Fiber in Animal Nutrition

Fiber in Swine Nutrition 26 These morphological changes were accom- panied by an increase of cytokine expression in the gut.The cytokines investigated indicate a pro-inflammatory response. Certain fibrous feed stuffs are known to influence gut health because they have the ability to change the physicochemical cha- racteristics of the gut by influencing inte- stinal transit time, digesta viscosity, water content (through WBC), osmotic balance and pH. The most commonly used insoluble fibrous feed stuffs in post-weaning diets are cereal hulls/brans, lucerne meal and ligno-/ cellulose. Furthermore sugar beet pulp and apple/citrus pulp contribute to the fraction of soluble fibrous feed stuffs. There is some evidence that using insolu- ble fiber in weaning/early piglet rearing is favourable. The digestive system of piglets at weaning is not fully developed. Feeding soluble fiber at this point would increase the viscosity of the digesta and slow intestinal transit without being efficiently fermented in the hind gut. In the context of weaning this is inevitably counterproductive. The good WBC and bulking characteristics of insoluble fiber sources fill the gut, positively influence peristalsis and thereby intestinal transit time. These f iber sources are not susceptible to fermentation but positively influence the gut microflora by prohibiting the adhesion of pathogens and providing the surface and moisture penetration necessary for probiotic bacteria. Urbańczyk et al. (2004) investigated the influence of a cellulosic fiber (Vitacel) at 0.0%, 1.0%, 1.5%and 2.0%fed in a standard piglet rearing diet on the development of aerobic bacteria especially E. coli, anaerobic bacteria with focus on clostridia, molds and fungi in the digesta of the small intestine (SI) and caecum. Table 5 shows that in the caecum cellulosic fiber resulted in a clear reduction of aerobic bacteria accompanied by a decline in E. coli up to 2.0% inclusion rate. Furthermore clostridia were reduced by 90% in an average compared to the control group. There was no influence on fungi and molds detectable. In 1999 McDonald et al. trialed the influ- ence of guar gum (soluble) on the develop- ment of weaner piglets that had been infected with E. coli (ETEC). The basal diet consisted of pregelatinized rice combined with animal protein contributing to 1% percent soluble fiber. Including guar gum increased the so- luble fiber content by 5%. Seven days after Specification Group I standard mix without Vitacel Group II standard mix +1% Vitacel Group III standard mix +1.5% Vitacel Group IV standard mix +2% Vitacel Caecum chyme: Number of aerobic bacteria including E.coli Number of anaerobic bacteria including Clostridium sp. 2.2x10 8 3.0x10 5 6.5x10 4 5325 5.8x10 7 1.1x10 5 1.7x10 4 365 5.1x10 7 1.3x10 5 3.8x10 4 855 4.7x10 6 4.9x10 4 3.3x10 4 105 Number of Candida albicans Number of Candida sp . Number of moulds 566 733 433 875 1525 750 750 375 900 366 450 350 Table 5: Microbiological examination of intestine (per 1 g of chyme) in piglets (Urba ń czyk et al., 2004) © ERLING Verlag