断奶应激对犊牛血液生化、免疫和内分泌的影响

选择体质量和出生日期接近的26头犊牛,其中6头母犊,20头公犊。10日龄开始补充苜蓿干草、精饲料自由采食,60日龄断奶。分别在断奶前（-1d）和断奶后1,3,5,7,14d采集血液,测定血清中代谢物、激素及免疫球蛋白含量的变化情况。结果表明,断奶影响犊牛的消化代谢,血清中葡萄糖、总蛋白、尿素氮、甘油三酯含量变化显著（P〈0.01）。断奶造成犊牛血清皮质醇、急性反应蛋白、T3、T4、乳酸脱氢酶、碱性磷酸酶、溶菌酶显著变化（P〈0.01）,使免疫球蛋白、γ-IFN、IL-1含量有不同程度下降（P〉0.05）。因此,断奶不仅降低了犊牛的免疫力,而且对犊牛产生了严重的应激反应。     

不同种植模式对土壤质量及马铃薯生长的影响

为探究轮作藜麦、玉米及连作对马铃薯根系生理及根系发育的影响及其机制,比较了3种种植模式(轮作藜麦、轮作玉米及连作)对马铃薯根际土壤微环境、根系生理、根系发育及植株生长的影响,以期为减轻马铃薯连作障碍、筛选较好的轮作模式提供理论依据。结果表明:(1)轮作藜麦、玉米明显降低土壤pH,提高土壤中有机质、碱解氮和有效磷含量,增强土壤肥力相关酶的活性,增加土壤细菌、放线菌数量和细菌与真菌数量比值(B/F),降低真菌数量,改善马铃薯根际土壤微环境,对植株生长发育起到促进作用,表现在马铃薯的株高、茎粗、地上部干重、根干重、单株薯重均有一定程度的增加。(2)轮作藜麦、玉米使得马铃薯根系超氧化物歧化酶(SOD)、过氧化物酶(POD)和过氧化氢酶(CAT)活性上升,超氧阴离子产生速率下降,丙二醛(MDA)含量减少,渗透调节物质含量增加,表明通过轮作藜麦和玉米使得连作对马铃薯植株造成的胁迫得到了一定程度缓解。(3)轮作藜麦、玉米显著提高了马铃薯根系总根长、根表面积、根体积、根平均直径和根尖数,说明轮作藜麦及玉米促进了马铃薯根系的生长发育,这与轮作藜麦及玉米改善土壤理化性质、生物学性质及促进马铃薯地上部分的发育相对应。比较轮作藜麦及轮作玉米的整体表现,以轮作玉米调控马铃薯连作障碍的效果较好。     

斑马鱼幼鱼嗜中性粒细胞对副溶血弧菌清除的动态变化

副溶血弧菌(Vibrio parahaemolyticus)是人-兽-鱼共患的致病菌,严重威胁食品安全和人类的健康。为了研究宿主嗜中性粒细胞清除细菌感染的动态变化过程,利用红色荧光蛋白标记的副溶血弧菌Vp57~(RFP)菌株感染受精后48 h(hours post fertilization,hpf)的斑马鱼(Danio rerio)幼鱼耳泡,建立局部感染模型,并以大肠杆菌(Escherichia coli)Ec01菌株为对照,系统比较了副溶血弧菌和大肠杆菌的半数致死剂量(median lethal dose,LD_(50))、存活曲线以及和嗜中性粒细胞相互作用的动态过程,RT-qPCR验证炎症相关基因il1b和il10在感染前后的表达量变化。结果显示副溶血弧菌和大肠杆菌感染斑马鱼幼鱼的LD_(50)分别为7.90×10~8 CFU/mL和1.14×10~(11) CFU/mL,与感染大肠杆菌相比,斑马鱼感染副溶血弧菌后招募嗜中性粒细胞的速度更快,且数量更多。RT-qPCR结果发现斑马鱼感染副溶血弧菌后在相同时间点能够激活更高的il1b和il10基因的表达,引起强烈的炎症反应。基于以上研究,我们建立的副溶血弧菌-斑马鱼幼鱼耳泡局部感染模型,为进一步研究嗜中性粒细胞清除副溶血弧菌感染的动态过程,以及深入揭示天然免疫应答机制提供了依据。     

不同供磷水平对辣椒根系形态和根际特征的影响

以辣椒品种线椒王为试验材料，采用盆栽方式，通过分析不同施磷水平下辣椒根系形态和根系生理的变化，探究辣 椒磷高效利用的主要根系及根际过程。结果表明，辣椒地上部和根系生物量随供磷水平的增加呈现先增加后下降的趋势，整 株磷浓度以及整株磷累积量呈增加趋势。随供磷水平增加，根系总根长呈先增加后下降趋势，根系平均直径、根冠比呈逐渐 降低趋势；辣椒根系菌根侵染率和土壤酸性磷酸酶活性呈现先增加后下降的趋势。相关分析结果表明，土壤有效磷浓度和整 株磷浓度与根系平均直径、菌根侵染率呈极显著负相关，与总根长可用一元二次方程拟合，表明辣椒根系适应低磷的根际特 征可能是通过增加根系生物量及总根长，同时降低根系平均直径来实现的。     

口蹄疫疫苗对牛的应用效果调查

牛口蹄疫是传染性疾病,为研究青海省峰堆乡口蹄疫疫苗的免疫效果,于2018—2019年对该乡的7个村开展牛口蹄疫疫苗免疫效果调查,共调查牛634头,7个村总体的口蹄疫合格率为100.00%和97.56%,最低合格率为81.63%和88.63%。为更好地控制该类疾病发生流行,提升免疫效果,该文探讨口蹄疫疫苗免疫失败原因,并制定了相应的预防措施。     

根际氧浓度对番茄幼苗生长发育的影响

为了探究设施园艺作物栽培时适宜的水气环境,采用水培试验,以河南四号和粉珍珠2个栽培番茄品种为研究对象,设置3个氧水平:低氧(0.5~2.0 mg/L)、正常氧(7.0~8.0 mg/L)和饱和氧(14.0~17.0 mg/L)处理,以不通气作为空白对照CK,研究根际不同氧浓度对番茄幼苗植株的形态生长、生物量、根系活力和光合色素的影响。结果表明,随着根际氧浓度的增加,番茄幼苗的长势越好,根系活力增加,但叶绿素含量降低。在处理末期,正常氧处理与饱和氧处理显著提高番茄幼苗的最长根长并增加番茄幼苗的干、鲜质量。其中,在18 d河南四号正常氧和饱和氧处理下总干质量比CK分别增加24.00%和74.86%,而低氧处理比CK降低3.43%;最长根长分别增加67.23%和230.55%,而低氧处理比CK降低1.63%。饱和氧处理下根系更发达健壮,地上部分长势更好,生物量积累最多。因此,在设施园艺栽培管理中,增加营养液中根际氧浓度有利于番茄生物量的积累,进而提高产量。     

Dietary administration of Bacillus (B. licheniformis and B. subtilis) and isomaltooligosaccharide influences the intestinal microflora,immunological parameters and resistance against Vibrio alginolyticus in shrimp,Penaeus japonicus (Decapoda: Penaeidae)

The experiment was conducted to investigate the effects of oral administration of probiotics (Bacillus licheniformis and Bacillus subtilis) in combination with prebiotic isomaltooligosaccharide (IMO) on the intestinal microflora and immunological parameters of Penaeus japonicus and its resistence against Vibrio alginolyticus. A basal diet was supplemented with 0% probiotics and prebiotic (control), 10⁸ colony forming unit (CFU) g^?1B. licheniformis and 0.2% IMO (T1), 10⁸ CFU g^?1B. subtilis and 0.2% IMO (T2), 10⁸ CFU g^?1B. licheniformis in combination with 10⁸ CFU g^?1B. subtilis and 0.2% IMO (T3). The results showed that the total bacterial counts significantly increased (P<0.05) and Vibrio counts significantly decreased (P<0.05) in the intestine of shrimp with supplementation of dietary synbiotics. Shrimp fed the diet with both Bacillus probiotics and IMO (T3) produced significantly higher immune parameters (phenoloxidase activity, lysozyme activity and nitric oxide synthase activity and superoxide dismutase activity) than the control group (P<0.05). Significant lower cumulative mortality after challenge with V. alginolyticus was also observed in shrimp fed diet with both Bacillus probiotics and IMO (T3) than that in the control group (P<0.05). The results indicated that the oral administration of probiotics (B. licheniformis and B. subtilis) and prebiotic IMO has positive effects on bacterial flora in P. japonicus gut, and can activate non‐specific immunity of shrimp.     

雏鸡中枢免疫器官内B淋巴细胞变化规律

为了研究雏鸡在正常发育过程中免疫器官内B淋巴细胞的变化规律,以不同日龄的SPF鸡为研究对象,用流式细胞术检测鸡脾脏、胸腺及法氏囊内IgA+、IgG+及IgM+B淋巴细胞含量的变化情况。结果显示,在脾脏中,4日龄时B淋巴细胞含量比较多,7日龄时B淋巴细胞含量下降,随后,7至21日龄细胞含量逐渐升高;胸腺内则是在4日龄时IgM+B淋巴细胞含量相对较高,而IgA+、IgG+B淋巴细胞几乎没有;在法氏囊中,IgA+、IgG+及IgM+B淋巴细胞含量在4至14日龄时逐渐升高,并且IgA+和IgG+细胞含量在21日龄时基本趋于稳定,但是IgM+B细胞含量则在21日龄时有所下降。试验结果表明,雏鸡出壳后各免疫器官B淋巴细胞始终以IgM+细胞含量最多。     

蜂王浆对尾静脉注射4T1细胞小鼠抗氧化能力的影响

探讨蜂王浆对尾静脉注射4T1细胞小鼠的抗氧化和免疫力的影响.将4T1细胞或其与蜂王浆的混合物通过尾静脉注射入小鼠体内,ELISA法检测蜂王浆对小鼠血清、肝脏和肾脏中与抗氧化能力相关的指标及血清中和免疫力相关细胞因子水平的影响.结果表明,和模型对照组相比,蜂王浆(50、100 mg·mL~(-1))可以显著提高小鼠血清内T-AOC、IFN-α(P0.05)水平,降低IL-4的水平(P0.05);蜂王浆剂量为50 mg·m L~(-1)时,IFN-γ的含量显著增加(P0.05).蜂王浆(100 mg·mL~(-1))显著提高肾脏中T-AOC的水平(P0.05).可见,蜂王浆可以改善尾静脉注射4T1细胞小鼠的抗氧化能力和免疫力.     

Effect of Dietary Supplementation with Hydrolyzed Wheat Gluten on Growth Performance,Cell Immunity and Serum Biochemical Indices of Weaned Piglets （Sus scrofa）

To investigate the effects of dietary supplementation with hydrolyzed wheat gluten (HWG) on growth performance, cell immunity and serum biochemical indices of weaned piglets, 160 crossed (Large White×Landrace) and weaned piglets were randomly divided into 4 treatments with 4 replicates of 10 piglets each. The piglets in each treatment were fed an experimental diet containing either 0 g kg-1 HWG (control group), 30 g kg-1 HWG (3% HWG group), 50 g kg-1 HWG (5% HWG group), or 2.5 g kg-1 glycyl-L-glutamine (0.25% Gly-Gln group). The results showed that the diarrhea rates in 3% HWG and 5% HWG groups were significantly lower than in control group from d 1 to 14 (P＜0.05), while the average daily gain (ADG) in each of two groups was increased (P＞0.05). When compared with control group, dietary supplementation with 3% HWG increased the ratio of CD4+:CD8+ and the ratio of serum albumin and globulin concentrations (A:G) on d 14 and 28, as well as the proliferation of T- and B-lymphocytes (P＞0.05) on d 28. In addition, on d 14 and 28, the A:G ratio in 5% HWG group was significantly higher than in control group (P＜0.05), while the ratio of CD4+:CD8+ increased slightly (P＞0.05). Interestingly, 0.25% Gly-Gln group had higher proportion of CD3+ (P＞0.05) and CD4+ (P＜0.05) on d 14 than control group, but growth performances of 0.25% Gly-Gln group were negatively affected at all experiment stages. These results suggested that HWG might improve the growth performance of piglets by strengthening cell immunity and decreasing the occurrence of diarrhea during the prophase after weaning.