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151.
152.
This study examined whether in vitro-cultured Trypanosoma danilewskyi were susceptible to lysis in the presence or absence of anti-parasite antibodies and complement. Cultured trypanosomes were resistant to lysis by either immune or non-immune goldfish serum. However, trypanosomes treated with the proteolytic enzyme trypsin, which destroys surface proteins of the parasites, became susceptible to lysis when exposed to either immune or non-immune goldfish serum. The lysis by goldfish serum was dependent on the presence of heat-labile factors and occurred at 4 and 20 degrees C. The lysis was also dependent on the presence of Mg(2+) ions but not Ca(2+) ions. Furthermore, treatment of the parasites with different sialidases did not enhance their susceptibility to lysis by goldfish serum. Trypsinized parasites regained resistance to lysis after at least 6-h cultivation in the absence of trypsin and the restoration of full resistance was observed after 24-h cultivation. The resistance to lysis was abrogated when the protein synthesis inhibitor, puromycin, was added to the cultures. These results suggest that trypsinized trypanosomes were susceptible to lysis by goldfish complement (alternative pathway) and that protective surface proteins of the parasite were required for the resistance of normal trypanosomes to lysis. 相似文献
153.
影响动物免疫后抗体保护率低的原因有很多,主要包括疫苗、动物机体自身、药物使用、人为操作等因素.为有效地提高动物的抗体免疫效果,可通过合理选用疫苗、加强禽畜的饲养管理、制定科学的免疫程序、规范免疫操作等措施,解决抗体保护率的问题. 相似文献
154.
分别用质量分数为0、15%、30%、45%、60%的饲料酵母替代饲料中0、17%、34%、51%、68%的鱼粉,配制成5种等氮、等能的试验饲料,分别记为Ⅰ(对照组)、Ⅱ、Ⅲ、Ⅳ和Ⅴ组。将195尾大菱鲆Scophthatmus maximus(9.02 g±0.15 g)随机分为5组,每组设3个重复,每个重复组放养13尾鱼。将试验鱼饲养于设有循环流水系统的水族箱(60 cm×40 cm×50 cm)中,用5种饲料投喂,每天投喂3次,投饲率为鱼体质量的3%~4%,以生长及免疫指标来评价饲料酵母替代鱼粉对大菱鲆幼鱼生长的影响。经过56 d的饲养,结果表明:Ⅱ组的增重率(275.30%)和特定生长率(1.91%/d)最高,但与对照组(235.66%、1.82%/d)无显著差异(P〉0.05);Ⅱ组的饲料系数(1.34)最低,但与对照组(1.53)无显著差异(P〉0.05);Ⅱ组(97.44%)和Ⅳ组(94.87%)的成活率均显著高于对照组(84.62%)(P〈0.05),而Ⅴ组的成活率(74.36%)则显著低于对照组(P〈0.05);鱼体的粗蛋白含量随着饲料酵母替代比例的增加而逐渐降低(P〈0.05),粗灰分则逐渐升高(P〈0.05);溶菌酶、超氧化物歧化酶和血浆中蛋白的含量随着替代比例的增加而减少,且当饲料酵母替代比例超过51%时,与对照组差异显著(P〈0.05)。综合考虑大菱鲆的生长指标、形体指标、鱼体成分和免疫机能等因素,要获得最佳的养殖效益,大菱鲆幼鱼饲料中用饲料酵母替代鱼粉的比例以17%为宜。 相似文献
155.
本试验分年度在同一开放性网栏精养水域进行。分析发现,接种了草鱼(Ctenopharyngodon idellus)"四联"疫苗的试验组Ⅲ、组Ⅱ的发病率较未接种疫苗的对照组Ⅰ低,且差异显著,且它们的成活率比对照组Ⅰ分别高37.24%、25.06%;保健费开支上来分析,试验Ⅰ组>Ⅱ组>Ⅲ组。试验结果表明:接种草鱼"四联"疫苗与内服免疫增强剂相结合,可有效地提高草鱼对"四病"的抵御能力,是经济且能行之有效地提高草鱼成活率、单位面积产量及养殖效益的有力措施之一。 相似文献
156.
发酵黄芪对断奶仔猪日增重、腹泻率及免疫能力的影响 总被引:1,自引:0,他引:1
将发酵黄芪添加于断奶仔猪基础日粮中,与基础日粮及抗生素作比较,研究其对断奶仔猪日增重、腹泻及免疫功能的影响。结果表明,与基础日粮组相比,发酵黄芪能显著提高仔猪日增重、降低腹泻率及免疫能力;与抗生素组相比,发酵黄芪能显著降低仔猪腹泻率,提高免疫能力。为生产新型功能饲料提供良好途径,为中药饲料添加剂替代抗生素研究奠定基础。 相似文献
157.
158.
【目的】评估以H1N2亚型猪流感病毒(SIV)制成油乳剂灭活苗的免疫效果,为预防SIV的发生和蔓延提供参考依据。【方法】采用不同剂量的SIV H1H2亚型油乳剂灭活苗对猪只进行免疫,免疫后采血,用HI试验测定抗体效价,连续测定至第10周,然后对猪只进行攻毒,并观察其临床症状及进行病毒检测等。【结果】中免疫剂量组(4 mL/头)和高免疫剂量组(6 mL/头)的抗体滴度高于低免疫剂量组(2 mL/头);免疫组与对照组在攻毒后猪只的体温无显著差异(P >0.05),免疫组攻毒后无明显的临床症状,除中免疫剂量组在攻毒后第1 d检测出鼻粘液病毒外,其他时间及其他剂量组均未检测到SIV,对猪只起到良好的保护作用。【结论】SIV H1N2亚型油乳剂灭活苗具有良好的免疫效果,对同亚型病毒的攻击具有一定保护作用,其最佳免疫剂量为4 mL/头。 相似文献
159.
160.
For studying the effect of dietary supplementation of guduchi (Tinospora cordifolia) peripartum on lactation an investigation was conducted on 15 pregnant Karan Fries crossbred cows which were divided into two groups: treatment group of eight cows which were supplemented with guduchi at 60 g/day for 45 days prepartum and 120 g/day for 45 days postpartum; control group of seven pregnant cows which were not supplemented with guduchi. Jugular blood samples were collected from all cows during the periparturient period for analysis of various blood cell and plasma parameters. A significantly higher total leukocyte count, lymphocyte count, neutrophil count and neutrophil/lymphocyte ratio was recorded in the guduchi supplemented treatment group in comparison to untreated control cows throughout the experimental period. The increase of milk production over 305 days of lactation due to guduchi supplementation was significant (p < 0.05). A significant (p < 0.05) reduction in somatic cell count was also observed during the experimental period. Milk composition (fat, protein, lactose and SNF) was similar (p > 0.05) for both the groups. Plasma non esterified fatty acid (NEFA) concentrations were significantly higher (p < 0.01) in cows supplemented with guduchi throughout the course of study. Plasma concentration of growth hormone in the treated cows was also significantly higher beginning on the day of parturition up to 3 weeks postpartum (p < 0.05) in comparison to unsupplemented group. 相似文献