Can diet be used as an alternative to antibiotics to help control enteric bacterial infections of pigs?
Hampson, D.J., Pethick, D.W. and Pluske, J.R. (1999) Can diet be used as an alternative to antibiotics to help control enteric bacterial infections of pigs? In: Manipulating Pig Production VII. Proceedings of the seventh biennial conference of the Australasian Pig Science Association (APSA), 28 November - 1 December, Adelaide, Australia pp. 210-219.
In response to a need to develop alternative methods to control the major enteric bacterial infections of pigs, studies have been undertaken to investigate whether or not it is possible to reduce susceptibility to colonisation by pathogens through the use of specific diets. These diets are intended to alter the intestinal environment, including the resident microflora, such that conditions are no longer conducive to growth of the pathogens. In the case of swine dysentery, caused by the spirochaete Brachyspira (Serpulina) hyodysenteriae, it has been shown that diets with very low levels of soluble nonstarch polysaccharides and resistant starch offer complete protection against experimental disease. The only fully protective diet identified to date comprises cooked white rice and animal protein, but substituting the rice with steam-flaked maize or sorghum, or finely ground sorghum, gives a diet that tends to reduce susceptibility to experimental infection. To date the application of exogenous enzymes to standard pig diets has not produced intestinal conditions that inhibit colonisation by the spirochaete. In the case of the related intestinal spirochaete Brachyspira (Serpulina) pilosicoli, the aetiological agent of porcine intestinal spirochaetosis, feeding the rice-based diet retards the rate of colonisation of the large intestine but does not completely prevent either colonisation or the development of disease in pigs after experimental challenge. The same rice-based diet reduces colonisation of the small intestine by enterotoxigenic Escherichia coli after experimental infection of weaners, whilst addition of a source of soluble nonstarch polysaccharide to the rice diet results in greater colonisation by the E. coli strain. Finally, the stomachs of weaner pigs fed a finely ground wheat-based diet have been shown both to have severe ulceration of the pars oesophagea and to be colonised by Helicobacter spp. Feeding finely ground extruded wheat resulted in no ulceration and an absence of the bacteria. It is possible that the Helicobacter spp. are involved in the aetiology of the ulceration, and that their presence is influenced by the treatment of the diet consumed.
From these studies it is clear that a number of important enteric bacterial infections can be modified by the use of specific diets. The main challenges are to understand how these effects work and to develop cost-effective diets that can be applied in the field to help supplement current control measures for these and other enteric infections of pigs.
|Publication Type:||Conference Paper|
|Murdoch Affiliation:||School of Veterinary and Biomedical Sciences|
|Item Control Page|
Downloads per month over past year