Effect of fibre sources on performance,serum parameters,intestinal morphology,digestive enzyme activities and microbiota in weaned pigs

ABSTRACT

This study was conducted to evaluate the effects of wheat bran (WB) as insoluble fibre source, and sugar beet pulp (SBP) as soluble fibre source, on performance, serum parameters and intestinal health in weaned pigs. A total of 90 weaned pigs (BW: 7.33 ± 1.24 kg) were randomly assigned to three dietary treatments: (1) a control diet (CON) based on corn and soybean meal; (2) CON + 6% WB; (3) CON + 6% SBP. Each treatment had five replicate pens with six pigs per pen. The experimental period was divided into two phases (d 0 to 14 and d 14 to 28). Pigs in group WB tended to have greater avarage daily gain than those in group SBP. Compared with CON, SBP reduced (p < 0.05) the apparent total tract digestibility (ATTD) of dry matter, organic matter (OM), gross energy and neutral detergent fibre on d 14 and 28, while WB decreased (p < 0.05) the ATTD of OM on d 28. Pigs in group SBP had higher (p < 0.05) glucagon-like peptide 1 concentration than the other groups on d 14 and 28. The villus height to crypt depth (V:C) ratio of duodenum and jejunum in pigs fed diet WB were greater (p < 0.05) than in group SBP. The WB increased (p < 0.05) the V:C ratio of ileum compared with CON or SBP. Compared with SBP, WB increased (p < 0.05) the sucrase activity in the duodenum. Moreover, pigs in WB had higher (p < 0.05) activities of maltase and sucrase in the jejunum compared with CON or SBP. The abundances of Ruminococcaceae and Prevotellaceae were increased (p < 0.05) in WB, while the Lachnospiraceae abundance was increased (p < 0.05) in SBP. WB increased (p < 0.05) concentrations of acetate, butyrate and total short-chain fatty acids (SCFA), while SBP increased (p < 0.05) concentrations of acetate and total SCFA when compared with CON. In conclusion, WB was beneficial to performance in weaned pigs by improving morphology, enzyme activities and microbiota when compared with SBP, highlighting that effects of fibre depends on the fibre sources.     

Effects of extrusion of corn on growth performance,nutrient digestibility and short-chain fatty acid profiles in the hindgut of weaned piglets

Abstract

The experiment was conducted to investigate the effects of different inclusion levels of extruded corn on growth performance, nutrient digestibility and short-chain fatty acids profiles in the hindgut of weaned piglets. Ninety weaning piglets (28 d of age; 8.21 ± 0.69 kg BW) were allotted to one of five dietary treatments only substituted for unprocessed corn at varying levels (0, 1/4, 2/4, 3/4, 4/4) with extruded corn in a 28-d experiment. On day 28, 30 piglets were killed to measure concentrations and molar ratios of short-chain fatty acids in the hindgut. From day 0 – 14, digestibility of DM, N and GE was increased linearly and diarrhea frequency was decreased due to the increasing inclusion levels of extruded corn. From day 14 – 28, digestibility of GE and N was enhanced linearly due to the increasing proportion of extruded corn. On day 28, as proportion of extruded corn increased, the level of butyrate in the caecum and colon was increased linearly and the relative proportion of propionate was reduced. Results indicated that increasing proportions of extruded corn had no effect on growth performance, but significantly improved digestibility of N and energy at day 10 of trial and may be advantageous to the intestinal health of piglets.     

Effects of Bacillus subtilis and antibiotic growth promoters on the growth performance,intestinal function and gut microbiota of pullets from 0 to 6 weeks

The development of digestive organs and the establishment of gut microbiota in pullets play an important role throughout life. This study was conducted to investigate the effects of Bacillus subtilis (BS) on growth performance, intestinal function and gut microbiota in pullets from 0 to 6 weeks of age. Hy-line Brown laying hens (1-day-old, n = 504) were randomly allotted into four diets with a 2 × 2 factorial design: (1) basal diet group (control); (2) antibiotics group (AGP), the basal diet supplemented with 20 mg/kg Bacitracin Zinc and 4 mg/kg Colistin Sulphate; (3) BS group, the basal diet supplemented with 500 mg/kg BS and (4) mixed group, the basal diet supplemented with both AGP and BS. As a result, when BS was considered the main effect, BS addition (1) reduced the feed conversion ratio at 4 to 6 weeks (P < 0.05); (2) decreased duodenal and jejunal crypt depth at 3 weeks; (3) increased the villus height : crypt depth (V : C) ratio in the duodenum at 3 weeks and jejunal villus height at 6 weeks and (4) increased sucrase mRNA expression in the duodenum at 3 weeks as well as the jejunum at 6 weeks, and jejunal maltase and aminopeptidase expression at 3 weeks. When AGP was considered the main effect, AGP supplementation (1) increased the V : C ratio in the ileum at 3 weeks of age; (2) increased sucrase mRNA expression in the duodenum at 3 weeks as well as the ileum at 6 weeks, and increased maltase expression in the ileum. The BS × AGP interaction was observed to affect average daily feed intake at 4 to 6 weeks, and duodenal sucrase and jejunal maltase expression at 3 weeks. Furthermore, dietary BS or AGP addition improved caecal microbial diversity at 3 weeks, and a BS × AGP interaction was observed (P < 0.05) for the Shannon and Simpson indexes. At the genus level, the relative abundance of Lactobacillus was found to be higher in the mixed group at 3 weeks and in the BS group at 6 weeks. Moreover, Anaerostipes, Dehalobacterium and Oscillospira were also found to be dominant genera in pullets with dietary BS addition. In conclusion, BS could improve intestinal morphology and change digestive enzyme relative expression and caecum microbiota, thereby increasing the efficiency of nutrient utilization. Our findings suggested that BS might have more beneficial effects than AGP in the study, which would provide theoretical evidence and new insight into BS application in layer pullets.     

The in ovo administration of l-trans pyrrolidine-2,4-dicarboxylic acid regulates small intestinal growth in chicks

Glutamate, which is one of the most important contributors to oxidative metabolism in the intestinal mucosa, is mainly transported by the excitatory amino acids transporters (EAATs) that are expressed in enterocytes. The objective of this study was to evaluate the effects of in ovo administration of l-trans pyrrolidine-2,4-dicarboxylic acid (l-trans-PDC), a potent competitive inhibitor of glutamate uptake by EAATs, on the growth of the small intestine in chicks. Two series of experiments were conducted with hatching eggs; 100 μl of various l-trans-PDC solutions (0, 0.075 or 0.225 mg/egg for the Control group, low-dose l-trans pyrrolidine 2,4-dicarboxylic acid group (L-PDC) or high-dose l-trans pyrrolidine 2,4-dicarboxylic acid group (H-PDC), respectively) was injected into the albumen sac of these hatching eggs before incubation. Hatchlings were sacrificed by cervical dislocation to determine the embryonic development in Experiment I, whereas the birds in Experiment II were raised or sampled at hatching, days 7 and 14 (D7 and D14) for further study. Gene expression in the small intestines was determined by real-time RT-PCR; and serum concentration of free amino acids was determined by an amino acid analyzer. The results showed that the hatchability was decreased by in ovo administration of l-trans-PDC. The small intestinal weights of the H-PDC group were decreased (P<0.05) at hatching and increased (P<0.05) on D7 and D14 compared with those in the Control group. In addition, the gene expression of EAAT2 in the completed or segmental small intestines was not changed (P>0.05); EAAT3 gene expression in the duodenum (P<0.05), jejunum (P=0.084) and ileum (P=0.060) on D14 was lower in the H-PDC group than in the Control group. Furthermore, the serum concentrations of free proline, threonine and phenylalanine but not glutamate or aspartate were increased (P<0.06) in H-PDC group. In conclusion, this paper is the first to report that in ovo administration of l-trans-PDC induces small intestinal growth retardation during the embryonic period and catch-up growth after hatching.     

The intestinal microbiome associated with lipid metabolism and obesity in humans and animals

Intestinal microbiota is considered to play an integral role in maintaining health of host by modulating several physiological functions including nutrition, metabolism and immunity. Accumulated data from human and animal studies indicate that intestinal microbes can affect lipid metabolism in host through various direct and indirect biological mechanisms. These mechanisms include the production of various signalling molecules by the intestinal microbiome, which exert a strong effect on lipid metabolism, bile secretion in the liver, reverse transport of cholesterol and energy expenditure and insulin sensitivity in peripheral tissues. This review discusses the findings of recent studies suggesting an emerging role of intestinal microbiota and its metabolites in regulating lipid metabolism and the association of intestinal microbiota with obesity. Additionally, we discuss the controversies and challenges in this research area. However, intestinal micro-organisms are also affected by some external factors, which in turn influence the regulation of microbial lipid metabolism. Therefore, we also discuss the effects of probiotics, prebiotics, diet structure, exercise and other factors on intestinal microbiological changes and lipid metabolism regulation.     

Effects of low-protein diets supplemented with indispensable amino acids on growth performance,intestinal morphology and immunological parameters in 13 to 35 kg pigs

The objective of this study was to determine if a moderate or high reduction of dietary CP, supplemented with indispensable amino acids (IAA), would affect growth, intestinal morphology and immunological parameters of pigs. A total of 40 barrows (initial BW=13.50±0.50 kg, 45±2 day of age) were used in a completely randomized block design, and allocated to four dietary treatments containing CP levels at 20.00%, 17.16%, 15.30% and 13.90%, respectively. Industrial AA were added to meet the IAA requirements of pigs. After 4-week feeding, blood and tissue samples were obtained from pigs. The results showed that reducing dietary CP level decreased average daily gain, plasma urea nitrogen concentration and relative organ weights of liver and pancreas (P<0.01), and increased feed conversion ratio (P<0.01). Pigs fed the 13.90% CP diet had significantly lower growth performance than that of pigs fed higher CP at 20.00%, 17.16% or 15.30%. Moreover, reducing dietary CP level decreased villous height in duodenum (P<0.01) and crypt depth in duodenum, jejunum and ileum (P<0.01). The reduction in the dietary CP level increased plasma concentrations of methionine, alanine (P<0.01) and lysine (P<0.05), and decreased arginine (P<0.05). Intriguingly, reducing dietary CP level from 20.00% to 13.90% resulted in a significant decrease in plasma concentration of IgG (P<0.05), percentage of CD3⁺T cells of the peripheral blood (P<0.01), also down-regulated the mRNA abundance of innate immunity-related genes on toll-like receptor 4, myeloid differentiation factor 88 (P<0.01) and nuclear factor kappa B (P<0.05) in the ileum. These results indicate that reducing dietary CP level from 20.00% to 15.30%, supplemented with IAA, had no significant effect on growth performance and had a limited effect on immunological parameters. However, a further reduction of dietary CP level up to 13.90% would lead to poor growth performance and organ development, associated with the modifications of intestinal morphology and immune function.     

Postnatal growth retardation is associated with intestinal mucosa mitochondrial dysfunction and aberrant energy status in piglets

Individuals with postnatal growth retardation (PGR) are prone to developing chronic disease. Abnormal development in small intestine is casually implicated in impaired growth performance. However, the exact mechanism is still unknown. In this present study, PGR piglets (aged 42 days) were employed as a good model to analyse changes in nutrient absorption and energy metabolism in the intestinal mucosa. The results showed lower serum concentrations of free amino acids, and lipid metabolites in PGR piglets, which were in accordance with the down‐regulated mRNA expressions involved in fatty acid and amino acid transporters in the jejunal and ileal mucosa. The decreased activities of digestive enzymes and the marked swelling in mitochondria were also observed in the PGR piglets. In addition, it was found that lower ATP production, higher AMP/ATP ratio, deteriorated mitochondrial complex III and ATP synthase, and decreased manganese superoxide dismutase activity in the intestinal mucosa of PGR piglets. Furthermore, altered gene expression involved in energy metabolism, accompanied by decreases in the protein abundance of SIRT1, PGC‐1α and PPARγ, as well as phosphorylations of AMPKα, mTOR, P70S6K and 4E‐BP1 were observed in intestinal mucosa of PGR piglets. In conclusion, decreased capability of nutrient absorption, mitochondrial dysfunction, and aberrant energy status in the jejunal and ileal mucosa may contribute to PGR piglets.     

The role of short-chain fatty acids in the interplay between diet,gut microbiota,and host energy metabolism

Short-chain fatty acids (SCFAs), the end products of fermentation of dietary fibers by the anaerobic intestinal microbiota, have been shown to exert multiple beneficial effects on mammalian energy metabolism. The mechanisms underlying these effects are the subject of intensive research and encompass the complex interplay between diet, gut microbiota, and host energy metabolism. This review summarizes the role of SCFAs in host energy metabolism, starting from the production by the gut microbiota to the uptake by the host and ending with the effects on host metabolism. There are interesting leads on the underlying molecular mechanisms, but there are also many apparently contradictory results. A coherent understanding of the multilevel network in which SCFAs exert their effects is hampered by the lack of quantitative data on actual fluxes of SCFAs and metabolic processes regulated by SCFAs. In this review we address questions that, when answered, will bring us a great step forward in elucidating the role of SCFAs in mammalian energy metabolism.     

藏猪小肠形态、消化酶及微生物多样性研究

[目的]肠道是动物的主要消化器官,同时也是机体抵抗外源病原菌的重要屏障,已有研究表明,动物的品种、饲养方式、生长阶段均会影响动物的肠道菌群结构,但对舍饲和放牧饲养条件下藏猪的肠道菌群结构,以及藏猪和长白、约克与杜洛克三元杂交猪(DLY猪)的肠道菌群结构是否有差异,尚未见报道.[方法]本研究选取6-7月龄的放牧藏猪、舍饲...     

Effects of dietary grape pomace on the intestinal microbiota and growth performance of weaned piglets

ABSTRACT

Grape pomace (GP) is an abundant by-product from wine production and is rich in phenolic compounds, unsaturated fatty acids, dietary fibre and beneficial bacteria. In this study, weaned piglets were fed a basic diet supplemented with 5% GP for 4 weeks. Compared with those in the control (CON) group, it was found that the proportion of Lactobacillus delbrueckii, Olsenella umbonata and Selenomonas bovis in the caecum and the villus height and villus height/crypt depth ratio (VCR) of the jejunum were both significantly increased in the GP group (p < 0.05). Meanwhile, at the mRNA expression level, several proinflammatory cytokines (IL-1β, IL-8, IL-6 and TNF-α) were significantly downregulated (p < 0.05) in piglet caecal tissue, and the short-chain fatty acid receptors (GPR41 and GPR43) were not significantly upregulated. In contrast, the levels of IgG was significantly increased (p < 0.05) in the sera of weaned piglets in the GP group. However, no difference in growth performance between the two groups of piglets was detected. These results show that GP had no adverse effects on the growth performance of piglets, but GP can promote the content of some beneficial bacteria in the caecum; this effect is conducive to improving the disease resistance potential of piglets.     

不同生长性能苏姜猪保育猪肠道菌群差异分析

【背景】苏姜猪是优质瘦肉型新品种猪,断奶仔猪受到多方面应激影响会出现生长性能差异。【目的】研究不同生长性能的苏姜猪保育猪肠道菌群结构的异同。【方法】试验选取了同日龄、体重相近、健康情况良好的的保育仔猪100头,在相同的饲养条件下饲养42 d,试验结束选取体重较轻的为弱仔猪,3头弱仔猪体重为18.43±2.37kg;体重较大的为健康仔猪,3头健康仔猪体重为27.37±1.36 kg。屠宰后,采集其空肠和盲肠内容物,提取微生物基因组DNA进行高通量测序分析其菌群结构。【结果】苏姜猪仔猪空肠和盲肠在菌群丰度、多样性上有极显著的差异(P<0.01)。苏姜猪仔猪空肠菌群优势菌群为变形菌门(Proteobacteria)假单胞菌属(Pseudomonas)的非致病性菌株,占比超过90%。苏姜猪仔猪盲肠优势菌门依次为拟杆菌门(Bacteroidetes)、厚壁菌门(Firmicutes)、变形菌门(Proteobacteria)。门水平组成结构存在差异,弱仔猪厚壁菌门丰度低于健康仔猪、变形菌门丰度高于健康仔猪。苏姜猪盲肠中普雷沃氏菌属(Prevotella)、疣微菌科UCG-005 (Rumi...     

Effects of Enterococcus faecium and Bacillus cereus var. toyoi on the morphology of the intestinal mucous membrane in piglets

Eighty piglets aged 14, 28, 35 and 56 days — weaned at day 28 — were subjected to this investigation. Each age-group consisted of five animals which were fed an Enterococcus faecium NCIMB 10415 (Cylactin®) and Bacillus cereus var. toyoi (Toyocerin®) based diet. Five animals served as controls. Tissue samples were collected immediately after sacrifice at 8.30 h a.m. from duodenum, jejunum, ileum, cecum and colon to examine intestinal morphology and histochemistry. The results showed that with respect to villus height and crypt depth supplementation of probiotics in piglets feed seemed to influence the morphology and enlargement factor not at all or only to a certain extent. With respect to the number of goblet cells, the difference between probiotic fed animals and control animals was generally extremely low. The shape of the villi of the small intestinal segments greatly varied in all age groups of control and probiotic fed animals. However, this morphological variety does not depend on the mode of feeding.     

Changes in digestive enzyme activity, intestine morphology, mucin characteristics and tocopherol status in mink kits (Mustela neovision) during the weaning period

Weaning of livestock mammals is often associated with digestive problems related to profound changes in the physiology of the gastrointestinal tract. This study was undertaken to study the developmental changes in the gastrointestinal tract of mink kits during the period of 34 to 59 days of age. Twenty-four mink kits from eight litters were included in the experiment. The dams and their litters were kept under standard farm conditions. The dams and the kits were fed a diet consisting of 48.1% protein, 40.7% fat and 11.1% carbohydrate of metabolizable energy. The mink kits were weaned at 42 days of age. At 34, 47 and 59 days of age, one male mink kit from each litter was euthanized. The activity of amylase, trypsin, chymotrypsin and lipase in the pancreatic tissue increased during the experimental period, whereas the activity of carboxyl ester hydrolase remained constant. The vitamin E concentration in plasma was stable from 34 to 59 days of age, whereas the concentration decreased in the liver. The stereochemical composition of α-tocopherol showed a steep decrease in the concentration of the biologically most active natural isomer in both plasma and liver through the whole weaning period, whereas the biologically less active 2S isomers showed a clear increase. The concentration of bile salts did not change during the experimental period. The villous height increased in the proximal part of the small intestine and decreased in the distal part, whereas the crypt depth was doubled in both the proximal and distal part of the small intestine. The mucin-staining area on the villi was markedly reduced during the experimental period but no change in the mucin-staining area in the crypts was observed.     

Early intervention with faecal microbiota transplantation: an effective means to improve growth performance and the intestinal development of suckling piglets

Recent studies indicate that early postnatal period is a critical window for gut microbiota manipulation to optimise the immunity and body growth. This study investigated the effects of maternal faecal microbiota orally administered to neonatal piglets after birth on growth performance, selected microbial populations, intestinal permeability and the development of intestinal mucosal immune system. In total, 12 litters of crossbred newborn piglets were selected in this study. Litter size was standardised to 10 piglets. On day 1, 10 piglets in each litter were randomly allotted to the faecal microbiota transplantation (FMT) and control groups. Piglets in the FMT group were orally administrated with 2ml faecal suspension of their nursing sow per day from the age of 1 to 3 days; piglets in the control group were treated with the same dose of a placebo (0.1M potassium phosphate buffer containing 10% glycerol (vol/vol)) inoculant. The experiment lasted 21 days. On days 7, 14 and 21, plasma and faecal samples were collected for the analysis of growth-related hormones and cytokines in plasma and lipocalin-2, secretory immunoglobulin A (sIgA), selected microbiota and short-chain fatty acids (SCFAs) in faeces. Faecal microbiota transplantation increased the average daily gain of piglets during week 3 and the whole experiment period. Compared with the control group, the FMT group had increased concentrations of plasma growth hormone and IGF-1 on days 14 and 21. Faecal microbiota transplantation also reduced the incidence of diarrhoea during weeks 1 and 3 and plasma concentrations of zonulin, endotoxin and diamine oxidase activities in piglets on days 7 and 14. The populations of Lactobacillus spp. and Faecalibacterium prausnitzii and the concentrations of faecal and plasma acetate, butyrate and total SCFAs in FMT group were higher than those in the control group on day 21. Moreover, the FMT piglets have higher concentrations of plasma transforming growth factor-β and immunoglobulin G, and faecal sIgA than the control piglets on day 21. These findings indicate that early intervention with maternal faecal microbiota improves growth performance, decreases intestinal permeability, stimulates sIgA secretion, and modulates gut microbiota composition and metabolism in suckling piglets.