Short-term effect of supplemental yeast extract without or with feed enzymes on growth performance, immune status and gut structure of weaned pigs challenged with Escherichia coli lipopolysaccharide

Background： This study investigated the response of piglets receiving a yeast extract without or with a multi-enzyme mixture compared with an antimicrobial growth promoter（AGP） on performance, immune status and gut structure after an E. coli lipopolysaccharide（LPS） challenge. Thirty-six pigs were allotted to six treatments including： a non-challenged control（NCC）; LPS-challenged control（CC）; CC ＋ AGP; CC ＋ yeast extract; CC ＋ enzymes; and CC ＋ enzymes ＋ yeast extract. On d 7, pigs were bled and thereafter injected with LPS or sterile saline. Blood samples were collected at 6, 48, and 96 h post-challenge. After 96 h post-challenge, pigs were euthanized to obtain duodenal, jejunal and ileal samples.Results： Overall（d 1 to 11）, compared with CC pigs, AGP attenuated the LPS-induced reduction in ADG（P = 0.004）,ADFI（P = 0.03） and gain/feed ratio（P = 0.01）. At 6 h post-challenge, AGP pigs had lower plasma urea N（PUN; P = 0.02）and serum TNF-α concentration（P = 0.07）, and higher platelet count（P = 0.04） and serum IL-10 concentration（P = 0.02） than CC pigs. At 48 h post-challenge, AGP pigs had lower PUN（P = 0.02） than CC pigs, whereas enzymes ＋ yeast extract interacted non-additively（P = 0.001） to reduce PUN. At 96 h post-challenge, AGP pigs had lower PUN（P = 0.02）and higher duodenal（P = 0.03）, jejunal（P = 0.01） and ileal（P = 0.07） villus height than CC pigs. In addition, enzymes ＋yeast extract interacted additively and non-additively to reduce ileal IFN-γ（P 0.10） were observed between AGP and enzymes ＋ yeast extract pigs on other measured parameters except for the downregulation of ileal IFN-γ（P ＆lt; 0.0001） and TNF-α（P = 0.003） in enzymes ＋ yeast extract pigs at 96 h post-challenge.Conclusions： The LPS challenged piglets receiving enzymes ＋ yeast extract showed beneficial responses in gut structure and immunity commensurate with those receiving antibiotics, though the latter had better overall growth performance.

Effect of Konjac Mannan Oligosaccharides on Growth and Antibacterial Ability of Pseudosciaena crocea

[Objective]This experiment was conducted on Pseudosciaena crocea to study the effects of mannan oligosaccharides on growth and antibacterial ability. [Method]1 500 experimental fishes were divided into five groups. The control group（ C） contained no mannan oligosaccharides,the treatment groups were contained 100,200,400,800 mg /kg of konjac mannan oligosaccharides in basal diet,respectively. The experiment continued 4 months. [Result]The results showed that Konjac Mannan oligosaccharides could significantly improve weight gain Pseudosciaena crocea. Compared with control group,Test 2 group intestine protease activity increased by 45. 74%,hepatopancreatic lipase activity increased by 31. 37%,amylase activity increased by 27. 16%. Comparison with the control group,the test group serum SOD activity was significantly higher than that in the control group（ P 〈0. 05）. Lysozyme（ LZM） activity,spleen and serum test group was significantly higher than that in the control group（ P 〈0.05）. Pseudosciaena crocea were infected by Anguillarum,compared with control group,the survival rate is higher than that of the control group（ P 〈0. 05） when the dosage of 200 mg /kg,400 mg /kg. [Conclusion]According to the test results,the Konjac Mannan oligosaccharides in the basal diet suitable dosage were 200 mg /kg.

Effects ofβ-alanine on intestinal development and immune performance of weaned piglets

Beta-alanine is an important amino acid involved in several metabolic reactions in the body.The study aimed to investigate the effect ofβ-alanine supplementation on intestinal development and the immune performance of weaned piglets.Thirty-two 21-day-old healthy weaned piglets(half female and half male;Duroc×Landrace×Yorkshire)with an initial body weight of 8.11±0.21 kg were randomly divided into 4 groups with 8 replicates of 1 pig each.The control group was fed a basal diet and the three experimental treatment groups were fed diets supplemented with 300,600 and 1,200 mg/kgβ-alanine,respectively.The trial lasted 28 days and the diets fed were divided into 2 phases:the late lactation period(day 1 to 14)and the nursery period(day 15 to 28),during which the weaned piglets had free access to food and water.The regulatory effects ofβ-alanine were further investigated in vitro using organoids obtained from the jejunum of piglets.In vivo,the addition ofβ-alanine to the diet had no significant effect on the growth performance of weaned piglets(P>0.05),but significantly reduced serum levels of immunoglobulin G(IgG)(P<0.01),immunoglobulin M(IgM)(P=0.005),and complement 3(C3)(P=0.017).The serum interleukin-6(IL-6)levels(P<0.01)were significantly reduced in the 1,200 mg/kg treatment group.The addition ofβ-alanine increased ileal villus height,with the most significant effect at a concentration of 300 mg/kg(P=0.041).The addition of 600 mg/kgβ-alanine significantly up-regulated the expression of superoxide dismutase(SOD)activity(P=0.020)and the zonula occludens-1(ZO-1)gene(P=0.049)in the jejunum.Diets supplemented with 300 mg/kgβ-alanine significantly increased the number of Ki67 positive cells in the jejunal crypts(P<0.01).In vitro,β-alanine increased the organoid budding rates(P=0.001)and the budding height of the crypt significantly(P=0.004).In conclusion,β-alanine can improve intestinal morphology and barrier function,reduce inflammatory responses and alleviate the adverse effects of weaning stress on piglet intestinal health.

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.