Dietary cellulose could reduce cytokine responses without compromising growth performance in weaner pigs under a farm-like circumstance

Insoluble non-starch polysaccharide (iNSP) could reduce growth performance of host animals due to decreased access of endogenous enzymes, and a subsequent increased flow rate of dietary chime; however, indigestible particles increase health-promoting bacteria along with suppressed protein fermentation in the large intestine of weaner pigs (Heo et al. 2013). The present study tested the hypothesis that dietary iNSP would reduce cytokine responses without compromising growth performance in weaner pigs.

A total of 108 male pigs (Duroc × (Yorkshire × Landrace)) weaned at 21 days of age with initial bodyweight (BW) of 6.2 ± 0.4 kg (mean ± s.e.m.) were randomly allocated to one of three dietary treatments (0, 1, 2% cellulose; Accent Microcell Pvt. Ltd, India). The BW was measured individually on d 0, 7, and 14. Feed consumption was recorded weekly on a pen basis. The concentrations of interleukin 1β (IL-1β; R&D Systems, Minneapolis, MN, USA), tumour necrosis factor α (TNF-α; R&D Systems), prostaglandin E₂ (PGE₂; MyBioSource, San Diego, CA, USA), leukotriene B₄ (LTB₄; MyBioSource), and cyclooxygenase-2 (COX-2; MyBioSource) in plasma were quantified using commercially available ELISA kits according to the manufacturers’ instructions described by Piñeiro et al. (2009) on d 0, 7 and 14. Data were analysed as completely randomised block design, using general linear model procedure of ANOVA (SPSS v22.0, IBM, Armonk, NY, USA).

Pigs reared under sanitary environmental conditions had higher ADG (P < 0.05) and improved feed efficiency for 14 days after weaning compared to their counterparts (Table 1). Pigs housed in poor sanitary conditions reduced the cytokines TNF-α, COX-2, and PGE₂ (P < 0.05) for 14 days after weaning compared to those in sanitary environmental conditions. Feeding a diet with dietary cellulose (i.e. up to 2%) lowered COX-2 concentration (P < 0.05) without compromising growth performance for 14 days after weaning independent of environmental conditions. Our results indicated that pigs fed a diet supplemented with cellulose (i.e. up to 2%) did not impair growth performance of weaned pigs, and could maintain and/or reduce plasma cytokine concentrations (i.e. COX-2) for 14 days after weaning regardless of environmental conditions.

Table 1.  Effects of environmental conditions or dietary treatments of cellulose on growth performance, diarrhoea index and circulating pro-inflammatory cytokines in weaned pigs