Blood glucose, amino acid profiles and nutrient transporter gene expressions in the small intestine of low and normal birthweight piglets during the early suckling period

Recombinant Phytase Modulates Blood Amino Acids and Proteomics Profiles in Pigs Fed with Low-Protein, -Calcium, and -Phosphorous Diets

A beneficial effect of corn-expressed phytase (CEP) on the growth performance of pigs fed with very low-protein (VLP) diets was previously shown. Little is known whether this improvement is related to alterations in the expression profiles of blood proteins and amino acids (AAs). The objective of this study was to investigate whether supplementation of VLP, low-calcium (Ca), and low-P diets with a CEP would alter the blood AAs and protein expression profiles in pigs. Forty-eight pigs were subjected to one of the following groups (n = 8/group) for 4 weeks: positive control (PC), negative control-reduced protein (NC), NC + low-dose CEP (LD), NC + high-dose CEP (HD), LD with reduced Ca/P (LDR), and HD with reduced Ca/P (HDR). Plasma leucine and phenylalanine concentrations were reduced in NC; however, the LD diet recovered the concentration of these AAs. Serum proteomics analysis revealed that proteins involved with growth regulation, such as selenoprotein P were upregulated while the IGF-binding proteins family proteins were differentially expressed in CEP-supplemented groups. Furthermore, a positive correlation was detected between growth and abundance of proteins involved in bone mineralization and muscle structure development. Taken together, CEP improved the blood profile of some essential AAs and affected the expression of proteins involved in the regulation of growth.

Effects of oral glutamine supplementation on jejunal morphology, development, and amino acid profiles in male low birth weight suckling piglets

Background

It has been shown that small intestine development in low birth weight (LBW) piglets is impaired. Glutamine (Gln) has been reported to improve piglet health and intestinal function in weaned piglets, but data is scarce in suckling piglets. This study was conducted to investigate the effects of oral Gln supplementation compared to Alanine (Ala) on jejunal development and function in 5 and 12 d old male LBW and normal birth weight (NBW) suckling piglets.

Results

Gln had no effect on the jejunal morphology, development, tissue and digesta amino acid profiles and mRNA abundance of genes involved in amino acid transport, metabolism, glutathione synthesis in LBW piglets when compared to Ala supplementation and birth weight controls at 5 and 12 d. Only the concentration of Gln in jejunal tissue was higher in NBW piglets supplemented with Gln compared to Ala at 5 d (P < 0.05). A comparison of the birth weight groups showed no differences between LBW and NBW piglets at 5 and 12 d in any parameter. Jejunal crypt depth, villus height / width, tunica muscularis thickness, number of goblet and IgA positive cells, the ratio of jejunal RNA to DNA and the concentration of DNA, protein and RNA changed (P < 0.05) from 5 compared to 12 d. The concentrations of several free, and protein bound amino acids as well as amino metabolites differed between age groups in jejunal tissue but the digesta concentrations were affected to a lesser extent.

Conclusions

Oral Gln supplementation to suckling male piglets over the first 12 d of life was not associated with changes in jejunal parameters measured in this study. The absence of effects may indicate that Gln is absorbed as well as metabolized in the upper intestinal tract and thus could benefit intestinal development at a more proximal location.

Extruded Enzyme-Added Corn Improves the Growth Performance, Intestinal Function, and Microbiome of Weaning Piglets

The objective of this study was to evaluate the effects of extruded corn with added amylase under different moisture conditions on the growth performance, intestinal function, and microbiome of weaning piglets. Fourty-eight 24-day-old weaning piglets (Duroc × Landrace × Yorkshire, weaned at 22 ± 1 d) with an initial body weight of 6.76 ± 0.15 kg were randomly assigned to one of four dietary treatments with six replicates per treatment and two pigs per replicate: (1) NL (adding 7.5% water before corn extrusion, negative treatment with low moisture); (2) NH (adding 15.0% water before corn extrusion, negative treatment with high moisture); (3) PL (adding 7.5% water and 4 kg/t α-amylase before corn extrusion, positive treatment with low moisture); and (4) PH (adding 15% water and 4 kg/t α-amylase before corn extrusion, positive treatment with high moisture). Results showed that amylase supplementation (4 vs. 0 kg/t) increased the contents of small molecular oligosaccharides of extruded corn (p < 0.05). Amylase supplementation significantly improved the average daily feed intake, apparent total tract digestibility (ATTD) of dry matter, crude protein, gross energy, crude fat, ash, phosphorus, and calcium, and also increased the activities of jejunal trypsin, α-amylase, lipase, sucrase, maltase, γ-glutamyl transferase and alkaline phosphatase activities, improved the duodenal, jejunal and ileal morphology, and increased the relative mRNA expressions of the ZO-1, OCLN, SGLT1, and GLUT2 genes in the jejunum (p < 0.05), whereas it decreased the contents of isobutyric acid in cecal digesta, as well as acetic acid and isobutyric acid in colonic digesta (p < 0.05). Moreover, the linear discriminant analysis effect size (LEfSe) showed that piglets fed extruded corn with added enzymes contained less intestinal pathogenic bacteria, such as Holdemanella and Desulfovibrio, compared with piglets fed just extruded corn. In summary, the results of the present study indicated that the supplementation of α-amylase during the conditioning and extruding process of corn increased the small molecular oligosaccharide content of corn starch. Moreover, piglets receiving extruded enzyme-added corn had better growth performance, which was associated with the improved intestinal digestive and absorptive function, as well as the intestinal microbiome.

Birth Weight and Nutrient Restriction Affect Jejunal Enzyme Activity and Gene Markers for Nutrient Transport and Intestinal Function in Piglets

Simple Summary

Birth weight and nutrient utilization are thought to have significant effects on intestinal development in neonatal pigs. The present study evaluated the impact of low and normal birth weight with and without nutrient restriction during the neonatal period on jejunal development. The results observed suggest that during the first 28 d of life, birth weight had greater effects on intestinal development than nutrient level, however, at d 56, the nutrient level was a significant contributor to intestinal function and enzyme activity compared to birth weight. Taken together, both birth weight and nutrient restriction have effects on intestinal development, but may have a greater impact in early life (d 28).

Abstract

Significant variation in the birth weight of piglets has arisen due to increased sow prolificacy. Intestinal development and function may be affected by birth weight. Low birth weight (LBW) pigs may also have reduced feed intake, leading to further impairment of intestinal development. The objective of this study was to examine the intestinal development pattern of LBW and normal birth weight (NBW) piglets with normal nutrition (NN) or restricted nutrition (RN) in the pre-weaning period. Jejunal intestinal samples were analyzed for target gene expression and enzyme activity at d 28 (weaning) and d 56 (post-weaning). At d 28, excitatory amino acid transporter (EAAC1) and sodium-dependent neutral amino acid transporter (B⁰AT1) were downregulated in LBW compared to NBW pigs (p < 0.05). On d 56, B⁰AT1 and ASCT2 (glutamine transporter) were downregulated in RN compared to NN pigs (p < 0.05), regardless of birth weight. Peptide transporter 1 (PepT1) expression was downregulated in LBW compared to NBW pigs at 28 d (p < 0.05), with no effects of treatments at 56 d. Sodium-glucose transporter-1 (SGLT1) was upregulated in NBW-NN compared to LBW-NN pigs (p < 0.05) at 28 d. Alkaline phosphatase (ALP) was upregulated in LBW-RN at d 28. At d 56, claudin-3 (CLDN-3) and Zonular occludin-1 (ZO-1) were upregulated in NN compared to RN pigs (p < 0.05). There were no treatment effects on ALP, maltase, or sucrase activity at 28 d. However, at 56 d, ALP was upregulated in NBW-NN pigs while sucrase activity was upregulated in NN pigs (p < 0.05). The results demonstrate differences in jejunal gene expression associated with birth weight, with reduced gene expression of amino acid transporters (PepT1, EAAC1, B⁰AT1) in LBW compared to NBW pigs (p < 0.05). While neonatal nutrient restriction had minimal effects at 28 d and d 56 for tight junction protein transcript abundance, neutral amino acid transporter abundance was upregulated in NN pigs compared to RN piglets (p < 0.05).

Serum biochemical parameters and amino acids metabolism are altered in piglets by early-weaning and proline and putrescine supplementations

The study was to investigate the effect of early-weaning stress and proline (Pro) and putrescine (Put) supplementations on serum biochemical parameters and amino acids (AA) metabolism in suckling and post-weaning pigs. Blood and small intestinal mucosa were harvested from suckling piglets at 1, 7, 14, and 21 d of age and piglets on d 1, 3, 5, and 7 after weaning at 14 d of age, as well as from piglets received oral administration of Pro and Put from 1 to 14 d old. In suckling piglets, the serum glucose, albumin and total cholesterol levels were increased (P < 0.05) with increasing age, whereas the serum globulin, urea nitrogen (BUN), alkaline phosphatase (ALP) and aspartate aminotransferase (AST) levels were lowered (P < 0.05). The concentrations of most serum AA and the AA transporters related gene expressions were highest in 7-d-old piglets (P < 0.05), whereas the phosphorylation status of the mammalian target of the rapamycin (mTOR) signaling pathway in the small intestine increased in piglets from 1 to 21 d old (P < 0.05). Weaning at 14 d old increased (P < 0.05) the BUN and triglycerides levels in serum, as well as jejunal solute carrier family 7 member 6 (SLC7A6), ileal SLC36A1 and SLC1A1 mRNA abundances at d 1 or 3 post-weaning. Weaning also inhibited (P < 0.05) the phosphorylation levels of mTOR and its downstream ribosomal protein S6 kinase 1 (S6K1) and 4E-binding protein-1 (4EBP1) in the small intestine of weanling pigs. Oral administration of Put and Pro decreased (P < 0.05) serum ALP levels and increased (P < 0.05) intestinal SLC36A1 and SLC1A1 mRNA abundances and mTOR pathway phosphorylation levels in post-weaning pigs. Pro but not Put treatment enhanced (P < 0.05) serum Pro, arginine (Arg) and glutamine (Gln) concentrations of weaning-pigs. These findings indicated that early-weaning dramatically altered the biochemical blood metabolites, AA profile and intestinal mTOR pathway activity, and Pro and Put supplementations improved the AA metabolism and transportation as well as activated the intestinal mTOR pathway in weanling-pigs. Our study has an important implication for the broad application of Pro and Put in the weaning transition of piglets.

Effect of a Phytogenic Water Additive on Growth Performance, Blood Metabolites and Gene Expression of Amino Acid Transporters in Nursery Pigs Fed with Low-Protein/High-Carbohydrate Diets

Simple Summary

Low-protein (LP) diets can be potentially used to reduce the excretion of nitrogenous compounds and feed cost in commercial swine production; however, new strategies are required to be developed to improve the growth performance of pigs receiving these diets. Little is known about the effect of phytogenic additives on the performance of pigs fed with LP diets and the underlying factors involved. The objective of this study was to assess the effect of a phytogenic water additive (PWA) on growth performance, nutrient digestibility, blood metabolites, plasma amino acid (AA) concentration, and gut and skeletal muscle AA transporters in nursery pigs fed with LP diets. Supplemental PWA increased the concentration of circulating essential AA, reduced the transcript of some of the AA transporters in the small intestine and skeletal muscle, improved growth performance when the dietary protein was adequate, and increased muscle lean%, but reduced muscle fat% when the dietary protein was deficient. The used PWA in this study had differential effects on blood calcium and its digestibility depending on the level of dietary protein. This study suggests that PWA can be used for improving the meat composition in protein-restricted pigs, but PWA improves growth performance only when dietary protein is adequate.

Abstract

The objective of this study was to investigate the effect of a phytogenic water additive (PWA) on growth performance and underlying factors involved in pigs fed with low-protein (LP)/high-carbohydrate diets. Forty-eight weaned barrows were allotted to six treatments for 4 weeks: CON-NS, control (CON) diet-no PWA; CON-LS, CON diet-low dose PWA (4 mL/L); CON-HS, CON diet-high dose PWA (8 mL/L); LP-NS, LP diet-no PWA; LP-LS, LP diet-low dose PWA; LP-HS, LP diet-high dose PWA. Relative to CON-NS, pigs fed with CON-HS had increased average daily gain, body weight and serum calcium (Ca) and phosphorous (P) and had decreased mRNA abundance of solute carrier family 7 member 11 and solute carrier family 6 member 19 in jejunum. Compared to LP-NS, pigs fed with LP-HS had increased muscle lean%, decreased muscle fat%, decreased serum Ca and increased serum P. Compared to their NS counterparts, CON-LS, CON-HS, and LP-LS increased the concentration of plasma essential AA and those fed with CON-HS and LP-HS tended to reduce the abundance of the solute carrier family 7 member 1 transcript in skeletal muscle. Thus, PWA improved the performance of weaned pigs fed with protein-adequate diets likely through increased blood essential AA and affected the muscle composition when dietary protein was deficient.

Effect of fumonisin B1 on oxidative stress and gene expression alteration of nutrient transporters in porcine intestinal cells

Fumonisin B₁ (FB₁ ) is a common environmental mycotoxin produced by molds such as Fusarium verticillioides. The toxin poses health risks to domestic animals, including pigs, through FB₁ -contaminanted feed. However, the cytotoxicity of FB₁ to porcine intestines has not been fully analyzed. In the present study, the effects of FB₁ on oxidative stress and nutrient transporter-associated genes of the porcine intestinal IPEC-J2 cells were explored. FB₁ decreased IPEC-J2 proliferation but did not trigger reactive oxygen species (ROS) overproduction. Meanwhile, FB₁ reduced the expression levels of the transporters l-type amino acid transporter-1 (y⁺ LAT1), solute carrier family 7 member 1 (SLC7A1), solute carrier family 1 member 5 (ASCT2), and excitatory amino acid carrier 1 (EAAC1); in addition, FB₁ reduced the levels of the fatty acid transporters long-chain fatty acid transport protein 1 (FATP1) and long-chain fatty acid transport protein 4 (FATP4) as well as glucose transporters Na⁺ /glucose cotransporter 1 (SGLT1) and glucose transporter 2 (GLUT2). FB₁ stimulation increased the expression levels of peptide transporter peptide transporter 1 (PepT1) and metal ion transport-related gene zinc transporter 1 (ZNT1). Moreover, metal ion transporter divalent metal transporter 1 (DMT1) expression was depressed by a higher dosage of FB₁ . The data indicate that FB₁ results in aberrant expression of nutrient transporters in IPEC-J2 cells, thereby exerting its toxicity even though it fails to exert ROS-dependent oxidative stress.