Location: Livestock Behavior ResearchTitle: The effect of Brazilian propolis on serum thyroid hormones in broilers reared under chronic heat stress Author
|Cheng, Heng Wei|
Submitted to: International Poultry Scientific Forum
Publication Type: Abstract Only
Publication Acceptance Date: 12/20/2014
Publication Date: N/A
Citation: N/A Interpretive Summary:
Technical Abstract: This experiment evaluated the effect of dietary supplement with green Brazilian propolis on serum thyroxin (T4) and tri-iodothyronine (T3) levels in broiler chickens exposed to chronic heat stress for 4 wks (from 15 to 42 d of age). Five hundred and four 15-d-old, male broiler chickens (Ross 708) were randomly allocated to 1 of 6 treatments (4 pens/treatment; 21 birds/pen). The dietary treatments were basal diet (control) and 5 concentrations of propolis (100, 250, 500, 1000, and 3000 mg /kg diet, respectively). The average temperature and relative humidity during the day time was (31.7±0.3°C and 56±4%) while at night was (28.8±0.4°C and 58±3%) respectively. At 42 d of age, serum was collected from 12 birds in each treatment (3 birds per pen x 4 pens per group), and the thyroid hormones levels were measured using T4 and T3 chicken ELISA commercial kits. The data were analyzed by SPSS 22.00 software using the general linear models (GLM) followed by simple regression model procedure. Supplementation of broiler chickens diets with propolis did not significantly (P > 0.05) affect T4 and T3 concentrations in comparison to controls. However, there were treatment effects on the T3/T4 ratio. The hens fed with 250 mg/kg-1 had the highest T3/T4 ratio, which was significantly increased (P = 0.023) in comparison to controls, reflecting improvement in thyroid hormones secretions and higher conversion rate to the active form of thyroid hormone which is responsible for metabolism. In conclusion, the results indicated that dietary supplement with 250 mg kg-1 green Brazilian propolis may help broiler chickens to accommodate with the heat stress condition, so further investigation is recommended.