Effects of dietary supplementation of β-mannanase on digesta viscosity and intestinal health of nursery pigs

Abstract Text:

This study was conducted to determine the effects of β-mannanase (CTCBIO INC, Seoul, Korea) on digesta viscosity and intestinal health of nursey pigs. Pigs (36 barrows and 36 gilts at 15.5 ± 2.3 kg BW) at 45 d of age were housed individually and randomly allotted to 3 treatments (24 pens/treatment). Experimental diets had 3 levels of β-mannanase (0, 400, and 600 Unit/kg), and fed to pigs for 10 d. Feed intake and BW were measured on d 7 and 10 to calculate growth performance. On d 10, all pigs were euthanized to obtain jejunal digesta to measure viscosity and mucosa from the duodenum and jejunum to measure tumor necrosis factor-alpha (TNF-α), immunoglobulin G (IgG), and malondialdehyde (MDA). Duodenal and jejunal tissues were used to measure morphology and proliferation of mucosa cells by Ki-67 immunohistochemistry. Tight junction proteins between jejunal mucosa cells were measured by the Western blot. Data were analyzed using polynomial contrasts in Mixed procedure of SAS. Statistical differences among treatment means were considered significant with P < 0.05. Overall, viscosity of jejunal digesta was decreased (P < 0.05, 2.50 to 2.10 cP) as increasing β-mannanase from 0 to 600 Unit/kg diets. Increasing β-mannanase in the diets linearly decreased (P < 0.05) TNF-α (5.81 to 3.81 in the duodenum, 6.23 to 4.19 ng/g protein in the jejunum), IgG (1.44 to 1.07 in the duodenum, 1.20 to 0.80 mg/g protein in the jejunum), MDA (1.46 to 1.26 in the duodenum, 1.06 to 0.69 µmol/g protein in the jejunum) and PC (7.11 to 4.22 µmol/g protein in the duodenum) of mucosa. Increasing β-mannanase in the diet linearly increased (P < 0.05) villus height (579 to 651 of duodenum, 426 to 516 µm of jejunum) and crypt depth (281 to 301 of duodenum, 175 to 246 µm of jejunum). Increasing β-mannanase in the diet linearly increased (P< 0.05) the number of proliferating cells (29.3 to 35.5%) and ZO-1 tight junction proteins (0.81 to 1.41) in jejunum. Increasing β-mannanase in the diet, however, did not affect growth performance of pigs during 45 to 55 d of age. In conclusion, dietary supplementation of β-mannanase (up to 600 Unit/kg diet) enhanced intestinal health by reducing inflammatory response and oxidative stress which may be related to reduced viscosity of jejunal digesta. A 10 d feeding of β-mannanase, however, did not benefit the growth performance in nursery pigs.

Keywords: digesta viscosity, intestinal health, mannanase, nursery pig