Feed Enzymes Altered Sorghum Nutrient Digestibility of Sorghum Bioassay Diet

Sorghum due to presence of various antinutritional factors possesses reduced nutritive value for broiler birds. Microbial feed enzymes were examined to enhance the digestibility of sorghum nutrients by broilers at day-42. Sixty three birds, 35-day-old, were randomly allotted to three replicated (n=3) groups. Bioassay diets (n=3) in mash form with sorghum as sole source of protein (918 g/kg) with celite as an indigestible marker were prepared; a control and to others xylanase (4000 U/g) and phytase (10000 FTU/g) were added. All birds were offered these bioassay diets ad libitum from day 35 to 42 days of age. Bird were euthanized intracardially using sodium pentobarbitone injection (5ml/bird) and contents of the lower half of the ileum were collected and freeze dried. Approved standard scientific lab procedures were used to measure ileal nitrogen (Dumas combustion method) and gross energy (bomb calorimeter) of feed, ileal digesta and faeces. Digestibility coefficients and AME was measured. Phytase improved significantly ileal protein digestibility (0.80), IDE (14.32 MJ/Kg DM) and apparent metabolisable energy (AME) (14.90 MJ/kg DM). Xylanase also enhanced ileal digestible energy (IDE) (13.92 MJ/kg DM) and AME (14.40 MJ/kg DM) but did not significantly improved ileal protein digestibility (IPD). It was revealed from present research findings that microbial feed enzymes possesses the potentials to target certain antinutritional factors of sorghum to enhance its nutritive value for broiler birds at day-42.

Keyword: sorghum, broiler, digestibility, AME