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1.
本试验选用BTS、商品BTS、MODENA1和MODENA2四种不同的稀释液，各对5头杜洛克种公猪的精液进行稀释，置17℃精液保存箱中保存，并每天观察精子活力变化。然后利用在17℃精液保存箱中保存24h左右的精液进行人工授精。结果表明：四种不同稀释液所稀释保存的精液，精子活力无明显变化的保存时间，MODENA10为110．8±12．9h，MODENA2为101．2±14．62h，BTS为99．6±9．21h，商品BTS为90．8±8．05h，四者相互比较，差异不显著（P〉0．05）。而有效保存时间，即精子活力不低于0．7的保存时间，MODENA1为154．2±7．14h，MODENA2为153．6±6．28h，BTS为119．8±2．80h，商品BTS为108．2±4．96h。MODENA1与MODENA2比较，差异不显著（P〉0．05），与BTS、商品BTS相比，差异极显著（P〈0．01）；MODENA2与BTS、商品BTS相比，差异极显著（P〈0．01）；BTS与商品BTS相比，差异不显著（P〉0．05）。在输精后24天内观察不返情率，MODENA1为96．67％（29／30），MODENA2为96．67％（29／30），BTS为97．22％（35／36），商品BTS为94．12％（32／34），四者相互比较，差异不显著（P〉0．05）。 相似文献
2.
饲料中添加微生态制剂对奥尼罗非鱼生长、饲料利用和抗病力的影响 总被引：5，自引：0，他引：5
本试验采用初始体重（5．13±0．15g）的雄奥尼罗非鱼作为饲养对象．在饲料中分别添加不同水平微生态制剂（0、0．05％、0．1％、0．2％和0．3％）,共设5个处理,采用开放式流水养殖．饲养8周．研究饲料中添加不同水平微生态制剂对奥尼罗非鱼生长、饲料利用、体组成成分的影响。8周后注射嗜水气单胞菌进行感染试验．观察7d,计算存活率,研究添加微生态制剂对奥尼罗非鱼抗病力的影响。结果表明：饲料中添加微生态制剂对奥尼罗非鱼的增重率、饲料系数、特定生长率、肥满度及蛋白效率均有显著影响（P〈0．05）,但对成活率影响不显著（P〉0．05）。增重率和特定生长率．对照组均显著低于添加量在0．1％～0.3％组（P〈0．05）．与添加量为0．05％组差异不显著（P〉0．05）。饲料系数,对照组与0．05％组差异不显著（P〉O．05）,均显著高于0．1％-0．3％组（P〈0．05）。蛋白效率和肥满度,添加0．2％和0.3％组显著高于对照组和0．05％组（P〈0．05）。罗非鱼全鱼水分和蛋白含量．各组间有显著差异（P〈0．05）,而全鱼体脂肪和灰分含量,各组间差异不显著（P〉0．05）。罗非鱼攻毒24h、48h、96h和168h后,对照组存活率显著低于其他各组（P〈0．05）．但微生态制剂添加量为0．2％和0．3％时．存活率显著高于对照组和0．05％添加量组（P〈0．05）。综合增重率、特定生长率、饲料系数、蛋白质效率等生长性能指标以及攻毒后的成活率,建议在罗非鱼配合饲料中微生态制剂的适宜添加量为0．1％～0．2％。 相似文献
3.
分光光度法与肉眼评分评定猪肉肉色的研究 总被引：2，自引：0，他引：2
本试验挑选不同品种猪24头，宰后取其眼肌（背最长肌）。用肉眼评分法给出各个肉样的评分。然后，分别将每个肉样用分光光度法测出12h、24 h和48 h的色素含量。分析不同品种猪宰后同一时间的肉色差别和同一品种猪宰后不同时间肉色变化，并比较肉眼评分法与分光光度法的准确程度。试验结果表明：长白纯公猪的评分和色素总含量最小。约克纯公猪的评分最大。其余各品种猪肉肉色差异不大。在宰后12 h和48 h各品种猪的肉色差异显著（P〈0．05），宰后24 h长白纯公猪、约克纯公猪、约克纯母猪之间的差异显著（P〈0．05）并和其他品种之间的差异也显著（P〈0．05），但其余几个品种之间的差异不显著（P〉0．05）。杜约杂母猪、长白纯母猪和约克纯公猪在宰后12 h和48 h的肉色差异不显著（P〉0．05）但与24 h差异显著（P〈0．05）。长白纯公猪宰后12 h和24 h肉色差异不显著（P〉0．05），但与48 h差异显著（P〈0．05）。长大杂公猪和约克纯母猪宰后各时间肉色差异都不显著（P〉0．05）。大长杂母猪和杜洛克纯母猪宰后各时间肉色差异都显著（P〈0．05）。 相似文献
4.
试验旨在研究急性热应激对泰和乌骨鸡胸肌酪氨酸酶基因表达及黑色素含量的影响。选取144只42日龄泰和鸟骨鸡．随机分为2组：即常温对照组和急性热应激组,每组4个重复．每个重复18只鸡。结果表明,急性热应激极显著地提高了热应激12h时泰和乌骨鸡胸肌酪氨酸酶mRNA的表达（P〈0．01）,并具有提高其热应激24h时的表达量的趋势（P〉0．05）,对其恢复常温后24h、6d、20d的表达量无显著影响（P〉0．05）;急性热应激极显著地降低了热应激24h时泰和乌骨鸡胸肌黑色素的含量（P〈0．01）。并具有降低其热应激12h时黑色素含量的趋势（P〉0．05）,极显著地提高了其恢复常温后24h时胸肌黑色素的含量（P〈0．01）,对其恢复常温后6d、20d的黑色素含量无显著影响（P〉0．05）。 相似文献
5.
通过对不同发育阶段猪孤雌激活胚胎进行离心去脂处理，比较胚胎冷冻效果，优化冷冻体系。以猪孤雌激活胚胎为材料，比较实施电激活后第1天（2～3细胞）、第2天（4～6细胞）、第3天（6～8细胞）进行离心处理，取培养到第6天所得到扩张囊胚进行玻璃化冷冻保存，未离心处理直接进行冷冻的胚胎作为对照组。结果显示第3天离心组和第2天离心组所得的囊胚形成率（30．23％，28．22％）虽好于第1天离心组和不处理组（21．73％，22．43％），但4个试验组差异不显著（P〉0．05）；第3天离心组和第2天离心组的冷冻后胚胎复苏率（28．57％，20．56％）显著高于不处理组（7．73％）、第1天离心组（12．24％），差异显著（P〈0．05）；第3天离心组的解冻后囊胚内细胞计数（30．40）显著高于对照组（18．25）、第1天离心组（16．60），差异显著（P〈0．05），高于第2天处理组（23．71），但差异不显著（P〉0．05）。结果表明，在孤雌激活后第3天进行离心处理，对胚胎发育到囊胚没有影响，且进行冷冻后所得复苏率及胚胎内细胞团数较好。 相似文献
6.
豆油和油脂粉对断奶仔猪生产性能的影响 总被引：1，自引：0，他引：1
试验豆油及HTL316脂肪粉对早期断奶仔猪的添加效果。选择28日龄体质量为（6．6±0．51）kg的断奶仔猪150头，分为3组，分别饲喂3种饲粮：对照日粮（组1）、对照日粮＋豆油（组2）、对照日粮＋HTL316（组3）。试验分3期。试验结果表明，在断奶后0～10、11～22、23～38、0～38d，组3的平均日增质量比组2分别提高12．9％（P〈0．05）、5．4％（P〉0．05）、10．6％（P〈0．05）、6．6％（P〉0．05），料肉比分别降低9．7％（P〉0．05）、8．0％（P〉0．05）、10．1％（P〈0．05）、7．0％（P〉0．05）。在断奶后0～10d，组3的有机物消化率、粗脂肪消化率及总能消化率分别比组2提高11．08％、10．89％和11．31％，差异均显著。在断奶后23～38d，组3的有机物消化率和粗脂肪消化率显著高于组2。在断奶后0～10、11～38和0～38d，组3的增质量饲料成本比组2分别低0．46、0．35和0．37元／kg。结论是断奶仔猪日粮中添加HTL316可提高生产性能，降低饲养成本。 相似文献
7.
研究了母羔超排方法、成熟培养时间及成熟液添加EGF对绒山羊母羔卵母细胞体外成熟的影响。结果表明,直径〉130μm组PbI率（73．27％）显著高于直径120～130μm组（P〈0．05）,直径〈120μm组PbI率（32．22％）极显著低于其他组（P〈0．01）;卵母细胞成熟培养24～27h组PbI率（68．06％）显著高于21～24h组（P〈0．05）,27～30h组PhI率（73．47％）高于24～27h组,但差异不显著（P〉0．05）;10ng／mL组和20ng／mLEGF组PhI率极显著高于对照组（P〈0．01）,20ng／mLEGF组pbI率（71．43％）显著高于10ng／mL（P〈0．05）。 相似文献
8.
分别用CIDR（孕酮阴道栓）＋PMSG（处理1）和CIDR＋PMSG＋LH（处理2）两种处理方法对山羊进行同期发情处理。结果发现,两种处理均以撤栓后第1d发情率最高。撒栓后0-24h和24h-48h的发情率,处理1和处理2（61．4％,13．6％和48％,20％）之间差异不显著;撤栓后48h-72h的发情率,处理1（4．59,6）显著低于处理2（24％）（P〈0．05）;撤栓后0～72h发情率,两种处理（79．5％,92％）无显著差异（P〉0．05）。从手术时对卵巢的观察可以看出,有大卵泡或排卵的发情羊,处理1为91．2％,处理2为100％,二者无显著差异;排卵的发情羊,处理1为（58．8％）显著低于处理2为（91．2％）（P〈0．05）。 相似文献
9.
10.
饲喂脆茎全株水稻对生长肥育猪生长性能、养分消化和胴体品质的影响 总被引：14，自引：1，他引：14
体重相近的杜洛克生长母猪54头，随机分成3组（每组3个重复），研究脆茎全株水稻（3个水平0、10％和20％）用于生长肥育猪日粮，对猪的生长性能、养分消化、胴体品质和肉质的影响。结果表明，生长猪阶段（29～52kg）对照组、10％组和20％组的采食量、平均日增重和料重比均无显著差异（P〉0．05）。肥育猪阶段（54～85kg）采食量和平均日增重，20％组显著低于对照组（P〈0．01），10％组与对照组之间无显著差异（P〉0．05）；各组料重比均无显著差异（P〉0．05）。生长猪阶段10％组和20％组各种养分的消化率都低于对照组；而肥育猪阶段，两组NDF消化率显著低于对照组（P〈0．01），其它养分消化率与对照组无显著差异。与对照组相比，10％组和20％组屠宰率有所下降，而瘦肉率提高，眼肌面积增大，背膘厚降低，但差异均不显著（P〉0．05）。10％组和20％组的背最长肌蛋白含量增加，脂肪含量降低，其中20％组与对照组差异显著（P〈0．05）；滴水损失和大理石纹及肉色评分各组之间均无显著差异（P〉0．05），20％组宰后24h的pH，显著高于对照组（P〈0．01）。 相似文献
11.
本试验旨在检测2株枯草芽孢杆菌对致病性大肠杆菌和沙门氏菌抑菌作用。以致病性大肠杆菌和沙门氏菌作为指示菌,采用2株枯草芽孢杆菌与大肠杆菌和沙门氏菌同时接种及先后接种的方法,对其与大肠杆菌和沙门氏菌的生物颉颃作用进行了研究。结果表明,先接种枯草芽孢杆菌再接种致病菌抑制作用最明显且在24 h时抑菌作用最强,同时接种枯草芽孢杆菌和致病菌抑制作用次之,先接种致病菌再接种枯草芽孢杆菌的抑制作用最弱。提示,2株枯草芽孢杆菌对致病性大肠杆菌和沙门氏菌都有一定的抑制作用,但抑制作用的强弱有差异,且与枯草芽孢杆菌和致病菌接种的时间长短有关。 相似文献
12.
Seventy-two Angus feedlot bulls were observed to determine the effects of implanting with zeranol (0, 36 or 72 mg; four groups of six/level) at 8 mo of age (d 0), and of castration midway through the feedlot period (d 115) vs remaining intact (six groups/treatment) on sexual, agonistic and handling behaviors. All 36-mg-treated cattle were re-implanted (36 mg) on d 112; 72-mg-treated cattle were not re-implanted. Each group was observed for a total of 8 h at the time of sunset +/- 30 min for sexual and agonistic behaviors during the trial. Observations on handling were made during 15 weighings and on seven occasions in the pens of the animals. Zeranol did not affect sexual or agonistic behavior. Before imposition of castration, implanted bulls entered the scales more quickly, took longer to stand still on the scales and were less quiet than non-implanted bulls (P less than .05). Castration decreased the sexual behaviors of masturbation (.75 vs .08 X pen-1 X h-1; P less than .05), attempted mounts (.75 vs .33 X pen-1 X h-1; P less than .05) and chinning (10.70 vs 4.75 X pen-1 X pen-1; P less than .10) and the agonistic behavior of butting (42.42 vs 31.50 X pen-1 X h-1; P less than .01) in contrast to intact bulls. Castrated animals entered (P less than .10) and exited (P less than .05) the scales more quickly than did intact males.(ABSTRACT TRUNCATED AT 250 WORDS) 相似文献
13.
活性氧(ROS)对小鼠早期胚胎胚细胞分裂的影响 总被引：1，自引：0，他引：1
在体外CZB培养的不同时期添加过氧化氢(2.1μmol/L),发育至囊胚阶段,制作胚胎标本,观察其囊胚发育率、胚细胞数和分裂相数。结果显示:0~12 h组和0~72 h组的胚胎发育率显著低于其他几组(P<0.05),对照组、12~24 h组、24~36 h组、36~48 h组之间均差异不显著(P>0.05);各组之间的胚细胞数和分裂指数均无显著差异。说明胚胎在体外培养时,2细胞期胚胎对外源性H2O2最敏感,也最容易发生发育阻滞。但是经H2O2处理之后,度过2细胞期发育阻滞的胚胎能在以后的发育中发生补偿性生长,其胚细胞数和分裂指数都和体外正常发育的胚胎没有差异。 相似文献
14.
Sattar A Rubessa M Di Francesco S Longobardi V Di Palo R Zicarelli L Campanile G Gasparrini B 《Reproduction in domestic animals》2011,46(6):1090-1097
The objectives of this work were to evaluate whether the sperm penetration speed is correlated to the in vitro fertility and whether adapting the gamete co-incubation length to the kinetics of the bull improves in vitro fertility and affects the sex ratio. In vitro matured oocytes were co-incubated with spermatozoa from four different bulls (A-D). At various post-insemination (p.i.) times (4, 8, 12, 16 and 20 h), samples of oocytes were fixed and stained with DAPI for nuclei examination, while the remaining ones were transferred into culture to evaluate embryo development. The blastocysts produced were sexed by PCR. Two bulls (A and B) had faster kinetics than the others (C and D), as shown by the higher penetration rates recorded at 4 h p.i. (43%, 30%, 11% and 6%, respectively for bulls A, B, C and D; p<0.01). The differences in the kinetics among bulls did not reflect their in vitro fertility. The incidence of polyspermy was higher for faster penetrating bulls (36%, 24%, 16% and 4%, respectively for bulls A, B, C and D; p<0.01) and at longer co-incubation times (0%, 16%, 19%, 30% and 34%, respectively at 4, 8, 12, 16 and 20 h p.i.; p<0.01). The fertilizing ability of individual bulls may be improved by adapting the co-incubation length to their penetration speed. A sperm-oocyte co-incubation length of 8 h ensured the greatest blastocyst yields for the two faster penetrating bulls. On the contrary, 16 h co-incubation was required to increase (p<0.01) cleavage rate of the two slower bulls. Bulls with a faster kinetics did not alter the embryo sex ratio towards males. The female/male (F/M) ratios recorded were 2.1, 1.4, 1.2, 1.3 and 1.6, respectively at 4, 8, 12, 16 and 20 h p.i. 相似文献
15.
对发酵黄芪样品中分离的1株产纤维素酶解淀粉芽胞杆菌的生物学特性进行了检测,试验结果表明,菌株在10℃~60℃环境均能生长,最适生长温度为35℃~40℃。pH5.0~8.0培养基均适宜菌株生长,其中最适pH为6.0。在37℃环境200r/min振荡培养的生长曲线在0~4h为延迟期,4h~12h为对数期,12h~24h为稳定期,24h以后为衰亡期。细菌37℃培养32h开始产生芽胞,在培养72h时芽胞形成率达到80.67%。菌株对多数抗菌药物敏感,且安全性良好。该菌株适应性强,生长条件较为宽松,这为其开发应用提供了依据。 相似文献
16.
Anderson RC Hume ME Genovese KJ Callaway TR Jung YS Edrington TS Poole TL Harvey RB Bischoff KM Nisbet DJ 《Veterinary research communications》2004,28(3):179-189
Foodborne disease caused by Salmonella is of public health and economic significance. In order to assess the practical effectiveness of a new intervention strategy, experimental chlorate preparations (ECP) were administered via the drinking water to weaned and finished pigs that had been orally challenged the previous day with 10(9)-10(10) colony-forming units of Salmonella serovar Typhimurium. After 24 or 36 h ad libitum access to 0X, 1X or 2X ECP treatment (where X is the concentration estimated to deliver a minimal daily effective dose), the pigs were euthanized and gut contents and lymph tissue collected at necropsy were cultured for the challenge Salmonella. Drinking water administration of ECP effectively reduced (p < 0.05) caecal Salmonella concentrations and, with the weaned pigs, tended (p < or = 0.10) to reduce rectal Salmonella concentrations. No negative effects of ECP treatment on water intake and animal wellbeing were observed and only marginal effects on gut fermentation characteristics occurred. The bactericidal effect of administering ECP in drinking water was relatively rapid, with reductions in caecal Salmonella concentrations occurring within 24 h. These results suggest that ECP administered to pigs just days before slaughter may reduce gut concentrations of Salmonella; however, the impacts of such reductions on slaughter hygiene have yet to be determined. 相似文献
17.
Conventionally-reared sheep were inoculated with (3.0 ± 0.6 × 107) viable Pasteurella haemolytica type A1 by the intratracheal route and were killed immediately (0-time) or 2, 4, 12, 16, 24, 48 or 72 h later. Lung-wash cells and free bacteria were recovered by pulmonary layage.The number of recoverable bacteria tended to increase between 0-time and 4 h post-in-oculation (p.i.) then decline rapidly over the next 8 h. However, the rate of clearance was extremely variable and viable bacteria were recovered from animals at 48 h p.i. and from at 72 h p.i.In parallel with the clearance of the majority of the bacteria, total neutrophil numbers in the lung-wash rose to a peak of (36 ± 6) × 108 cells/lung, which was, on average, 70-fold higher than 0-time levels. Their numbers remained constant from 12 to 24 h p.i. then fell to be 5-fold above 0-time levels at 72 h p.i. Macrophage numbers rose slowly throughout the experiment but most of the increase occurred between 24 and 48 h p.i. They reached a peak of (17 ± 11) × 108 cells/lung at 48 h i.p. which was 3-fold higher than 0-time levels. 相似文献
18.
基于康奈尔净碳水化合物与蛋白质体系的瘤胃非降解蛋白质小肠可吸收氨基酸流量的简化评定技术 总被引：1，自引：0，他引：1
本试验旨在简化基于康奈尔净碳水化合物与蛋白质体系(CNCPS)评定瘤胃非降解蛋白质(RUP)小肠可吸收氨基酸流量的技术。小肠可吸收氨基酸来自菌体蛋白和RUP,CNCPS根据溶解性将饲料粗蛋白质(CP)分为A、B1、B2、B3和C共5种组分,只有3种B组分可以过瘤胃并在小肠中消化。为评定RUP小肠可吸收氨基酸的贡献,CNCPS需要分别测定3种B组分的瘤胃降解率,3种过瘤胃B组分的小肠消化率需采用不同常数。选择18份饲料样品,其中精料12份,粗料6份,测定CNCPS评定RUP小肠可吸收氨基酸流量所需数据,同时对饲料CP的瘤胃动态降解率及不同时间点RUP的体外小肠消化率进行了测定,通过这些数据提出简化评定方法。结果表明:1)精料和粗料均以8 h的CP瘤胃降解率(X,%)与有效降解率(Y,%)间相关性最强,二者间呈线性相关,精料和粗料方程分别为Y=12.652+0.828X,r=0.990,P0.000 1和Y=10.967+0.886X,r=0.980,P=0.000 6。2)精料2 h RUP小肠消化率(X,%)与RUP小肠有效消化率(Y,%)间相关性最强,方程为Y=0.026+0.879X,r=0.970,P0.000 1;粗料8h RUP小肠消化率(X,%)与RUP小肠有效消化率(Y,%)间相关性最强,方程为Y=-0.002+0.960 X,r=0.995,P0.000 1。3)简化方案经可靠性评估得出,8 h CP瘤胃降解率和RUP小肠消化率简化CNCPS模型预测的小肠氨基酸流量(X,‰)与CNCPS预测的小肠氨基酸流量(Y,‰)相关性最强,精料方程为Y=-0.056+1.409X,r=0.999,P0.000 1;粗料方程为Y=0.003+2.120 X,r=0.999,P0.000 1。精料和粗料的简化评定结果与CNCPS评定结果的均方根误差分别为0.245和0.005,变异系数分别为7.08%和4.49%。综合得出,基于CNCPS,得到了预测RUP小肠可吸收氨基酸流量的简化模型,简化后的精料和粗料模型分别为Y=-0.056+1.409×[AA×(100-D8)×CP×ID8],r=0.999,P0.000 1和Y=0.002+2.120×[AA×(100-D8)×CP×ID8],r=0.999,P0.000 1,Y为RUP中的某种氨基酸小肠可吸收流量(‰),D8为CP的8 h瘤胃降解率(%),ID8为RUP的8 h小肠消化率(%),AA为不溶性蛋白质中该氨基酸含量(%)。 相似文献
19.
Background
The objective of this study was to characterize the changes in various metabolic parameters in blood and milk during IMI challenge with Escherichia coli (E. coli) for dairy cows during early lactation. Thirty, healthy primiparous Holstein cows were infused (h = 0) with ~20-40 cfu of live E. coli into one front mammary quarter at ~4-6 wk in lactation. Daily feed intake and milk yield were recorded. At –12, 0, 3, 6, 12, 18, 24, 36, 48, 60, 72, 96, 108, 120, 132, 144, 156, 168, 180 and 192 h relative to challenge rectal temperatures were recorded and quarter foremilk was collected for analysis of shedding of E. coli. Composite milk samples were collected at -180, -132, -84, -36, -12, 12, 24, 36, 48, 60, 72, 84, 96, 132 and 180 h relative to challenge (h = 0) and analyzed for lactate dehydrogenase (LDH), somatic cell count, fat, protein, lactose, citrate, beta-hydroxybutyrate (BHBA), free glucose (fglu), and glucose-6-phosphate (G6P). Blood was collected at -12, 0, 3, 6, 12, 18, 24, 36, 60, 72, 84, 132 and 180 h relative to challenge and analyzed for plasma non-esterified fatty acids (NEFA), BHBA and glucose concentration. A generalized linear mixed model was used to determine the effect of IMI challenge on metabolic responses of cows during early lactation.Results
By 12 h, E. coli was recovered from challenged quarters and shedding continued through 72 h. Rectal temperature peaked by 12 h post-challenge and returned to pre-challenge values by 36 h post-IMI challenge. Daily feed intake and milk yield decreased (P <0.05) by 1 and 2 d, respectively, after mastitis challenge. Plasma BHBA decreased (12 h; P <0.05) from 0.96 ± 1.1 at 0 h to 0.57 ± 0.64 mmol/L by 18 h whereas concentration of plasma NEFA (18 h) and glucose (24 h) were significantly greater, 11 and 27%, respectively, after challenge. In milk, fglu, lactose, citrate, fat and protein yield were lower whereas yield of BHBA and G6P were higher after challenge when compared to pre-challenge values.Conclusions
Changes in metabolites in blood and milk were most likely associated with drops in feed intake and milk yield. However, the early rise in plasma NEFA may also signify enhanced adipose tissue lipolysis. Lower concentrations of plasma BHBA may be attributed to an increase transfer into milk after IMI. Decreases in both milk lactose yield and % after challenge may be partly attributed to reduced conversion of fglu to lactose. Rises in G6P yield and concentration in milk after challenge (24 h) may signify increased conversion of fglu to G6P. Results identify changes in various metabolic parameters in blood and milk after IMI challenge with E. coli in dairy cows that may partly explain the partitioning of nutrients and changes in milk components after IMI for cows during early lactation. 相似文献20.
Balaji R Wright KJ Turner JL Hill CM Dritz SS Fenwick B Carroll JA Zannelli ME Beausang LA Minton JE 《Journal of animal science》2002,80(1):202-207
This study evaluated the time course of systemic cytokine concentrations in an acute model of pneumonia in pigs challenged intranasally with Actinobacillus pleuropneumoniae. Feed intake and serum cortisol were measured as overt clinical and systemic markers of disease onset, respectively, and serum tumor necrosis factor-alpha, interleukin-1beta, and interferon-gamma as representative systemic inflammatory markers. Crossbred barrows (n = 15), approximately 5 wk of age, were used in the study. Pigs were housed in an environmentally controlled facility at 25 degrees C and under continuous illumination in pens measuring approximately 1.5 m2. Pigs had free access to water and an unmedicated diet. Approximately 1 wk prior to disease challenge, pigs were fitted nonsurgically with venous catheters. At challenge, pigs were given 5 x 10(8) CFU Actinobacillus pleuropneumoniae intranasally (n = 8) or a similar volume of sterile growth media intranasally (Control; n = 7). Feed intake was estimated by the change in feeder weight at 12-h intervals from -12 to 72 h relative to the time of disease challenge. Blood sampling began 12 h prior to challenge and continued until 72 h after challenge. Pigs were sampled at -12, -6, and 0 h, then at 90-min intervals until 12-h post-challenge, continuing at 3-h intervals until 24-h post-challenge, then again at 6-h intervals until 72 h after challenge. Serum was harvested and frozen until assayed for cortisol, tumor necrosis factor-alpha, interleukin-1beta, and interferon-gamma. Feed intake was reduced in Actinobacillus pleuropneumoniae pigs during the intervals 0 to 12 h (P < 0.001), 24 to 36 h (P < 0.001), 48 to 60 h (P <0.05), and 60 to 72 h (P < 0.05). TheActnobacillus pleuropneumoniae-challenged pigs had elevated serum cortisol from 180-min to 18-h post-challenge (P < 0.001) and also at 36 (P < 0.05), 42 (P < 0.001), and 60 (P < 0.05) h following infection. Circulating cytokines were not affected by disease challenge. Thus, in this experimental model of pneumonia, weaned pigs demonstrated expected behavioral and endocrine characteristics of disease in the absence of significant changes in circulating inflammatory cytokines. 相似文献