The protective role of prebiotics and probiotics on diarrhea and gut damage in the rotavirus-infected piglets

Rotavirus is one of the pathogenic causes that induce diarrhea in young animals, especially piglets, worldwide. However, nowadays, there is no specific drug available to treat the disease, and the related vaccines have no obvious efficiency in some countries. Via analyzing the pathogenesis of rotavirus, it inducing diarrhea is mainly due to disturb enteric nervous system, destroy gut mucosal integrity, induce intracellular electrolyte imbalance, and impair gut microbiota and immunity. Many studies have already proved that prebiotics and probiotics can mitigate the damage and diarrhea induced by rotavirus infection in hosts. Based on these, the current review summarizes and discusses the effects and mechanisms of prebiotics and probiotics on rotavirus-induced diarrhea in piglets. This information will highlight the basis for the swine production utilization of prebiotics and probiotics in the prevention or treatment of rotavirus infection in the future.

Lentinan administration alleviates diarrhea of rotavirus-infected weaned pigs via regulating intestinal immunity

Background:Lentinan(LNT)may regulate many important physiological functions of human and animals.This study aimed to verify whether LNT administration could relieve diarrhea via improving gut immunity in rotavirus(RV)-challenged weaned pigs.Methods:Twenty-eight weaned pigs were randomly fed 2 diets containing 0 or 84 mg/kg LNT product for 19 d(n=14).RV infection was executed on d 15.After extracting polysaccharides from LNT product,its major monosaccharides were analyzed.Then,LNT polysaccharide was used to administrate RV-infected IPEC-J2 cells.Results:Dietary LNT supplementation supported normal function of piglets even when infected with RV,as reflected by reduced growth performance loss and diarrhea prevalence,and maintained gut immunity(P<0.05).The polysaccharide was isolated from LNT product,which molecular weight was 5303 Da,and major monosaccharides included glucose,arabinose and galactose.In RV-infected IPEC-J2 cells,this polysaccharide significantly increased cell viability(P<0.05),and significantly increased anti-virus immunity via regulating pattern recognition receptors and host defense peptides(P<0.05).Conclusion:Those results suggest that LNT administration increases the piglets’resistance to RV-induced stress,likely by supporting intestinal immunity.

Infusion of short chain fatty acids in the ileum improves the carcass traits,meat quality and lipid metabolism of growing pigs

Short chain fatty acids(SCFA)are the main products of indigestible carbohydrates undergoing bacterial fermentation in the hindgut,which are related to some physiological functions.This study was designed to investigate the effects of SCFA infusion by ileum on the carcass traits,meat quality and lipid meta-bolism of growing pigs.In a 28-day study,24 growing barrows fitted with a T-cannula in distal ileum were divided into 4 treatments:1)Control,2)antibiotics(AB),3)AB+300 mL of SCFA1 solution(ABS1),4)AB+300 mL of SCFA2 solution(ABS2).The concentrations of acetate,propionate and butyrate in SCFA1 solution were respectively 61.84,18.62 and 12.55 mmol/L,and in SCFA2 were respectively 40.08,15.41 and 9.78 mmol/L The results showed that the SCFA infusion increased the average daily feed intake and average daily gain of pigs(P<0.05).Meanwhile,the SCFA treatments increased longissimus dorsi area(P<0.05)and carcass weight(P=0.058),decreased the drip loss of longissimus dorsi(P=0.059),and reduced serum concentrations of triglyceride,total cholesterol and urea nitrogen(P<0.05).Besides,the SCFA administration inhibited the mRNA expressions of fatty acid synthase(FAS)and acetyl-CoA carboxylase in longissimus dorsi(P<0.05),the mRNA expression of FAS in the liver(P<0.05),and the mRNA expression of hormone-sensitive lipase in abdominal fat(P<0.05).Short chain fatty acid infusion also enhanced the mRNA expression of carnitine palmitoyltransferase-1αin the liver(P<0.05),the mRNA expressions of peroxisome proliferator activated receptor gamma and lipoprotein lipase in abdominal fat(P<0.05),and the mRNA expressions of free fatty acid receptor 2,glucose-6-phosphatase and phosphoenolpyruvate carboxykinase 1 in the colon(P<0.05).These results suggested that SCFA administration in the ileum could improve the carcass traits and meat quality of growing pigs,which was possibly due to the fact that SCFA modulated lipid metabolism.

Dietary energy intake affects fetal survival and development during early and middle pregnancy in Large White and Meishan gilts

This experiment was designed to determine the effects of variations in dietary energy intake on reproductive performance and gene expression of luteal and endometrium tissues in Large White(LW)and Meishan(MS) gilts during early and middle pregnancy. After insemination, 32 LW gilts were assigned to high and low(HE_Land LE_L, 14.23 and 12.56 MJ DE/kg, respectively) diet treatment groups,while 32 MS gilts were allocated to HE_M and LE_M(12.56 and 10.88 MJ DE/kg) groups. Gilts were slaughtered on days 35, 55 and 90 of gestation. The fetal survival and luteal progesterone(P_4) concentration in the HE_Lgroup were higher on day 35 but lower on day 90 of gestation compared with the LE_L group(P < 0.05) for LW gilts. However, fetal survival and luteal P_4 concentration on day 35 of gestation were greater(P < 0.05) in the LE_M group than in the HE_M group for MS gilts, but no significant difference in mid-gestation was showed. The fetal weights of both breeds were higher for the high energy diets compared with the respective control group on day 90 of gestation(P < 0.05). In addition,the m RNA levels of P_4 synthesis-related proteins had correlated with luteal P_4 concentration in both breeds. Further, endometrial levels of uteroferrin(ACP5), retinol-binding protein 4(RBP_4) and secreted phosphoprotein 1(SPP1) m RNA were upregulated in the HE_Lgroup on day 35 of gestation but ACP5 and SPP1 were downregulated on day 55 of gestation compared with the LE_Lgroup(P < 0.05) for LW gilts. In MS gilts, diet only affected the expression of SPP1(P < 0.05). Our results revealed the differential sensitivity of LW and MS breeds to variations in dietary energy intake. For LW gilts, the HE_Lgroup improved fetal survival on day 35 but a sustained high energy diet decreased fetal survival on day 90 of gestation. The differences in dietary energy intake did not influence fetal survival on day 90 of gestation but the higher energy diet did increase fetal weight in the MS breed compared with the lower energy intake diet. These results may be due to differential luteal secretion activity and endometrium gene expression in these two breeds.

Lysine deficiency impaired growth performance and immune response and aggravated inflammatory response of the skin,spleen and head kidney in grown-up grass carp (Ctenopharyngodon idella)

This dissertation was primarily focused on the immune response,inflammatory response and molecular mechanisms in the skin,head kidney and spleen of grown-up grass carp(Ctenopharyngodon idella).Six iso-nitrogen diets differing in lysine concentrations(5.6,8.5,11.6,14.4,17.5 and 20.7 g/kg)were fed to 540 grass carp(164.85±0.79 g)for 60 d.After that,grass carp were challenged by Aeromonas hydrophila for 6 d.This study revealed that lysine deficiency(1)suppressed the growth performa,nce of the fish and decreased their ability to resist skin lesion morbidity,(2)impaired the immune organ s immune response by decreasing the gene expressions of mucin,liver-expressed antimicrobial peptide(LEAP)-2B,β-defensin-1 and LEAP-2A and the production of antibacterial compounds of grown-up grass carp,and(3)aggravated the inflammatory response of immune organs in the fish by increasing the gene expressions of pro-inflammatory cytokines(interferon y2[IFN-γ2],tumor necrosis factorα[TNF-α],interleukin[IL]-15,IL-17D,IL-12p40,IL-6 and IL-8)and down-regulating anti-inflammatory cytokines(IL-11,transforming growth factorβ1[TGF-β1],IL-10 and IL-4/13A),which were tightly correlated with signal transducer and activator of transcription(STAT)1 and STAT3 signaling pathway,respectively.The different phenomenon in the skin,spleen and head kidney of fish may be correlated with the difference in gene subtype.In addition,using quadratic regression analysis of percent weight gain(PWG),skin lesion morbidity,and the lysozyme activities in the spleen and head kidney,the dietary lysine requirements for grown-up grass carp were estimated to be 13.58,13.51,14.56 and 14.18 g/kg,respectively.

Dietary pectic oligosaccharide supplementation improves rat reproductive performance via regulating intestinal volatile fatty acids during middle gestation

As a kind of green additive,pectic oligosaccharide(POS) may regulate some physiological functions of animals,such as gut health,antioxidant capacity,immunity and lipid metabolism.This study aimed to identify whether POS administration can improve maternal reproduction,and to determine the possible metabolism.A total of 48 pregnant Wistar rats randomly allotted into 2 groups,and each group was fed a diet supplemented with 0 or 800 mg/kg of POS.Pectic oligosaccharide administration increased rat born number(P <0.05),did not affect rat embryo number on d 7 of gestation,but increased rat fetus number on d 14 of gestation(P <0.05).On d 14 of gestation,POS treatment improved Lactobacillus and Bifidobacterium populations and volatile fatty acid concentrations of cecal digesta(P <0.05),hormone(progesterone and nitric oxide) and cytokine(interleukin 2) concentrations of serum(P <0.05),and antioxidant capacity of serum(increased total antioxidant capacity and decreased malondialdehyde) and placenta(increased total superoxide dismutase,decreased malondialdehyde)(P <0.05) in pregnant rats.These results suggest that POS administration improved rat reproduction via decreasing fetus loss in middle gestation.This was due to the increased volatile fatty acid concentrations in rat gut improving hormone and inflammatory-cytokine productions,and antioxidant capacity.