Value of Aspergillus niger fermentation product as a dietary ingredient for broiler chickens

The experiment reported was a study on Aspergillus niger inoculation into the waste liquor from glutamate manufacturing and used as a dietary protein source for broilers. The program involved a toxicological and nutritional evaluation of the product using a short-term toxicity and a nutritional feeding trial in broilers. Both trials involved a total of 800 broilers from the commercial Arbor Acres strain. Equal numbers of males and females were randomly allocated into 20 pens with five dietary treatments and four replicates for the 6-week feeding trials. The dietary treatment involved graded levels of SCP inclusion, 0, 47, 95, 142, 189 g/kg and 0, 35.5, 71, 106.5, 142 g/kg, in starter and finisher maize–soya bean meal basal rations, respectively. Blood and specimens from various visceral organs were taken at the end of the toxicological trial for analysis of blood constituents and for clinical and pathological examination. Data on the performance and nutrient utilization efficiency were recorded during the feeding trial. Carcass analysis and a taste panel were also conducted to evaluate consumer acceptance at the end of the trial. Results showed that the intestinal weights of certain intestinal segments increased (P<0.05), and the red blood cell (RBC), hemoglobin (Hb), hematocrit and blood enzyme activity, aspartate amino transferase (AST) and alanine amino transferase (ALT), significantly decreased as the dietary level of SCP increased (P<0.05). Pathological results did not show any abnormality due to the SCP inclusion. Increasing amounts of SCP inclusion in the broiler diet linearly depressed weight gain and feed conversion in the 0–6 week broilers (P<0.05). Each 10 g increment of SCP in kilogram diet decreased the live-weight gain of the broilers by 6.3 g and required an increase of 0.14 g feed to convert to 100 g of gain. Increased levels of SCP inclusion, however, showed a trend toward depressed feed intake during the finishing period (P=0.053) and the entire feeding period (P=0.053). Inclusion of SCP did not significantly influence the color, aroma and tenderness of breast meat, but significantly influenced breast meat flavor (P<0.05). The flavor of the breast meat linearly increased as the concentration of dietary SCP increased (Y=2.88+0.0137X) (Syx=0.88; P<0.05).