Postweaning piglets are immediately imposed to remarkable environmental and psychosocial stressors, which adversely affect their intestinal development and health and predispose them to diarrhea. The ratio of postweaning mortality is 6–10% and may rise up to 20% with poor management strategies. Diarrhea per se accounts for 20–30% of cases of mortality in weanling pigs. E. coli postweaning diarrhea is one of the most important causes of postweaning diarrhea in pigs. This diarrhea is responsible for huge economic losses due to high mortality and morbidity, weight loss, and cost of medication. Burgeoning evidence suggested feed-based intervention are one of the promising measures to prevent postweaning diarrhea and to enhance overall health of weaned pigs. Although the exact protective mechanisms may vary and are still not completely understood, a number of feed ingredients or feed additives are marketed to assist in boosting intestinal immunity and regulating gut microbiota. The promising results have been demonstrated in several nutrients (i.e., functional amino acids, organic acids, micro minerals, nondigestible carbohydrates, and antimicrobial peptides), non-nutrients (i.e., phytochemicals and probiotics), and many other feed additives. The efficiencies of each candidate may differ based on their exact modes of action, the basal diet formulation, and the health status of pigs.
Part of the book: E. Coli Infections