Review on Preventive Measures to Reduce Post-Weaning Diarrhoea in Piglets

Abstract

In many countries, medical levels of zinc (typically as zinc oxide) are added to piglet diets in the first two weeks post-weaning to prevent the development of post-weaning diarrhoea (PWD). However, high levels of zinc constitute an environmental polluting agent, and may contribute to the development and/or maintenance of antimicrobial resistance (AMR) among bacteria. Consequently, the EU banned administering medical levels of zinc in pig diets as of June 2022. However, this may result in an increased use of antibiotic therapeutics to combat PWD and thereby an increased risk of further AMR development. The search for alternative measures against PWD with a minimum use of antibiotics and in the absence of medical levels of zinc has therefore been intensified over recent years, and feed-related measures, including feed ingredients, feed additives, and feeding strategies, are being intensively investigated. Furthermore, management strategies have been developed and are undoubtedly relevant; however, these will not be addressed in this review. Here, feed measures (and vaccines) are addressed, these being probiotics, prebiotics, synbiotics, postbiotics, proteobiotics, plants and plant extracts (in particular essential oils and tannins), macroalgae (particularly macroalgae-derived polysaccharides), dietary fibre, antimicrobial peptides, specific amino acids, dietary fatty acids, milk replacers, milk components, creep feed, vaccines, bacteriophages, and single-domain antibodies (nanobodies). The list covers measures with a rather long history and others that require significant development before their eventual use can be extended. To assess the potential of feed-related measures in combating PWD, the literature reviewed here has focused on studies reporting parameters of PWD (i.e., faeces score and/or faeces dry matter content during the first two weeks post-weaning). Although the impact on PWD (or related parameters) of the investigated measures may often be inconsistent, many studies do report positive effects. However, several studies have shown that control pigs do not suffer from diarrhoea, making it difficult to evaluate the biological and practical relevance of these improvements. From the reviewed literature, it is not possible to rank the efficacy of the various measures, and the efficacy most probably depends on a range of factors related to animal genetics and health status, additive doses used, composition of the feed, etc. We conclude that a combination of various measures is probably most recommendable in most situations. However, in this respect, it should be considered that combining strategies may lead to additive (e.g., synbiotics), synergistic (e.g., plant materials), or antagonistic (e.g., algae compounds) effects, requiring detailed knowledge on the modes of action in order to design effective strategies.

Effects of Exposure to Low Zearalenone Concentrations Close to the EU Recommended Value on Weaned Piglets’ Colon

“…These associations could also contribute to the apparition of diarrhoea symptoms and contribute to it. Many studies discussed the relationship between Lactobacillus and post-weaning diarrhoea [ 66 , 67 , 68 ] showing that lactic acid bacteria are frequently used as a probiotic in reducing diarrhoea incidence, as reported by Dell’Anno et al [ 69 ] or Wang et al [ 70 ]. Other studies also indicate increased diarrhoea incidence with decreased Lactobacillus counts [ 71 , 72 ].…”

Antibacterial plant combinations prevent postweaning diarrhea in organically raised piglets challenged with enterotoxigenic Escherichia coli F18

“…Indeed, organic acids have been used in piglet diets as antimicrobial agents and proven effective by providing an unfavorable environment for pathogenic bacteria and/or direct bactericidal action ( 56 ). Furthermore, the combination of organic acids with phytochemical compounds may synergistically contribute to productive performance reduced ETEC adherence to intestinal epithelium and overall enhanced intestinal health ( 57 ). The efficacy of the plant combinations was tested exclusively against ETEC F18 in this study.…”

“…Esposito et al ( 90 ) reported, for example, that blackcurrant anthocyanins have an anti-inflammatory effect that may be mediated by interaction with the local microbiota and their functions in the intestine. The dietary fiber fraction may also have an impact on the gut microbiome, particularly the fermentative species, and thus on the production of lactic acid and short-chain fatty acids, which may further lower the pH locally ( 57 ). However, the dietary fiber profiles of the experimental diets used in this study were similar, except for a higher fructan content in GA and GB diets.…”

Study on the mechanism of Wumei San in treating piglet diarrhea using network pharmacology and molecular docking

“…The larger the node area and the darker the color in the figure, the more important it is in the network. in pig production (20). However, long-term medication and a high zinc diet leads to adverse effects on human health and the environment by contributing to the development of antimicrobial resistance among bacteria and high zinc levels in soil.…”