Effect of probiotic and xylanase on growth performance, nutrient digestibility, blood profiles, and faecal microflora in growing pigs

There is evidence that probiotics, also referred to as direct-fed microbials (DFM), can improve gut microbial balance and intestinal health (Dersjant-Li et al. 2015). In addition, an interaction between multi-enzymes and DFM has been reported (Romero et al. 2013). The hypothesis of this study was that there might be a beneficial interaction when a probiotic and xylanase are fed to growing pigs.

A total of 120 growing pigs ((Yorkshire × Landrace) × Duroc) with an average bodyweight (BW) of 25.22 ± 1.88 kg were randomly allotted to four experimental diets based on initial BW and sex (six replicate pens per treatment; two gilts and three barrows/pen). The experiment lasted for 6 weeks and dietary treatments included: CON, basal diet, CON + 0.002% Enterococcus faecium (EF1), and CON + 0.005% E. faecium (EF2) and CON + 0.002% E. faecium + 0.01% Endo-1,4-β-xylanase (9000 U/g) (EX). Feed intake and BW were recorded initially at week 3 and 6 of the experimental period to calculate average daily gain (ADG), feed intake (ADFI), and gain to feed ration (G : F). Chromium oxide was added to the diet as an indigestible marker at 0.20% of the diet for 7 days before faecal collection at d 42, when samples were collected by rectal massage from at least two pigs per treatment to determine the digestibility (ATTD) of dry matter (DM), nitrogen (N) and energy. At week 6, blood samples (3 mL) were collected (four pigs/treatment) into non-heparinised tubes to obtain serum to determine the total cholesterol, high-density lipoprotein (HDL) cholesterol, and low-density lipoprotein (LDL), creatinine concentrations, blood urea nitrogen (BUN), and glucose concentrations. Faecal samples were collected directly via massaging the rectum of two pigs (one gilt and one barrow) in each pen and then pooled and placed on ice for transportation to the laboratory where analysis was immediately performed to determine faecal E. coli and Lactobacillus counts. Data were analysed in accordance as a completely randomised design using the GLM procedure (SAS v9, SAS Institute Inc., Cary, NC, USA). Pen was used as the experimental unit. Differences among the treatment means were determined by using the Tukey’s test with P < 0.05 indicating significance.

During the whole period, pigs fed the EX diet had increased ADG compared to pigs fed the CON and EF1 diets (718 g v. 643 and 681 g, respectively, P < 0.05). The ADG of pigs fed the EF2 diet increased compared to pigs fed the CON diet (703 g v. 643 g, respectively, P < 0.05). The G : F of pigs fed the EF2 and EX diets increased compared to pigs fed the CON and EF1 diets (0.431 and 0.436 v. 0.389 and 0.407, respectively, P < 0.05). At week 6, pigs fed the EF2 and EX diets had better G : F compared to pigs fed the CON diet (75.5 and 75.6% v. 73.2%, respectively, P < 0.05). Pigs fed the EF2 diet had decreased creatinine concentrations in the blood compared to pigs fed the CON diet (0.95 mg/dL v. 1.25 mg/dL, respectively, P < 0.05) at the sixth week. Pigs fed the EF2 and EX diets had higher faecal Lactobacillus spp. concentrations compared to the CON diet (7.55 and 7.61 v. 7.42 log₁₀ CFU/g, respectively, P < 0.05). In addition, pigs fed the EX diet had increased Lactobacillus spp. counts compared to pigs fed the EF1 diet (7.61 v. 7.48 log₁₀ CFU/g, respectively, P < 0.05). Pigs fed the EX diet had decreased E. coli counts compared to pig fed the CON diet (6.23 v. 6.46 log₁₀ CFU/g, respectively, P < 0.05) at week 6. However, no significant difference was observed for ATTD of DM and N, Glucose, BUN, HDL, LDL of blood at week 6, or ADFI during the overall study among treatments (P < 0.05).

In conclusion, supplementation of growing pig diets with a combination of E. faecium and endo-1,4-β-xylanase is capable of improving growth performance, nutrient digestibility, increasing faecal lactobacillus, reducing faecal E. coli counts and decreasing creatinine concentrations in the blood in growing pigs compared to pigs fed CON, and probiotic only supplementation. The data suggested that the combination of E. faecium and endo-1,4-β-xylanase could offer more benefits than when used alone.