蚕茧价格、蚕种饲养量与蚕药用量关系的格兰杰因果检验

研究蚕桑产业经济中蚕茧价格(CAP)、蚕种饲养量(简称发种量,SSQ)、蚕药用量(SMQ)3个变量之间的关系,有助于科学预测蚕桑产业经济的发展变化规律。选取1991-2009年江苏省海安县蚕桑生产的年度数据,应用格兰杰因果关系检验(Granger causality test)方法,对上述3个变量进行平稳性检验、变量的一阶差分与单位根检验和格兰杰因果关系检验。结果表明,蚕茧价格与发种量、发种量与蚕药用量之间存在格兰杰因果关系,蚕茧价格与蚕药用量之间不存在格兰杰因果关系,即:蚕茧价格增长能引起发种量的增加,但发种量增加却不是蚕茧价格增长的原因,蚕茧价格对发种量的影响滞后期为2年,到第3年影响程度已逐渐弱化;发种量增加能引起蚕药用量的增加,但影响滞后期只有1年,超过1年后的影响不显著;蚕茧价格与蚕药用量之间从实际趋势看有一定的关联性,但相互之间的影响关系不是直接的,难以建立函数关系。研究结果与蚕桑产业发展变化的实际情况基本相符,认为格兰杰因果关系检验方法可应用于蚕桑产业经济相关因素的发展变化规律研究。     

青脚白羽鸡测交羽色效应研究

青脚白羽鸡是近年来选育出的新品种,为了利用好该鸡种优良的种质特性,试验中用其他优良鸡种与其测交,以期使更多的优良性状组合在一起,甚至超过双亲,将杂交优势在生产中加以利用。目前的试验结果表明,以青脚白羽鸡作母本、川东大黑鸡作父本的测交组合经济性状效果最好,其测交的羽色遗传效应较复杂,认真研究该遗传效应,对于丰富遗传育种理论和指导育种实践有着重要的意义。     

不同工艺制备的水产开口饵料溶失规律试验研究

为了比较不同工艺制备的水产开口饵料中不同成分的溶失规律,试验对挤出滚圆法、挤出滚圆-流化床包衣法及膨化破碎法制备的饵料进行了质量损失率、粗蛋白溶失率、游离氨基酸(FAA)溶失率的比较研究,结果表明:膨化破碎工艺制备的开口饵料质量损失率、粗蛋白的溶失率和游离氨基酸的溶失率均高于挤出滚圆工艺;包衣没有明显改善饵料的溶失情况;游离氨基酸的溶失速度非常快,入水初期几乎全部溶失(5 min内溶失率就达到53.54%～91.71%)。     

Luteinizing hormone-dependent Cushing's syndrome in a pet ferret (Mustela putorius furo)

Hyperadrenocorticism in ferrets is associated with increased circulating concentrations of adrenal androgens, whereas plasma concentrations of cortisol and ACTH are usually not affected. Here, we report on a 5-year-old castrated male pet ferret (Mustela putorius furo) in which the major presenting signs were polyuria and polyphagia. Routine biochemistry values were within their reference ranges. The urinary corticoid:creatinine ratio (UCCR) was increased and the plasma ACTH concentration was suppressed. Abdominal ultrasonography revealed an enlarged right adrenal gland and atrophy of the left adrenal gland. Administration of hCG resulted in an increase of plasma cortisol and androstenedione concentrations. Based on these findings LH/hCG-dependent hypercortisolism and hyperandrogenism were suspected and treatment was started with a depot GnRH-agonist implant containing 9.4mg deslorelin. Within 3 weeks after placement of the implant all clinical signs had disappeared. Three months later the endocrine parameters had normalized, while abdominal ultrasonography revealed that the right adrenal gland had diminished in size and the left adrenal gland was considered of normal size. No recurrences of clinical signs were seen within 2 years after placement of the deslorelin implant. At that time urinary corticoid and plasma hormone concentrations were within their reference ranges, and no further change in the size of the adrenal glands was seen. In conclusion, this is the first confirmed case of LH-dependent hypercortisolism in a ferret that was treated successfully with a depot GnRH-agonist.     

中药复方对人工感染雏鸡大肠埃希菌病及沙门菌病的防治效果观察

为验证中药复方对鸡大肠埃希菌病和沙门菌病的临床效果,对人工感染大肠埃希菌和沙门菌鸡进行防治试验,用O78、O1、O2型大肠埃希菌菌株和鸡白痢沙门菌株对试验组鸡进行人工感染后,分为中药复方高、中、低剂量组,抗生素和健康、阳性对照组。结果表明,中药复方防治两类疾病疗效可靠,效果明显,其中以高剂量组防治效果最好。对人工感染引起的鸡大肠埃希菌病和鸡白痢的保护率为92%,治愈率分别为82%和88%。     

鹅源鸭疫里默氏杆菌的分离和鉴定

为研究鹅源鸭疫里默氏杆菌的生化特性、药敏情况、血清型和致病性,从扬州郊区发病鹅场分离到1株细菌,经分离培养、染色镜检、生化特性鉴定、玻片凝集试验,确定为Ⅱ型鸭疫里默氏杆菌。对病料进行病毒分离试验,经过血凝试验和琼脂扩散试验,没有发现鹅新城疫病毒、禽流感病毒和小鹅瘟病毒。动物致病性试验结果表明,鸭疫里默氏杆菌分离菌株可以通过静脉注射、皮下注射和滴鼻3种途径感染鹅,出现100%的死亡率,说明分离株对扬州鹅具有很强的致病性,同时提示在鹅的免疫计划中也应该充分考虑到鸭疫里默氏杆菌的致病和传播。     

獭兔链球菌的分离与鉴定

对通辽市某獭兔种免场采集到的病死兔组织进行细菌分离,通过形态鉴定、生化鉴定、药敏试验、动物致病性试验等一系列诊断,证实链球菌感染是引起兔死亡的主要原因。根据药敏试验结果,对免群进行针对性治疗．使病情得到有效控制。     

家兔临床型乳腺炎病理模型的血液学检验

本试验选取16只3~4 kg健康泌乳家兔,通过人工造模的方法诱发其乳腺发炎,建立临床型乳腺炎模型。然后分别在造模前1 h和造模后4、12、24、36、487、2 h采集血液0.5 mL、血清1 mL,进行血常规、血生化检测和炎性细胞因子测定(ELISA)。结果显示:①外周血白细胞总数在造模后4 h显著高于造模前水平(P0.05),12~72 h内极显著高于造模前水平(P0.01);红细胞总数、红细胞压积、血红蛋白含量在造模前至造模后72 h内无显著差异(P0.05)。②血清磷离子含量、血清总胆红素含量、血清直接胆红素含量在造模前至造模后72 h内无显著差异(P0.05);血清钙离子含量在造模后4 h显著低于造模前水平(P0.05),12~72 h内极显著低于造模前水平(P0.01)。③血清TNF-α和IL-6含量造模后开始升高,12~72 h内极显著高于造模前水平(P0.01)。结果证明白细胞总数、血清钙离子含量、血清TNF-α和IL-6含量的变化可作为急性乳房炎炎症发展情况的指标。     

气肿疽梭菌CctA基因的原核表达及其间接ELISA检测方法的建立

研究旨在原核表达气肿疽梭菌细胞毒素A （CctA）基因,用纯化的重组蛋白建立其间接ELISA检测方法,a。利用大肠杆菌密码子的偏爱性优化CctA基因序列,克隆至原核表达载体pET-28a （+）,双酶切鉴定原核表达质粒pET28a-CctA并测序。将重组质粒转入大肠杆菌,经IPTG诱导得到高表达的重组CctA包涵体蛋白。包涵体蛋白变性后经镍（Ni）柱纯化,SDS-PAGE检测其纯化效果。以豚鼠抗气肿疽梭菌抗血清为一抗,用Western blotting方法检测重组CctA蛋白的反应原性。用棋盘滴定法建立间接ELISA检测方法,以复性后的重组CctA蛋白作为检测抗原,摸索抗原包被浓度、封闭液的种类及浓度、抗体的最适稀释度和反应条件等。选用3批气肿疽灭活疫苗免疫豚鼠后采集血清,同时用攻毒和间接ELISA两种方法验证疫苗的免疫效力。质粒双酶切结果显示,得到大小约853 bp的条带,与预期相符,且测序结果正确。SDS-PAGE结果表明,成功表达并纯化大小为35 ku的重组CctA蛋白。Western blotting结果显示,豚鼠抗气肿疽梭菌抗血清与重组CctA蛋白具有良好的反应原性。建立的间接ELISA法的最适条件为：抗原的包被浓度为0.5 μg/mL,于4 ℃包被过夜;封闭液选择10%胎牛血清,37 ℃孵育2 h;二抗的稀释度为1：8 000;室温避光显色10 min后终止反应,测定D_{450 nm}值。当P/N>4.6时,间接ELISA法检测结果与豚鼠攻毒试验结果拟合度较好。本研究成功表达CctA基因并纯化了重组CctA蛋白,建立的以重组CctA蛋白为检测抗原的间接ELISA检测方法,有望成为气肿疽灭活疫苗免疫效果验证的替代方法。     

Carrier rate of the c.235G>C mutation in the bovine isoleucyl-tRNA synthetase (IARS) gene of Japanese Black cows at Kagoshima prefecture, Japan,and analysis of the metabolic profiling and reproductive performance of heterozygous cows

Bovine isoleucyl-tRNA synthetase (IARS) disorder, a major cause of weak calf syndrome, is caused by a homozygous missense (c.235G>C) mutation in the bovine IARS gene of Japanese Black (JB) cattle, which was identified in 2013. However, the extent to which the carrier rate has changed at Kagoshima prefecture, Japan, and whether the carrier status is associated with any clinical or reproductive problems, have yet to be ascertained. In this study, using a real-time polymerase chain reaction-based genotyping assay, we determined the carrier rate in a regional JB cow population at Kagoshima prefecture. Comparative analyses were performed on the metabolic profile test (MPT) results and reproductive performance data obtained for heterozygous carrier and homozygous wild-type cows. In 2009 and 2018, DNA samples were collected from 130 and 462 clinically healthy JB cows, respectively, in Kagoshima prefecture. MPT results and reproductive performance data were evaluated for 62 cows, comprising four heterozygous carriers and 58 wild-type cows. Genotyping revealed that the carrier rate was 6.9% in 2009 and 1.5% in 2018, the difference of which was statistically significant (P<0.005). There were no statistically significant differences between the carrier and wild-type cows with respect to either MPT results or reproductive performance, indicating that the carrier cows have necessary IARS activity to maintain minimal health and reproductive potential.