Impact of mash feeding versus pellets on propionic/butyric acid levels and on total Escherichia coli load in the gastrointestinal tract of growing pigs1

Abstract

Feed characteristics may influence the bacterial community composition and metabolic activities in the pig gastrointestinal tract, known to be associated with positive effects on the gut. Use of mash feed is associated with reduced excretion, but little is known of its effect on the population or of the mechanism of action. Our objectives were to assess the effect of feed texture combined with feed particle size on VFA profiles and levels, total count, and the presence of genes encoding virulence factors of pathogenic strains in the digestive tract along with their impact on pig performance of fattening pigs. Pigs ( = 840) on a commercial farm received mash or pellet diets of different particle sizes during the fattening period. Caecal and colon contents from 164 pigs were sampled at the slaughterhouse for enumeration of by quantitative PCR (qPCR) and for VFA quantification by capillary gas chromatography. The gene was used to enumerate total . Improved pig performances associated with pellet texture and a 500-μm size were observed. Caecal ( = 0.02) and colon (< 0.01) propionic acid concentrations were lower for pigs receiving pellet rather than mash feed. Similarly, caecal ( = 0.01) and colon ( < 0.001) butyric acid concentrations were also lower for pigs receiving pellet rather than mash feed, as determined by capillary gas chromatography. Moreover, caecal ( = 0.03) and colon ( < 0.001) butyric acid concentrations were higher for pigs receiving a feed with a 1,250-μm particle size rather than a 500-μm particle size. On the other hand, total caecal and colon levels were higher for pigs receiving pellet feed than for those receiving mash feed. For total enumeration, caecal ( < 0.01) and colon ( < 0.01) gene copies were higher for pigs receiving pellet rather than mash feed. No effect of particle size on fatty acid concentrations or on numbers was observed. Virulence gene quantification revealed no trend. Taken together, results showed that mash feed is associated with lower growth performance but with favorable intestinal changes linked to VFA levels and reduction in the intestine.

In vivo therapeutic efficacy and pharmacokinetics of colistin sulfate in an experimental model of enterotoxigenic Escherichia coli infection in weaned pigs

“…The strain was passaged in a weaned pig to enhance its pathogenicity. A hemolytic, Nal r colony isolated from the feces of this pig was confirmed to be positive for O149 and the virulence genes F4, STa, STb, LT by multiplex PCR as previously described [ 27 ]. This strain, designated ECL8559A, was used in the experimental challenge in this study.…”

The fecal presence of enterotoxin and F4 genes as an indicator of efficacy of treatment with colistin sulfate in pigs

“…Fecal presence of genes encoding ETEC virulence factors STa, STb, LT, F4 and F18 was evaluated using PCR as previously described [12]. DNA was extracted by heat lysis.…”

Role of Feed Processing on Gut Health and Function in Pigs and Poultry: Conundrum of Optimal Particle Size and Hydrothermal Regimens

“…Feed particle size not only impacts gastric ecology but also other parts of the GIT particularly the large intestine. Studies have demonstrated that coarse diets were strongly associated with higher propionic and butyric acid levels in the cecum and colon contents (42, 44). It is possible that coarse feed particle size may promote an increase of bacteria populations producing SCFA and, thus, contribute to gastrointestinal health by preventing the proliferation and/or virulence of harmful bacteria such as Salmonella spp.…”