This study evaluated the effect of substituting corn and soybeans in broiler chickens' diets by incorporating unfermented or fermented palm kernel cake (PKC). Totally, 240 of 3-day-old male Arbour Acres chicks were divided into 4 groups, with 6 replications each and 10 chicks per replicate. Broiler chickens consumed the basal diet in the control group, the basal diet with a 10% substitution of either unfermented PKC in the PKC group or fermented PKC in the LPKC group, and the basal diet with a 20% substitution of fermented PKC in the MPKC group. The experiment period was 42 days, and the PKC fermentation process took 48 h in an incubator set at pH 4.8 and 37 degrees C with a mix of Lactobacillus plantarum LY19, Bacillus natto NDI, acid protease (250 U/g), cellulase (160 U/g), and mannanylanase (45 U/g). The results showed that there was no significant difference across the PKC, LPKC, or MPKC groups in the broiler chickens' growth performance (ADG, FI, FCR) and most serum biochemical indices (p > 0.05) compared to the control group. Fermented PKC, particularly LPKC, improved the broiler chicken's nutrient digestibility and digestive enzyme activity compared to the control group (p < 0.05). The nutrient transporter gene expressions of SLC3A1 and SLC5A1, or SLC3A1 and SLC5A10, were downregulated, respectively, in the MPKC and PKC groups compared to those in the control group (p < 0.05). Considering our findings and the feed costs, the PKC and LPKC should be suggested to farmers for broiler chickens." in the publication instead of "This study evaluated the effect of substituting corn and soybeans in broiler chickens' diets by incorporating unfermented or fermented palm kernel cake. 240 broiler chicks (3-day-old male Arbor Acres chicks) were divided into 4 groups, with 6 replications each and 10 chicks per replicate. Broiler chickens consumed the basal diet in the control group, the basal diet with a 10% substitution of either unfermented or fermented palm kernel cake (PKC) regarded as the unfermented palm kernel cake (PKC group) or fermented palm kernel cake (LPKC group), and the basal diet with a 20% substitution of fermented palm kernel cake regarded as the MPKC group. The experiment period was 42 days, and the PKC fermentation process took 48 hours in an incubator set at pH 4.8 and 37 degrees C with a mix of Lactobacillus plantarum LY19 and Bacillus natto NDI. Acid protease (250 U/g), cellulase (160 U/g), and mannanylanase (45 U/g) were also added. The results showed that there was no significant difference across the PKC, LPKC, or MPKC groups in the broiler chickens' growth performance (ADG, FI, FCR) and most serum biochemical indices (p > 0.05) compared to the control group. Fermented PKC, particularly LPKC, improved the broiler chicken's digestibility of crude protein, gross energy, crude fiber, lactase, and trypsin enzyme activities compared to the control group (p < 0.05). The nutrient transporters gene expressions of solute carrier family 3 member 1 (SLC3A1) and solute carrier family 5 member 1 (SLC5A1), or solute carrier family 3 member 1 (SLC3A1) and solute carrier family 5 member 10 (SLC5A10) were downregulated, respectively, in the MPKC and PKC groups compared to those in the control group (p < 0.05). Based on our findings (higher growth performance, nutrients digestibility, and gene expression of nutrient transporters) and the feed's cost (associated with bacteria and hydrolysis enzymes), the PKC and LPKC should be suggested to farmers for broiler chickens.
