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1.
Sources of stray electrical leakage from Power Supply Authority alternating current (AC), fence energiser pulses and randomly generated pulses and spikes on 55 dairy farms in the Waikato area were identified between December 1986 and March 1988. The electrical measurements were made using a specifically designed voltmeter able to detect voltages between 0.1V and 1500V, from single voltage spikes of two microseconds oi- greater duration from direct current (DC) as well as 50 Hz AC. Ninety-five sources of stray voltage were identified, and 53 per cent of properties had more than one source of >0.5V. The major source was from electric fence energisers. Rotary platform parlours were among the commonest sources of random or transient voltage spikes. Leakage of AC into one or other of the components of the milk transport system such as vat, plate cooler, milk lift pump and milk line was common. Owners acknowledged the improvements in milk production, reproductive performance and growth rate of calves after reduction of the exposure of dairy cattle to stray electrical leakage. A representative summary of five case records helps define the range of improvement that may possibly be achieved. 相似文献
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Sources of stray electrical leakage from Power Supply Authority alternating current (AC), fence energiser pulses and randomly generated pulses and spikes on 55 dairy farms in the Waikato area were identified between December 1986 and March 1988. The electrical measurements were made using a specifically designed voltmeter able to detect voltages between 0.1V and 1500V, from single voltage spikes of two microseconds or greater duration from direct current (DC) as well as 50 Hz AC. Ninety-five sources of stray voltage were identified, and 53 per cent of properties had more than one source of >0.5V. The major source was from electric fence energisers. Rotary platform parlours were among the commonest sources of random or transient voltage spikes. Leakage of AC into one or other of the components of the milk transport system such as vat, plate cooler, milk lift pump and milk line was common. Owners acknowledged the improvements in milk production, reproductive performance and growth rate of calves after reduction of the exposure of dairy cattle to stray electrical leakage. A representative summary of five case records helps define the range of improvements that may possibly be achieved. 相似文献
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为探究非遗传因素影响荷斯坦奶牛在群寿命的规律,了解奶牛利用情况,本研究收集了新疆昌吉地区规模化牛场2011-2018年4 057头荷斯坦奶牛的离群、生产性能数据。运用SAS 9.2软件分析了场、离群年份、离群季节、淘汰类型对荷斯坦奶牛离群胎次、在群天数的影响,并进行最小二乘及多重比较分析。结果表明,离群年份和淘汰类型均对离群胎次和在群天数有极显著影响（P<0.01）;场、离群季节对离群胎次和在群天数影响不显著（P>0.05）。随着离群年份的增加,离群胎次呈先下降后上升再下降的趋势,2016年的离群胎次最高,为3.222胎,高于其他年份（P<0.01）;2018年的离群胎次最低,且极显著低于其他年份（P<0.01）;2015年在群天数高于其他年份,2018年的在群天数最低,为1 890.692 d,且极显著低于其他年份（P<0.01）;根据季节的不同,春季的离群胎次低于其他季节,在群天数极显著或显著低于秋季和冬季（P<0.01;P<0.05）;淘汰类型中肢蹄类疾病的离群胎次和在群天数极显著高于其他各类疾病（P<0.01）,乳房类疾病极显著低于其他各类疾病（P<0.01）。因此,通过分析上述各非遗传因素对离群胎次和在群天数的影响,可以为规模化牧场奶牛日常管理提供理论依据,从而提高奶牛综合使用效率,延长奶牛寿命。 相似文献
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J. Hultgren 《Veterinary research communications》1990,14(4):287-298
The literature on the electrical properties of the body and sensitivity to steady electric current in humans and farm animals is reviewed and the problem of stray voltage is examined. Stray voltage poses a problem to animal health and protection in cattle and pigs and possibly also in other animals. Dairy cattle can perceive alternating currents exceeding 1 mA between the mouth and all four hooves. Behavioural effects in cows usually occur above 3 mA. In practice, the major influence on dairy cows appears to be behavioural. In experimental research on sensitivity to electric current, the effects studied should be related primarily to the actual current densities or electric fields in the affected tissues rather than to the total voltages applied. Under normal conditions, herdsmen are less likely to be affected by stray voltage than their animals. 相似文献
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为了解我国部分省（区）规模化牧场中牛副结核病的流行情况,对2015年采集自内蒙古自治区、黑龙江省、湖北省、四川省、安徽省、江苏省6个省（区）规模化牧场的16 172份奶牛血清样品进行了副结核分枝杆菌抗体检测。结果显示,检测样品的副结核分枝杆菌抗体总阳性率为2.59%,6个省（区）的抗体阳性率分别为：内蒙古自治区2.09%、黑龙江省3.90%、湖北省2.05%、四川省5.23%、安徽省8.00%、江苏省1.22%;不同饲养规模牧场的阳性率分别为：大型牧场2.42%、中型牧场2.01%、小型牧场4.32%,小型牧场的阳性率极显著高于中型牧场（P〈0.01）,显著高于大型牧场（P〈0.05）。综上提示,我国安徽省、四川省、黑龙江省等地规模化牧场奶牛的副结核分枝杆菌感染率较高,大型牧场和中型牧场的阳性率低于小型牧场。该次流行病学调查结果可为我国牛副结核病的预防和控制提供参考数据。 相似文献
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The prevalence of chronic wasting in cattle in March and April 2000 was studied on 218 dairy farms with a history of health problems accompanied by wasting, following reports in the media suggesting that chronic wasting was a substantial problem on Dutch dairy farms. A telephone call revealed that the health problems had resolved on 41 farms; 16 of these farms had culled all cattle. Two farmers refused co-operation. On the remaining 175 farms the animals were inspected and was completed a questionnaire. A high percentage of culling for of health reasons (on average 18.1% of young stock and adult cattle) and an increased mortality rate (4.8%) were reported on the farms visited. In only two of the 175 inspected herds, more than 20 percent of cattle were found showing signs of wasting. These two herds were identified as 'chronic wasting herds'. The prevalence of such herds was low in this study. Consequently, it is likely that there were very few 'chronic wasting herds' among the whole Dutch dairy population in March/April 2000. 相似文献
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A survey was performed to characterize the dairy production, educational experiences, decision making practices, and income
and expenses of dairy farms and to determine any differences of these practices among two dairy farm populations. Farm groups
were identified as farms from the Muaklek dairy cooperative (Muaklek farms) and farms from other dairy cooperatives (Non-Muaklek
farms). In April, 2006 questionnaires were distributed to 500 dairy farms located in Lopburi, Nakhon Ratchisima, and Saraburi
provinces. A total of 85 farms completed and returned questionnaires. Means and frequencies were calculated for questions
across categories and Chi-square tests were performed to determine differences among Muaklek and Non-Muaklek farms. Results
showed that most farms from both groups had a primary or high school educational level, used a combination confinement and
pasture production system, gave a mineral supplement, raised their own replacement females, milked approximately 16 cows/day,
used crossbred Holstein cows (75% Holstein or more), and mated purebred Holstein sires to their cows. More Non-Muaklek farms
(P < 0.05; 80%) used a combination of genetic and phenotypic information when selecting sires than Muaklek farms (54%). Monthly
profit per lactating cow, were 1,641 and 1,029 baht for Muaklek and Non-Muaklek farms, respectively. Overall, information
from the study should be useful for dairy cooperatives and other dairy organizations when training farmers in the future and
furthering dairy production research in Thailand. 相似文献
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运动场是保障奶牛生产力和动物福利的重要设施。2021年6—9月,频繁降雨导致北京地区多家奶牛场的运动场积水,为奶牛生产力、奶牛场生防安全、环境卫生、运动场舒适性和动物福利带来隐患。通过线上线下结合,调研了北京地区27 家规模化奶牛场的运动场防雨、排水及垫料现状。结果表明：调研奶牛场中,88.90%奶牛场配备了运动场,其中83.33%奶牛场通过设置地面倾角、设置挡雨棚、雨污分离槽及布设排水管道（沟渠）、雨后水泵排水等方式实现运动场防雨及排水。此外,针对运动场建设、运动场防雨、运动场舒适性展开讨论,以期改善运动场防雨现状,满足集约化奶牛场可持续发展需求和提升动物福利。 相似文献
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Kenji Murakami Sota Kobayashi Misako KonishiKen-ichiro Kameyama Takehisa YamamotoToshiyuki Tsutsui 《Veterinary microbiology》2011
A seroepidemiological survey of bovine leukemia virus (BLV) infection was conducted in Japan in 2007 using an enzyme-linked immunosorbent assay (ELISA) and an agar gel immunodiffusion (AGID) test. A total of 5420 cattle (dairy, 3966; breeding beef, 797; fattening beef, 657) from 209 farms in seven prefectures in Japan were tested. The overall prevalence of BLV infection was 28.6%. The prevalence of BLV infection in dairy cattle (34.7%) was higher than for both fattening beef cattle (7.9%) and breeding beef cattle (16.3%). Age-specific prevalence showed that BLV prevalence increased with age in all types of cattle and was notably different between dairy and beef cattle under 1 year of age. Among 207 farms, 141 herds (68.1%) had one or more positive animals. The proportion of these positive farms was significantly higher among dairy farms (79.1%) than among beef breeding farms (39.5%) and beef fattening farms (51.9%) (P < 0.001). Dairy farms (40.5%) also showed a significantly higher within-herd prevalence than beef breeding (27.4%) and fattening (14.9%) farms (P = 0.001). This study indicated that BLV is more widely spread in dairy cattle than in beef breeding cattle in Japan. Given the prevalence of BLV infection in dairy and beef cattle was 8- and 1.7-fold higher, respectively, than rates previously found in 1980–1982, BLV appears to be spreading particularly among the dairy cattle population during the last two decades. Further investigation is required to determine the risk factors necessary to control BLV infection that take into account the different farming practices that exist between dairy and beef sectors. 相似文献
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为探索奶牛临床型乳房炎的发病情况与泌乳量、泌乳期、季节之间的联系,以河北保定地区5个奶牛场为例进行调查研究。通过对调查结果的统计分析,结果显示：奶牛乳房炎多发生在泌乳90~150 d,泌乳天数越长发病头数越多;从产奶量来看,泌乳量越高发病牛比例越高;从发病季节来看,奶牛乳房炎在秋季发病率高,春季、夏季和冬季发病率低。 相似文献
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van den Brom R van Engelen E Luttikholt S Moll L van Maanen K Vellema P 《The Veterinary record》2012,170(12):310
In 2007, a human Q fever epidemic started, mainly in the south eastern part of The Netherlands with a suspected indirect relation to dairy goats, and, to a lesser degree, to dairy sheep. This article describes the Q fever prevalences in Dutch dairy goat and dairy sheep bulk tank milk (BTM) samples, using a real-time (RT) PCR and ELISA. Results of BTM PCR and ELISA were compared with the serological status of individual animals, and correlations with a history of Q fever abortion were determined. When compared with ELISA results, the optimal cut-off value for the RT-PCR was 100 bacteria/ml. In 2008, there were 392 farms with more than 200 dairy goats, of which 292 submitted a BTM sample. Of these samples, 96 (32.9 per cent) were PCR positive and 87 (29.8 per cent) were ELISA positive. All farms with a history of Q fever abortion (n=17) were ELISA positive, 16 out of 17 were also PCR positive. BTM PCR or ELISA positive farms had significantly higher within-herd seroprevalences than BTM negative farms. In the south eastern provinces, the area where the human Q fever outbreak started in 2007, a significantly larger proportion of the BTM samples was PCR and ELISA positive compared to the rest of The Netherlands. None of the BTM samples from dairy sheep farms (n=16) were PCR positive but three of these farms were ELISA positive. The higher percentage of BTM positive farms in the area where the human Q fever outbreak started, supports the suspected relation between human cases and infected dairy goat farms. 相似文献
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The associations between milk production, milk composition and Salmonella in the bulk milk supplies of dairy farms in Ontario. 
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下载免费PDF全文 The purpose of this study was to assess changes in dairy herd milk production and milk composition associated with changes in Salmonella contamination of bulk milk on dairy farms in southwestern Ontario. Twenty-three dairy farms that had submitted milk filters for culture from which Salmonella were isolated (cases) and 23 farms that submitted Salmonella-negative milk filters (controls) were included in the study. The rolling herd averages for milk and fat of case and control farms for the months of December 1985, December 1986 and April 1987 were compared and no significant differences were detected. Case and control farms were divided into three groups (A,B,C) on the basis of Salmonella culture results of milk filters submitted at various time periods throughout the study. Daily and monthly changes in milk production and composition parameters that reflected the time periods of milk filter culture were compared. The following unconditional associations between a changing Salmonella infection status on dairy farms and changes in milk production or composition variables were significant (p less than or equal to 0.05): group A: case farms had higher plate loop counts than control farms; group B: case farms had younger cows than control farms; group C: case farms had cows with longer average days in lactation than control farms. After analytical control of confounding variables, the disappearance of Salmonella from bulk milk supplies of dairy farms was associated with a decrease in percent fat and in somatic cell count. 相似文献
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[目的]以新疆天山北坡昌吉市郊区散养和规模化奶牛养殖场为对象,对奶牛体况、环境压力、牛体污染、乳房炎、血液性状等健康指标进行了调查分析。[方法]选择奶牛散养户5户和规模化奶牛养殖场的干奶期、泌乳初期和泌乳中期奶牛,分别于冬季和夏季进行体况、环境压力、乳房炎、血液性状等健康指标的测定与分析。[结果]干奶牛体况值略低于奶牛体况评分的理想值（3．5）;奶牛呼吸数夏季增加,超过50次／min;规模化奶牛养殖场的污染程度比散养户要高,尤其是冬季50％以上奶牛的牛体污染评价值高于3。规模化奶牛养殖场的奶牛乳房炎发病率达40％,并发现了感染金黄色葡萄球菌的病例。低血糖奶牛占一半以上．特别是干奶期比较突出。血液Alb和BUN偏低,干奶期牛群的BUN大多低于7mg／dL。血液中谷草转氨酶（AST）偏高,谷氨酰转肽酶（GGT）偏低,Ca含量正常,Mg含量较低。[结论]规模化奶牛养殖场存在干奶期奶牛能量及蛋白质不足;冬季环境恶劣并且污染程度较重,牛体污染及乳房炎发病率高;飞节损伤引起的肝功能衰退等现象,需要改进。 相似文献
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Antimicrobial susceptibility of Escherichia coli isolates from dairy farms using organic versus conventional production methods 总被引：3，自引：0，他引：3
Sato K Bartlett PC Saeed MA 《Journal of the American Veterinary Medical Association》2005,226(4):589-594
OBJECTIVE: To compare antimicrobial susceptibility patterns of Escherichia coli isolates cultured from fecal samples from cows and calves on dairy farms that used organic (ie, no or severely limited antimicrobial use) versus conventional production methods. DESIGN: Cross-sectional study. SAMPLE POPULATION: Fecal samples from 10 cows and 10 calves on each of 30 organic dairy farms and 30 neighboring conventional dairy farms in Wisconsin. PROCEDURE: E. coli isolates obtained from the fecal samples were tested for susceptibility to 17 antimicrobials by means of a microbroth dilution test. Prevalence of antimicrobial resistance was compared between organic and conventional dairy farms. RESULTS: E. coli was isolated from 1,121 (94%) fecal samples. Farm type (organic vs conventional) and animal age (cow vs calf) were significantly associated with odds that E. coli isolates would be resistant to various antimicrobials. After controlling for age, logistic regression analyses indicated that isolates from conventional dairy farms had significantly higher rates of resistance to ampicillin, streptomycin, kanamycin, gentamicin, chloramphenicol, tetracycline, and sulfamethoxazole than did isolates from organic dairy farms. However, no significant differences were detected for the 10 other antimicrobials that were tested. CONCLUSIONS AND CLINICAL RELEVANCE: Results indicated that compared with isolates from conventional dairy farms, E. coli isolates from organic dairy herds have significantly lower prevalences of resistance to 7 antimicrobials; however, prevalence of resistance was not significantly different for 10 other antimicrobials. Resistance was more common for isolates from calves than for isolates from adult dairy cows. 相似文献
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内蒙古地区奶牛病毒性腹泻/黏膜病血清流行病学调查 《畜牧与饲料科学》2014,35(3):106-106
应用ELLSA试验对来自内蒙古地区17个大﹑中﹑小型奶牛场的2391份牛血清样品进行了牛病毒性腹泻/黏膜病抗体检测,并对其中222份抗体阴性牛应用ELISA试验进行牛病毒性腹泻/黏膜病的抗原检测。结果表明：17个奶牛场均检出BVDV抗体阳性,共检出阳性血清2125份,阳性率最高达100%,最低为46.8%,平均为88.9%。对14个奶牛场进行了BVDV抗原检测,在5个奶牛场检出BVDV抗原阳性,阳性率为3.6%（8/222）。表明内蒙古地区奶牛场普遍存在牛病毒性腹泻/黏膜病感染,感染率较高,并且牛群中存在持续性感染（PI）牛。 相似文献
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