This study aimed to determine the impact of dietary black peppercorn (BP) and xylanase (XYL) alone or in combination on growth performance, dietary energy, nutrient digestibility and blood lipid profile when fed to male Ross 308 broiler chickens from the ages of 7 to 21 d. A wheat-soy-based basal feed that was formulated to be 0.42 MJ lower in metabolizable energy (ME) was mixed. The basal feed was then split into four batches, with the first batch set aside as the basal control; the second batch was supplemented with freshly milled BP; the third batch was supplemented with XYL; the fourth batch was supplemented with both BP and XYL, as in the previous two batches. Each diet was fed to eight pens, with two birds in a pen, following randomization. Feeding BP reduced bird growth and most of the digestibility coefficients but increased blood high-density lipoprotein (p < 0.05). Dietary XYL increased bird growth, dietary ME and nutrient digestibility (p < 0.05). In addition, XYL increased hepatic carotenoids and coenzyme Q10, but reduced blood low-density lipoprotein (p < 0.05). There were no BP by XYL interactions (p > 0.05) observed. Further research is needed to identify the optimum level of BP in broiler diets.
Keywords: ME; black pepper; blood lipid profile; broilers; digestibility; performance; xylanase.