No abstract

Four cellulolytic and hemicellulolytic bacterial cultures were purchased from the Leibniz Institute DSMZ-German Collection of Microorganisms and Cell Culture (DSMZ) and the American Type Culture Collection (ATCC). Two experiments were conducted; the objective of the first experiment was to determine the optimum time period required for solid state fermentation (SSF) of palm kernel cake (PKC), whereas the objective of the second experiment was to investigate the effect of combinations of these cellulolytic and hemicellulolytic bacteria on the nutritive quality of the PKC. In the first experiment, the SSF was lasted for 12 days with inoculum size of 10% (v/w) on different PKC to moisture ratios. In the second experiment, fifteen combinations were created among the four microbes with one untreated PKC as a control. The SSF lasted for 9 days, and the samples were autoclaved, dried, and analyzed for proximate analysis. Results showed that bacterial cultures produced high enzymes activities at the 4th day of SSF, whereas their abilities to produce enzymes tended to be decreased to reach zero at the 8th day of SSF. Findings in the second experiment showed that hemicellulose and cellulose was significantly (P < 0.05) decreased, whereas the amount of reducing sugars were significantly (P < 0.05) increased in the fermented PKC (FPKC) compared with untreated PKC.

A feeding trial was conducted to investigate the effect of palm kernel cake fermented by Paenibacillus polymyxa ATCC 842 (FPKC) on broiler performance. A total of 245 1-day-old broiler chicks (Cobb 500) were raised in the conventional open-sided house. The birds were fed diets containing 0 (Control), 5%, 10% and 15% palm kernel cake (PKC) and 5%, 10%, 15% FPKC. The bodyweight and the feed intake were recorded. The bodyweight gain (BWG) and feed conversion ratio (FCR) were calculated. Carcass characteristics and meat quality were measured at the end of the experiment, whereas blood was collected at 21 (starter) and 42 days (finisher) to determine blood biochemistry. The results showed that the addition of 10% or 15% PKC in broiler diets led to a significant (P < 0.05) decrease in BWG and increase in FCR during the finisher phase or overall performance. However, BWG and FCR were improved (P < 0.05) in chickens fed with 10% or 15% FPKC compared with those fed with 10% or 15% PKC or the Control group. The relative weight of the gizzard was higher (P < 0.05) for the broiler group fed with 15% PKC compared with those birds fed the Control diet or FPKC at 3 weeks of age. No significant differences were observed among the dietary treatments in blood biochemistry, breast meat colour, drip loss, cooking loss and tenderness. In conclusion, the present experiment showed that palm kernel cake fermented by P. polymyxa ATCC 842 could be fed to broiler chickens up to 15% in their rations without any adverse effect on the growth performance and meat quality.