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1.
Three experiments were conducted to investigate the effects of beta-glucan supplementation on pig performance and immune function. In Exp. 1, 100 weaned pigs (8.65 +/- 0.42 kg of BW and 28 +/- 2 d of age) were used in a 35-d experiment to determine the effects of graded levels of beta-glucan. Pigs were randomly allotted to 1 of 5 treatments containing beta-glucan supplemented at 0, 25, 50, 100, or 200 ppm. Each treatment was replicated using 5 pens containing 4 pigs per pen. The ADG of pigs between d 14 to 28 and d 0 to 28 responded to dietary beta-glucan in a quadratic fashion (P < 0.05), whereas beta-glucan had no effect on ADFI and G:F in any period. In Exp. 2, 80 crossbred pigs (8.23 +/- 0.56 kg of BW and 28 +/- 2 d of age) were used in a 35-d experiment. Pigs were allotted to 1 of 2 dietary treatments (0 or 50 ppm of beta-glucan in the diet) using 10 pens with 4 pigs per pen. Pigs treated with beta-glucan had greater ADG in the 14- to 28-d (P = 0.05) and 0-to 28-d (P = 0.035) periods. The ADFI of pigs receiving beta-glucan was increased (P < 0.05) in the periods from 0 to 14, 0 to 28, and 28 to 35 d. The lymphocyte proliferation index in response to phytohemagglutinin (P = 0.051) and concanavalin A (P = 0.052) tended to decrease on d 14 in pigs supplemented with beta-glucan compared with pigs without supplementation. In Exp. 3, 24 barrows (8.89 +/- 0.20 kg of BW and 28 d of age) were used to investigate the immunological and somatotropic responses of pigs challenged with lipopolysaccharide (LPS). Experimental treatments were arranged in a 2 x 2 factorial, with the main effects of LPS challenge (saline vs. LPS) and dietary addition of beta-glucan (0 vs. 50 ppm). Pigs were raised individually in metabolic cages. Pigs were fed 0 or 50 ppm of beta-glucan for 28 d and then challenged with LPS (25 microg/kg of BW) or saline. After LPS injection, blood was obtained at 0, 1.5, 3, 4.5, 6, and 7.5 h to determine cytokine production and the somatotropic response. Dietary beta-glucan increased plasma interleukin-6 at 1.5, 3, and 4.5 h and tumor necrosis factor-alpha at 3 and 4.5 h and increased plasma interleukin-10 from 3 to 7.5 h after LPS challenge. The beta-glucan treatments had no effect on growth hormone. In conclusion, beta-glucan can selectively influence performance and partially offer benefits on somatotropic axis and immune function in weaned piglets challenged with LPS.  相似文献   

2.
试验研究日粮添加1%α-酮戊二酸(AKG)对多次脂多糖(LPS)刺激断奶仔猪空肠黏膜蛋白、RNA、DNA浓度和抗氧化能力的影响。选用24头健康杜洛克×长白×大白(7.25±0.23)kg断奶仔猪,随机分成3个处理,每个处理8个重复,公、母各半。对照组和LPS组饲喂基础日粮+1%淀粉、AKG组饲喂基础日粮+1%AKG,在试验第10、12、14、16天分别在LPS组和AKG组仔猪的腹膜注射80μg/kgBW脂多糖,对照组注射相应剂量的灭菌生理盐水。第17天清晨屠宰空腹仔猪,刮取空肠黏膜待测。结果表明:多次LPS刺激显著降低断奶仔猪空肠黏膜RNA/DNA、蛋白/DNA、蛋白质浓度及SOD活性(P<0.05),显著升高MDA含量(P<0.05),而日粮中添加AKG能在一定程度上抑制LPS刺激引起的空肠黏膜蛋白合成减少和抗氧化能力降低,维持肠道屏障完整性。  相似文献   

3.
We tested the effect of Trp addition to a standard weaning diet and oral challenge with enterotoxigenic Escherichia coli K88 (ETEC) on growth and health of piglets susceptible or nonsusceptible to the intestinal adhesion of ETEC. Sixty-four pigs weaned at 21 d of age were divided into 3 groups based on their ancestry and BW: a control group of 8 pigs fed a basal diet (B), the first challenged group of 28 pigs fed B diet (BCh), and the second challenged group of 28 pigs fed a diet with Trp (TrpCh). The Trp diet was produced by the addition of 1 g of l-Trp/kg to the basal diet. On d 5, pigs were orally challenged with 1.5 mL suspension containing 10(10) cfu ETEC/mL or placebo, and killed on d 9 or 23. Based on in vitro villus adhesion assay, the pigs (except the B group) were classified as susceptible (s(+)) or nonsusceptible (s(-)) to the intestinal ETEC adhesion. Thus, after the challenge, treatments were B, BChs(-), BChs(+), TrpChs(-), and TrpChs(+). Pigs susceptible to ETEC were 50.0% in the BChs(+) group (3 pigs lost included) and 46.4% in the TrpChs (+) group (1 pig lost included). During the first 4 d after challenge, the challenge reduced ADG (P < 0.05), and this reduction was greater in susceptible pigs (P < 0.05) than nonsusceptible ones. Tryptophan increased ADG and feed intake in susceptible pigs (P < 0.05) from challenge to d 4, but not thereafter. Tryptophan supplementation did not improve the fecal consistency and did not reduce the number of pigs positive for ETEC in feces on d 4 after the challenge. The K88-specific immunoglobulin A activity in blood serum tended to be greater in challenged pigs (P = 0.102) and was not affected by the addition of Trp. Villous height was affected by the addition of Trp and challenge in different ways, depending on the site of small intestine. The need to consider the phenotype for the adhesion of the ETEC in studies with different supply of Trp was clearly evident. When compared with practical weaning standard diets, Trp supplementation allowed susceptible pigs to partially compensate for the effects of ETEC challenge by increasing feed intake and maintaining an adequate BW growth. This is of practical importance for the formulation of diets for pigs selected for lean growth because of the presence of an association between this trait and the susceptibility to the intestinal adhesion of ETEC.  相似文献   

4.
选用12头(21±1)d断奶仔猪,随机分为2个处理,研究脂多糖(LPS)刺激对肠黏膜免疫屏障功能的影响。禁食12h后,LPS组仔猪腹膜注射100μg/kgBW LPS,对照组注射等量的生理盐水。48h后,屠宰仔猪,打开腹腔,取小肠组织样品,测定小肠上皮间淋巴细胞、杯状细胞、肥大细胞数、肠集合淋巴结增殖、凋亡细胞数。结果表明:LPS刺激显著降低十二指肠、回肠上皮间淋巴细胞数(P<0.01),极显著增加小肠各段肥大细胞数(P<0.01);LPS刺激显著增加回肠集合淋巴结凋亡细胞数(P<0.05),但对增殖细胞数没有影响(P>0.05);LPS刺激可增加仔猪小肠杯状细胞数,但两处理组间差异不显著(P>0.05)。这些结果显示,LPS应激可导致肠黏膜免疫屏障功能改变,进而加重机体出现急性感染症状。  相似文献   

5.
L-精氨酸对脂多糖刺激断奶仔猪肠黏膜免疫屏障的影响   总被引：1，自引：0，他引：1  
本试验旨在研究L-精氨酸(L-Arg)对脂多糖(LPS)刺激仔猪肠黏膜免疫的影响。选用24头21日龄断奶仔猪,随机分为4个处理,即对照组(基础日粮)、LPS组(基础日粮+LPS)、0.5%Arg组(基础日粮添加0.5%Arg+LPS)、1.0%Arg组(基础日粮添加1.0%Arg+LPS)。结果表明:LPS刺激损伤小肠黏膜结构;Arg则有效阻止LPS应激导致的肠道损伤,维持肠黏膜结构的完整性;LPS刺激显著增加仔猪小肠肥大细胞数(P<0.01);1.0%Arg则减少肥大细胞数(P<0.05);LPS刺激降低回肠IgA分泌细胞、CD4+、CD8+阳性细胞数(P<0.05),而0.5%Arg则增加IgA分泌细胞、CD4+、CD8+阳性细胞数(P<0.05)。这表明LPS刺激可导致仔猪小肠黏膜结构受损,免疫屏障功能降低,而日粮添加精氨酸可有效阻止LPS对肠黏膜屏障的损伤,促进及改善肠黏膜结构及免疫屏障功能。  相似文献   

6.
本研究旨在N-乙酰半胱氨酸(NAC)对脂多糖(LPS)刺激仔猪肝脏免疫应激和能量状况的影响及其机理进行探讨.选取18头健康仔猪(杜洛克×长白×大白,体质量(11.58±0.26)kg),随机分成3个处理(对照组、LPS组和NAC组),每个处理6个重复,每个重复1头猪.对照组和LPS组饲喂基础日粮,NAC组饲喂基础日粮+500 mg·kg-1 NAC,LPS和NAC组仔猪分别于试验的第10、13、20天腹膜注射100 μg·kg-1 BW的LPS,对照组注射等量的灭菌生理盐水.第10、20天注射LPS后3h前腔静脉采血,第21天仔猪麻醉后进行屠宰,取肝脏样品待测.试验结果显示:(1)日粮中添加NAC显著缓解了LPS刺激导致的ADG降低(P＜0.05)和F/G的升高(P ＜0.05).(2)日粮中添加NAC缓解了LPS刺激导致的血浆、肝脏中TNF-α、IL-6和PGE2的升高(P＜0.05).(3)日粮中添加NAC缓解了LPS刺激导致的肝脏核因子-κB(NF-κB)和热休克蛋白70 (HSP70)蛋白表达量的升高(P＜0.05).(4)日粮中添加NAC缓解了LPS刺激导致的肝脏中三磷酸腺苷(ATP)、二磷酸腺昔(ADP)和能荷(EC)水平的降低(P＜0.05)及一磷酸腺苷(AMP)水平和AMP/ATP比值的升高(P＜0.05).由此可见,日粮中添加500 mg·kg-1 NAC可能通过缓解LPS导致的免疫应激和能量的过度损耗,促进仔猪生长.  相似文献   

7.
共轭亚油酸对免疫应激仔猪生长抑制的缓解作用   总被引：5，自引：0，他引：5  
试验选用 72头 (2 8± 2 )d断奶的仔猪 ,采用 2× 2因子试验设计 ,研究共轭亚油酸 (CLA)是否有缓解仔猪免疫应激的作用。结果显示 ,添加CLA缓解了因注射脂多糖 (LPS)引起的日增重降低 (P <0 .0 5 ) ,并改善了试验全期的饲料转化效率 (P <0 .0 5 )。两次LPS刺激后 ,CLA抑制 (P <0 .0 5 )了由LPS诱导的血浆白细胞介素 6 (IL 6 )、肿瘤坏死因子 α(TNF α)和α 乙酰糖蛋白 (AGP)浓度的上升。在第 14d和 2 1d ,LPS刺激提高 (P <0 .0 5 )了血浆IL 1β和皮质醇含量 ,而CLA则降低了IL 1β和皮质醇含量。本试验证明 ,CLA能缓解免疫应激引起的仔猪生长抑制 ,其防止免疫应激诱导的生长抑制作用可能与CLA抑制炎性细胞因子的分泌有关  相似文献   

8.
本试验旨在研究N-乙酰半胱氨酸(NAC)对脂多糖(LPS)单次刺激仔猪肠黏膜免疫应激的影响。选取24头健康仔猪,随机分成4组,每组6个重复,每个重复1头猪。对照组和LPS组饲喂基础饲粮,250和500 mg/kg NAC组在基础饲粮中分别添加250和500 mg/kg NAC。试验第17天,LPS组、250和500 mg/kg NAC组仔猪腹膜分别注射100μg/kg BW的LPS,对照组注射相应剂量的灭菌生理盐水。注射后6 h屠宰,取肠黏膜。结果表明:与对照组相比,饲粮中添加250或500 mg/kg NAC缓解了LPS刺激导致的肠黏膜中白细胞介素-2、白细胞介素-6和前列腺素E2水平的升高及热应激蛋白70(HSP70)表达量的升高(P<0.05)。由此可见,饲粮中添加250和500 mg/kg NAC可有效抑制LPS刺激导致的肠黏膜中炎性因子的升高,缓解急性免疫应激。  相似文献   

9.
A trial using 64 weanling pigs (TR4×PIC C22) was conducted to determine the effects of menhaden fish oil supplementation and diet complexity on performance and immune response of nursery pigs. Pigs (17 days and 6.27±1.16 kg) were weaned into a segregated early wean facility and given free access to a complex diet for 7 days post-weaning. At day 0 (day 7 post-weaning), pigs were blocked by weight and allotted to 64 pens. Treatments (Trt) were arranged as a 2×2×2 factorial arrangement. Main effects included diet (complex versus simple), oil (menhaden fish (MFO) versus corn (CO)), and immunogen (saline versus lipopolysaccharide (LPS)). Experimental diets contained 6% oil (6% CO or 5% MFO+1% CO) and were fed for 14 days. On day 12, i.v. injections of either LPS (150 μg/kg) or saline were given, followed by blood collection at 30 min intervals for 6 h. After the immune challenge (day 14), pigs were placed onto a common corn-soybean meal fortified diet and growth performance was evaluated until termination of the study (day 28). Pigs were weighed and feed intakes recorded at 7, 14, and 28 days. Prior to immune challenge (day 12), there were differences in BW for pigs fed complex versus simple diets (P<0.01; 13.1 and 12.1 kg, respectively) and pigs fed CO versus MFO diets (P<0.05; 12.9 and 12.3 kg, respectively). During the challenge period, for pigs treated with LPS there was a Time×Immunogen×Oil effect (P<0.001) for serum cortisol with MFO fed pigs having lower serum cortisol as compared to CO fed pigs. Also, during the challenge period, for pigs treated with LPS there was a Time×Diet×Immunogen×Oil effect (P<0.001) for serum tumor necrosis factor- (TNF-) with pigs fed complex diets supplemented with CO having higher serum TNF- as compared with pigs fed complex diets supplemented with MFO. At days 14 and 28, LPS-treated pigs had lower BW than saline injected controls (P<0.001 and 0.01, respectively). In addition, pigs fed simplified diets continued to have lower BW after challenge compared to pigs fed a complex diet. Interestingly, there were no differences (P>0.10) in BW after challenge in pigs fed MFO. This study suggests that MFO supplementation alters the immune response during LPS challenge and that simplified diets may compromise nursery performance.  相似文献   

10.
The present study was conducted to investigate the effect of maternal dietary supplementation (n = 10 sows/treatment) with seaweed extract (SWE: 0 vs. 10.0 g/d) from d 107 of gestation until weaning (d 26) on neonatal piglet growth, humoral immunity, intestinal morphology, selected intestinal microflora, and VFA concentrations. Furthermore, this study examined the effect of dietary treatment on the immune response after an ex vivo Escherichia coli lipopolysaccharide (LPS) tissue challenge at weaning in a 2 × 2 factorial arrangement. The main factors consisted of sow dietary treatment (SWE or control) and immunological challenge (yes or no). The SWE supplement (10.0 g/d) contained laminarin (1.0 g), fucoidan (0.8 g), and ash (8.2 g) and was extracted from a Laminaria spp. The SWE-supplemented sows had greater colostrum IgA (P < 0.01) and had a trend for greater IgG (P = 0.062) concentrations compared with non-SWE-supplemented sows. Piglets suckling SWE-supplemented sows had greater serum IgG (P < 0.05) concentrations on d 14 of lactation compared with those suckling non-SWE-supplemented sows. Dietary SWE supplementation decreased fecal Enterobacteriaceae populations in sows at parturition (P < 0.05), and piglets suckling SWE-supplemented sows had a decreased colonic E. coli population at weaning (P < 0.01) compared with non-SWE-supplemented sows. Lipopolysaccharide challenge increased the mRNA abundances of the pro-inflammatory cytokines IL-1α and IL-6 (P < 0.01) in ileal tissue and tumor necrosis factor (TNF)-α in colonic (P < 0.01) tissue. There was a treatment × LPS challenge interaction for ileal TNF-α mRNA expression (P < 0.05). Piglets suckling SWE-supplemented sows had greater TNF-α mRNA expression after ex vivo LPS challenge compared with non-SWE-supplemented sows (P < 0.05). However, there was no effect of sow dietary treatment on TNF-α mRNA expression in the unchallenged ileal tissue. Piglet BW at birth and weaning, and small intestinal morphology were unaffected by sow dietary treatment under current experimental conditions. In summary, these results demonstrate an important immunomodulatory role of SWE supplementation characterized by enhanced colostral IgA and IgG concentrations, greater piglet circulatory IgG concentrations on d 14 of lactation, and enhanced TNF-α mRNA expression in the ileum after an ex vivo LPS challenge. These results indicate that SWE supplementation enhanced piglet immune function and colonic microflora at weaning.  相似文献   

11.
Forty barrows (TR4 x C22) were weaned at 17 d of age (BW = 6.27 +/- 0.30 kg), housed (two pigs/pen) in a thermal-neutral environment (TN; constant 26.7 degrees C), and fed diets with or without 7% (as-fed basis) spray-dried plasma (SDP). On d 7, one pig/ pen was moved into a cold environment (CE; constant 15.6 degrees C). Pigs were fitted with jugular catheters on d 11. On d 12, 16 pigs per environment (eight pigs per dietary treatment) were challenged i.v. with 75 microg of lipopolysaccharide (LPS)/kg of BW. Blood samples were collected over a 4.5-h period. Pigs were then killed and tissue samples were harvested for messenger RNA (mRNA) analysis. From d 0 to 7, pigs fed SDP diets had a lower gain:feed ratio (G/F) than pigs fed no SDP (533 +/- 14 vs. 585 +/- 17 g/kg; P < 0.03). Pigs housed in the CE consumed more feed and had a lower G/F than pigs housed in TN from d 7 to 11 (P < 0.001). There were no environment x diet interactions from d 7 to 11 (P > 0.78). Baseline concentrations of serum ACTH and cortisol were lower in the TN pigs than in the CE pigs (P < 0.001). Pigs fed diets without SDP had lower serum cortisol concentrations over the 4.5-h period than pigs fed SDP (time x diet, P < 0.001). Serum concentrations of tumor necrosis factor-alpha (TNF-alpha) were highest for pigs consuming SDP in the CE, whereas there were no differences among the other treatments (time x diet x environment, P < 0.02). Pigs housed in the CE had higher serum interleukin-1beta (IL-1beta) (P < 0.001) and interleukin-6 (IL-6; P < 0.001) than TN pigs. Pigs fed SDP also had slightly higher serum IL-1beta concentrations (P < 0.10) and higher (P < 0.001) IL-6 concentrations than pigs fed no SDP. Pigs fed SDP had 9% lower liver and 13% lower thymus mRNA expression of tumor necrosis factor-alpha (TNF-alpha) than pigs that consumed no SDP (P < 0.06). Liver IL-1beta, IL-6, and LPS-binding protein mRNA were higher in the CE than in the TN (P < 0.03, P < 0.001, and P < 0.05; respectively). In addition, spleen TNF-alpha (P < 0.03) and IL-6 (P < 0.01) mRNA levels were higher in the CE than in the TN. Pigs consuming SDP and challenged with LPS responded with elevated serum concentrations of cortisol and cytokines compared with pigs fed diets with no SDP. Housing pigs in a CE increased the baseline concentrations of ACTH and cortisol, and when coupled with an LPS challenge, resulted in elevated serum and tissue mRNA levels of cytokines. Cold stress and feeding SDP during a LPS challenge may result in increased stress and immune responses in young pigs.  相似文献   

12.
A total of 108 crossbred piglets (7.75 +/- 0.24 kg of BW) weaned at 28 d was used to study the interactive effects of beta-glucan obtained from the Chinese herb Astragalus membranaceus (AM) and Escherichia coli lipopolysaccharide (LPS) challenge on performance, immunological, adrenal, and somatotropic responses of weaned pigs. The treatments were in a 2 x 3 factorial arrangement; main effects were level of Astragalus membranaceus glucan (AMG; 0, 500, or 1,000 mg/kg; as-fed basis) and presence of immunological challenge (with or without LPS). The experiment included six replicate pens per treatment and three pigs per pen. Lipopolysaccharide challenges were conducted on d 7 and 21 of the trial. Blood samples were obtained from the vena cava from one pig per pen at 3 h after LPS challenge to determine plasma responses. Weight gain and feed:gain ratio were unaffected by glucan. However, there was a quadratic effect on feed intake (P < 0.05): pigs fed 500 mg of glucan/kg had the highest feed intake. Immunological challenge with LPS decreased weight gain (P = 0.02). An interaction (P = 0.01 to 0.09) between AMG and LPS was observed for glucose, IL-1beta, PGE2, and cortisol. Astragalus membranaceus glucan had a quadratic effect on the plasma concentrations of glucose, IL-1beta, PGE2, and cortisol (P < 0.05) after both LPS challenges. Plasma concentrations of glucose, IL-1beta, PGE2, and cortisol (P < 0.05) were all increased in LPS-challenged pigs compared with the control pigs after both LPS challenges. The IGF-I concentrations were less for LPS-challenged pigs than for unchallenged pigs. The lymphocyte proliferation response of peripheral blood induced by 5 microg of concanavalin A/mL (P < 0.01) and IL-2 bioactivity (P < 0.05) increased linearly with increasing addition of glucan. Pigs challenged with LPS had greater T-lymphocyte proliferation (P = 0.06) and IL-2 bioactivity (P = 0.07) than unchallenged pigs after the first immunological challenge but not after the second. In conclusion, although glucan did not improve pig performance under the conditions of the present experiment, when included at 500 mg/kg, it decreased the release of inflammatory cytokine and corticosteroid and improved the lymphocyte proliferation response of weanling piglets via enhanced IL-2 bioactivity.  相似文献   

13.
Two experiments were conducted to investigate the effect of fermented garlic by Weissella koreensis powder (WKG) on pig growth performance and immune responses after an Escherichia coli lipopolysaccharide (LPS) challenge. In Exp. 1, 120 growing barrows (23.5 ± 0.5 kg of BW and 56 d of age) were used in a 35-d experiment to determine the optimal amounts of WKG. Pigs were randomly allotted to 1 of 5 treatments with 6 replicate pens and 4 pigs per pen. Dietary treatments included 1) NC (negative control; basal diet without antibiotics), 2) PC (positive control; basal diet + 1 g of tylosin/kg), 3) WKG1 (basal diet + 1 g of WKG/kg), 4) WKG2 (basal diet + 2 g of WKG/kg), and 5) basal diet + 4 g of WKG/kg. At the end of the feeding period, 12 pigs each were selected from the NC and WKG2 treatment groups, and 6 pigs were injected with LPS (50 μg/kg of BW) and the other 6 pigs with an equivalent amount of sterile saline, resulting in a 2 × 2 factorial arrangement of treatments. Blood samples and rectal temperature data were collected at 0, 2, 4, 6, 8, and 12 h after challenge. The ADG of pigs fed WKG- and antibiotic-supplemented diets was greater (P<0.05) than NC from d 14 to 35 and the overall phase, but no dosage-dependent effects were observed. At the end of the experiment, the fecal E. coli count was linearly reduced by the increasing amounts of WKG at d 35 (P=0.01). Challenge with LPS increased white blood cell counts at 6 and 8 h (P<0.01) and depressed lymphocyte concentration at 4, 8, and 12 h (P<0.01). During challenge, LPS injection increased rectal temperature at 2, 4, 6, and 8 h postchallenge (P<0.05), and WKG2 alleviated (P<0.05) the increase in the temperature at 2 h postchallenge. The LPS injection increased plasma tumor necrosis factor-α and IGF-1 concentrations at 2, 4, 6, 8, and 12 h (P<0.01), whereas an alleviating effect of WKG was observed at 4, 6, and 8 h after LPS challenge (P<0.05). At 2, 4, and 6 h postchallenge, concentration of cluster of differentiation-antigen-4-positive cells and cluster of differentiation-antigen-8-positive cells (CD4(+) and CD8(+), respectively) increased in the LPS treatments (P<0.05), and the WKG2 boosted this effect (P<0.05). In conclusion, dietary supplementation of WKG2 in growing pigs can improve ADG and have a beneficial effect on the immune response during an inflammatory challenge.  相似文献   

14.
Seventy-two crossbred pigs (7.58 +/- 0.30 kg BW) weaned at 28 +/- 3 d of age were used to investigate the effects of fish oil supplementation on pig performance and on immunological, adrenal, and somatotropic responses following an Escherichia coli lipopolysaccharide (LPS) challenge in a 2 x 2 factorial design. The main factors consisted of diet (7% corn oil [CO] or 7% fish oil [FO]) and immunological challenge (LPS or saline). On d 14 and 21, pigs were injected intraperitoneally with either 200 microg/kg BW of LPS or an equivalent amount of sterile saline. Blood samples were collected 3 h after injection for analysis of interleukin-1beta (IL-1beta), prostaglandin E2 (PGE2), cortisol, growth hormone (GH), and insulin-like growth factor (IGF)-I. On d 2 after LPS challenge, peripheral blood lymphocyte proliferation (PBLP) was determined. Lipopolysaccharide challenge decreased ADG (487 vs. 586 g; P < 0.05) and ADFI (as-fed, 776 vs. 920 g; P < 0.05) from d 14 to 21 and ADG (587 vs. 652 g; P < 0.10) from d 21 to 28. Fish oil improved ADG (554 vs. 520 g; P < 0.10) and ADFI (891 vs. 805 g; P < 0.10) from d 14 to 21. On d 14, LPS challenge x diet interactions were observed for IL-1beta (P < 0.10), PGE2 (P < 0.001), and cortisol (P < 0.05) such that these measurements responded to the LPS challenge to a lesser extent (IL-1beta: 93 vs. 114 pg/mL, P < 0.05; PGE2: 536 vs. 1,285 pg/mL, P < 0.001; cortisol: 143 vs. 206 ng/mL, P < 0.05) in pigs receiving the FO diet than in pigs fed the CO diet. In contrast, among LPS-treated pigs, pigs fed the FO diet had higher IGF-I (155 vs. 101 ng/mL; P < 0.10) than those fed the CO diet. On d 21 among LPS-treated pigs, pigs fed FO had lower IL-1beta (70 vs. 84 pg/mL; P < 0.10) and cortisol (153 vs. 205 ng/mL; P < 0.05) than those fed CO. Pigs fed FO had lower PGE2 (331 vs. 444 pg/mL; P < 0.05) and higher IGF-I (202 vs. 171 ng/mL; P < 0.10) compared with those fed CO. Lipopolysaccharide challenge decreased GH (0.27 vs. 0.33 ng/mL; P < 0.05) on d 14, whereas it had no effect on GH on d 21. During both LPS challenge periods, the challenge increased PBLP when these cells were incubated with 8 (1.46 vs. 1.32; P < 0.10) or 16 microg/mL (1.46 vs. 1.30; P < 0.05) of concanavalin A. Fish oil had no effect on PBLP. These results suggest that FO alters the release of proinflammatory cytokines, which might lead to improved pig performance during an immunological challenge.  相似文献   

15.
The objective of this research was to provide an integrated look at systemic adrenal, somatotropic, and immune responses of growing pigs to challenge with lipopolysaccharide (LPS). Weaned pigs were challenged intraperitoneally with 100 microg/kg BW of LPS or sterile saline, and rectal temperature and blood data were collected for 72 h. Daily feed intake also was monitored. Plasma was analyzed for concentrations of cortisol, tumor necrosis factor alpha (TNFalpha), the acute phase protein haptoglobin, growth hormone (GH), insulin-like growth factor I (IGF-I), and prostaglandin E2 (PGE2). As expected, LPS decreased feed intake, stimulated a febrile response, and activated the hypothalamic-pituitary-adrenal (HPA) axis as demonstrated by increased cortisol levels. Cortisol reached maximum elevation 2 h after treatment (P < .001) and remained elevated through 12 h (P < .001). Circulating TNFalpha was increased by LPS at 2 and 4 h after treatment (P < .001), and an apparent (not statistically significant) increase in haptoglobin also occurred in challenged animals. The LPS injection suppressed IGF-I by 2 h following treatment (P < .01), and circulating IGF-I remained reduced relative to controls through 44 h. Overall, GH was increased in LPS-treated pigs (P < .05), although the treatment x time interaction was not significant. Plasma PGE2 was increased transiently at 2 h (P < .05) and then subsequently suppressed at 4, 8, and 12 h following LPS (P < .05). This study provides a comprehensive view of systemic effects of LPS on components of the HPA, growth, and immune axes. In addition, these are the first data to document changes in circulating PGE2 in unrestrained animals during the early hours of the acute phase response to LPS.  相似文献   

16.
Early-weaned pigs (n = 64) averaging 5.3 +/- 0.3 kg and distributed into two environments (dirty and clean) were used to evaluate effects of conjugated linoleic acid (CLA) on growth performance, immune competence, and empty body composition. A factorial (2 x 4) arrangement within a split-plot design, with four littermate pigs as the experimental unit for the environment, pig within litter as the experimental unit for dietary treatment, and d-0 body weight used as covariate, were used in data analysis. Diets were formulated to contain CLA at 0, 0.67, 1.33, or 2% and to exceed the NRC (1988) nutrient needs of pigs. Animals were given ad libitum access to feed for 7 wk in three phases (I, 1 to 2; II, 3 to 5; and III, 6 to 7 wk). Within phases, diets were isocaloric and isonitrogenous. In Phase I, as dietary CLA concentration increased, ADG and ADFI decreased linearly (P < 0.05 and P < 0.02, respectively). In Phase II, upon adaptation to dietary CLA supplementation, ADG increased quadratically (603, 623, 622, and 548 g/d; P < 0.01), ADFI decreased linearly (873, 840, 867, and 717 g/d; P < 0.02) and gain:feed ratio tended to increase linearly (691, 742, 715, and 763; P < 0.07). In Phase III, no differences in growth performance were attributed to either dietary or environmental treatments. The poor health status associated with the dirty environment induced a growth suppression; pigs in the clean room had a greater cumulative ADG (P < 0.01) and ADFI (P < 0.01) than pigs in the dirty room. In Phase I, lower plasma urea nitrogen levels observed in pigs found in the dirty room (P < 0.03) indicated a lower protein intake caused by a lower ADFI. The effects of dietary CLA on peripheral phenotypic profiles of lymphoytes did not appear until d 42. However, as indicated by the growth suppression of pigs in the dirty room, the negative effects of the environmental challenge on pig health and growth had already appeared during phase I. On d 42, CLA induced a linear increase in percentages of CD8+ lymphocytes (21.7, 22.3, 28.0, and 32.7%; P < 0.001). These data suggest that a 42-d dietary CLA supplementation preceding a disease challenge could have prevented disease-associated growth suppression. Also, CLA-mediated amelioration of particular infectious diseases will depend on which CD8+ T cell subset (i.e., CD8alphaalpha-immunoregulatory or CD8alphabeta-cytotoxic) is most influenced by dietary CLA supplementation.  相似文献   

17.
It was hypothesized in these studies that differences would exist in baseline immune and performance measures among different breeds of pigs, and that these differences would be affected by age of the pig. Baseline immune, plasma cortisol (CORT) concentrations, and performance measures were determined among Berkshire (n = 36), Duroc (n = 18), Meishan (n = 54), Landrace x Yorkshire (White X; n = 36), and Yorkshire (n = 36) pigs at 4, 8, and 12 wk of age. All piglets were weaned at 17 to 21 d of age and moved to a common nursery environment. Total white blood cell (WBC), leukocyte differential, plasma CORT, immunoglobulin G (IgG) concentrations, natural killer cytotoxicity, neutrophil phagocytosis (PHAGO), and chemotaxis (CHTX) were evaluated. At all ages, plasma CORT was greatest in Meishan pigs, and least in Yorkshires (P < 0.05). Plasma IgG increased with age for all breeds (age: P < 0.01; breed x age: P < 0.005), except that in Meishans, IgG decreased. Natural killer cytotoxicity was greatest (P < 0.05) among Meishan pigs. There were breed x age interactions for neutrophil PHAGO (P < 0.001) and CHTX (P < 0.001). Overall, Yorkshire pigs showed the greatest (P < 0.05) percentage of PHAGO but the least (P < 0.05) CHTX. White X pigs had the greatest (P < 0.05) CHTX response. Berkshire pigs had the greatest (P < 0.001) numbers of neutrophils. At 12 wk of age, Meishan pigs had the least BW gain (P < 0.001), and Durocs had the greatest G:F (P < 0.001). There were no significant sex differences for immune (P > or = 0.15), performance (P > or = 0.20), or CORT (P = 0.70) measures. Pig breed and age influenced both baseline immune measures and plasma CORT in growing pigs, suggesting that pig breed and age are important factors influencing the response to various stressors or infectious challenges.  相似文献   

18.
试验旨在探讨牛膝多糖(ABPS)对脂多糖(LPS)刺激的断奶仔猪生长性能、炎性介质和内分泌激素的影响。选用48头(28±3)d(8.45±0.14)kg的杜洛克×长白×大白断奶仔猪,采用2×2因子设计,包括日粮处理(0或500 mg/kg ABPS)和免疫应激(注射LPS或生理盐水)。试验期28 d。在第14天和第21天,每日粮组一半的猪注射100μg/kg BW的LPS,另一半注射生理盐水作对照。注射后3 h,采血测定血浆肿瘤坏死因子-α(TNF-α)、前列腺素E2(PGE2)、皮质醇、生长激素(GH)和类胰岛素生长因子-I(IGF-I)含量。结果表明:LPS刺激显著降低了第14~21、22~28天的日增重(ADG)和日采食量(ADFI)(P<0.05或P=0.05);ABPS显著提高了22~28 d的ADG(P<0.05)。LPS刺激显著提高了14 d和21 d的TNF-α、PGE2和皮质醇的含量,降低了IGF-I的含量(P<0.01);ABPS显著缓解了LPS刺激导致的TNF-α(14 d和21 d)和皮质醇(14 d)含量的上升以及IGF-I(14 d和21 d)含量的下降(P<0.05)。说明ABPS缓解了免疫应激仔猪生长的抑制,其机制可能与其抑制了炎性介质的分泌有关。  相似文献   

19.
We investigated conjugated linoleic acid (CLA) supplementation administered to heavy pigs, assessing carcass characteristics, meat quality, and sensory characteristics of dry-cured (Parma) ham. Thirty-six pigs, averaging 97 kg BW, were assigned randomly to three feeding groups in which diets were supplemented with either 0, 0.25, or 0.5% (as-fed basis) of a CLA preparation containing 65% CLA isomers. All pigs were slaughtered at 172 kg BW. No (P > 0.05) differences were observed in dressing percentage, loin and ham weight, or pH and color of longissimus and semimembranosus muscle. Tenth-rib backfat thickness tended to be lower (P < 0.10) in carcasses from CLA-fed pigs. The oxidative stability of longissimus muscle was greater (P < 0.05) in pigs fed CLA than control, but only at the longer (300 min) oxidation time. Acetyl-CoA carboxylase activity in adipose tissue of CLA-fed pigs was less (P < 0.05) than that of pigs fed diets devoid of supplemental CLA. Composition of ham fat was markedly affected (P < 0.01) by dietary CLA, with higher saturated fatty acids, lower monounsaturated fatty acids, and higher CLA in the fat of CLA-fed pigs regardless of supplementation level. Although melting quality was improved (P < 0.05), most sensory characteristics and the chemical composition of dry-cured hams were not (P > 0.05) affected by incorporation of CLA. Results indicated that dietary CLA alters lipid metabolism, producing lower concentrations of monounsaturated fatty acids and increased concentrations of CLA isomers in the fat of heavy pigs. Moreover, supplementing diets with CLA produced only minimal improvements in Parma ham sensory traits and had no appreciable effects on fresh pork quality.  相似文献   

20.
Two experiments involving 168 10-d-old weaned pigs were conducted to compare growth-promoting properties of dietary spray-dried animal plasma (SDAP), spray-dried porcine plasma (SDPP), and chicken egg-yolk antibodies (EYA) or egg-yolk powder (EYP, contains no specific antibodies) from d 0 to 14 postweaning. In Exp. 1, 96 pigs (3.2 +/- 0.2 kg BW) were used to test the hypothesis that the superior performance of piglets fed SDPP-based diets was partly due to the presence of specific antibodies against enterotoxigenic Escherichia coli (ETEC), which could be replaced with EYA. Four experimental diets in a completely randomized design and arranged in a 2 x 2 factorial (SDPP without or with autoclaving [AuSDPP] and without [EYP] or with supplementation of EYA) were used. Autoclaving SDPP at 121degrees C for 15 min completely destroyed anti-K88/F18 antibodies. Overall feed intake and gain:feed ratio were similar (P > 0.05) among treatments and averaged 122.7 g/d and 0.688, respectively. However, pigs fed AuSDPP+EYP diets had poorer (P < 0.001) ADG compared with those fed SDPP+EYP or SDPP+EYA from 0 to 14 d. Scours were four times higher (P < 0.05) for treatment AuSDPP+EYP compared with all other treatments. Plasma urea nitrogen concentration was higher (P < 0.05) in AuSDPP+EYP- and AuSDPP+EYA-fed pigs. Also twice the number of piglets fed AuSDPP+EYP appeared unhealthy compared with piglets on treatment AuSDPP+EYA. In Exp. 2, 72 10-d-old weaned pigs (3.5 kg BW) were used to compare the effect of EYA supplementation and oral challenge of ETEC strain F18 on performance and visceral organ weights. The experimental diets consisted of SDAP+EYP, SDAP+EYA, SDPP+EYP, and SDPP+EYA. From d 0 to 7, and the entire experimental period, dietary treatment did not influence (P > 0.05) growth rate and feed consumption. Plasma urea N concentration was higher (P < 0.05) in piglets fed the SDAP+EYP diet before and after the oral challenge. Gain:feed ratio, organ weights, villi heights, and crypt depths were not affected (P > 0.05) by dietary treatments. The results indicate that SDPP contains specific anti-ETEC antibodies, which is one of the factors responsible for its superior growth-enhancing effects. Spray-dried animal plasma, SDPP and EYA have similar growth promoting effect in early-weaned pigs.  相似文献   

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