Effects of fermented palm kernel cake on growth performance, intestinal health, cecal microbiota, and ammonia emission in broilers

This study was conducted to evaluate the effects of fermented palm kernel cake (FPKC) on growth performance, intestinal health, cecal microbiota, nitrogen metabolism, and ammonia emission reduction of broiler chickens. A total of 900 healthy 21-d-old Arbor Acres broilers were randomly assigned to 5 dietary treatments with 6 replicates per treatment: a basal diet (control (CON) group) and diets containing 4% (T1 group), 8% (T2 group), 12% (T3 group), or 16% (T4 group) FPKC for a 21-d feeding period. The results showed that compared with the CON group, T1, T2 and T3 groups had no adverse effects on growth performance (P > 0.05), whereas T4 group significantly increased feed-to-gain ratio (P < 0.05). Compared with the CON group, T2 and T3 groups significantly increased villus height, villus height-to-crypt depth ratio, and digestive enzyme activities in the duodenum and jejunum (P < 0.05). Moreover, the T2 and T3 groups showed significantly lower serum d-lactate, diamine oxidase, endotoxin, fecal pH, and ammonia emissions than the CON group (P < 0.05). In contrast, compared with the CON group, T4 group impaired intestinal morphology, disrupted nitrogen metabolism, and reduced serum total protein (P < 0.05). 16S rRNA sequencing showed that FPKC inclusion altered the cecal microbiota composition by increasing Faecalibacterium, Shuttleworthia, Erysipelatoclostridium, Flavonifractor and reducing Lactobacillus, Bacillus, Eubacterium, and Bifidobacterium abundance (at genus level), which are mainly associated with the production of short-chain fatty acids and protein fermentation. Collectively, FPKC can be included in broiler diets at levels up to 12% to improve intestinal health and reduce ammonia emission without compromising growth performance.