Proteomic-Level Responses of Early-Weaned Piglets to Dietary Arginine Supplementation

Dietary arginine supplementation enhances the immune status and protein synthesis in early-weaned pigs. However, the underlying mechanisms remain largely unknown. To investigate how arginine affects the expression of key proteins that regulate growth and nutrient transport of jejunum, a total of 12 healthy piglets （21 day-old, similar body weight, Landrace x Yorkshire） delivered by four sows were randomly divided into two groups. Piglets in the test group were reared with feed supplemented L-arginine at a concentration of 6.0 g/kg, while piglets in the control group were fed with feed supplemented L-alanine at a concentration of 12.3 g/kg （isonitrogenous control）. After 7 d, jejunum mucosae was collected and analyzed with the 2-D PAGE MS technology. Compared with the control pigs, arginine decreased the levels of proteins that regulate the protein syn- thesis, intermediary metabolism and tissue growth （ similar to anterior gradient 2 homolog, cyclophilin_ABHJike, hypothetical protein FLJ39502 and tetratrioopeptide repeat domain 16, similar to KIAA0156, mitechondrial ATP synthase, hydrion transporting F1 complex, beta subunit and alpha-tu- bulin ubiquitous isoform 19, prolyl 4-hydroxylase, beta subunit precursor）. In addition, arginine increased the levels of proteins that are involved in proteolysis and immune response （ PGAM1, T cell receptor beta variable 20, membrane steroid binding protein, similar to myomesin-1, and chain A, structure of pig muscle Pgk complexed with MgATP）. Therefore, arginine influences the immune response and protein synthesis mechanisms as well as improves eady weaned stress syndrome of piglets.

Lactobacillus frumenti mediates energy production via fatty acid β-oxidation in the liver of early-weaned piglets

Background:Early-weaning of piglets is often accompanied by severe disorders,especially diarrhea.The gut microbiota and its metabolites play a critical role in the maintenance of the physiologic and metabolic homeostasis of the host.Our previous studies have demonstrated that oral administration of Lactobacillus frumenti improves epithelial barrier functions and confers diarrhea resistance in early-weaned piglets.However,the metabolic response to L.frumenti administration remains unclear.Then,we conducted simultaneous serum and hepatic metabolomic analyses in early-weaned piglets administered by L.frumenti or phosphatebuffered saline(PBS).Results:A total of 1006-day-old crossbred piglets(Landrace×Yorkshire)were randomly divided into two groups and piglets received PBS(sterile,2 m L)or L.frumenti(suspension in PBS,10~8 CFU/m L,2 m L)by oral administration once per day from 6 to 20 days of age.Piglets were weaned at 21 days of age.Serum and liver samples for metabolomic analyses were collected at 26 days of age.Principal components analysis(PCA)showed that L.frumenti altered metabolism in serum and liver.Numerous correlations(P<0.05)were identified among the serum and liver metabolites that were affected by L.frumenti.Concentrations of guanosine monophosphate(GMP),inosine monophosphate(IMP),and uric acid were higher in serum of L.frumenti administration piglets.Pathway analysis indicated that L.frumenti regulated fatty acid and amino acid metabolism in serum and liver.Concentrations of fatty acidβ-oxidation related metabolites in serum(such as3-hydroxybutyrylcarnitine,C4-OH)and liver(such as acetylcarnitine)were increased after L.frumenti administration.Conclusions:Our findings suggest that L.frumenti regulates lipid metabolism and amino acid metabolism in the liver of early-weaned piglets,where it promotes fatty acidβ-oxidation and energy production.High serum concentrations of nucleotide intermediates,which may be an alternative strategy to reduce the incidence of diarrhea in early-weaned piglets,were further detected.These findings broaden our understanding of the relationships between the gut microbiota and nutrient metabolism in the early-weaned piglets.

Effect of Glutamine Supplementation on Intestinal Mucosal Protein,DNA and Mucosal Morphology of Early-Weaned Piglets

Forty piglets weaned at 21 days age were randomly assigned to one of two groups. The treatment group contained 1. 2% glutamine. The diets were calculated to be isonitrogenous and isoenergetic, each treatment contained five replicates of four piglets. Five piglets from each dietary treatment were killed at 35 days and 49 days age. The results showed that dietary glutamine supplementation increased jejunal DNA content of piglets in the treatment group at 35 days and 49 days age. There was no significant change of ileum DNA content and intestinal protein content between the treatment and control ones. Dietary glutamine supplementation increased mucosal thickness of piglets in treatment group markedly at 35 days age. The intestinal villus heights were significantly higher in treatment than that in control. The results of electron micrograph showed that dietary glutamine supplementation prevented deterioration of intestinal epithelium, and maintained normal intestinal microvillus structure. The results suggested that glutamine supplementation prevented villus atrophy, and had protective effect on intestinal structure.

Replacing dietary sodium selenite with biogenic selenium nanoparticles improves the growth performance and gut health of early-weaned piglets

Selenium nanoparticles(SeNPs)are proposed as a safer and more effective selenium delivery system than sodium selenite(Na_(2)SeO_(3)).Here,we investigated the effects of replacing dietary Na_(2)SeO_(3)with SeNPs synthesized by Lactobacillus casei ATCC 393 on the growth performance and gut health of earlyweaned piglets.Seventy-two piglets(Duroc×Landrace×Large Yorkshire)weaned at 21 d of age were divided into the control group(basal diet containing 0.3 mg Se/kg from Na_(2)SeO_(3))and SeNPs group(basal diet containing 0.3 mg Se/kg from SeNPs)during a 14-d feeding period.The results revealed that SeNPs supplementation increased the average daily gain(P=0.022)and average daily feed intake(P=0.033),reduced(P=0.056)the diarrhea incidence,and improved(P=0.013)the feed conversion ratio compared with Na_(2)SeO_(3).Additionally,SeNPs increased jejunal microvilli height(P=0.006)and alleviated the intestinal barrier dysfunction by upregulating(P<0.05)the expression levels of mucin 2 and tight junction proteins,increasing(P<0.05)Se availability,and maintaining mitochondrial structure and function,thereby improving antioxidant capacity and immunity.Furthermore,metabolomics showed that SeNPs can regulate lipid metabolism and participate in the synthesis,secretion and action of parathyroid hormone,proximal tubule bicarbonate reclamation and tricarboxylic acid cycle.Moreover,SeNPs increased(P<0.05)the abundance of Holdemanella and the levels of acetate and propionate.Correlation analysis suggested that Holdemanella was closely associated with the regulatory effects of SeNPs on early-weaned piglets through participating in lipid metabolism.Overall,replacing dietary Na_(2)SeO_(3)with biogenic SeNPs could be a potential nutritional intervention strategy to prevent earlyweaning syndrome in piglets.

Effects of Milk Replacer on the Performance and Blood Biochemical Indices in Lambs

[Objective] In this study, the performance and blood biochemical indices in lamps fed on milk replacer were researched, the feasibility of early weaned in lamps was discussed. [Method] 37 of 10 days lambs of Suffolk（♂） x XiaoWeiHanYang（ ♀ ） were randomly divided into group A, B, C, D for this experiment. Group A, B, C were fed by 3 milk-replacers containing milk for different protein source respectively, and ten Iambs in each group; group D （seven lambs） were fed by ewes as the control. The performance and blood biochemical indices of the lamps were determined. [ Result] The results showed that the average daily gains of 10 - 15 days of age was not significantly different between group A and D （ P 〉 O. 05 ）, the control were higher significandy than the group B,C （P 〈0.05）. The average daily gains of 16 -25, 26 -35 days of age were not significantly different in group A, B, C, D. The daily weight gains of Group A, B, C in 45 - 55 days of age were higher significantly than the control （P〈0.05 ）. Plasma urea nitrogen （PUN） of group B and C were higher than group A significantly （P〈0.05 ） ;Total protein （ TP）, Plasma albumin （ALB） and Plasma total amino acid were no significant difference among the other 3 groups （P〉0.05 ）. [Conclusion] So, the milk-replacers were available for early-weaned lamb.

Early weaning leads to the remodeling of lipid profile in piglet jejunal crypt cells during post-weaning days

Reportedly,proteins involved in lipid metabolism change significantly in the jejunal crypt cells of earlyweaned piglets,but the exact lipid profile change remains uncertain.In the present study,32 piglets weaned at 21 d of age were randomly divided into 4 groups with 8 replicates.The jejunal crypt cells of a group of piglets on the post-weaning day(PWD)1,3,7,and 14 were isolated per time point.Crypt cell lipid profiles were analyzed using ultra-high-performance liquid chromatography coupled with hybrid quadrupole time-of-flight mass spectrometry.This study showed that piglets suffered the greatest weaning stress on PWD 3 in terms of the lowest relative weight of the small intestine,the highest relative weight of the spleen,and the highest levels of malondialdehyde,cholesterol,and low-density lipoprotein cholesterol.The lipid profile of jejunal crypt cells including carnitine,sulfatide,sphingomyelin,hexosylceramide,and ceramide greatly changed after weaning,especially between PWD3 and 14(P<0.05).The differential lipid species between these 2 d were mainly involved in the glycerophospholipid metabolism pathway.In addition,potential lipid biomarkers for weaning stress in crypt cells such as phosphatidylcholine(PC)(9:0/26:1),PC(17:0/18:2),carnitine(24:0),carnitine(22:0),sphingomyelin(d14:1/22:0),PC(P-18:0/18:4),phosphatidylethanolamine(P-16:0/20:4),phosphatidylinositol(15:1/24:4),and dihexosylceramide(d14:1/26:1)were identified.The changes in lipid profile might be related to the inflammation caused by early weaning.These findings might provide new therapeutical targets for intestinal dysfunctions caused by weaning stress.