Dietary fibre improved ileal morphology without reducing ileal digestibility in weaned pigs housed in an inferior environmental condition

A recent study demonstrated that insoluble non-starch polysaccharide (iNSP) could attenuate gastrointestinal disturbance by suppressing proliferation of unfavourable microbial population and by maintaining intestinal integrity (i.e. increasing villous height; Pluske et al. 2001). In addition, the notion existed that dietary NSP could support a healthy gut to resistant enzymatic digestion and could be beneficial to microbes in the large intestine (Choct 1997). The hypothesis tested in the present study was that supplementing iNSP would reduce the incidence of post-weaning diarrhoea (PWD) through improving intestinal morphology without impairing apparent ileal digestibility (AID) in weaned pigs.

A total of 108 male pigs (Duroc × (Yorkshire × Landrace); initial birthweight (BW) 6.2 ± 0.4 kg (mean ± s.e.m.)) were randomly allocated to one of three dietary treatments and two environmental conditions (sanitary v. unsanitary) (six replicate pens per treatment with three pigs per pen). Diets were formulated to contain similar digestible energy content with increasing amounts of cellulose as top dressing (0, 1 and 2%). Chromium oxide was added as an indigestible marker to measure the AID of dry matter, crude protein and energy. One pig per pen (n = 6) was killed to harvest ileal digesta, tissue at the terminal ileum on d 0, 7 and 14 as described by Heo et al. (2010). The effects of cellulose supplementation and sanitary conditions were analysed using the general linear model (GLM) procedure of ANOVA of SPSS software (v22.0, IBM, Armonk, NY, USA).

There were interactions between sanitary conditions and dietary treatments in crypt depth and villous-crypt ratio (V : C) on d 7 (P < 0.01) and 14 (P < 0.001) (Table 1). Pigs that were housed in poor sanitary conditions had lower (P < 0.05) AID of dry matter than pigs that were housed in sanitary conditions on d 14. A diet supplemented with 2% cellulose decreased (P < 0.05) AID of crude protein compared to pigs fed a diet with 0 or 1% cellulose. Our results indicated that a diet with 1% added cellulose increased V : C ratio, but feeding a diet containing cellulose impaired the AID of crude protein and energy on d 14 in both sanitary and poor sanitary conditions.

Table 1.  Effects of environmental conditions and dietary treatments of cellulose on ileal morphology and apparent ileal digestibility (AID; %) in weaned pigs over 14 days