Abstract
The objective of this study was to evaluate the effects of supplementing Pediococcus acidilactici CNCM I-4622 MA 18/5 M (PA) into diets with two energy levels on the production performance and intestinal function of Lohmann pink laying hens from 49 to 65 weeks of age. A total of 1400 hens were used in this study. A 2 × 2 + 1 experimental design with 2 metabolic energy levels (2700.00 kcal/kg, NE; 2625.00 kcal/kg, LE), two PA levels (0 mg/kg, 110 mg/kg), and one group with intermittent PA supplementation (LE-0/PA). The experiment comprised 5 treatments with 14 replications each, and each replication had 20 hens. The results showed that reducing the dietary energy level tended to decrease body weight (P = 0.056). However, supplementing PA in low-energy diets tended to increase body weight in 16 weeks (P = 0.063). The LE-0/PA group had higher laying rates and feed utilization rates compared to other groups (P > 0.05), maybe resulting in greater economic benefits. The LE group had significantly lower eggshell strength, Haugh unit, trypsin activity, lipase activity, and tibia breaking strength compared to the NE group (P < 0.05). Dietary supplementation with PA significantly increased eggshell strength (P < 0.05), tibia breaking strength, villus height/crypt depth ratio (VH/CD), lipase activity, and secretory immunoglobulin A (SIgA) content in the jejunum (P < 0.05). Additionally, PA supplementation significantly reduced the expression of interleukin 8 (IL-8), tumor necrosis factor-α (TNF-α), toll-like receptor 4 (TLR-4), and nuclear factor kappa-B (NF-κB) mRNA (P < 0.05). In conclusion, reducing the dietary energy level of hens can reduce the body weight and feed utilization efficiency. However, dietary PA supplementation improved body weight, reduced the expression of intestinal inflammation-related factors, and enhanced intestinal health, particularly in low-energy diets. Intermittent PA supplementation may enhance performance benefits, suggesting its potential as a strategy to optimize production performance and intestinal health in hens.