SUMMARY
  • Butyric acid is well documented to have beneficial effects in the gastrointestinal tract (Borycka-Kiciak et al., 2017), the addition of Butyric acid however needs to be in a protected form.
  • Feeding pHorce (formic and propionic acid blend) has been shown to increase butyric acid in the caeca and provide a beneficial gut environment.
  • Feeding pHorce decreased intestinal digesta pH, which can provide a good environment to promote beneficial microbiota growth.
  • Birds fed pHorce had significantly increased caecal lactobacilli and decreased E.coli, thereby helping to promote a healthy microbiota.

 

BACKGROUND
  • pHorce is part of Anpario’s Acid Based Eubiotics (ABE) range and is a blend of liquid formic and propionic acid on a unique mineral carrier delivery system; chosen to ensure maximum efficacy during feed manufacture and steady release throughout the gastrointestinal tract (GIT).
  • Formic acid is now classified as a bacterial decontaminating agent including, but not limited to Salmonella (Feed Additive Register 2017/940).

 

TRIAL DESIGN

A 2 X 3 factorial study was conducted by the Department of Animal Science, University of Mashhad, Iran (Adapted from Emami et al., 2017). 750 Ross 308 broilers were randomly assigned to 1 of 3 treatments; Control (0kg/t), pHorce 0.7kg/t in starter and 0.5kg/t in grower and finisher; and pHorce 1kg/t in starter and 0.7kg/t in grower and finisher. Broilers were either non-challenged or challenged orally with E. coli (K88+ strain) on Day 7 to induce a sub-clinical disease. At 10 and 35 days intestinal pH, caecal microbial populations and concentration of caecal short chain fatty acids (SFCA) were measured, for brevity day 35 information of challenged broilers is shown below.

RESULTS

Caecal lactobacilli and E. coli counts at of challenged broilers at 35 days of age

Figure 1. Caecal lactobacilli and E. coli counts at of challenged broilers at 35 days of age. Different letters (a-b) denote significant differences (p<0.05)

  • pHorce promotes a beneficial microbiota by increasing the number of lactobacilli spp. and reducing the level of E.coli after challenge.

 

Digesta pH of each intestinal region of challenged broilers at 35 days of age

Figure 2. Digesta pH of each intestinal region of challenged broilers at 35 days of age. Different letters (a-b) denote significant differences (p<0.05)

  • A small change in pH can have a large effect on the microbiota. For example, Salmonella prefer a more alkaline environment (Foster, 1995). A small lowering of pH reduces the risk of colonisation in the proximal intestine.
  • pHorce does not lower the gut pH directly, but promotes growth of bacteria that prefer a low pH, therefore the proliferation of these acid tolerant species leads to reduced pH in the intestinal lumen.

 

Caecal concentrations of propionate and butyrate of challenged broilers at 35 days of age

Figure 3. Caecal concentrations of propionate and butyrate of challenged broilers at 35 days of age. Different letters (a-b) denote significant differences (p<0.05)

  • By promoting a beneficial microbiota, the concentration of propionate and butyrate were increased due to their production by the microbiota.
  • Propionate and butyrate produced by the microbiota can be used by the bird as a source of carbon and energy, additionally, the increase in propionate and butyrate concentrations are negatively correlated with populations of Enterobacteriacae (Pan & Yu, 2013).
  • Overall pHorce helps to improve the gut environment through the proliferation of acidophilic bacteria, this in turn increases the production of propionate and butyrate, thereby reducing the digesta pH and ultimately providing benefits to the bird.