上海地区奶牛场球虫感染现状调查

为了解上海地区规模化奶牛场奶牛感染球虫的情况,我们对上海地区17个牧场的奶牛球虫感染状况进行了随机抽样调查,分别于2005年10月和2006年4月按不同年龄阶段共采集粪样316份。调查结果显示:17个牧场都有球虫感染,1个牧场的感染率最高达70%,其中10月份调查的感染率为36.45%,4月份调查的感染率为40.05%,两者没有明显的差异;从不同年龄阶段奶牛的感染情况来看,发现感染率最高的2个阶段为0~2月龄和4~6月龄,感染率高达为45%,感染率最低的年龄阶段为12月龄以上的奶牛,感染率为25%;从感染强度来看,上海地区牧场奶牛的球虫感染强度大部分平均OPG低于1000,占58.82%,只有一个牧场的平均OPG比较高,为14250;从本次调查结果发现有6种艾美耳球虫(Eimeria),分别是牛艾美耳球虫(E.bovis)、椭圆艾美耳球虫(E.ellipsoidallis)、邱氏艾美耳球虫(E.zurnii)、怀俄艾美耳球虫(E.wyomingensis)、柱状艾美耳球虫(E.cylindrica)、亚球形艾美耳球虫(E.subspherica),优势虫种为牛艾美耳球虫、邱氏艾美耳球虫、椭圆艾美耳球虫,其他3种球虫所占比例较少。     

新疆乌鲁木齐绵羊球虫感染调查及驱虫试验

试验旨在对新疆乌鲁木齐绵羊球虫感染季节动态变化进行调查及药物驱虫试验。采用饱和盐水漂浮法和麦克马斯特计数法计算感染率和感染强度,使用磺胺二甲嘧啶进行驱虫试验,计算卵囊减少率和转阴率,用SPSS 17.0软件分析成年羊和羔羊驱虫前后平均OPG。结果表明,绵羊总感染率为71.38%,夏季感染率为65.28%,秋季感染率为78.24%,冬季感染率为62.18%,春季感染率为81.58%;羔羊感染率最高;经形态学鉴定共发现7种绵羊球虫,感染单一虫种的占42.75%,感染2~4种的占53.94%,感染5种以上的占3.31%。成年羊高剂量组的卵囊减少率和转阴率最高,与中、低剂量组相比,驱虫效果较好;羔羊使用低剂量就能取得明显的驱虫效果。因此针对新疆乌鲁木齐绵羊球虫感染,今后应做好羔羊及春、秋季节的驱虫工作,使用磺胺二甲嘧啶进行驱虫,能取得较好的驱虫效果。     

提高寒冷季节乳牛配种受胎率的措施

1　冬、春季受胎率低的原因分析由于冬季寒冷 ,气温偏低 ,牛体热量散失增加 ,用于防寒方面的能量消耗加大 ,影响乳牛正常性机能活动 ,导致受胎率下降。饲料单一 ,供给量不足。特别是缺乏富含维生素的饲料 ,时间一长 ,不仅使产奶量和发情受影响 ,也导致排卵机能失调 ,奶牛表现发情不排卵或排卵时间延后等现象 ,失去了正常的受胎机会。由于天气寒冷 ,配种场所缺乏取暖设备 ,虽在室内配种 ,但气温在 0℃以下 ,解冻后的冷冻精液温度在 36～38℃ ,二者温差大 ,降低了精子活力和存活时间 ,甚至造成精子冷休克。冬季昼短夜长 ,光照严重不足 ,乳牛舍…     

石河子地区绵羊球虫感染季节调查

在石河子市对绵羊球虫卵囊的感染季节动态进行了调查，结果表明，绵羊球虫卵囊在羊的不同生长期检出率和检出数量均不相同，在新羔羊4月初粪便中出现球虫卵囊，4月下句检出率大大提高，夏季时达以数量高峰，以后逐渐下降，甚至消失，在下一个产羔季节到来之前，虽然是隆冬季节，产前母羊粪便中又出现球虫卵囊，成为新一代羔羊球是现的传染源。     

一氧化氮与球虫感染

一氧化氮(NO)是一种气体自由基,化学性质非常活泼。现已证实NO能在动物机体的许多组织中合成。在机体内,NO的作用广泛,它不但参与调节血管平滑肌松弛、血小板聚集以及信号转导,而且还是机体免疫系统的调节分子和效应分子,在微生物和寄生虫感染以及宿主免疫过程中发挥着一定的作用。本文就NO的生物特性、作用机制及其与球虫感染的关系和影响因素进行简要综述。     

乳牛附红细胞体感染的诊治

附红细胞体是一种人畜共患的疾病 ,现已证实附红细胞体可感染牛、羊、猪、犬、猫、鹿等动物。该病原体呈圆形、卵圆形 ,它们单个或成链状附着在红细胞表面 ,或围绕在整个细胞周围 ,在血浆中可看到自由运动的附红细胞体。此病在我国猪群中发生较多 ,自 1999年以来 ,全国各地许多地区都有发生 ,但牛附红细胞体病报道较少 ,笔者在临床诊治中遇到此病例 ,将有关诊治过程总结如下 ,以供同行参考。1　传播途径此病有水平传播和垂直传播两种方式 ,可通过吸血昆虫、螨虫、疥癣、空气飞沫、水源、饲草、母体胎盘、血液等传播。2　临床症状牛附红细胞…     

柔嫩艾美尔球虫和巨形艾美尔球虫混合感染致病性研究

材料和方法１．试验动物ＡＡ肉鸡，购自江苏省家禽研究所，出壳后运回实验室饲养在杀灭卵囊的笼具中至１５日龄，经数次粪检未见卵囊后供试验。２．球虫卵囊为本教研室分离鉴定的纯种柔嫩艾美尔球虫和巨形艾美尔球虫孢子化卵囊，４℃保存。３．试验分组挑选体况相近的１５日龄ＡＡ肉鸡５０羽，分成５组。第１组为不感染对照组；第２组为单种球虫感染组，每羽经口接种柔嫩艾美尔球虫孢子化卵囊１万个；第３、４和５组为混合感染组，每羽分别同时感染柔嫩艾美尔球虫和巨形艾美尔球虫孢子化卵囊：０．５＋５万、１＋１０万和２＋２０万个。４．…     

球虫感染与家禽生理生化变化

<正> 球虫感染可引起家禽发生一系列生理生化变化,其中包括组织器官生理常数及血液成分的改变,某些物质及元素代谢的异常和内分泌系统功能的变化等。深入研究这些变化,不但对于阐明球虫病病理生理学有重要意义,同时对通过改变日粮组成或使用某些有添加物质来减轻或消除球虫病所造成的某些有害影响而减轻或挽回经济损失也十分有益。本文的目的在于     

青海省格尔木市乳牛新孢子虫病的血清学调查

用重组蛋白GST-NcSAG1t作为ELISA诊断抗原,对格尔木市乳牛犬新孢子虫病进行了调查.结果,从 35份乳牛血清样品中检出犬新孢子虫抗体阳性血清4份,阳性率为11.42%.检测结果说明,青海省格尔木市饲养的乳牛牛群中存在犬新孢子虫感染.     

Follicular cysts in dairy cows

Follicular cysts are the most critical reproductive disorder in dairy cows and disturb the normal ovarian cycle, resulting in a prolonged interval from calving to conception. Therefore, this condition causes significant economic losses to the dairy industry. Two direct causal factors for cysts are suggested in this review; ovulation disorder and the delay of regression. Ovulation disorder has been accepted to be a main etiology of cystic follicle. This seems to be caused by the deficiency of positive feedback of estrogen to the hypothalamus, leading to the lack of luteinizing hormone surge. On the other hand, if a large anovulatory follicle is regressed immediately after the failure of ovulation, its follicle does not continue to grow, resulting in no cystic follicle being formed. Therefore, it is proposed that another cause of a cystic follicle is the delay (or absence) of the degeneration system of the follicle. This review will introduce these two causes separately, referring to recent advances in understanding the follicular cyst in dairy cows.     

Characterization of ruminal dynamics in Holstein dairy cows during the periparturient period

We used four pregnant Holstein cows to delineate ruminal adaptations as cows transitioned from one lactation to the next. Cows were fed typical diets through far-off and close-up dry periods and lactation. We measured ruminal characteristics on day 72 (late lactation), 51 (far-off dry), 23 and 9 (close-up dry) prepartum and on days 6, 20, 34, 48, 62, 76 and 90 postpartum (early lactation). Measurements included: ruminal fill (weight of actual contents), ruminal capacity (volume of rumen when fully filled), digestibilities and ruminal passage rates. Ruminal capacity tended to increase linearly during early lactation but was stable during dry and transition periods. Both total and liquid fill decreased linearly during the dry period, increased across parturition, and increased linearly through early lactation. Dry matter fill decreased as cows were fed the close-up diet at day 23 prepartum then increased near parturition and continued to increase across early lactation. Solid passage rate was greatest when cows were fed the close-up diet, and decreased throughout the transition period. In lactation, solid passage rate responded quadratically with peak at day 48 followed by decreases through day 90 postpartum. Liquid passage increased linearly across the transition period. Total tract organic matter digestibilities increased linearly over the dry period with significant increases prior to or immediately after parturition, then they remained relatively stable over early lactation until they increased at day 90. Fibre digestibilities demonstrated quadratic responses over early lactation, being higher on day 6 and day 90 than at other times. Starch digestibilities decreased linearly across both the dry and transition periods with decreases in lactation until day 62 followed by increases until day 90. High producing lactating dairy cows go through a multitude of ruminal adaptations, in terms of digestion, passage, capacity and fill, as they transition from one lactation to the next.     

Gossypol pharmacokinetics in mid-lactation Brown swiss dairy cows

A bolus equivalent to 450 ppm (dosage based on average feed intake for lactating dairy cows of similar mass) of gossypol was administered orally to three Brown Swiss dairy cows in mid lactation daily for a 7-day treatment period. Blood samples were taken daily during a 2-day pretreatment period, the 7-day treatment period and a 6-day recovery period. The serum recovered from the cows was stored at -20°C until analysis for extractable gossypol content. The highest concentration of gossypol (a mean of 0.53 g/ml serum) was attained in all the cows on day 6 of the treatment period, indicating that a steady-state condition had been reached before the end of the treatment period. The gossypol concentrations then gradually declined during the 6-day recovery period but never fell to the zero baseline. The cows exhibited terminal elimination half-lives of 67, 67.5 and 40 h. Gossypol elimination was best described by a bi-exponential decay curve in two cows and a mono-exponential decay curve in the remaining cow.     

不同生理状态乳牛卵巢卵母细胞基因的差异表达

为了研究不同生理状态下的卵巢卵母细胞基因的表达情况，采集乳牛的卵巢，分离了卵母细胞，以单个卵母细胞的mRNA作为模板，用设计的随机引物和锚定引物，采用一步法RT-PCR扩增了卵母细胞基因。经聚丙烯酰胺凝胶电泳检测，发现有功能黄体和无黄体卵巢卵母细胞基因的电泳条带之间无明显差异，对一条明显差异条带进行回收、纯化，将纯化的PCR产物连接到T载体，阳性克隆经鉴定后，进行测序和同源性比较。结果显示，与体外培养的牛早期胚胎的一条序列具有很高的同源性。     

Time course of changes in antioxidant activity of milk from dairy cows fed a trehalose‐supplemented diet

This study was to investigate the time course of changes to the antioxidant activity of milk from cows fed a trehalose‐supplemented diet, and to determine possible underlying mechanisms for observed changes. Six Holstein cows were used, and subjected to two experimental feeding periods consisting of a 1% trehalose‐supplemented diet for 10 days, followed by a basal diet only (no trehalose) for 10 days. 1,1‐Diphenyl‐2‐picrylhydrazyl (DPPH) radical scavenging activities in milk were gradually increased during the trehalose supplementation period and were highest at the end of the second period. However, trehalose was not detected in the milk and plasma of dairy cows fed a diet supplemented with trehalose for 10 days, indicating that the increased antioxidant activity in the milk of trehalose‐fed cows is not due to the direct transfer of trehalose to the milk. Plasma DPPH activities exhibited a similar time course to that seen for milk. Relative superoxide dismutase (SOD) activities in the rumen were higher 3 days after the end of trehalose supplementation than at any other time during the experimental periods. These results suggested that the improved antioxidant activity in milk and plasma of cows fed a trehalose‐supplemented diet was due to improved ruminal relative SOD activity.     

一起群发性奶牛尿素中毒的临床研究

2004年南京某奶牛公寓由于饲养户在奶牛饲料中添加尿素方法不当,引起群发性尿素中毒。该牛群共有奶牛87头,发病64头,药物治疗56头,治愈54头,死亡10头,均为成母牛。作者调查了发病牛群的病史、临床症状、病理变化、治疗情况,对中毒奶牛的血液进行生化分析,并与正常奶牛比较,结果血清谷草转氨酶(AST)、γ-谷氨酰转移酶(GGT)、碱性磷酸酶(ALP)、磷酸肌酸激酶(CK)、磷酸肌酸激酶同工酶(CK-MB)、肌酐(CRE)、尿素氮(UN)、葡萄糖(GLU)、乳酸脱氢酶(LDH-L)等差异极显著(P<0·01),尿素(UREA)、血清K等差异显著(P<0·05),这些指标活性升高说明病牛心肌、胃肠平滑肌、肝肾等存在与病死牛的病理变化相一致的损伤。     

Preanalytical factors affecting blood inorganic phosphate concentration in dairy cows

BACKGROUND: Hypophosphatemia is a condition that affects feed intake and milk production in dairy cows, and, to assess it, a precise biological parameter is needed. Plasma inorganic phosphate (Pi) can be used as a potential indicator of bioavailability of feed phosphorus in dairy cows. OBJECTIVE: The purpose of this study was to evaluate the effects of sample type (serum vs. plasma), blood sampling site (jugular vs. coccygeal), and morning feeding on blood Pi concentration in dairy cows. METHODS: Blood samples from 28 clinically healthy multiparous Holstein cows were analyzed for Pi concentration. The animals were sampled twice by coccygeal vessel into Vacutainer tubes both with and without sodium heparin, 3 hours after the morning feeding. In 4 additional cows, the concentration of Pi was measured in blood samples obtained simultaneously by jugular and coccygeal venipuncture into heparinized tubes before the morning feeding and 2, 4, and 6 hours after the feeding. The results were analyzed using parametric statistical tests. RESULTS: Serum and plasma concentrations of Pi were correlated (r(2) = 0.999, P < .0001), but serum Pi concentration was higher than plasma Pi (P < .02). Plasma Pi concentration 2 hours after feeding tended to be higher than that before feeding in jugular samples, but the difference was not significant. There was no significant variation in plasma Pi during the morning postfeeding times, although jugular concentrations were 19% lower than coccygeal (P = .04). CONCLUSION: To increase the precision of plasma Pi measurements as an indicator of bioavailability of feed phosphorus, sample type, sampling time, and site must be taken into account, to correctly interpret plasma Pi concentrations.     

奶牛亚临床酮病对乳房炎发病情况和抗氧化功能的影响

为研究奶牛亚临床酮病与乳房炎的关系以及血液中的酮体成分对奶牛抗氧化功能的影响,以156头健康荷斯坦奶牛为试验动物（SCC〈200000／mL）,共筛选亚临床酮病奶牛69头（1．0mmol／L≤BHBA〈2．6mmol／L）作为试验组,根据年龄、胎次、产奶量、泌乳天数配对的69头奶牛作为时照组（血液BHBA〈1．0mmol／L）,监测乳房炎发病情况并在各组中选取12头奶牛检测血液酮体水平和抗氧化指标。结果表明亚临床酮病奶牛试验期间乳房炎的发病率为43．48％,对照组试验期间乳房炎的发病率为31．88％,但差异不显著（P〉0．05）;试验组奶牛乳房炎高发期为分娩后3～6周,对照组奶牛乳房炎发病时间为分娩后5～8周,亚临床酮病发病后1～3周内为乳房炎的高发期,占试验组奶牛乳房炎总发病比例的73．33％,试验组和对照组病原菌的组成无显著差异（P〉0．05）;试验组奶牛血液中T—AOC显著低于对照组（P〈0．05）,GSH—PX活力、MDA和N0显著高于对照组（P〈0．05）,血液ACAC浓度与GSH—PX活力呈显著正相关（P〈0．05,r=0．595）,ACAC浓度与NO呈显著正相关（P〈0．05,r=0．655）,T—AOC与MDA呈显著负相关（P〈0．05,r=0．533）。结果表明奶牛亚临床酮病可以导致乳房炎的发病率升高,但不是主要影响因素,亚临床酮病对乳房炎病原体构成无影响;外周血酮体水平升高导致机体总抗氧化能力的降低并引起机体脂质过氧化反应;谷胱甘肽过氧化物酶在发挥抗氧化功能时具有一定的抵抗力和自我调节能力。     

The effect of life history events on carcass merit and price of cull dairy cows

Cull dairy cows contribute almost 10% of national beef production in the United States. However, different factors throughout the life of dairy cows affect their weight and overall body condition as well as carcass traits, and consequently affect their market price. Therefore, the objectives of this study were: (1) to assess relationships between price ratio and carcass merit of cull dairy cows sold through several sites of an auction market and (2) to investigate the effect of animal life history events and live weight on sale barn price (BP) and price ratio (as a measure of relative price), as an indicator of carcass merit. Data from 4 dairy operations included 3,602 cull dairy cow records during the period of 2015 to 2019. Life history events data were collected from each dairy operation through Dairy Comp software; live weight and price were obtained periodically from the auction market, and the carcass data were provided by a local packing plant. Cow price in dollars per unit of live weight ($/cwt) and price ratio were the 2 outcome variables used in the analyses. Price ratio was created aiming to remove seasonality effects from BP (BP divided by the national average price for its respective month and year of sale). The association between price ratio and carcass merit traits was investigated using canonical correlation analysis, and the effect of life history events on both BP and price ratio was inferred using a multiple linear regression technique. More than 70% of the cows were culled in the first 3 lactations, with an average live weight of 701.5 kg, carcass weight of 325 kg, and dressing percentage of 46.3%. On average, cull cows were sold at $57.0/cwt during the period considered. The canonical correlation between price ratio and carcass merit traits was 0.76, indicating that price ratio reflected carcass merit of cull cows. Later lactations led to lower BP compared with cows culled during the first 2 lactations. Injury, and leg and feet problems negatively affected BP. Productive variables demonstrated that the greater milk production might lead to lower cow prices. A large variation between farms was also noted. In conclusion, price ratio was a good indicator of carcass merit of cull cows, and life history events significantly affected sale BP and carcass merit of cull cows sold through auction markets.