Low-protein diets supplemented with glutamic acid or aspartic acid ameliorate intestinal damage in weaned piglets challenged with hydrogen peroxide

Glutamic acid (Glu) and aspartic acid (Asp) are acidic amino acids with regulatory roles in nutrition, energy metabolism, and oxidative stress. This study aimed to evaluate the effects of low-protein diets supplemented with Glu and Asp on the intestinal barrier function and energy metabolism in weaned piglets challenged with hydrogen peroxide (H₂O₂). Forty piglets were randomly divided into 5 groups: NC, PC, PGA, PG, and PA (n = 8 for each group). Pigs in the NC and PC groups were fed a low-protein diet, while pigs in the PGA, PG, or PA groups were fed the low-protein diet supplemented with 2.0% Glu +1.0% Asp, 2.0% Glu, or 1.0% Asp, respectively. On day 8 and 11, pigs in the NC group were intraperitoneally injected with saline (1 mL/kg BW), while pigs in the other groups were intraperitoneally administered 10% H₂O₂ (1 mL/kg BW). On day 14, all pigs were sacrificed to collect jejunum and ileum following the blood sample collection in the morning. Notably, low-protein diets supplemented with Glu or Asp ameliorated the intestinal oxidative stress response in H₂O₂-challenged piglets by decreasing intestinal expression of genes (P < 0.05) (e.g., manganese superoxide dismutase [MnSOD], glutathione peroxidase [Gpx]-1, and Gpx-4) encoding oxidative stress-associated proteins, reducing the serum concentration of diamine oxidase (P < 0.05), and inhibiting apoptosis of the intestinal epithelium. Glu and Asp supplementation attenuated the upregulated expression of energy metabolism-associated genes (such as hexokinase and carnitine palmitoyltransferase-1) and the H₂O₂-induced activation of acetyl-coenzyme A carboxylase (ACC) in the jejunum and adenosine monophosphate-activated protein kinase–acetyl-ACC signaling in the ileum. Dietary Glu and Asp also ameliorated intestinal barrier damage as indicated by restored intestinal histology and morphology. In conclusion, low-protein diets supplemented with Glu and Asp protected against oxidative stress-induced intestinal dysfunction in piglets, suggesting that this approach could be used as a nutritional regulatory protectant against oxidative stress.     

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.     

谷氨酰胺对断奶仔猪生长性能、营养物质表观消化率、空肠碱性磷酸酶活性及与肠道健康相关因子基因表达的影响

本研究的目的是探讨饲粮中添加谷氨酰胺对断奶仔猪生长性能、营养物质表观消化率、空肠碱性磷酸酶活性及与肠道健康相关因子基因表达的影响.将128头21日龄断奶的“杜×长×大”三元杂交仔猪按照体重、性别一致的原则随机分成2组,分别为对照组和添加1.00％谷氨酰胺组,每组4个重复,每个重复16头仔猪.在仔猪断奶后第10天和第30天,分别从每个重复中采集新鲜粪便样本,然后选择1头接近平均体重的仔猪进行屠宰,取空肠,刮取黏膜.试验期为30 d.结果表明:在断奶后第10天,与对照组相比,谷氨酰胺组平均日增重、干物质、粗蛋白质表观消化率和表观代谢能分别显著提高了19.05％、9.06％、4.77％和7.02％(P＜0.05),大多数必需氨基酸和非必需氨基酸表观消化率均有显著的提高(P＜0.05);在断奶后第30天,谷氨酰胺组干物质、粗蛋白质表观消化率和表观代谢能分别显著提高了5.90％、2.80％和6.43％ (P ＜0.05).在断奶后第10天和第30天,谷氨酰胺组仔猪空肠刷状缘碱性磷酸酶活性比对照组分别提高了30.09％(P＜0.05)和5.98％ (P ＞0.05).谷氨酰胺组空肠过氧化物酶体增殖体激活受体-γ和丙酮酸激酶基因mRNA表达水平在断奶后第10天比对照组分别下降了10.00％和30.00％ (P ＞0.05);在断奶后第30天比对照组分别显著下降了42.22％和44.52％ (P ＜0.05).在断奶后第10天和第30天,谷氨酰胺组空肠雷帕霉素靶蛋白基因mRNA表达水平分别比对照组提高了22.00％ (P ＞0.05)和22.38％ (P ＜0.05).以上结果提示,谷氨酰胺通过提高空肠碱性磷酸酶活性和调控与肠道健康相关因子基因表达水平来提高断奶仔猪的生长性能和营养物质表观消化率.     

N-Acetyl-D-glucosamine improves the intestinal development and nutrient absorption of weaned piglets via regulating the activity of intestinal stem cells

Early weaning in piglets can cause a series of negative effects.This causes serious losses to the livestock industry.N-Acetyl-D-glucosamine(D-GlcNAc)plays an important role in regulating the homeostasis of the intestine.This study aimed to investigate the effects of D-GlcNAc on the growth performance and intestinal function of weaned piglets.Twenty-four weaned piglets([Yorkshire×Landrace]
Duroc,6.58±0.15 kg,n=8)at 21 d old were fed 3 diets supplemented with 0(control),1 and 3 g/kg D-GlcNAc.The intestinal organoid model was used to verify the regulatory mechanism of D-GlcNAc on intestinal epithelial cells.On the whole,supplementation of D-GlcNAc in the piglet diet has no significant effect on the growth performance and diarrhoea of weaned piglets(P>0.05).The apparent digestibility of nutrients and mRNA abundance of nutrient transporters in the 1 g/kg D-GlcNAc group were increased significantly(P<0.05).D-GlcNAc did not affect villus height(VH)and crypt depth(CD)but resulted in a numerically shorter VH and shallower CD,which lead to an increase in ileal VH:CD ratio(P<0.05).Cell shedding rates in the ileum villi increased(P<0.05).The relative length and weight of the small intestine of weaned piglets increased(P<0.05).In vitro studies found that the budding rates of organoids treated with 0.1 mmol/L D-GlcNAc increased on the d 3 and 5(P<0.05).The average budding numbers per budding organoid treated with 0.1 and 10 mmol/L D-GlcNAc increased on d 3(P<0.05).D-GlcNAc upregulated leucine rich repeat containing G protein-coupled receptor 5(Lgr5⁺)and Chromogranin A mRNA abundance in organoids(P<0.05).Mucin 2(Muc2)expression increased when treated with 1 and 10 mmol/L D-GlcNAc(P<0.05).In conclusion,dietary D-GlcNAc cannot improve the growth performance of weaned piglets.However,it can promote the growth and development of the intestinal tract and improve the digestion and absorption capacity of the intestine,which is achieved by affecting the activity of intestinal stem cells.     

Intestinal growth and morphology is associated with the increase in heat shock protein 70 expression in weaning piglets through supplementation with glutamine

The objectives of this study were to determine the effects of oral Gln supplementation on growth performance, intestinal morphology, and expression of heat shock protein (Hsp) 70 in weaning piglets. A total of 65 piglets after weaning at 21 d of age (d 0) were used in this experiment. Five piglets were randomly selected and euthanized initially at d 0 to determine baseline values for the expression of Hsp70 in the small intestine. The remaining piglets were randomly assigned to 1 of 2 treatments and received 0 or 1 g of oral Gln/kg of BW every 12 h. After piglets were humanely killed at d 3, 7, and 14 postweaning, the duodenum, jejunum, and ileum of piglets were sampled to evaluate intestinal morphology and the expression and localization of Hsp70. The results indicated that oral Gln supplementation increased plasma concentrations of Gln compared with those in control piglets (P < 0.05). Average daily gain and ADFI were greater in piglets orally supplemented with Gln than in control piglets during the whole period (P < 0.05). The incidence of diarrhea in piglets orally supplemented with Gln was 24% less than (P = 0.064) that in control piglets at 8 to 14 d after weaning. The weights of the jejunum and ileum were greater in piglets orally supplemented with Gln compared with those of control piglets relative to BW on d 14 postweaning (P < 0.05). The villus height and the villus height:crypt depth ratio in the jejunum and the ileum were greater in piglets receiving oral Gln on d 14 postweaning (P < 0.05) than in control piglets. These results indicate that Gln supplementation can influence the intestinal morphology of weaned piglets. The expression of hsp70 mRNA and Hsp70 proteins in the duodenum and jejunum was greater in piglets supplemented with Gln than in control piglets (P < 0.05). However, Gln supplementation had no effect on the expression of hsp70 mRNA and Hsp70 proteins in the ileum. Moreover, the localization of Hsp70 in the cytoplasm indicated that Hsp70 has a cytoprotective role in epithelial cell function and structure. These results indicate that Gln supplementation may be beneficial for intestinal health and development and may thus mitigate diarrhea and improve growth performance. The protective mechanisms of Gln in the intestine may be associated with the increase in Hsp70 expression.     

Influence of the probiotic Bacillus cereus var. toyoi on the intestinal immunity of piglets

In a feeding trial, sows and piglets were fed with the probiotic bacterium Bacillus cereus var. toyoi as a feed additive, and the effects on immune cell populations were examined. The development of the gut immune system was determined for piglets at the ages of 14, 28, 35 and 56 days post partum. Tissue samples of the Jejunum and the continuous Peyer's patch were used for enumeration of intraepithelial lymphocyte populations by fluorescence activated flow cytometry and fluorescence microscopy. Both independent methods of investigation led to similar results: the population of intraepithelial CD8+ T cells was significantly enhanced in the probiotic group piglets (p ≤ 0.05), and the numbers of γδ T cells tended to be higher in the intestinal epithelium (p < 0.1) at the time of weaning (day 28). Lamina propria lymphocytes were also influenced by the treatment. Application of B. cereus var. toyoi resulted in significantly more CD25+ lymphocytes and γδ T cells in the probiotic group post-weaning. The occurrence of pathogenic Escherichia coli serogroups was also less frequent in the feces of piglets from the probiotic group. The finding that the CD8+ T cell population in the intestinal mucosa showed changes on day 28 indicated that the influence of B. cereus var. toyoi supplementation on the intestinal immune system started before weaning, an observation supported by changes in the intestinal microflora observed during the suckling-period. The results suggest that feeding of B. cereus var. toyoi to sows may result in beneficial effects on piglet health status independent of their feed supplementation.     

Dietary nucleotide supplementation reduces occurrence of diarrhoea in early weaned pigs

In the weaning period, transition from sow's milk to the post-weaning diet causes the withdrawal of important nutrients as milk nucleotides, which are known to be determinant for the development of the gastrointestinal tract and immune function. The objective of these investigations was to study the effect of including these nucleotides in solid diets for piglets. Nucleotide composition of sow's milk was analyzed using 5 sows at 21 days of lactation. The average free nucleotide concentration was 102.8 ± 9.16 μmol/100 mL. Two experiments were performed to assess the effect of a product based on this composition (Nucleoforce Piglets®) on digestive adaptation and incidence of diarrhoea of nursery piglets. In Exp. 1, three groups of 6 piglets were weaned at 21 days of age and fed with a diet supplemented with 0 (control), 1000 or 2000 ppm of nucleotides, and a fourth group of 6 piglets was maintained in lactation. Seven days after weaning, piglets were euthanized and samples of jejunal mucosa were processed for histological measurements. Villus height decreased from 448 μm in un-weaned pigs to 275 μm in the control group 7 days after weaning. Although there were no differences in feed intake among groups, the reduction in villous height was less pronounced (P < 0.001) in nucleotide supplemented groups showing a villous height of 351 and 378 μm with the doses of 1000 or 2000 ppm respectively. In Exp. 2, 384 early weaned pigs were fed during 14 days with a diet supplemented with 0 (control), 750 and 1000 ppm of nucleotides. ADG and ADFI were not modified by the treatment, but nucleotide supplementation reduced the number of pigs treated with antibiotic as a result of diarrhoea (15.63% vs 3.13% and 1.56%; for control, 750 and 1000 ppm; P < 0.001). These results suggest that dietary supplementation with nucleotides from yeast might help to prevent post-weaning diarrhoea in piglets.     

谷氨酰胺对早期断奶仔猪生长性能及肠道形态发育的影响

选21日龄断奶的杜大长仔猪72头,按试验要求分为2组,每组3个重复,每重复12头。分别饲喂基础日粮和含1%谷氨酰胺(Gln)日粮,试验期21 d,在断奶后0 d、7 d和14 d分别屠宰取小肠测重,并取十二指肠、空肠、回肠测定绒毛高度和隐窝深度。试验结果表明:断奶后7 d,日粮中添加Gln可显著提高仔猪的平均日增重和小肠相对重量,提高十二指肠和空肠绒毛的高度,降低十二指肠和空肠的隐窝深度;断奶后14 d,日粮中添加Gln对断奶仔猪的生长和肠道形态发育影响与基础日粮组相比差异不显著。     

Creep feed intake during lactation enhances net absorption in the small intestine after weaning

The aim of the study was to measure the effect of creep feeding during lactation on net absorption in the small intestine at 4 days after weaning. Intermittent suckling was used to increase creep feed intake during lactation. Creep feed containing chromic oxide was provided. Based on the colour of the faeces, piglets were classified as ‘eaters’ or ‘non-eaters’, respectively. At day 4 after weaning, an in vivo small intestine segment perfusion test was performed at 5 sites along the small intestine in 24 piglets (12 eaters and 12 non-eaters). At both sides of each intestinal segment a tube was fitted to perfuse and drain fluid in order to assess net absorption. Net absorption was higher in eaters than in non-eaters (P < 0.001). Net absorption varied greatly between and within piglets and was highest in the caudal segments of the small intestine (P < 0.001). These data suggest that creep feeding could be a useful tool in the prevention of post-weaning diarrhoea.     

Natural capsicum extract replacing chlortetracycline enhances performance via improving digestive enzyme activities,antioxidant capacity,anti-inflammatory function,and gut health in weaned pigs

The objective of this study was to investigate the effects of natural capsicum extract (NCE, containing 2% natural capsaicin, the rest is carrier) replacing chlortetracycline (CTC) on performance, digestive enzyme activities, antioxidant capacity, inflammatory cytokines, and gut health in weaned pigs. A total of 108 weaned pigs (Duroc × [Landrace × Yorkshire], initial body weight = 8.68 ± 1.34 kg; weaned on d 28) were randomly allotted into 3 treatments with 6 replicate pens per treatment (3 barrows and 3 gilts per pen). The treatments include a corn-soybean meal basal diet as a control group (CON), a CTC group (basal diet + CTC at 75 mg/kg), and a NCE group (basal diet + NEC at 80 mg/kg). Compared with CON and CTC, NCE had increased (P < 0.05) average daily gain in phase 2 (d 15 to 28) and overall (d 1 to 28), and higher (P < 0.05) apparent total tract digestibility of gross energy, dry matter, crude protein, and organic matter in phase 1 (d 1 to 14). These pigs also had increased (P < 0.05) pancrelipase activity in pancreas, α-amylase, lipase and protease activities in the jejunal mucosa, and lipase activity in the ileal mucosa on d 28. Moreover, NCE had increased (P < 0.05) the contents of growth hormone, β-endorphin, 5-hydroxytryptamine, total antioxidant capacity, total superoxide dismutase, catalase, and IL-10, as well as decreased (P < 0.05) contents of malondialdehyde, tumor nuclear factor-α, interferon-γ, and interleukin-6 in serum on d 28 compared with CON and CTC. NCE showed higher (P < 0.05) propionic acid, butyric acid and total volatile fatty acids (VFA) contents, and increased (P < 0.05) relative abundance of Faecalibacterium in colon, as well as higher (P < 0.05) propionic acid and total volatile fatty acids in cecum on d 28 compared with CON. In conclusion, NCE replacing CTC could enhance performance via improving digestive enzyme activities, antioxidant capacity, anti-inflammatory function, gut VFA composition and microbiota community in weaned pigs, and it could be used as a potential target for the development of feed additives.     

饲粮不同能量来源对断奶仔猪肠道黏膜功能的影响

仔猪早期断奶常常导致仔猪能量摄入不足,使肠道黏膜细胞处于"饥饿状态",影响仔猪正常的肠道功能,从而加剧断奶应激,因此满足肠道黏膜细胞的能量供给至关重要。本文就谷氨酰胺(Gln)、葡萄糖(Glu)、脂肪这3种肠黏膜细胞主要的供能物质来分别论述它们对于断奶仔猪肠道黏膜功能的影响。     

Pre-weaning eating activity and morphological parameters in the small and large intestine of piglets

The effect of pre-weaning eating activity on the intestinal morphology in piglets was investigated on the day of weaning and 5 days post-weaning. The eating activity of each piglet was recorded by means of direct observations. On day 5 post-weaning the villous heights were reduced and the crypt depths were increased irrespective of the pre-weaning eating activity. In the caecum and colon the crypt depth was increased post-weaning and no effect of pre-weaning eating activity was observed. The muscle thickness in the small intestine did not change during the immediate post-weaning period whereas the muscle thickness in the large intestine was doubled in the same period. In conclusion, pre-weaning eating activity did not affect the structural alterations of the small and large intestine. However, the actual number of piglets consuming creep feed prior to weaning was low and the eating activity was highly variable. Therefore, more or later weaned piglets may be needed to show effects of pre-weaning eating activity.     

Source of fiber influences growth,immune responses,gut barrier function and microbiota in weaned piglets fed antibiotic-free diets

This study examined the impacts of different fiber sources on growth, immune status and gut health in weaned piglets fed antibiotic-free diets. Sixty piglets (BW = 8.18 ± 1.35 kg) were assigned to 3 dietary treatments based on BW and gender in a randomized complete block design (5 replicates/treatment and 4 piglets [2 barrows and 2 gilts]/replicate): (1) an antibiotic-free diet (control, CON); (2) CON + 6% wheat bran (WB); (3) CON + 4% sugar beet pulp (SBP). Dietary WB supplementation tended to increase ADG compared with CON from d 1 to 14 (P = 0.051) and from d 1 to 28 (P = 0.099). Supplementation of WB increased (P < 0.05) G:F compared with CON and SBP from d 1 to 14 and from d 1 to 28. Compared with CON, the addition of WB reduced (P < 0.05) diarrhea rate from d 1 to 14 and tended (P = 0.054) to reduce diarrhea rate from d 1 to 28. The addition of WB decreased (P < 0.05) serum diamine oxidase activity on d 14, and up-regulated (P < 0.05) ileal mRNA levels of occludin on d 28 when compared with CON. Piglets fed WB showed decreased (P < 0.05) serum interleukin-6 levels compared to those fed SBP and decreased (P < 0.05) ileal interleukin-8 levels compared to those fed CON and SBP on d 28. Supplementation of WB increased (P < 0.05) serum levels of immunoglobulin A (IgA), IgG and IgM compared with SBP on d 14, and increased (P < 0.05) the levels of serum IgA and ileal sIgA compared with CON and SBP on d 28. Piglets fed WB showed an enhanced (P < 0.05) α-diversity of cecal microbiota than those fed SBP, while piglets fed SBP showed reduced (P < 0.05) α-diversity of cecal microbiota than those fed CON. Compared with CON, the addition of WB elevated (P < 0.05) the abundance of Lachnospira and cecal butyric acid level. Piglets fed WB also showed increased (P < 0.05) abundances of Lachnospira and unclassified_f_Lachnospiraceae compared with those fed SBP. Collectively, the supplementation of WB to antibiotic-free diets improved performance, immune responses, gut barrier function and microbiota compared with the CON and SBP fed piglets. Therefore, supplementing weaned piglets with WB was more effective than SBP.     

Early life administration of milk fat globule membrane promoted SCFA-producing bacteria colonization,intestinal barriers and growth performance of neonatal piglets

Milk fat globule membrane (MFGM) possesses various nutritional and biological benefits for mammals, whereas its effects on neonatal gut microbiota and barrier integrity remained unclear. This study investigated the effects of MFGM administration on microbial compositions and intestinal barrier functions of neonatal piglets. Sixteen newborn piglets were randomly allocated into a CON group or MFGM group, orally administered with saline or MFGM solution (1 g/kg body weight) respectively during the first postnatal week, and all piglets were breastfed during the whole neonatal period. The present study found that the MFGM oral administration during the first postnatal week increased the plasma immunoglobulin (Ig) G level, body weight and average daily gain of piglets (P < 0.05) on 21 d. Additionally, MFGM administration enriched fecal SCFA-producing bacteria (Ruminococaceae_UCG-002, Ruminococaceae_UCG-010, Ruminococaceae_UCG-004, Ruminococaceae_UCG-014 and [Ruminococcus]_gauvrearuii_group), SCFA concentrations (acetate, propionate and butyrate; P < 0.05) and their receptor (G-protein coupled receptor 41, GPR41). Furthermore, MFGM administration promoted intestinal villus morphology (P < 0.05) and barrier functions by upregulating genes of tight junctions (E-cadherin, claudin-1, occludin and zonula occludin 1 [ZO-1]), mucins (mucin-13 and mucin-20) and interleukin (IL)-22 (P < 0.05). Positive correlation was found between the beneficial microbes and SCFA levels pairwise with the intestinal barrier genes (P < 0.05). In conclusion, orally administrating MFGM during the first postnatal week stimulated SCFA-producing bacteria colonization and SCFA generation, enhanced intestinal barrier functions and consequently improved growth performance of neonatal piglets on 21 d. Our findings will provide new insights about MFGM intervention for microbial colonization and intestinal development of neonates during their early life.     

Effect of weaning age, protein nutrition and enterotoxigenic Escherichia coli challenge on the health of newly weaned piglets

The objective of this experiment was to determine whether decreasing dietary protein content and increasing weaning age could improve piglet health and decrease the occurrence and severity of post-weaning colibacillosis (PWC) in the absence of in-feed antimicrobial growth promoters (AGPs). The experiment consisted of a 2 × 2 × 2 factorial combination of weaning age (4 vs 6 weeks), dietary protein content (H vs L; 230 vs 130 g CP/kg) and experimental enterotoxigenic Escherichia coli (ETEC) challenge (+ vs −). On day 3 post-weaning half of the piglets were challenged per os with 10⁹ cfu ETEC. A sample of piglets was euthanased on days 0 and 6 to assess digesta pH and lactobacilli to coliform (L:C) ratio. ETEC excretion persisted longer in the 4-week-weaned piglets than those weaned at 6 weeks (P = 0.003), and the numbers of ETEC shed tended to be higher on the H than L diet, especially in the 4-week-weaned piglets (P = 0.093). Decreasing protein level led to significantly firmer faeces, decreased pH and increased L:C ratio of proximal colon digesta. These results suggest that in the absence of AGPs, increasing weaning age and decreasing dietary protein level, especially in earlier weaned piglets, may help to minimize the effects of PWC.     

Different dietary protein sources influence growth performance,antioxidant capacity,immunity,fecal microbiota and metabolites in weaned piglets

The inclusion of high-quality proteins are commonly used in swine production.Our research investigated the effects of hydrolyzed wheat protein(HWP),fermented soybean meal(FSBM),and enzyme-treated soybean meal(ESBM)on growth performance,antioxidant capacity,immunity,fecal microbiota and metabolites of weaned piglets.A total of 144 piglets(weaned at 28 d)were allotted to 3 dietary treatments with 6 replicate pens per treatment and 8 piglets per pen.This study included 2 periods:d 0 to14 for phase 1 and d 15 to 28 for phase 2.Dietary treatments contained 15.90%HWP,15.80%FSBM,and 15.10%ESBM in phase 1,and 7.90%HWP,7.80%FSBM,and 7.50%ESBM in phase 2,respectively.The ADG of piglets in ESBM was increased(P<0.05)compared with HWP and FSBM during d 1e28.Compared with HWP and FSBM,ESBM increased(P<0.05)the ferric reducing ability of plasma(FRAP),and the serum level of superoxide dismutase(SOD)in piglets on d 14,as well as increased(P<0.05)the serum FRAP level in piglets on d 28.ESBM decreased(P<0.05)serum levels of DAO and IL-1b in piglets compared with HWP on d 28.ESBM enhanced(P<0.05)the relative abundance of Bacteroidetes,Oscillospiraceae and Christensenellaceae,as well as reduced the relative abundance of Clostridiaceae in the feces compared with HWP and FSBM.The PICRUSt analysis revealed that the number of gene tags related to degradation of valine,leucine and isoleucine,as well as lysine degradation in ESBM were lower(P<0.05)than that in HWP and FSBM.ESBM increased(P<0.05)the fecal butyrate level in piglets compared with FSBM,and ESBM tended to decrease(P=0.076)the fecal cadaverine level.Overall,ESBM had advantages over HWP and FSBM in improving antioxidant status,immune function,fecal bacteria and metabolites for weaned piglets.     

Intermittent suckling improves post-weaning feed uptake but does not change functional gut characteristics of piglets

Suckling pigs were separated from their dam for 24 h on day 21 (1 × 24 h fasting, n = 10) or day 21 and 24 (2 × 24 h fasting, n = 10). Pigs in the control group (n = 10) were not fasted before weaning. All pigs were weaned on day 28 postpartum. Feed intake during the first 4 days post-weaning was higher (P < 0.05) for pigs exposed to 1 × 24 h fasting compared with controls. Water consumption was not affected by fasting prior to weaning. The difference in post-weaning feed uptake was not reflected in any clinical traits, intestinal morphology, or activity of digestive enzymes (maltase, dipeptidylpeptidase IV, aminopeptidases A and N; P > 0.15). In conclusion, a short period of fasting prior to weaning can increase post-weaning feed uptake, although this had no clinical impact under the present experimental conditions.     

Effects of dietary changes on the antibacterial activity of pancreatic juice in weaned piglets

At weaning, low feed intake level is a major factor responsible for gut disorders. However, less is known on adaptation of the antibacterial activity of pancreatic juice in response to variations in feed intake level. Moreover bovine colostrum has been demonstrated to decrease coliform counts in duodenal digesta and to improve health status of weaned piglets. Aims of the present study were to evaluate effects of feed intake level and of a bovine colostrum-supplemented diet on the pancreatic secretion of antibacterial activity in piglets at weaning. At 33 days of age, twenty-eight piglets fitted with two permanent catheters (for pancreatic juice collection and reintroduction) were weaned and allocated to one of the following three dietary treatments for 5 days: low feed allocation with a starter diet (L), gradually increased feed allocation with a starter diet (Ctrl), or gradually increased feed allocation with a starter diet supplemented with bovine colostrum (Col). In Ctrl piglets, the post-weaning secretion of antibacterial activity did not significantly differed from pre-weaning values. The pancreatic secretion of antibacterial activity in L piglets was higher than that in Ctrl piglets at day 5 (+ 300%; P < 0.05). Moreover in Col piglets the secretion of the antibacterial activity tended to increase by 55% (P = 0.08) compared to Ctrl piglets. Variations in the pancreatic secretion of antibacterial activity could constitute an adaptive phenomenon to maintain bacterial homeostasis in the upper small intestine during the early post-weaning period.     

Dietary inclusion of multispecies probiotics to reduce the severity of post-weaning diarrhea caused by Escherichia coli F18+ in pigs

This study was aimed to determine the efficacy of multispecies probiotics in reducing the severity of post-weaning diarrhea caused by enterotoxigenic Escherichia coli (ETEC) F18⁺ on newly weaned pigs. Thirty-two pigs (16 barrows and 16 gilts, BW = 6.99 ± 0.33 kg) at 21 d of age were individually allotted in a randomized complete block design with 2 × 2 factorial arrangement of treatments. Pigs were selected from sows not infected previously and not vaccinated against ETEC. Pigs were fed experimental diets for 25 d based on 10 d phase 1 and 15 d phase 2. The factors were ETEC challenge (oral inoculation of saline solution or E. coli F18⁺ at 2 × 10⁹ CFU) and probiotics (none or multispecies probiotics 0.15% and 0.10% for phase 1 and 2, respectively). Body weight and feed intake were measured on d 5, 9, 13, 19, and 25. Fecal scores were measured daily. Blood samples were taken on d 19 and 24. On d 25, all pigs were euthanized to obtain samples of digesta, intestinal tissues, and spleen. The tumor necrosis factor alpha (TNFα), malondialdehyde (MDA), peptide YY (PYY), and neuropeptide Y (NPY) were measured in serum and intestinal tissue. Data were analyzed using the MIXED procedure of SAS. The fecal score of pigs was increased (P < 0.05) by ETEC challenge at the post–challenge period. The ETEC challenge decreased (P < 0.05) jejunal villus height and crypt depth, tended to increase (P = 0.056) jejunal TNFα, increased (P < 0.05) ileal crypt depth, and decreased (P < 0.05) serum NPY. The probiotics decreased (P < 0.05) serum TNFα, tended to reduce (P = 0.064) jejunal MDA, tended to increase (P = 0.092) serum PYY, and increased (P < 0.05) jejunal villus height, and especially villus height-to-crypt depth ratio in challenged pigs. Growth performance of pigs were not affected by ETEC challenge, whereas the probiotics increased (P < 0.05) ADG and ADFI and tended to increase (P = 0.069) G:F ratio. In conclusion, ETEC F18⁺ challenge caused diarrhea, intestinal inflammation and morphological damages without affecting the growth performance. The multispecies probiotics enhanced growth performance by reducing intestinal inflammation, oxidative stress, morphological damages.