libitum. Feed conversion ratio(FCR) during finisher phase was improved quadratically(P < 0.05) with increasing PFA level. Overall, increasing PFA level increased body weight gain(BWG) in a linear(P < 0.05) and quadratic(P < 0.05) manner with treatments PFA-100 and PFA-150 being greater(P < 0.05) compared with PFA-0. Total tract apparent digestibility of dry matter increased linearly(P < 0.05) and quadratically(P < 0.05) with increasing PFA level. The apparent metabolizable energy corrected for nitrogen(AMEn) also increased linearly(P < 0.05). Increasing PFA level resulted in a linear(P < 0.05) increase in blood plasma TAC. Expression of pro-inflammatory cytokine interleukin-18(IL-18) was reduced linearly(P < 0.05) in spleen with increasing PFA level. In conclusion, PFA inclusion at 100 mg/kg diet positively influenced performance, whereas PFA inclusion at150 mg/kg resulted in a stronger improvement in AMEn and plasma TAC. Finally, PFA inclusion resulted in a pattern of reduced pro-inflammatory biomarker IL-18 at spleen. Overall, this study provides evidence for the beneficial role of PFA as a natural growth and health promoter in broiler chickens that needs to be further confirmed in field studies.展开更多
The aim of this work was to compare the efficacy of a commercially available phytogenic feed additive(PFA) and an antibiotic growth promoter, which was bacitracin methylene disalicylate(BMD), on performance, nutrient ...The aim of this work was to compare the efficacy of a commercially available phytogenic feed additive(PFA) and an antibiotic growth promoter, which was bacitracin methylene disalicylate(BMD), on performance, nutrient retention, caecal colonization of bacteria and humoral immune responses against Newcastle disease in broiler chickens challenged orally with Salmonella enteritidis and Escherichia coli.One-day-old male Cobb 400 broiler chicks(n = 120) were fed with 1) a negative control(NC) diet, which is the basal diet without any added growth promoter, 2) a positive control(PC) diet, the basal diet supplemented with BMD, 500 mg/kg and 3) a diet supplemented with PFA(150 mg/kg) for 39 days and the birds were inoculated with S. enteritidis and E. coli on d 28. Supplementation of PFA improved body weight, feed conversion ratio, retention of N and crude fiber, increased fecal moisture content and decreased digesta transit time as compared with the NC and PC groups(P <0.01). Both the PC and the PFA was found to be equally effective in controlling the surge in numbers of Salmonella and E. coli following oral inoculation of these bacteria as compared with the NC group(P <0.05) at 24 h past inoculation. Caecal content analysis on d 39 indicated lower numbers of Salmonella, E. coli and Clostridium in the PC and PFA groups as compared with the NC group(P <0.05). The number of Lactobacillus in the PFA group was higher than those in the NC and PC groups(P <0.05). Humoral immune response,measured as hemagglutination inhibition titer against Newcastle disease, was better in the PC and PFA groups compared with the NC group(P <0.05) at d 21 but the difference did not last till d 39. The heterophil to lymphocyte ratio was narrower(P <0.001) and alkaline phosphatase activity was higher(P <0.01) in the PFA group as compared with the NC and PC groups on d 39. It was concluded that the PFA, which is animal, environment and consumer friendly, may be used as an effective replacement for common in-feed antibiotics like BMD to enhance broiler performance especially when the birds are exposed to heavy infections on fields.展开更多
基金Biomin Holding GmbH for provision of the PFA and acknowledge for funding(grant no 73.00.00.06.0012) this research work
文摘The effects of inclusion levels of a phytogenic feed additive(PFA), characterized by menthol anethol and eugenol, on broiler growth performance, nutrient digestibility, biochemical biomarkers and total antioxidant capacity(TAC) of plasma and meat, as well as on the relative expression of selected cytokines,were studied in a 42-d experiment. A total of 225 one-day-old male Cobb broiler chickens were assigned into 3 treatments, with 5 replicates of 15 chickens each. Chickens were fed maize-soybean meal basal diets following a 3 phase(i.e., starter, grower and finisher) feeding program. Depending on PFA inclusion level, treatments were: no PFA(PFA-0), PFA at 100 mg/kg(PFA-100) and PFA at 150 mg/kg(PFA-150).Feed and water were available ad libitum. Feed conversion ratio(FCR) during finisher phase was improved quadratically(P < 0.05) with increasing PFA level. Overall, increasing PFA level increased body weight gain(BWG) in a linear(P < 0.05) and quadratic(P < 0.05) manner with treatments PFA-100 and PFA-150 being greater(P < 0.05) compared with PFA-0. Total tract apparent digestibility of dry matter increased linearly(P < 0.05) and quadratically(P < 0.05) with increasing PFA level. The apparent metabolizable energy corrected for nitrogen(AMEn) also increased linearly(P < 0.05). Increasing PFA level resulted in a linear(P < 0.05) increase in blood plasma TAC. Expression of pro-inflammatory cytokine interleukin-18(IL-18) was reduced linearly(P < 0.05) in spleen with increasing PFA level. In conclusion, PFA inclusion at 100 mg/kg diet positively influenced performance, whereas PFA inclusion at150 mg/kg resulted in a stronger improvement in AMEn and plasma TAC. Finally, PFA inclusion resulted in a pattern of reduced pro-inflammatory biomarker IL-18 at spleen. Overall, this study provides evidence for the beneficial role of PFA as a natural growth and health promoter in broiler chickens that needs to be further confirmed in field studies.
文摘The aim of this work was to compare the efficacy of a commercially available phytogenic feed additive(PFA) and an antibiotic growth promoter, which was bacitracin methylene disalicylate(BMD), on performance, nutrient retention, caecal colonization of bacteria and humoral immune responses against Newcastle disease in broiler chickens challenged orally with Salmonella enteritidis and Escherichia coli.One-day-old male Cobb 400 broiler chicks(n = 120) were fed with 1) a negative control(NC) diet, which is the basal diet without any added growth promoter, 2) a positive control(PC) diet, the basal diet supplemented with BMD, 500 mg/kg and 3) a diet supplemented with PFA(150 mg/kg) for 39 days and the birds were inoculated with S. enteritidis and E. coli on d 28. Supplementation of PFA improved body weight, feed conversion ratio, retention of N and crude fiber, increased fecal moisture content and decreased digesta transit time as compared with the NC and PC groups(P <0.01). Both the PC and the PFA was found to be equally effective in controlling the surge in numbers of Salmonella and E. coli following oral inoculation of these bacteria as compared with the NC group(P <0.05) at 24 h past inoculation. Caecal content analysis on d 39 indicated lower numbers of Salmonella, E. coli and Clostridium in the PC and PFA groups as compared with the NC group(P <0.05). The number of Lactobacillus in the PFA group was higher than those in the NC and PC groups(P <0.05). Humoral immune response,measured as hemagglutination inhibition titer against Newcastle disease, was better in the PC and PFA groups compared with the NC group(P <0.05) at d 21 but the difference did not last till d 39. The heterophil to lymphocyte ratio was narrower(P <0.001) and alkaline phosphatase activity was higher(P <0.01) in the PFA group as compared with the NC and PC groups on d 39. It was concluded that the PFA, which is animal, environment and consumer friendly, may be used as an effective replacement for common in-feed antibiotics like BMD to enhance broiler performance especially when the birds are exposed to heavy infections on fields.
