Effects of dietary probiotic (Pediococcus acidilactici) supplementation on productive performance, egg quality, and body composition in laying hens fed diets varying in energy density

This study was conducted to determine the effect of probiotic Pediococcus acidilactici (PA) strain MA18/5M supplementation of diets with different dietary energy levels on productive performance, egg quality, and body composition in Hy-Line Brown hens during a 16-week period from 32 to 47 wk of age. The experimental treatments with a 2 × 2 factorial design received a 2 wheat–corn–soybean diet: a moderately low energy density diet with 2,650 kcal ME/kg (M-LED) and a low energy density diet based on the M-LED diet with 2,550 kcal ME/kg (LED), each diet without and with probiotic supplementation (M-LED, LED, M-LEDp, and LEDp, respectively). Reduced dietary energy levels had a particularly negative effect on egg weight (61.7 vs. 63.3 g; −2.6%, P < 0.001), egg mass output (1.67 vs. 1.71 kg; −2.4%, P = 0.015), and FCR (2.01 vs. 1.97 kg feed/kg egg; +2%, P = 0.028). In hens administered the LED diet, deteriorated productive performance was accompanied by greater body weight loss (P < 0.001) and reduced abdominal fat content (P < 0.033) as compared with the M-LED group. Dietary probiotic inclusion increased egg weight (P = 0.015), including relative eggshell weight (P = 0.008) and eggshell thickness (P = 0.002) and significantly improved FCR (P = 0.010). No interactions between the PA-based probiotic and dietary energy levels were found in any of the tested parameters. Adding the probiotic on top of the M-LED diet improved layers performance but resulted in nonbioequivalence for the egg weight, egg mass output, and FCR compared with this group without probiotic. Probiotic supplementation of the LEDp diet improved all performance parameters except for egg weight. As a result, the laying rate, egg mass output, daily feed intake, and FCR in the LEDp treatment were bioequivalent to those noted in the M-LED group without the probiotic. The results of a bioequivalence test suggest that a low energy diet fed to laying hens promoted a probiotic response to improve energy utilization by birds.