Effects of different ratios of soluble to insoluble dietary fiber on growth performance and intestinal health of piglets

This study investigated the impact of different ratios of soluble to insoluble dietary fiber(SDF:IDF)formulations by sugar beet pulp(SBP)supplementation on piglet growth performance,nutrient digestibility,immune function,intestinal morphology,intestinal microbiota and intestinal health.A total of 60 crossbred piglets(Duroc×[Landrace×Yorkshire])at 40 d old with body weight of 10.0±0.3 kg were randomly assigned to 5 treatments with 6 replicates per treatment and 2 piglets per replicate in a 21-d trial.The dietary treatments included a corn-soybean meal diet(0%SBP supplementation;CON),and diets supplemented with 2%,4%,6%,and 8%SBP,representing different SDF:IDF ratios at 10.16%,13.53%,16.79%,19.86%,and 24.81%,respectively.The results indicated that the 8%SBP treatment had a negative effect on feed-to-gain ratio(linear,P=0.009)compared with the CON treatment(P=0.021).The apparent total tract digestibility(ATTD)of crude protein was lower in treatments supplemented with SBP(P=0.002)and showed a linear decrease(P=0.001),while the ATTD of IDF showed a linear increase(P=0.037)in four SBP treatments compared to the CON treatment.The 4%SBP treatment increased serum concentrations of triglyceride(quadratic,P=0.019)and K(linear,P<0.0037),and decreased alanine transaminase concentration(quadratic,P=0.015)compared with the CON treatment.The concentrations of Cit,Cys,Ile,Leu,Orn,Arg,taurine,urea,1-methylhistidine,α-aminoadipic acid,α-aminobutyric acid and cystathionine in the 4%SBP treatment were highest among all treatments(P<0.05).The serum concentrations of interleukin-6,interleukin-8,interleukin-10,transforming growth factor-β,and tumor necrosis factor-αin the 6%SBP treatment were higher than those in the CON treatment(P<0.05),which also increased mucin-2 and G protein-coupled receptor 41 mRNA expression(P<0.05)in colonic mucosa compared with the CON treatment and improved the intestinal barrier function.Diets containing more than 19.86%SDF:IDF could impair the intestinal health in piglets when SBP was used as the SDF source.Supplementing nursery piglet diets with 16.79%to 19.86%SDF:IDF is recommended for improving intestinal barrier function,increasing short-chain fatty acids concentrations,and improving intestinal microbiota composition.

Failure behavior of interfacial domain in SiC-matrix based composites

In this work,the microstructure,failure behavior and interfacial properties with respective to the interfacial domain in SiCf/BN/SiC and C_(f)/PyC/SiC composites were studied via the fiber push-in test.The differences in the mechanical response of the interfacial domain were observed.During the fiber push-in test for SiCf/BN/SiC,the interface debonding accompanied with interphase fracture occurred,resulting in an obvious sign of the onset of debonding on loading-displacement(P-u)curves.While the good continuity of P-u curves can be observed for Cf/PyC/SiC,which is due to that the failure is in the form of interface debonding along with interphase lateral slipping caused by the extension of buckled carbon fiber,without any interphase fracture.The interfacial properties calculated from the fiber push-in test show that Cf/PyC/SiC possesses a weaker interfacial domain compared with SiC_(f)/BN/SiC.The interfacial shear stress of SiCf/BN/SiC and C_(f)/PyC/SiC composites amounts 94.2 and 48.1 MPa,respectively.

Applications and prospects of functional oligosaccharides in pig nutrition:A review

Oligosaccharides are low molecular weight carbohydrates between monosaccharides and poly-saccharides,which consist of 2 to 20 monosaccharides linked by glycosidic bonds.They have the effects of promoting growth,regulating immunity,improving the structure of intestinal flora,and are anti-inflammatory and antioxidant.With the comprehensive implementation of the antibiotic prohibition policy in China,oligosaccharides as new green feed additive have been paid more attention.Oligosac-charides can be divided into the following 2 categories according to their digestive characteristics:one is easy to be absorbed by the intestine,called common oligosaccharides,such as sucrose and maltose oligosaccharide;the other is difficult to be absorbed by the intestine and has special physiological functions,called functional oligosaccharides.The common functional oligosaccharides include mannan oligosaccharides(MOS),fructo-oligosaccharides(FOS),chitosan oligosaccharides(COS),xylo-oligosaccharides(XOS)and so on.In this paper,we review the types and sources of functional oligo-saccharides,their application in pig nutrition,and the factors limiting their efficacy in recent years.This review provides the theoretical basis for further research of functional oligosaccharides,and the future application of alternative antibiotics in pig industry.

Physiological function and application of dietary fiber in pig nutrition:A review

Dietary fiber(DF),divided into soluble dietary fiber(SDF)and insoluble dietary fiber(IDF),has attracted increasing attention in the field of pig nutrition.Although DF reduces nutrient digestibility and inhibits energy deposition in most cases,fiber-rich feeds have been widely used in pig diets.This is not only because of lower feed costs,but also from the continuous discovery about the nutritional value of DF,mainly including the improvement of piglet intestinal health and sow reproductive performance.The addition timing has also been further considered,which potentially enables the nutritional value of DF to be accurately used in applicable pig models.Furthermore,fiber degrading enzymes have been shown to alleviate the anti-nutritional effects of DF and have ensured the improvement effect of fiber on intestinal health in young piglet models.However,the regulatory effect of fiber on pork quality is still unclear,which requires consideration of the wide range of fiber sources and the complexity of the basic diet composition,as well as the impact of pig breeds.Taken together,future research needs to gain more insight into the combined effects of SDF and IDF,processing methods,and addition timing to improve the nutritional value of DF,and further explore the physiological functions and regulatory mechanisms of DF fermentation products short-chain fatty acids in pigs.

Provenance of Late Mesozoic Strata and Tectonic Implications for the Southwestern Ordos Basin,North China:Evidence from Detrital Zircon U-Pb Geochronology and Hf Isotopes

In order to determine the provenance and variation characteristics of sandstone-type uranium deposits located in the southwest Ordos Basin,U-Pb geochronology and Hf isotope analyses were conducted on detrital zircons from the Late Mesozoic strata of the SD01 well in the Zhenyuan area.The detrital zircon U-Pb ages of four samples exhibited four main peaks at 250–330,420–500,1720–2000,and 2340–2580 Ma,with a small number of zircons dated at 770–1100 Ma.The detrital zircon age spectrum and further restriction provided by the in-situ Hf isotopic data suggest that the provenance of each stratum was mainly derived from the crystalline basement rock series(Khondalites,intermediate-acidic intrusive rocks,and metamorphic rocks)of the Alxa Block to the northwest and the Yinshan Block to the north,with minor amounts of Caledonian magmatic rocks and Jingning Period rocks from the western part of the northern Qilian orogenic belt to the west and the northern Qinling orogenic belt to the south.The provenance of the sandbody has not changed significantly and is of the Middle Jurassic–Early Cretaceous.The clear variations in the zircon ages of the samples from the Zhiluo and Anding formations were likely influenced by climate change during the Middle–Late Jurassic.The Triassic zircon age(<250 Ma)first appeared in Early Cretaceous strata,suggesting that tectonic activity was relatively strong in the northern Qinling orogenic belt during the Late Jurassic and produced extensive outcrops of Indo-Chinese granite,which were a source of basin sediments.

4-Phenylbutyric acid accelerates rehabilitation of barrier function in IPEC-J2 cell monolayer model

As the first line of defence against pathogens and endotoxins crossing the intestine-blood barrier,the intestinal epithelial barrier plays a determinant role in pigs’health and growth.4-Phenylbutyric acid(4-PBA),an aromatic fatty acid,was reported to benefit homeostasis of endoplasmic reticulum and protein synthesis.However,whether 4-PBA affects intestinal epithelial barrier function in pigs is unknown.This study aimed to explore the effects of 4-PBA on the intestinal barrier function,using in vitro models of well-differentiated intestinal porcine epithelial cell(IPEC-J2)monolayers in the transwell plates.Cell monolayers with or without 4-PBA(1.0 mmol/L)treatment were challenged with physical scratch,deoxynivalenol(DON,2.0μg/mL,48 h),and lipopolysaccharide(LPS,5.0μg/mL,48 h),respectively.Transepithelial electrical resistance(TEER)and fluorescein isothiocyanate-dextran(FD-4)permeability were measured to indicate barrier integrity and permeability.Real-time PCR and Western blot were conducted to determine relative gene and protein expressions of tight junction proteins.As expected,physical scratch,DON,and LPS challenges decreased TEER and increased FD-4 permeability.4-PBA treatment accelerated cell mitigation and rehabilitation of the physical scratch-damaged intestinal epithelial barrier but did not alleviate DON or LPS induced barrier damage.However,once 48-h DON and LPS challenges were removed,rehabilitation of the epithelial barrier function of IPEC-J2 monolayer was accelerated by the 4-PBA treatment.Also,the relative gene and protein expressions of zonula occludens-1(ZO-1),occludin,and claudin-1 were further upregulated by the 4-PBA treatment during the barrier rehabilitation.Taken together,4-PBA accelerated the IPEC-J2 cell monolayer barrier recovering from physical scratch,DON-,and LPS-induced damage,via enhancing cell mitigation and expressions of tight junction proteins.