This study evaluated the efficacy of red-osier dogwood extracts (RDE) as an alternative to in-feed antibiotics on performance, intestinal digestive and absorptive function, intestinal microbiota and meat quality in broiler chickens. A total of 320 day-old Cobb 500 chicks (48.3 ± 3.3 g) were assigned to 4 dietary treatments (8 replicates per treatments) as follows:1) negative control (NC) corn-soybean basal diet, 2) positive control (PC) basal diet and 30 ppm avilamycin, 3) basal diet supplemented with 1000 ppm RDE (RDE1) 4) basal diet with 3000 ppm RDE (RDE2). There were no significant differences in average daily gain, average daily feed intake, feed conversion ratio and organ weights among treatments (P > 0.05). Intestinal morphology showed reduced jejunal crypt depth and increased villus: crypt ratio in groups treated with RDE (P < 0.05). Cationic amino acid transporter mRNA expression was lower (P < 0.05) in the RDE and PC treatments while peptide transporter and neutral amino acid transporter were highly expressed (P < 0.05) in broilers in the RDE2 treatment compared to the NC. Ileal crude fat digestibility was higher in the RDE and PC compared to the NC while the ileal digestibility of amino acids was higher in the RDE1, RDE2 and PC groups (P < 0.05). The relative abundance of the ileal bacteria of orders (Turicibacterales, Bacillales and Clostridiales and Staphylococcus species) differed among treatments. Species richness between bacterial communities in the ileum and cecum was affected by treatments (P < 0.05). Tight junction proteins zonula occludens-1, and E-cadherins were expressed lower in RDE1, RDE2 and PC (P < 0.05) while claudin 1 remained unchanged (P > 0.05). Meat quality showed no difference in pH, drip loss, myofibrillar fragmentation index, shear force, lipid peroxidation and cook traits (P > 0.05). However, RDE2 treatment showed reduced redness compared to the NC (P < 0.05). In conclusion, RDE improved the intestinal environment and functions by improving digestion, absorption, barrier functions and microbiota diversity.
Keywords: red-osier dogwood, broiler chickens, growth performance, digestibility, meat quality.
Published in the proceedings of the Animal Nutrition Conference of Canada 2020. For information on the event, past and future editions, check out https://animalnutritionconference.ca/.