Effect of butyrate infusion into the rumen on butyrate flow to the duodenum, selected gene expression in the duodenum epithelium, and nutrient digestion in sheep1

Abstract

The aim of the study was to determine the effect of butyrate infusion into the rumen on butyrate flow to the duodenum, expression of short-chain fatty acid (SCFA) transporters (monocarboxylate transporter-1, -2, and -4) and receptors (G protein coupled receptor-41 and -43) in the duodenal epithelium and nutrient digestion in sheep. Eight wethers (39.0 ± 3.00 kg; mean ± SD) with ruminal and T-shape duodenal cannulas were allocated to 4 × 4 replicated Latin square design with each experimental period lasting for 21 d (12 d of adaptation and 9 d for data and sample collection). Experimental treatments were: 1) distilled water infusion into the rumen (CONT); 2) 15 g/d of butyric acid infusion into the rumen (BUT15); 3) 30 g/d of butyric acid infusion into the rumen (BUT30); and 4) 45 g/d of butyric acid infusion into the rumen (BUT45). The daily dose of butyrate was infused into the rumen via the rumen cannula, with 200 mL of solution of butyric acid and distilled water, at a constant rate (0.1389 mL/min) throughout the day using a peristaltic pump. Correspondingly, 200 mL/d of distilled water was infused into the rumen of CONT. The wethers were fed daily 900 g of chopped meadow hay and 200 g of concentrate in two equal meals at 0600 and 1800 h. Butyrate infusion into the rumen did not affect total SCFA concentration in the rumen fluid ( > 0.11). Molar proportion of butyrate in total SCFA linearly increased, and molar proportion of acetate and isovalerate linearly decreased ( ≤ 0.02) with an increasing amount of butyrate infused into the rumen. The molar proportion of butyrate in total SCFA in the duodenal digesta linearly increased ( < 0.01), and butyrate flow to duodenum tended to linearly increase ( = 0.06) with an increasing dose of exogenous butyrate delivered to the rumen. Butyrate infusion into the rumen did not affect ( ≥ 0.14) the mRNA expression of monocarboxylate transporter-2 and -4 and G protein coupled receptor-43 in the duodenal epithelium. The G protein coupled receptor-41 and monocarboxylate transporter-1 mRNA expression in the duodenal epithelium was very low in many of the analyzed samples. Digestibility of organic matter, neutral detergent fiber, and acid detergent fiber in the stomach (forestomach and abomasum) decreased for BUT15 and BUT30 and then increased for BUT45 (quadratic, ≤ 0.04); however, neither digestibility in the intestine nor total tract digestibility differed between treatments ( ≥ 0.10).

Effect of exogenous butyrate on the gastrointestinal tract of sheep. II. Hydrolytic activity in the rumen and structure and function of the small intestine1

“…Within each block, the rams were paired by BW and, within pairs, randomly allocated to 1 of 2 treatments (9 rams/treatment) and fed a diet without (CTRL) or with sodium butyrate (BUT). Sodium butyrate was supplemented in the feed at the rate of 36 g/kg of offered DM that corresponded with the doses of butyrate used in previous studies in cattle (Huhtanen et al, 1993) and sheep (Wilson et al, 2012;Wiese et al, 2013;Górka et al, 2017b). The diet consisted of chopped meadow hay (65%), concentrates (19.5%), and ensiled ground high-moisture corn grain (15.5%, DM basis).…”

“…Short-chain fatty acids concentration in duodenal digesta was determined by gas chromatography (3400 CX; Varian Star, Palo Alto, CA, USA) equipped with a flame ionization detector using a DB-FFAP column (30 m × 0.5 mm; J&W Scientific, Folsom, CA, USA), as described previously by Górka et al (2017b).…”

“…Total RNA was isolated from tissue samples stored in RNAlater according to the method described by Chomczyński and Sacchi (1987), and subsequently subjected to reverse transcription reaction. Validation of the quality and quantity of RNA as well as reverse transcription reaction procedure were done as described previously (Górka et al, 2017b). The concentration and integrity of RNA was estimated spectrophotometrically using NanoDrop (Thermo Fisher Scientific, Waltham, MA, USA) and verified electrophoretically in the agarose gel.…”

“…The obtained cDNA was stored at −20 °C until analyzed for expression of sodium-dependent glucose cotransporter 1 (SGLT1), glucose transporter 2 (GLUT2), peptide transporter 1 (PepT1), monocarboxylate transporter 1 (MCT1), monocarboxylate transporter 2 (MCT2), monocarboxylate transporter 4 (MCT4), G-proteincoupled receptor 41 (GPR41), G-protein-coupled receptor 43 (GPR43), and 3 reference genes [glyceraldehyde-3-phosphate dehydrogenase (GAPDH), Na/K-ATPase, and β-actin (ACTB)]. Gene expression was determined in duplicate, and each reaction was performed as previously described (Górka et al, 2017b) using specific primers (Supplementary Table S1). NormFinder was used to determine the most optimal reference gene(s) (Andersen et al, 2004), and geometric mean of GAPDH and Na/K-ATPase was chosen for the normalization of the target genes.…”

“…Therefore, nutritional strategies promoting butyrate production in the rumen or its dietary supplementation are commonly used to enhance ruminal epithelium functions and, in turn, performance of animals (Górka et al, 2011a;Chibisa et al, 2015;Kowalski et al, 2015). However, direct infusion of butyrate into the reticulorumen resulted in greater butyrate flow into the duodenum (Górka et al, 2017b), and butyrate infusion into the abomasum affected the expression of numerous genes in the duodenal epithelium in sheep (Foote et al, 2017). As a result, increased ruminal butyrate may affect not only the rumen, but also lower parts of the gastrointestinal tract (GIT), including the small intestine.…”