Dietary Glutamic Acid Modulates Immune Responses and Gut Health of Weaned Pigs

Abstract

Dietary glutamic acid (GLU) is used as a feed additive because of its functional characteristics that may affect the growth performance and health of pigs. This study was carried out to determine the effects of dietary GLU on growth performance, nutrient digestibility, immune responses, and intestinal health of weaned pigs. A total of ninety-six weaned pigs (8.07 ± 1.17 kg of body weight; 28 days of age) were assigned to two dietary treatments (8 pigs/pen; 6 replicates/treatment) in a randomized complete block design (block: body weight): 1) a typical weaner diet (CON) and 2) CON supplemented with 0.5% GLU. The experimental period was for 4 weeks. All data and sample collections were performed at the specific time points during the experimental period. Pigs fed GLU had higher average daily gain and average daily feed intake for the first two weeks and nutrient digestibility than pigs fed CON. In addition, dietary GLU increased villus height to crypt depth ratio, number of goblet cells, and ileal gene expression of claudin family and occludin compared with CON, but decreased serum TNF-α and IL-6 and ileal gene expression of TNF-α. Moreover, pigs fed GLU had increased relative composition of bacterial communities of genus Prevotella and Anaerovibrio and decreased genus Clostridium and Terrisporobacter compared with those fed CON. This study suggests that dietary GLU influences growth performance and health of weaned pigs by modulating nutrient digestibility, intestinal morphology, ileal gene expression of tight junction proteins and cytokines, immune responses, and microbial community in the gut.

Effects of Bacillus-based probiotics on growth performance, nutrient digestibility, and intestinal health of weaned pigs

“…Stained sections were examined using a charge-coupled device camera-equipped microscope (TE2000; Nikon, Tokyo, Japan) with digital imaging software for measurements and counts (NIS Elements BR; Nikon Instruments Italia). The 15 longest and straightest villi and their associated crypts were selected to evaluate morphological changes [22]. The morphometric measurements of intestinal tissue were carried out as follows: villus height; crypt depth; villus height to crypt depth ratio (VH:CD); and the number of goblet cells.…”

Stimbiotic Supplementation Alleviates Poor Performance and Gut Integrity in Weaned Piglets Induced by Challenge with E. coli

“…The gastrointestinal (GI) tract digests and absorbs nutrients while also acting as a barrier against harmful substances and pathogens ingested through the diet [ 1 ]. Pigs are exposed to a variety of pathogenic challenges, which causes the GI immune system to become activated [ 2 ].…”

Effects of supplementation of graded level of glutamic acid to crude protein reduced diets on the performance of growing pigs

“…In a study by Hu et al (2017), it was reported that supplementation of 1% Glu and 1.44% L‐alanine reduced BW and ADFI in growing‐finishing pigs. However, improvement in performance and nutrient digestibility were observed in weaned piglets fed 1% glutamine or 0.5% Glu supplemented diet (Kyoung et al, 2021; Zou et al, 2006). In the present study, the non‐significant effects on growth performance and nutrient digestibility in growing pigs receiving low CP diets may be due to the reduction of CP by only 2%.…”