Table 3 Benefits and limitations of the major alternative feed strategies for the control of post weaning diarrhea (PWD) in pigs

Zinc oxide

Inhibition of bacterial adhesion to the intestinal mucosa

High levels increased PWD

[112, 115]

Stimulated growth rate

Soil heavy metal contamination

Maintained intestinal mucosal integrity

Bacterial resistance

Modulated immune functions

Co-resistance

Organic acids

Decreased pH in the stomach

Exact modes of action still unknown

[108]

Improved growth performance

Anti microbial activities is different between acids

Reduced PWD

Prebiotics, probiotics and synbiotics

Improved intestinal health

Sometimes contradictory studies on their effectiveness

[127, 130]

Improved growth performance

Lack of information on the potential synergism between pre- and probiotics

Reduced ETEC: F4 attachment to the ileal mucosa

Reduced diarrhea

Spray dried plasma (SDP)

Improved growth performance

High cost

[111]

Reduced incidence and severity of diarrhea

Required rigorous control during the preparation process

Reduced the markers of intestinal inflammation

Potential source of pathogens?

Maintained mucosal integrity

Antimicrobial peptides (AMPs)

Improved growth performance

The pharmacokinetics in vivo is unknown

[89, 139]

Decreased diarrhea

Bacterial resistance

Reduced the markers of intestinal inflammation

Enhance immune function

Cocktails of AMPs might be used to mitigate selection for resistance

Specific egg yolk antibodies

Improved growth performance

High cost

[111]

Decreased diarrhea

Antibodies are sometime not specific against the infecting ETEC strains on farms

Maintained intestinal mucosal integrity

Bacteriophages

Reduced E. coli mucosal adhesion

Narrow spectrum of activity

[144]

Maintained intestinal mucosal integrity

Development of bacterial resistance

Decreased diarrhea

A combination of phages is needed