The effects of prebiotics on growth performance and in vitro immune biomarkers in weaned pigs

The objective of the experiment was to investigate the effects of prebiotics in nursery pigs on growth performance and immune biomarkers. Sixty-four weaned pigs (31 [+ or -] 1 d; BW 8 [+ or -] 0.1 kg) of mixed gender were housed (4 pigs/pen) in an environmentally controlled nursery with ad libitum access to feed and water over a 35-d study. Pigs were randomly assigned to one of four treatments: control (53% corn, 32% SBM, 7% fishmeal, 8% others), control + 2.5% GroBiotic-S (GS), control + 0.05% chicory (CL), or control + 0.5% chicory (CH). Feeders and pigs were weighed weekly. On day 21, blood samples were obtained from three pigs/treatment for collection of peripheral blood mononuclear cells (PBMC). Isolated PBMC were cultured and subsequently challenged with lipopolysaccharide (LPS; 20 ng/mL). Cell culture supernatants were collected for quantification of the pro- and anti-inflammatory cytokines, interleukin (IL)-8 and IL-10, respectively. Dietary treatment had no effect on BW. At days 28 to 35, pigs fed GS (790 [+ or -] 15 g), CL (704 [+ or -] 15 g), or CH (692 [+ or -] 15 g) had greater (P < 0.05) ADG compared with control (643 [+ or -] 15 g) pigs. In addition, overall (days 0-35), pigs fed GS (823 [+ or -] 18 g), CL (783 [+ or -] 18 g), or CH (782 [+ or -] 18 g) had greater (P < 0.05) ADFI compared with control, and ADFI for GS-fed pigs was greater (P < 0.05) than either CL or CH. There was no difference in G:F among treatments. In vitro LPS challenge increased (P < 0.05) IL-8 secretion from PBMC isolated from CL (23,731 [+ or -] 3,221 [micro]g/mL) pigs compared with control (10,061 [+ or -] 3,221 [micro]g/mL) and CH (12,411 [+ or -] 3,221 [micro]g/mL) pigs. Secretion of IL-10 from PBMC isolated from CL (63 [+ or -] 9 [micro]g/mL) pigs was greater (P < 0.05) compared with control (22 [+ or -] 9 [micro]g/mL) pigs and tended (P < 0.1) to be greater compared with CH (34 [+ or -] 9 [micro]g/mL) pigs. Results indicate that inclusion of prebiotics in nursery pig diets has positive effects on growth performance and may have immunomodulatory effects (in vitro) on cells isolated from prebiotic-fed pigs. Key words: growth performance, immune biomarker, prebiotic, weaned pigs