Transport and expression of transporters for 3-O-methyl-D-glucose and L-methionine along the intestine of broiler chickens receiving different methionine supplements

TL;DR

This study examines how different methionine supplements affect nutrient absorption in the intestines of broiler chickens, finding that the jejunum is the main site for absorption with some gender differences.

Contribution

The study identifies the jejunum as the primary site for sodium-dependent absorption of methionine and 3-OMG in broilers and reveals gender-based differences in nutrient uptake.

Findings

Jejunum is the main site for sodium-dependent absorption of l-Met and 3-OMG in broilers.

Male broilers showed higher jejunal l-Met uptake with DL-Met or DL-HMTBA supplements.

Sexual dimorphism was observed in duodenal nutrient uptake and B0AT1 mRNA abundance.

Abstract

The present study hypothesized that supplementation of different methionine (Met) sources might influence the intestinal absorption of l-Met and 3-O-methyl-d-glucose (3-OMG) in broilers. In a completely randomized study, a total of 53 Cobb500 broilers (30 males and 23 females) received a grower-finisher diet that was either not supplemented with Met (Met + Cys, 0.49 %; control) or supplemented with either 0.27 % l-Met, 0.27 % DL-Met or 0.47 % DL-2‑hydroxy-4-(methylthio) butanoic acid (HMTBA). After ≥10 days on the diets, uptakes of 3-OMG and l-Met were measured in duodenum, mid-jejunum and caecum at 50 µM and 5 mM concentrations in Ussing chambers, each in the presence and absence of Na+. We also investigated the mRNA expression of apical glucose and Met transporters. Dietary supplements had no effect on 3-OMG and l-Met uptakes (P > 0.05), except for male broilers receiving DL-Met or DL-HMTBA, that showed higher jejunal uptakes of l-Met than control at 5 mM (P < 0.001). Except for l-Met uptakes at 5 mM, tissue × sodium interactions (P ≤ 0.05) for 3-OMG and l-Met uptakes verified higher uptakes in jejunum compared to duodenum and caecum; with higher uptakes in the presence vs. absence of Na+ in jejunum only. In duodenum, uptakes of l-Met and 3-OMG at 50 µM concentration were higher in males vs. females. Expression of SGLT1, B0AT1, ATB0,+ and rBAT, but not ASCT1, were lowest in caecum (P ≤ 0.05). Expression of B0AT1 was higher in males vs. females (P ≤ 0.05). Expression of ASCT1 was higher with DL-Met and DL-HMTBA supplements compared to l-Met and control (P ≤ 0.05). These findings indicate that jejunum is the main intestinal segment for Na+-dependent l-Met and 3-OMG absorption in broilers with minor effects of dietary Met source. A sexual dimorphism for duodenal nutrient uptake and mRNA abundance of B0AT1 was congruent with the more efficient growth performance of male chickens known from the literature.

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