Effect of eucalyptus oral extract and adding black pepper powder in diet on performance, blood metabolites and microbial population of intestine and syrinx of broiler chickens

Effect of using eucalyptus (Eucalyptus SPP) leaf chloroform oral extract (EE) and black pepper (Piper nigrum) powder (BP) in diet on growth performance, carcass traits, blood parameters and microbial populations of intestine and syrinx was investigated in a 42 days trial with 160 Cobb 500 day-old chicks divided into four treatments and four replicates as a completely randomized design. The treatments were 1- basal diet (control), 2- basal diet and adding 0.1 % EE solution in drinking water, 3- diet having 0.2% BP, and 4- diet having 0.2% BP and 0.1% EE solution in drinking water. Over the study, feed intake of chickens consumed oral EE or BP in diet and/or the combination of them was lower than chickens in control group (P<0.05). Weight gain and feed conversion ratio of chickens were not affected by the treatments. Oral EE resulted in greater percentile lungs weight and lower heart and abdominal fat weights in chickens (P<0.05). Using oral EE or BP in diet and/or the combination of them caused a significant decrease in serum concentrations of glucose, cholesterol and uric acid in chickens (P<0.05). Hematological parameters of chickens were not affected by the experimental treatments. Chickens consumed oral EE or BP in diet and/or the combination of them showed a significant lower intestinal E-coli population than control birds (P<0.05). Furthermore, using oral EE caused a decrease in Mycoplasma population of broilers Syrinx (P<0.05). The results showed that using oral EE leads to lowered abdominal fat and microbial populations of intestine and syrinx while adding BP in diet leads a decrease in microbial populations of intestine in broiler chickens.