Response to an Escherichia coli K88 oral challenge and productivity of weanling pigs receiving a dietary nucleotides supplement

Background： Dietary nucleotides, considered as antibiotics alternative, were shown to have positive effects on intestinal hyperaemia, systemic immunity, small-intestinal growth, and hepatic composition in pigs. However, there is no previous research on nucleotide supplementation in weanling pigs under an oral challenged E. coil K88. Therefore, 2 experiments were conducted to investigate the effects of dietary nucleotides on weanling pig growth performance, nutrient digestibility, fecal score, and blood profile after being orally challenged with E. coli K88. Methods： In Exp. 1, a total of 140 weanling pigs [8.33 ± 0.33 kg of body weight （BW）, 28-d old] were used in this 42-d feeding trial. Pigs were distributed into 1 of 4 treatments, 5 pigs/pen （3 barrows and 2 gilts） and 7 pens/treatment. Treatments were a control basal diet （CON） or the CON supplemented with 150 （R150）, 220 （R220）, or 275 （R275） mg/kg to give the three treatment diets. In Exp. 2, 28 weanling pigs （BW = 8.40 ± 0.22 kg, 28-d old） were distributed into 1 of 4 treatments to give 1 pig/pen and 7 pens/treatment in a 42-d feeding and challenge trial. Dietary treatments were the same as in Exp. 1. 0n d 14, all those pigs （BW= 13.3±0.15 kg, 42-d old） were orally dosed with 1.5 mL suspension containing 10 cfu/mL of E. coli K88. Twenty four hours after challenge, blood and excreta samples were collected from each pigs for analysis. Fecal scores were measured on d 7, 14, 21, and 28 of the study. Results： In Exp. 1, overall BW, average daily gain （ADG）, gain/feed （G/F） ratio, and nutrient digestibilities were lower （P 〈 0.05） in CON group compared with the nucleotides fed pigs. In Exp. 2, after challenge, IgA, IgM, and IGF-I were higher （P〈 0.05） in the nucleotide groups compared with CON. However, the nucleotide groups had lower （P 〈 0.05） cortisol and TNF-o compared with CON. Fecal E. coil counts and fecal score for the nucleotide groups were lower （P 〈 0.05） than for CON. Conclusions： In conclusion, dietary nucleotides supplementation could improve growth performance, nutrient digestibility, immune status, microbial balance, reduce diarrhea, and provide protection against enterotoxigenic E. coli K88 infection in weanling pigs.

The role of lactose in weanling pig nutrition:a literature and meta-analysis review

Lactose plays a crucial role in the growth performance of pigs at weaning because it is a palatable and easily digestible energy source that eases the transition from milk to solid feed.However,the digestibility of lactose declines after weaning due to a reduction in endogenous lactase activity in piglets.As a result,some lactose may be fermented in the gastrointestinal tract of pigs.Fermentation of lactose by intestinal microbiota yields lactic acid and volatile fatty acids,which may positively regulate the intestinal environment and microbiome,resulting in improved gastrointestinal health of weanling pigs.We hypothesize that the prebiotic effect of lactose may play a larger role in weanling pig nutrition as the global feed industry strives to reduce antibiotic usage and pharmacological levels of zinc oxide and supra-nutritional levels of copper.Evidence presented in this review indicates that high dietary lactose improves growth performance of piglets,as well as the growth of beneficial bacteria,particularly Lactobacillus,with the positive effects being more pronounced in the first 2 weeks after weaning.However,the risk of post-weaning diarrhea may increase as pigs get older due to reduced lactase activity,high dietary lactose concentrations,and larger feed intakes,all of which may lead to excessive lactose fermentation in the intestine of the pig.Therefore,dietary lactose levels exert different effects on growth performance and gastrointestinal physiological functions in different feeding phases of weanling pigs.However,no formal recommendation of lactose for weanling pigs has been reported.A meta-analysis approach was used to determine that diets fed to swine should include 20%,15%,and 0 lactose from d 0-7,d 7-14,and d 14-35 post-weaning,respectively.However,sustainable swine production demands that economics must also be taken into account as lactose and lactose containing ingredients are expensive.Therefore,alternatives to lactose,so called“lactose equivalents”have also been studied in an effort to decrease feed cost while maintaining piglet performance with lower dietary lactose inclusions.In summary,the present review investigated dose-response effects of dietary lactose supplementation to exert positive responses and begin to elucidate its mechanisms of action in postweaning pig diets.The results may help to replace some or all lactose in the diet of weanling pigs,while improving production economics given the high cost of lactose and availability in some swine production markets.

Effects of fish meal and sodium butyrate on growth performance, gut development and glucagon-like peptide-2 secretion in weanling piglets

The experiment was conducted to study the effects of fish meal and sodium butyrate on growth performance, gut development and GLP-2 secretion in weanling piglets. A 2×2 factorial design was used with two fish meal levels （0, 5%）, and two sodium butyrate levels （0, 0.3%）. There were 4 dietary treatments： control diet （CD）; control diet supplemented with fish meal （CF）, control diet supplemented with sodium butyrate （CB）, control diet supplemented with fish meal and sodium butyrate （FB）. A total of 44 28-days-old Large White×Landrace weanling piglets were randomly allotted into 4 treatment averagely. The experiment period was 14 days. The results showed that sodium butyrate＇s addition increased average diary gain （ADG）, average diary feed intake （ADFI） and gain to feed intake ratio （G：F） of weanling piglets （all P〈0,05）, improved gut morphology （mucosa thickness, ratio of villous height to crypt depth） and sucrase activity, and fish meal＇s addition increased maltase activity （all P〈0.05）. Either sodium butyrate or fish meal addition decreased cecum colibacillus quantity, sodium butyrate increaded ratio of cecum lactobacilli to colibacillus （P〈0.05）. Consequently, diarrhea was reduced in diet supplemented with fish meal （P=-0.08） and diet supplemented with sodium butyrate （P=0.15） through 14 days of experiment, significant reduction of diarrhea rate was observed in diet supplemented with fish meal through the first 7 days （P〈0.05）. In addition, sodium butyrate and fish meal addition in diets tended to increase plasma GLP-2 concentration, however, GLP-2 concentration on the 4th day was consistently decreased in diet supplemented with fish meal relative to that on day 0 （P=0.08）. Overall, it could be concluded that both sodium butyrate and fish meal addition improve intestinal development and sodium butyrate addition significantly increase growth performance. The gut trophic response to sodium butyrate or may be in agreement with development. peptide GLP-2 increases in fish meal addition in diet and the alteration of intestinal

Injection of pGRF Gene Plasmid May Relieve Growth Depression Induced by Lipopolysaccharide in Weanling Piglets

The purpose of this study was to evaluate the effect and the potential mechanism of administering a pGRF gene plasmid on the growth and immunological function of weanling piglets subjected to immune-stress.Eighteen weanling(Duroc×Landrace×Large White) piglets aged 35 d±2 d and initial BW of 7.86 kg±0.59 kg were randomly assigned to three treatments according to gender and BW by using a single factor design.The three treatments were injections of a pGRF gene plasmid,pGRF gene plasmid followed by challenge with lipopolysaccharide(LPS),and LPS to piglets not receiving the plasmid.Each treatment group consisted of six piglets.The results were as follows:piglets in the pGRF gene plasmid plus LPS treatment had a better growth performance than those only receiving LPS(P【0.05), and F/G of piglets in the pGRF gene plasmid plus LPS group were very slightly lower(P】0.05) than those in the LPS group;serum levels of IGF-1 in the pGRF gene plasmid plus LPS group were significantly higher than those in the LPS group(P【0.05 or P【0.01);serum levels of IgG in the pGRF gene plasmid plus LPS group were higher than those in the LPS group(P【0.05);serum levels of IL-1 and IL-6 in the pGRF gene plasmid plus LPS group were significantly lower than those in the LPS group(P【0.05 or P【0.01).

Dietary ellagic acid supplementation attenuates intestinal damage and oxidative stress by regulating gut microbiota in weanling piglets

Intestinal oxidative stress triggers gut microbiota dysbiosis,which is involved in the etiology of postweaning diarrhea and enteric infections.Ellagic acid(EA)can potentially serve as an antioxidant supplement to facilitate weaning transition by improving intestinal oxidative stress and gut microbiota dysbiosis.Therefore,we aimed to investigate the effects of dietary EA supplementation on the attenuation of intestinal damage,oxidative stress,and dysbiosis of gut microbiota in weanling piglets.A total of126 piglets were randomly assigned into 3 groups and treated with a basal diet and 2 m L saline orally(Ctrl group),or the basal diet supplemented with 0.1%EA and 2 m L saline orally(EA group),or the basal diet and 2 m L fecal microbiota suspension from the EA group orally(FEA group),respectively,for 14 d.Compared with the Ctrl group,EA group improved growth performance by increasing average daily feed intake and average daily weight gain(P<0.05)and decreasing fecal scores(P<0.05).EA group also alleviated intestinal damage by increasing the tight junction protein occludin(P<0.05),villus height,and villus height-to-crypt depth ratio(P<0.05),while decreasing intestinal epithelial apoptosis(P<0.05).Additionally,EA group enhanced the jejunum antioxidant capacity by increasing the total antioxidant capacity(P<0.01),catalase(P<0.05),and glutathione/oxidized glutathione(P<0.05),but decreased the oxidative metabolite malondialdehyde(P<0.05)compared to the Ctrl group.Compared with the Ctrl group,EA and FEA groups increased alpha diversity(P<0.05),enriched beneficial bacteria(Ruminococcaceae and Clostridium ramosum),and increased metabolites short-chain fatty acids(P<0.05).Correspondingly,FEA group gained effects comparable to those of EA group on growth performance,intestinal damage,and intestinal antioxidant capacity.In addition,the relative abundance of bacteria shifted in EA and FEA groups was significantly related to the examined indices(P<0.05).Overall,dietary EA supplementation could improve growth performance and attenuate intestinal damage and oxidative stress by regulating the gut microbiota in weanling piglets.

Feed supplementation with arginine and zinc on antioxidant status and inflammatory response in challenged weanling piglets

Although supplementing the diet with zinc oxide and arginine is known to improve growth in weanling piglets, the mechanism of action is not well understood. We measured the antioxidant status and inflammatory response in 48 weanling castrated male piglets fed diets supplemented with or without zinc oxide(2,500 mg Zn oxide per kg) and arginine(1%) starting at the age of 20 days. The animals were injected with lipopolysaccharide(100 μg/kg) on day 5. Half of them received another injection on day 12.Blood samples were taken just before and 6, 24 and 48 h after injection and the mucosa lining the ileum was recovered following euthanizing on days 7 and 14. Zinc supplementation increased reduced and total glutathione(GSH)(reduced and total) during days 5 to 7 and arginine decreased oxidized GSH measured on days 5 and 12 and the ratio of total antioxidant capacity to total oxidative status during days12 to 14. Zinc decreased plasma malondialdehyde measured on days 5 and 12 and serum haptoglobin measured on day 12 and increased both metallothionein-1 expression and total antioxidant capacity measured in the ileal mucosa on day 14. Tumour necrosis factor a concentration decreased from days 5 to12(all effects were significant at P < 0.05). This study shows that the zinc supplement reduced lipid oxidation and lipopolysaccharide-induced inflammation during the post-weaning period, while the arginine supplementation had only a limited effect.

Glutamic acid supplementation recovers the reduced performance of weanling pigs fed reduced crude protein diets

This study was conducted to evaluate the supplementation of glutamic acid(Glu)to reduced protein diets on the performance of weanling pigs.One hundred and eighty crossbred weanling pigs([YorkshireLandrace]Duroc,21 d old)having similar body weight(BW)of 6.45 kg were randomly allotted to 1 of 6 dietary treatments(5 pigs per pen[2 barrows and 3 gilts];6 pens per treatment)based on BW and sex during a 6-week trial.Dietary treatments consisted of positive control(PC)diet formulated to have 226.9,205.6,and 188.8 g crude protein(CP)during phases 1,2,and 3,respectively,and negative control(NC)diets with 20 g CP reduction from PC diets and addition of Glu with increasing levels,resulting in the calculated Lys-to-Glu ratios of 1:2.25,1:2.30.1:2.35,1:2.40,and 1:2.45,designated as NC,NC1,NC2,NC3,and NC4,respectively.The BW of pigs receiving PC diet was higher(P<0.05)than those receiving NC diet at d 7,21 and 42.A higher(P<0.05)average daily gain(ADG)from d 1 to 7,8 to 21,22 to 42 and during the overall experiment period was observed in pigs fed PC than NC diet.Pigs fed NC diets including the graded level of Glu linearly increased(P<0.05)BW at d 42,ADG and gain-to-feed ratio(G:F)during the overall experimental period.In addition,trends in linear increase in BW(P=0.056)at d 7 and ADG from d 1 to 7 and d 22 to 42(linear effect,P=0.081,P=0.058 respectively)were observed.A tendency in the linear increment of NH3(P=0.082)at d 21 and linear reduction in methyl mercaptans(P=0.054)emission at d 42 was observed in pigs fed NC diets supplemented with graded level of Glu.In conclusion,supplementing the reduced protein diet with Glu enhanced the growth performance in weanling pigs suggesting that supplementation of Glu can compensate the reduction of 2%CP in the basal diets.

Impact of zinc and arginine on antioxidant status of weanling piglets raised under commercial conditions

The effects of dietary zinc and L-arginine supplements on the weight gain,feed efficiency,antioxidant capacity and oxidative status of weanling piglets raised under commercial conditions were examined.A total of 288 piglets aged 21 d were fed for 15 d a diet supplemented or not with 2,500 mg/kg of zinc(provided as zinc oxide)and 1% L-arginine HCl.The 4 treatments were distributed in a randomized complete block design with 6 initial body weight categories(12 animals per pen).Access to feed and water was ad libitum.Data were analyzed as a 2 x 2 factorial experiment using the SAS MIXED procedure,with zinc and arginine as the main independent variables.Blood collection day(d 8 and 15,samples were collected from the same 2 piglets in each pen before the morning feeding)was included as a third factor.The zinc supplement increased the average daily gain(ADG)from d 0 to 7.d 8 to 15 and d 0 to 15(0.289 vs.0.217 kg/d).average daily feed intake(ADFR)from d 8 to 15 and d 0 to 15(0.338 vs.0.279 kg/d)and the gain to feed(G:F)ratio from d 0 to 7 and d 0 to 15(0.86 vs.0.77)(P<0.001).Both supplements significantly decreased the malondialdehyde concentration(zinc:4.37 vs.3.91 μmol/L,P= 0.005;arginine:4.38 vs.3.89 μmol/L,P = 0.002).Total antioxidant capacity and reduced glutathione(GSH)increased from d 8 to 15(0.953 vs.1.391 μmol/L,2.22 vs.3.37 μmol/L,P<0.05)regardless of dietary treatment.Total and oxidized GSH concentrations on d 8 were higher in response to the combined supplements(zinc x arginine interaction.P<0.05).Piglets fed either Zn-supplemented diet had a lower haptoglobin serum concentration(509 vs.1.417 mg/L;P<0.001).In conclusion,the zinc supplement improved piglet growth performance(ADG and ADFI)and oxidative status(based on malondialdehyde concentration).The arginine supplement had a limited effect on growth performance and oxidative status under these conditions.

Impact of age on host responses to diet-induced obesity:Development of joint damage and metabolic set points

Background:Osteoarthritis is one of the leading causes of pain and disability worldwide,and a large percentage of patients with osteoarthritis are individuals who are also obese.In recent years,a series of animal models have demonstrated that obesity-inducing diets can result in synovial joint damage(both with and without the superimposition of trauma),which may be related to changes in percentage of body fat and a series of low-level systemic inflammatory mediators.Of note,there is a disparity between whether the dietary challenges commence at weaning,representing a weanling onset,or at skeletal maturity,representing an adult onset of obesity.We wished to evaluate the effect ofthe dietary exposure time and the age at which animals are exposed to a high-fat and high-sucrose(HFS) diet to determine whether these factors may result in disparate outcomes,as there is evidence suggesting that these factors result in differential metabolic disturbances.Based on dietary exposure time,we hypothesized that rats fed an HFS diet for 14 weeks from weaning(HFS Weanling) would demonstrate an increase in knee joint damage scores,whereas rats exposed to the HFS diet for 4 weeks,starting at 12 weeks of age(HFS Adult) and rats exposed to a standard chow diet(Chow)would not display an increase in knee joint damage scores.Methods:Male Sprague-Dawley rats were fed either an HFS diet for 14 weeks from weaning(HFS Weanling) or an HFS diet for 4 weeks,starting at 12 weeks of age(HFS Adult).At sacrifice,joints were scored using the modified Mankin Criteria,and serum was analyzed for a defined subset of inflammatory markers(Interleukin-6,leptin,monocyte chemoattractant protein-1,and tumor necrosis factorα).Results:When the HFS Weanling and HFS Adult groups were compared,both groups had a similar percent of body fat,although the HFS Weanling group had a significantly greater body mass than the HFS Adult group.The HFS Weanling and HFS Adult animals had a significant increase in body mass and percentage of body fat when compared to the Chow group.Although knee joint damage scores were low in all 3 groups,we found,contrary to our hypothesis,that the HFS Adult group had statistically significant greater knee joint damage scores than the Chow and HFS Weanling groups.Furthermore,we observed that the HFS Weanling group did not have significant differences in knee joint damage scores relative to the Chow group.Conclusion:These findings indicate that the HFS Weanling animals were better able to cope with the dietary challenge of an HFS diet than the HFS Adult group.Interestingly,when assessing various serum proinflammatory markers,no significant differences were detected between the HTS Adult and HFS Weanling groups.Although details regarding the mechanisms underlying an increase in knee joint damage scores in the HFS Adult group remain to be elucidated,these findings indicate that dietary exposure time maybe less important than the age at which an HFS diet is introduced.Moreover,increases in serum proinflammatory mediators do not appear to be directly linked to knee joint damage scores in the HFS Weanling group animals but may be partially responsible for the observed knee joint damage in the adults over the very short time of exposure to the HFS diet.

Comparative study on the difference of obesity model induced by two kinds of high fat diet in Sprague-Dawley rats

Objective: To explore the differences of obese Sprague-Dawley(SD)rats model induced by lard oil high-fat(HF)diet or purified HF diet. Methods: SD weanling rats were randomly divided into three groups: D1 group,where rats were fed by lard oil HF diet;D2 group,where rats were fed by purified HF diet;C group,where rats were fed on chow. After 12 weeks,diet-induced obesity rat(stop 33% based on weight)were selected for further study,and the rest rats from group D1 and D2 were excluded. The food intake and weight were weighted daily and weekly,respectively. The subcutaneous,visceral and total fat contents of rats was measured by 256-row CT scan and the Lee index was calculated accordingly. The kidney,liver,testis,spleen and heart were weighted respectively. Serum leptin and insulin levels were quantified. The pathology in liver and adipose tissues were analyzed by HE staining. Oral glucose tolerance test(OGTT)was used to compare the glucose tolerance ability. Serum total cholestero(lT-CHO),high density lipoprotein(HDL-C),low density lipoprotein(LDL-C),triglyceride(TG)and inflammatory cytokines IL-6,TNF-α were detected as well. Results: After 12 weeks,the body weight,subcutaneous fat,visceral fat,total fat mass,wet weight of liver,kidney and heart,area under blood glucose curve and the levels of serum insulin,leptin,T-CHO,LDL-C,TG,IL-6 and TNF-α in group D2 were significantly increased compared to those of group C and group D1. HDL-C of group D2 was markedly lower than that in group C(P<0. 05). The visceral fat,total fat content and HDL-C in group D1 were significantly different from those of group C(P<0. 05). Steatosis and enlarged adipocyte were found in the livers of rats in group D1 and D2,and the lesions were more significant in group D2. Conclusion: Purified HF diet was more effective in inducing metabolic abnormalities,steatosis,peripheral chronic inflammation in obese SD rat models. But lard oil HF diet was more economical when only inducing visceral steatosis was required.

Dietary supplement of selenium-rich yeast may relieve lipopolysaccharide-induced growth depression in piglets via improving immune and antioxidant status

Selenium protects cells from oxidative damage and reduces lipopolysaccharide （LPS）-induced expression of inflammatory cytokines. Because inflammatory cytokines induce growth depression, we hypothesized that selenium-rich yeast （SeY） would inhibit growth depression caused by LPS. Twenty Meishan weanling pigs [28 （s.d. 2 d）, 7.6 （s.d. 0.3 kg） body weight （BW）] were used in a 2×2 factorial design （n=5）. The main factors were dietary Se sources [selenium-rich yeast （SeY） vs. sodium selenite （SSe）] with supplement level at 0.3 mg Se/kg, and immunological stress （LPS vs. saline）. The experiment lasted for 28 d. On d 14 and d 21, half of pigs in each dietary treatment were intramuscularly injected with either 50 μg/kg BW LPS or an equivalent amount of sterile saline. Blood samples were collected at 3 h post-injection. There were no interactions between dietary Se sources and immunological stress on growth performance. LPS depressed average daily gain （ADG） （d 14-21, P〈0.05; d 21-28, P〈 0.01）, and elevated feed to gain ratio （F/G） （d 21-28, P〈0.05）, while SeY elevated ADG （d 0-14, P〈0.05; d 21-28 and d 0-28, P〈0.01）, and decreased F/G （P〈0.01）. Interactions were observed on interleukin-1β（IL-1β） and interleukin-6 （IL-6） from serum samples of d 14 and d 21 （P〈0.01）, as well as superoxide dismutase （SOD） and insulin like growth factor （IGF-1） of d 21 （P〈0.05）. In conclusion, SeY relieved the growth depression of piglets immunologically stressed by LPS, which maybe resulted from the decreased externalization of inflammatory cytokines and improved antioxidant status.

布依族“weanl”的伦理道德理念探析

"weanl"作为布依族民间口头文字样式之一,是布依族文化的缩影,歌词中蕴含着谦恭有礼的传统道理思想,向往自由、追求幸福美满的爱情观念,鞭挞虚伪、颂扬真善美的道德理念,亲近自然、沟通万物的生态伦理情怀,其字里行间充分表现出布依族儿女优秀的道德品质。