Microbial activity in the gut of piglets: I. Effect of prebiotic and probiotic supplementation

Four groups of six 21 days-old piglets were used to evaluate the effect of a prebiotic or probiotic on the intestinal fermentative activity. In each group, piglets received one of the following diets: basal diet (C); basal diet supplemented with xylo-oligosaccharide (C-XOS); basal diet supplemented with Saccharomyces cerevisiae (C-SC); and basal diet supplemented with xylo-oligosaccharide and S. cerevisiae (C-XOS + SC).

The short chain fatty acids in the colon of piglets were decreased with the inclusion of S. cerevisiae in the diet (P < 0.01). The xylanolytic activity was higher (P < 0.05) in the small intestine of piglets fed C-XOS + SC diet, but no significant differences were found in the caecum and colon. In the caecum contents, the cellulolytic activity was increased (P < 0.05) by the C-XOS and C-SC diets, but remained similar when the diet was supplemented with the two additives combined.     

低聚木糖对断奶仔猪肠道pH和肠黏膜形态结构的影响

本试验通过在日粮中添加低聚木糖探讨其对早期断奶仔猪肠道结构功能的影响。试验选用72头35日龄、体重9.81±0.41 kg杜＆#215;长＆#215;大三元杂交仔猪,随机分配成4组,每组3个重复,每个重复6头仔猪,公母各半。第1组为对照组,饲喂玉米-豆粕基础日粮;其余3组分别在各组日粮中添加0.01%、0.02%、0.04%低聚木糖作为试验组。试验预饲期2 d,正试期为28 d。于试验的最后1 d从各重复中随机选取1头仔猪屠宰,并测定胃、十二指肠、空肠、回肠、盲肠和结肠内容物的pH及十二指肠、空肠和回肠黏膜上皮的绒毛高度和隐窝深度。试验结果显示,试验组猪的胃及各肠段的pH比对照组均有所降低,尤其是0.02%低聚木糖组,差异显著（P＜0.05）;试验组各肠段的绒毛高度均高于对照组,差异显著（P＜0.05）,隐窝深度低于对照组,但差异不显著（P＞0.05）,绒毛高度与隐窝深度之比显著高于对照组（P＜0.05）。本试验结果表明,在早期断奶仔猪的日粮中添加低聚木糖,能降低胃肠道内容物的pH,改善早期断奶仔猪肠道的形态结构,以0.02%低聚木糖组效果最为明显。     

Effect of dietary supplementation of fish oil for lactating sows and weaned piglets on piglet Th polarization

The present study was designed to investigate the effect of dietary fish oil supplementation on piglet T helper cells (Th) polarization in relation to its impact on piglet serum interferon γ (IFN-γ) and interleukin 10 (IL-10) concentrations and splenic expression of Th1/Th2 characteristic genes. The diets of 18 gestating sows were supplemented with 7% lard (C) (n = 10) or 7% fish oil (T) (n = 8) from 10 d before parturition to weaning. At weaning, a split plot experiment was designed, 56 piglets, 28 each from sows fed with fish oil diet or lard diet, were divided into four groups of 7 replicates (one female and one castrated male per replicate) based on both sow diet during lactation and post-weaning piglet diet (C had 7% lard and T had 7% fish oil): CC, CT, TC, TT, and were fed the 7% fish oil or lard diet from day 35 to day 70. Serum concentrations of IFN-γ and IL-10, and Th1/Th2 related genes expression levels in spleen were measured and analyzed. The results showed that piglets fed with fish oil diet during post-weaning tended to have higher serum IFN-γ/IL-10 ratio (P = 0.09) than lard diet fed piglets. Lactation fish oil feeding increased splenic IL-12b, IL-12 receptor β2 (IL-12Rβ2), IL-2 and IFN-γ genes expression (P < 0.05 or P < 0.01) and post-weaning fish oil feeding increased splenic IL-12b (P = 0.06), IL-2 (P < 0.01) and IFN-γ (P = 0.08) mRNA expression than that in lard diet fed piglets at the end of this experiment. On the other hand, IL-4 gene expression (P = 0.01) in spleen was lower in weaned piglet from fish oil diet fed sows than that from lard diet fed sows. However, post-weaning piglets fed fish oil diet had higher splenic IL-4 (P = 0.06), IL-6 (P < 0.01) and IL-10 (P = 0.05) mRNA abundances than that fed with lard diet. These results indicated that dietary fish oil during lactation could increase Th1 polarization and accelerate immune maturation; while 7% fish oil in weaned piglets' diet was likely to increase Th2 cytokines expression.     

Effect of dietary probiotic,prebiotic and synbiotic supplementation on performance,immune responses,intestinal morphology and bacterial populations in broilers

This study was conducted to investigate the effects of probiotic (Primalac), prebiotic (TechnoMos) and synbiotic (Primalac + TechnoMos) supplementation on performance, immune responses, intestinal morphology and bacterial populations of ileum in broilers. A total of 240 one‐day‐old broiler chicks were randomly divided into four treatment groups which included 60 birds. Control group did not receive any treatment. The chicks in the second, third and fourth groups were fed probiotic (0.9 g/kg), prebiotic (0.9 g/kg) and probiotic (0.9 g/kg) plus probiotic (0.9 g/kg; synbiotic), respectively, at entire period. Daily feed intake, daily weight gain and feed conversion ratio were evaluated. The birds were immunized by sheep red blood cell (SRBC) on days 12 and 29 of age and serum antibody titres were measured on days 28, 35 and 42. Newcastle vaccines administered on days 9, 18 and 27 to chicks and blood samples were collected on day 42. Intestinal morphometric assessment and enumeration of intestinal bacterial populations were performed on day 42. The results indicated that consumption of probiotic, prebiotic and synbiotic had no significant effect on daily feed intake, daily body weight gain, feed conversion ratio, carcass traits, intestinal morphology and bacterial populations of ileum (p > 0.05). Consumption of prebiotic increased total and IgM anti‐SRBC titres on days 28 and 42 and antibody titre against Newcastle virus disease on day 42 (p < 0.05). Synbiotic increased only total anti‐SRBC on day 28 (p < 0.05). It is concluded that consumption of prebiotic increased humoral immunity in broilers. Therefore, supplementation of diet with prebiotic for improvement of humoral immune responses is superior to synbiotic supplementation.     

Effects of benzoic acid,Bacillus coagulans and oregano oil combined supplementation on growth performance,immune status and intestinal barrier integrity of weaned piglets

This experiment was conducted to investigate the effects of benzoic acid, Bacillus coagulans and oregano oil combined supplementation on growth performance, immune status and intestinal barrier integrity of piglets. In a 26-d experiment, 25 piglets were randomly assigned to 5 treatments: 1) a basal diet, negative control (NC), 2) NC added with antibiotics, positive control (PC); 3) NC added with benzoic acid at 3,000 g/t and Bacillus coagulans at 400 g/t (AB); 4) NC added with benzoic acid at 3,000 g/t and oregano oil at 400 g/t (AO); 5) NC added with 3,000 g/t benzoic acid and Bacillus coagulans at 400 g/t and oregano oil at 400 g/t (ABO). On d 27, all piglets were euthanized to obtain jejunal mucosa to measure immune status and intestinal barrier integrity. Results showed that pigs fed AB diet increased the final body weight and average daily body weight gain and decreased the ratio of feed to gain compared with NC group (P < 0.05). Compared with NC group, AB, AO and ABO decreased serum tumor necrosis factor-α concentration and ABO decreased interleukin-1β concentration in serum and jejunal mucosa (P < 0.05). Compared with NC group, AB up-regulated mRNA expressions of sodium-glucose cotransporte1, claudin-1, occludin and mucin2 in jejunal mucosa and the populations of Bifidobacterium and Bacillus in cecal digesta (P < 0.05). Compared with NC group, ABO increased jejunal mucosal occludin mRNA abundance and Bifidobacterium population in cecal digesta, and decreased Escherichia coli population in cecal digesta (P < 0.05). Furthermore, AB and ABO increased Bacillus population in cecal digesta compared with PC group (P < 0.05). These results indicated that dietary AB supplementation could improve growth performance and intestinal barrier integrity of piglets when fed antibiotic-free diets, which was possibly associated with the improvement of immune status and intestinal microflora. Dietary ABO supplementation is also beneficial to improve immune status and intestinal barrier integrity and microflora of piglets.     

发酵豆粕对断奶仔猪肠道形态及消化酶活性的影响

为研究枯草芽孢杆菌发酵豆粕(FSBM)对仔猪肠道形态及消化酶活性的影响,试验选择初始体重为(7.5±0.5)kg的纯种大白断奶仔猪60头,随机分为两组,对照组饲喂含豆粕(SBM)饲料,试验组饲喂含发酵豆粕(FSBM)的饲料,试验期30d。试验结束时,每组随机选择6头仔猪,收集小肠内三个不同部位的组织样本观察肠道形态,同时采集肠道内容物样品,测定消化酶活性。结果表明:与SBM组相比,FSBM组仔猪小肠三个不同部位的绒毛高度均显著提高(P<0.05),十二指肠隐窝深度显著降低(P<0.05),十二指肠和空肠总蛋白酶和胰蛋白酶的活性显著提高(P<0.05),仔猪胰腺胰蛋白酶活性显著下降(P<0.05)。综上,FSBM能改善断奶仔猪肠道形态和消化酶活性。     

植物多糖对断奶仔猪小肠黏膜形态及肠黏膜屏障功能的影响

旨在探讨断奶仔猪饲粮中单独或联合添加黄芪多糖、牛膝多糖及白术多糖对其小肠黏膜形态及肠黏膜屏障功能的影响。选取256头35日龄的杜长大三元杂交断奶仔猪,随机分为8个组,每组4个重复,每个重复8头猪,采用三因素两水平(2×2×2)试验设计,饲粮中黄芪多糖、白术多糖和牛膝多糖的添加水平均为0,800mg/kg,试验共进行28d。结果显示:植物多糖能显著提高断奶仔猪十二指肠、空肠和回肠的黏膜绒毛高度,提高绒腺比(P0.05),3种多糖联用效果最适。与对照组相比,多糖组断奶仔猪回肠V/C比值显著提高(P0.05),各单一多糖组之间差异不显著(P0.05),3种多糖联合添加与两两添加及单一添加相比显著提高了V/C比值(P0.05)。多糖组断奶仔猪血清中二胺氧化酶(DAO)的活性、血清中内毒素(ET)含量及D-乳糖的含量均显著降低(P0.05),3种多糖联用效果最适。多糖能显著提高断奶仔猪肠道黏膜Occludin、Claudin和ZO-1的基因表达量(P0.05)。单一添加黄芪多糖、白术多糖及牛膝多糖能显著提高断奶仔猪肠道钠-葡萄糖共转运载体1(SGLT1)的mRNA相对表达量(P0.05),对葡萄糖转运载体2(GLUT2)mRNA相对表达量有提高的趋势,但差异不显著(P0.05)。多糖两两联用及3种多糖联合添加能显著提高断奶仔猪肠道SGLT1和GLUT2mRNA相对表达量(P0.05)。结果表明,在断奶仔猪饲粮中添加植物多糖可显著改善断奶仔猪肠道黏膜形态结构和肠道的通透性,其机制可能与植物多糖改善断奶仔猪肠黏膜屏障功能作用有关。     

Effect of dietary supplementation with protease on growth performance,nutrient digestibility,intestinal morphology,digestive enzymes and gene expression of weaned piglets

This study was conducted to investigate the effect of dietary protease supplementation on the growth performance, nutrient digestibility, intestinal morphology, digestive enzymes and gene expression in weaned piglets. A total of 300 weaned piglets(21 days of age Duroc x Large White x Landrace; initial BW = 6.27 ± 0.45 kg) were randomly divided into 5 groups. The 5 diets were: 1) positive control diet(PC), 2) negative control diet(NC), and 3) protease supplementations, which were 100, 200, and 300 mg per kg NC diet. Results indicated that final BW, ADG, ADFI, crude protein digestibility, enzyme activities of stomach pepsin, pancreatic amylase and trypsin, plasma total protein, and intestinal villus height were higher for the PC diet and the supplementations of 200 and 300 mg protease per kg NC diet than for the NC diet(P 0.05). Supplementations of 200 and 300 mg protease per kg NC diet significantly increased the ratio of villus height to crypt depth(VH:CD) of duodenum, jejunum and ileum compared with NC diet(P 0.05). Feed to gain ratio, diarrhea index, blood urea nitrogen, and diamine oxidase were lower for the PC diet and supplementations of 200 and 300 mg protease per kg NC diet than for the NC diet(P 0.05). Piglets fed the PC diet had a higher peptide transporter 1(PepTl) mRNA abundance in duodenum than piglets fed the NC diet(P 0.05), and supplementations of 100, 200 and 300 mg protease per kg NC diet increased the PepTl mRNA abundance in duodenum(P 0.05) comparing with the NC diet. Piglets fed the PC diet had a higher b0,+AT mRNA abundance in jejunum than piglets fed the NC diet(P 0.05), and supplementations of 200 and 300 mg protease per kg NC diet increased the b0,+AT mRNA abundance in jejunum and ileum comparing with the NC diet(P 0.05). In summary, dietary protease supplementation increases growth performance in weaned piglets, which may contribute to the improvement of intestinal development, protein digestibility, nutrient transport efficiency, and health status of piglets when fed low digestible protein sources.     

加温饲养和定时饲喂对断奶仔猪肠黏膜形态和肠道发育的影响

试验旨在探索对仔猪床进行加温处理以及采用定时饲喂的方式的对早期断奶仔猪不同肠段黏膜形态和肠道发育的影响,从而为确定断奶仔猪适宜的饲养温度和科学的饲喂方式提供理论依据。试验采用2×2因子设计。选用21日龄杜长大断奶仔猪240头,随机分到4个处理组:1):28~30℃的仔猪床加温处理组;2)23~25℃的低温对照组(炉火暖气管道舍内加热);加温处理组和低温对照组中又根据不同的饲喂模式分为每天6次定时饲喂组和自由采食组。每个处理6个重复,每个重复10头猪。经过14 d的试验之后,在每圈仔猪中随机抽取1头,屠宰后取样检测小肠黏膜的绒毛高度、隐窝深度和肠壁厚度。结果表明:加温饲养组(28~30℃)的仔猪空肠中段的绒毛高度显著高于低温对照组(23~25℃)(P<0.05)。加温饲养组十二指肠的隐窝深度和空肠中段的肠壁厚度显著低于低温对照组(P<0.05)。定时饲喂饲养的仔猪空肠后段的绒毛高度显著高于自由采食饲养的仔猪(P<0.05)。定时饲喂组仔猪空肠中段的肠壁厚度和十二指肠隐窝深度显著低于自由采食组(P<0.05)。2因子的互作效应表明:加温定时饲喂组饲养的仔猪空肠后段的绒毛高度显著高于其他处理组。低温自由采食组饲养的仔猪空肠后段的绒毛高度极显著低于其他处理组(P<0.01)。加温定时饲喂组的仔猪空肠中段的肠壁厚度极显著低于其他处理组(P<0.01)。由结果可知,28~30℃的加温饲养组以及定时饲喂的饲喂模式有利于仔猪的肠道黏膜形态的改善,有益于肠道的发育和健康。     

葡萄糖酸对断奶仔猪生产性能、肠道微生物区系和肠黏膜形态结构的影响

葡萄糖酸(GA)是由葡萄糖在葡萄糖酸菌不完全氧化下产生的,当饲喂单胃动物时,GA很难在小肠内吸收,而主要在肠后段发酵成丁酸.本试验研究了GA对断奶仔猪生产性能、肠道微生物和肠壁组织形态的影响.仔猪日粮中添加GA,体外盲肠发酵24h后,日粮中的GA增加了总产气量和最快产气速度(线性,P＜0.001).发酵4、8、24h,盲肠液中氨含量呈线性降低(二次,P＜0.01).发酵24h后,随着GA的添加量,总短链脂肪酸、乙酸、丙酸、正丁酸、乙酸:丙酸、(乙酸 丁酸):丙酸呈线性增加(P＜0.001).体内试验选择48头断奶仔猪,随机分成4个处理,日粮中的GA分别为0、3000、6000和12000mg/kg.试验结果表明,饲喂GA日粮与对照组相比,提高了断奶仔猪的平均日增重,GA为3000、6000mg/kg时,分别增加了13%(P=:0.11)和14%(P＜0.05);日粮中添加GA对饲料转化率无影响:GA对肠道中的梭状芽胞杆菌、肠杆菌科细菌和乳酸菌菌落数无影响:日粮中添加GA,提高了空肠中总的短链脂肪酸含量(GA为3000、6000和12000mg/kg时,分别增加了174%、87%和74%);但是,GA对空肠、回肠、盲肠中肠壁组织学形态无影响.结论:断奶仔猪日粮中添加GA可以提高动物的生产性能和改善肠道微生物区系.     

Effect of bovine colostrum supplementation on cytokine mRNA expression in weaned piglets

The aim of this study was to evaluate the influence of bovine colostrum supplementation on the immune Th1/Th2 response in weaned piglets. After weaning at 21 d, 3 groups of 7 piglets were fed ad libitum with a starter diet and received daily 0, 1 or 5 g of spray-dried bovine colostrum. Spleen and gut-associated lymphoid tissues (GALT): ileal Peyer's patch (iPP), jejunum wall (JW) and mesenteric lymph node (MLN)) biopsies were collected on each piglet after 3 wk of treatment and analysed for their cytokine mRNA expression (IL-2, IL-4, IL-10, IL-12 and IFNγ) by RT-PCR. The supplementation with bovine colostrum induced an increase (P < 0.05) in IL-12 in the JW, in IL-2, IL-10 and IL-12 in the MLN and in IL-4, IL-10 and IL-12 in the iPP. In the latter, bovine colostrum also decreased IFN-γ production (P < 0.01). Finally, no effect of the treatments was recorded in the spleen. These results suggest an immunomodulatory effect of bovine colostrum on the GALT, which responded by producing at different levels both Th1 pro-inflammatory cytokines (IL-2, IFN-γ and IL-12) and Th2 anti-inflammatory cytokines (IL-4 and IL-10). This Th1/Th2 bipolar response protects the weaned piglets from both allergic (food) and infectious (pathogens) diseases.     

Dietary glucose oxidase and/or catalase supplementation alleviates intestinal oxidative stress induced by diquat in weaned piglets

This study investigated the effects of dietary exogenous glucose oxidase (GOD) and/or catalase (CAT) on the intestinal antioxidant capacity and barrier function in piglets under oxidative stress. Sixty pigs assigned randomly to five treatment groups—CON: basal diet; DIQ: basal diet; GOD: basal diet + 40-U GOD/kg diet; CAT: basal diet + 50-U CAT/kg diet; and GC: basal diet + 40-U GOD/kg diet + 50-U CAT/kg diet—were analyzed. On Day 14, the CON group was injected with saline, and the others were treated with diquat. The results showed that in diquat-treated piglets, supplementation of dietary GOD and CAT elevated the superoxide dismutase and CAT activities and attenuated the malondialdehyde level in plasma and intestinal mucosa, enhanced the duodenal villus height and villus height/crypt depth ratio, upregulated ZO-1 mRNA level, and attenuated the apoptosis of the epithelial cells and caspase-3 mRNA level in the intestine. Additionally, the supplementation upregulated mRNA expression of the intestinal NF-E2-related factor 2-regulated genes in diquat-treated piglets. However, GOD combined with CAT could not alleviate oxidative damage better than supplementation of CAT or GOD alone under oxidative stress. Overall, the study provides a potential alternative that could relieve the weaning stress in piglets and help formulate antibiotic-free diets.     

日粮中添加蛋白酶对断奶仔猪生长性能、肠道形态和消化酶的影响

为研究日粮中添加蛋白酶对断奶仔猪生长性能、肠道形态和消化酶活性的影响,试验采用单因子完全随机试验设计,将50头28日龄断奶仔猪随机分为两组,对照组饲喂基础日粮,试验组在基础日粮中添加0.1%复合蛋白酶制剂。结果表明:与对照组相比,试验组断奶仔猪的平均日增重提高5.1%,料重比降低4.67%;试验组空肠的绒毛高度(VH)显著提高40.66μm(P<0.05),且绒毛隐窝比值提高了9.94%(P<0.05);试验组空肠的蛋白酶活性、淀粉酶活性均极显著升高,分别提高了2.89U/mL和23.25U/mL(P<0.01)。综上所述,在饲料中添加蛋白酶明显提高了仔猪的日增重,降低了料重比和成本,且促进了肠道绒毛和隐窝结构的发育和肠道消化酶的活性,改善了仔猪的生长性能。     

谷氨酰胺对早期断奶仔猪生长性能及肠道形态发育的影响

选21日龄断奶的杜大长仔猪72头,按试验要求分为2组,每组3个重复,每重复12头。分别饲喂基础日粮和含1%谷氨酰胺(Gln)日粮,试验期21 d,在断奶后0 d、7 d和14 d分别屠宰取小肠测重,并取十二指肠、空肠、回肠测定绒毛高度和隐窝深度。试验结果表明:断奶后7 d,日粮中添加Gln可显著提高仔猪的平均日增重和小肠相对重量,提高十二指肠和空肠绒毛的高度,降低十二指肠和空肠的隐窝深度;断奶后14 d,日粮中添加Gln对断奶仔猪的生长和肠道形态发育影响与基础日粮组相比差异不显著。     

哺乳期使用植物小肽对断奶后仔猪肠道微生物及肠道形态的影响

选用(25±2)日龄的PIC五元杂交断奶仔猪300头,根据哺乳期使用的4种不同的日粮(对照日粮,以及含有2%血浆蛋白、2%植物小肽和4%植物小肽日粮)分为4组,每组设3个重复,每个重复25头,探讨哺乳期使用植物小肽对断奶后仔猪肠道微生物和肠道形态的影响。结果表明,与对照组相比,哺乳期日粮中使用植物小肽,对减少断奶后仔猪肠道内大肠杆菌和沙门菌的繁殖,增加断奶仔猪肠道内有益菌属乳酸菌的繁殖有一定作用(P>0.05)。使用4%植物小肽提高了十二指肠、空肠和回肠的绒毛高度(P>0.05)和绒腺比(P<0.05),减小了隐窝深度(P<0.05)。植物小肽能够刺激断奶后仔猪肠道发育,使断奶后仔猪肠道绒毛高度增加,隐窝深度变浅,这种趋势随着植物小肽添加量的增加而提高。     

Microbial activity in the gut of piglets: II. Effect of fibre source and enzyme supplementation

Twenty four Duroc × Landrace male piglets, aged 21 days, were assigned to 1 of 4 experimental diets. Diets 1 and 2 contained 150 g kg^− 1 wheat bran and diets 3 and 4 contained 90 g kg^− 1 maize cobs as the major fibre source. All diets contained 480 g kg^− 1 wheat and 200 g kg^− 1 soybean meal. Diets 2 and 4 were supplemented with the following enzyme complex: 800 U/kg cellulase, 1800 U/kg glucanase and 2600 U/kg xylanase.

The replacement of wheat bran by maize cobs increased the acetic (P < 0.05) and decreased the butyric acid production (P < 0.05) in the cecum. Piglets fed diets with maize cobs had lower (P < 0.05) levels of butyric acid in the colon than those fed wheat bran.

The xylanolytic, pectinolytic and cellulolytic enzyme activities were higher (P < 0.05) in the cecum and colon of piglets fed the wheat bran based diets. The supplementation of the diet with the enzyme complex did not significantly affect the levels of short chain fatty acids formed in the small intestine and there was a non significant increase of the levels of acetic, propionic and butyric acids in the cecum and colon of piglets (P < 0.10). No interactions were present between fibre sources and enzyme addition.

The results suggest that the enzyme supplementation of the diet did not bring significant benefits to the animals and that when maize cobs replaces wheat bran in diets it negatively affects butyric acid production and fibre-degrading enzyme activity in the hindgut of piglets.     

羔羊不同断奶日龄对小肠黏膜形态的影响

为了探索不同断奶日龄对羔羊小肠黏膜形态的影响,试验分别选取15、30和45日龄波尔山羊(♂)×南江黄羊(♀)杂交一代断奶羔羊各10只,分为3个试验组;同时选15日龄羔羊14只,自然断奶作为对照组。各试验组断奶后10 d(对照组分别在25、40和55日龄),空腹屠宰取十二指肠、空肠、回肠中部各2 cm作组织切片,观察其绒毛高度、隐窝深度和绒毛形态结构。结果表明:与对照组相比,各断奶组羔羊十二指肠、空肠和回肠的绒毛高度、隐窝深度和绒毛形态均有不同程度的变化。断奶日龄越早,羔羊小肠黏膜变化越明显,其中绒毛高度下降幅度越大,隐窝深度加深越严重,断奶10 d后恢复情况越差,断奶日龄推迟到30日龄时损伤较小,恢复较好。羔羊30日龄断奶饲喂代乳料,对其小肠形态结构影响较小,实施断奶最好。     

Effects of dietary changes on the antibacterial activity of pancreatic juice in weaned piglets

At weaning, low feed intake level is a major factor responsible for gut disorders. However, less is known on adaptation of the antibacterial activity of pancreatic juice in response to variations in feed intake level. Moreover bovine colostrum has been demonstrated to decrease coliform counts in duodenal digesta and to improve health status of weaned piglets. Aims of the present study were to evaluate effects of feed intake level and of a bovine colostrum-supplemented diet on the pancreatic secretion of antibacterial activity in piglets at weaning. At 33 days of age, twenty-eight piglets fitted with two permanent catheters (for pancreatic juice collection and reintroduction) were weaned and allocated to one of the following three dietary treatments for 5 days: low feed allocation with a starter diet (L), gradually increased feed allocation with a starter diet (Ctrl), or gradually increased feed allocation with a starter diet supplemented with bovine colostrum (Col). In Ctrl piglets, the post-weaning secretion of antibacterial activity did not significantly differed from pre-weaning values. The pancreatic secretion of antibacterial activity in L piglets was higher than that in Ctrl piglets at day 5 (+ 300%; P < 0.05). Moreover in Col piglets the secretion of the antibacterial activity tended to increase by 55% (P = 0.08) compared to Ctrl piglets. Variations in the pancreatic secretion of antibacterial activity could constitute an adaptive phenomenon to maintain bacterial homeostasis in the upper small intestine during the early post-weaning period.     

The effects of dietary supplementation with porous zinc oxide on growth performance,intestinal microbiota,morphology, and permeability in weaned piglets

The objective of this experiment was to evaluate the effects of dietary supplementation with porous zinc oxide (HiZox) on growth performance, intestinal microbiota, morphology, and permeability in weaned piglets. A total of 128 weaned piglets [(Landrace × Yorkshire) × Duroc] with an average body weight (BW) of (6.55 ± 0.25 kg; 21 d of age) were randomly assigned to four dietary treatments: (1) a corn‐soybean basal diet; (2) basal diet + 3,000 mg/kg conventional ZnO; (3) basal diet + 200 mg/kg HiZox; (4) basal diet + 500 mg/kg HiZox. The experiments lasted for 28 days. Incremental HiZox in the diet increased ADG (linear p = 0.015; quadratic p = 0.043) and ADFI (linear p = 0.027; quadratic p = 0.038), and the diarrhea index decreased linearly and quadratically (p < 0.01) as HiZox supplemented increased. Furthermore, supplementation with HiZox increased the amounts of Lactobacillus spp. (p < 0.05) in the ileum and cecum in comparison with that of control treatment or 3,000 mg/kg ZnO treatment, while decreased the populations of Escherichia coli, Clostridium coccoides, and Clostridium. leptum subgroup (p < 0.05) in the ileum and cecum relative to those in control treatment. The addition of HiZox increased the villus height and villus‐to‐crypt ratio (VC) of duodenum, jejunum, and ileum (p < 0.05), while decreased the crypt depth of jejunum (p < 0.05) and tended to reduce the crypt depth of duodenum (p < 0.10) compared with the control treatment. Piglets fed with 500 mg/kg HiZox had lower serum D‐lactate and diamine oxidase (DAO) than those fed with basal control diet or 3,000 mg/kg ZnO diet (p < 0.01). The results suggested that supplementation with HiZox modulated intestinal microbial composition and improved intestinal morphology, which may exert protective effects on the integrity of the mucosal barrier function of weaned piglets, was as efficacious as pharmaceutical doses of ZnO in enhancing growth performance, indicating that the HiZox may be a promising alternative to pharmaceutical doses of ZnO.