Location: Livestock Behavior ResearchTitle: Brazilian propolis effects on performance, gut characteristics and physiological changes in broiler chickens
|MAHMOUND, U. - Assuit University|
|AMEN, O. - Assiut University|
|APPLEGATE, T. - University Of Georgia|
|Cheng, Heng Wei|
Submitted to: Animal Feed Science and Technology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 4/20/2017
Publication Date: N/A
Interpretive Summary: Propolis has received great attention for improving human health. Similar to human research, propolis has been used as a diet supplement in domesticated poultry species (broilers, layers, and ducks) with the aim to reduce or eliminate the use of antibiotics and synthetic chemicals as growth promoters. The positive findings of propolis on performance and health of broiler chickens reared under heat stress indicate that the use of propolis as a natural feed additive is promising. However, further research on the best technique and dose for its application to poultry farms is still needed. This information can be used by poultry producers and scientists to develop management guidelines for improving chicken welfare.
Technical Abstract: This study was to determine the effect of dietary propolis on the growth performance, physiological homeostasis and gut characteristics in broiler chickens reared under mild chronic heat stress (32 celsius), 9 hours daily for 28 days. Five hundred and four 15-d-old male broiler chicks were fed one of six diets (0, 100, 250, 500, 1000 and 3000 mg kg-1 propolis). The results indicated that dietary propolis supplementation had no effect on growth performance and liver, heart, gizzard and spleen weights. While, compared to controls, the abdominal fat weight was increased in birds fed propolis at 100, 250 or 500 mg kg-1 (P = 0.035). Propolis did not affect cecal concentrations of Escherichia Coli, total coliforms, Enterococcus spp., and total lactobacilli. However, compared to controls, the Bifidobacterium spp. population was reduced in birds fed propolis at 1000 mg kg-1 (P = 0.005). Compared to controls, propolis dietary supplementation did not affect the populations of blood white cells (eosinophil, monocyte and basophil) or measured serum metabolite profiles (total proteins, globulins, phosphate, calcium and glucose). In addition, there were no treatment effects on serum concentrations of thyroid hormones and mRNA expression of HSP70 in brain tissues. However, propolis, regardless of dose, reduced the number of heterophils, heterophil: lymphocyte ratio (H/L), serum corticosterone and aminotransferase concentrations (P < 0.05, respectively). In addition, all doses of propolis, except for 100 mg kg-1, increased circulating lymphocytes (P < 0.05) and reduced uric acid concentrations (P < 0.05). In addition, compared to controls, birds fed 250 mg kg-1 propolis had a higher T3/T4 ratio (P < 0.05), while birds from both 100 and 3000 mg kg-1 propolis groups had higher serum albumin concentrations (P < 0.05, respectively). In conclusion, our findings suggest that dietary supplementation of green propolis at the tested doses improves health status and welfare in birds by reducing adverse effects of heat stress.