Effect of chitin and protein constituents in shrimp head meal on growth performance, nutrient digestibility, intestinal microbial populations, volatile fatty acids, and ammonia production in broilers

Two experiments were conducted to evaluate the effects of chitin and protein constituents in shrimp meal (SM) on growth performance, nutrient digestibility and retention, intestinal microbial populations, volatile fatty acids, and ammonia production in broilers. In experiment 1, 54 seven-day-old male chicks were randomly allotted to individual cages and fed 1 of 9 diets (1 control, 4 SM, and 4 purified chitin) for 28 d (with 6 replicates of each treatment). In experiment 2, one-day-old-male chicks (n = 400) were randomly distributed into 5 dietary treatment groups [1 control and 4 SM (5, 10, 15, and 20%)] through 42 d of age. Growth performance and DM, organic matter, ash, and chitin digestibility values and N retention did not change significantly when SM was at or below 15%. Feeding broilers SM resulted in increased populations of intestinal Lactobacillus and decreased intestinal Escherichia coli and cecal Salmonella. The cecal butyric acid concentration in broilers fed SM was also significantly increased. There were no significant effects of purified chitin on any of the studied parameters. However, feeding chitin from SM and purified chitin resulted in similar effects in reducing ammonia levels. Therefore, we conclude that up to 15% SM can be used in broiler diets. In addition, SM may potentially modulate microbial population growth and alter volatile fatty acid and ammonia production.