The objective was to investigate the effect of increasing concentrations of fish waste silage (FWS) in diets on growth performance, gastrointestinal microbial population, and intestinal morphology of broiler chickens. Fish waste (FW) was fermented with 15 g/kg molasses and Lactobacillus plantarum (PTCC1058) and Aspergillus oryzae (PTCC5163). A total of two hundred forty 1-day-old male broiler chickens were assigned to one of 5 dietary treatments including a corn-soybean meal based control diet as well as 4 experimental diets in which the control diet was supplemented with 30, 60, 90, and 120 g FWS/kg feed. The use of the fermentation process resulted in the reduction of pH and ether extract and the increase in the crude protein content (from 570.2–608.1 g/kg) and lactic acid bacteria (LAB) count in FW. The results showed that feed conversion ratio improved (p < 0.05) linearly and quadratically as the inclusion of FWS increased at 42 day. Liver (g/100 g body weight) and LAB population in the crop increased (p < 0.05) and coliforms population in the ileum decreased (p < 0.05) linearly and quadratically with the increased concentration of FWS in diet. The soybean meal replacement by the FWS increased (p < 0.05) linearly and quadratically villus height to crypt depth ratio in the jejunum. In conclusion, fermentation process is effective in improving of the nutritive values of the FW. Moreover, FWS feeding improved the growth performance and intestinal health of broiler chickens, and can be considered as a suitable alternative protein source for soybean meal in the broiler chicken diet.

Keywords