Dietary Organic Acids Modulate Gut Microbiota and Improve Growth Performance of Nursery Pigs.

Xiaoyuan Wei,Hans H Stein,Robert Story,Laia Blavi,Jon Bergstrom,Tsungcheng Tsai,Jiangchao Zhao,Charles Maxwell,Joshua Knapp,Kristopher A Bottoms,Casey L Bradley

doi:10.3390/microorganisms9010110

Abstract

Feed additives have been suggested to improve animal growth performance through modulating the gut microbiota. The hypothesis of this study was that the combination of two organic acids would exert synergistic effects on the growth performance and gut microbiota of weaning pigs. To test this hypothesis, we followed 398 weaning pigs from two university experiment stations (University of Illinois at Urbana-Champaign (UIUC) and University of Arkansas (UA)) to determine the effects of increasing levels (0%, 0.035%, 0.070%, and 0.105%) of sodium butyrate combined with 0.5% benzoic acid on the growth performance of nursery pigs. At the UA, an additional negative control diet was included and the gut microbiota analysis was carried out. At both universities, increasing levels of sodium butyrate in a diet containing 0.5% benzoic acid improved growth performance, which reached a plateau in the pigs fed 0.035% (SBA0.035) or 0.070% (SBA0.070) butyrate. Gut microbiota analysis revealed that pigs fed the SBA0.035 diet had more diverse microbiota and contained more potentially beneficial bacteria such as Oscillospira, Blautia, and Turicibacter and reduced levels of Veillonella and Sarcina. Results of the present study indicated that the inclusion of sodium butyrate at moderate levels in a diet containing 0.5% benzoic acid improved growth performance of weaning pigs and established potential health benefits on gut microbiota.

Highlights

The same quadratic pattern was observed in phase 3 for average daily gain (ADG) (p = 0.05; Table S1) and body weight (BW) (Figure 2B, p = 0.03) and again for the ADG (Figure 2A)
A tendency for a quadratic increase in average daily feed intake (ADFI) for the overall study was observed in pigs fed increasing levels of butyrate (Figure 2C, p = 0.10)
We found that digestibility of dry matter, energy, nitrogen, ash, neutral- and acid-detergent fiber, and phosphorous increased in the pigs fed benzoic acid alone (BA), which is consistent with the higher numerical G:F observed in phase 3 and could be due to higher digestive enzyme activity [37,40]

Summary

Introduction

Organic acids have been used to improve weanling pig health and growth performance due to their ability to reduce gastrointestinal tract pH, improve nutrient digestibility, and inhibit pathogenic bacterial proliferation [2]. In addition to aiding nutrient digestion, growth-promoting effects observed from adding organic acids to pig diets may be due to their ability to reduce the presence of pathogenic bacteria [8,9]. This is a result of enhanced macrophage antimicrobial activity [10], which may reduce the coliform burden throughout the gastrointestinal tract [5,11,12].

Methods

Results

Discussion

Conclusion