Swine dysentery in a sow herd

Summary

An acute outbreak of swine dysentery (Doyle) on a farrowing farm is described. Besides clinical signs of enteritis a general loss of condition was seen throughout the herd. This resulted in a decreased fertility and breeding performance among sows and an increase in piglet mortality. Several dehydrated sows aborted.

The outbreak was stopped by oral treatment with lincomycin/spectinomycin 1:1. In the course of the treatment all animals and buildings were washed and disinfected. The use of pharmacotherapeutics in treating swine dysentery is discussed with emphasis on the involuntary induction of carriers.     

Multiresistant Brachyspira hyodysenteriae in a Dutch sow herd

This case study describes the isolation ofa multiresistant strain ofBrachyspira hyodysenteriae in April 2007 in a Dutch sow herd with recurrent diarrhoea. Examination of faecal samples taken from 7-month-old breeding gilts with diarrhoea revealed the presence of resistance against tiamulin, lincomycin, tylosin, doxycycline, and tylvalosin (the active substance in Aivlosin) in four of five samples. Tiamulin resistance has not been reported in The Netherlands before. The repeated use of tiamulin on the affected farm was assumed to be the main cause of the development of resistance to the drug. The farmer was advised to adopt a medication strategy and to implement management practices that would prevent an ongoing cycle of infection on the farm. It is important that the Dutch swine industry appreciates that tiamulin-resistant strains of B. hyodysenteriae may be found on other farms as well. The appropriate and prudent use of antibiotics is essential in order to prevent the development of resistance against the last option left to cure B. hyodysenteriae infections: valnemulin.     

Review of mathematical models for sow herd management

This paper is a survey of the different sow models described in literature, which made use of different mathematical methodologies, and were intended for sow herd management. Models were discussed under a wide classification, that is, simulation and optimisation. The latter included linear programming and dynamic programming with Markov decision models and optimal control as major representative models. In a first stage we recalled general traits and modelling foundations of herd management models and later, different aspects of sow herd models published up to now were reviewed. Special attention is paid to main variables, source of parameters, validation, output and intended use. Most of such models have been developed as research tools and teaching aids. Actually, the increasing ability to represent complex systems is not corresponded with an augmentation of decision support tools including such complex models in field conditions. Thus, a need of new proposals dealing with transient situations and non-time homogeneous parameters was detected. The inclusion of variability-risk features and multicriteria decision methods was also of interest for practical purposes. Actual changes in the pig sector lead to expect new management herd models, in particular considering more than one herd at a time.     

Control charts applied to simulated sow herd datasets

Statistical control charts were used to detect process change in pig production. Two charts were tested to detect small deviations in production processes: the cumulative sum (CUSUM) control chart and the exponentially weighted moving average (EWMA) control chart. A Monte-Carlo simulation was used for developing an optimal design of the EWMA and the CUSUM charts. The traits piglets born in total and the return to oestrus rate were considered. Over a given time period, small shifts were purposely implemented to test the performance of the charts. The average time to signal (ATS) and false positive rate (FPR) were taken as classification parameters to evaluate the performance of the charts. All shifts in the number of piglets born in total were detected with CUSUM and EWMA control charts. The trait piglets born in total showed an ATS ranging from 1.3 (FPR = 33.5%) to 6.8 weeks (FPR = 1.2%) using the CUSUM chart. The EWMA chart presented an ATS which ranged between 2.0 (FPR = 14.9%) and 6.3 (FPR = 1.9%) weeks. The application of the CUSUM to the return to oestrus rate resulted in an ATS of 2.6 (FPR =  38.3%) to 15.6 weeks (FPR = 3.0%) and the EWMA chart produced a signal between 4.1 (FPR = 14.5%) and 16.4 weeks (FPR = 1.4%). Both charts appear to be useful tools for tracking commercial swine farm processes and detecting emerging change in process performance.     

Porcine Parvovirus infection: review and diagnosis in a sow herd with reproductive failure

In a commercial swine herd a rise was noted during the summer of 1981 in the number of repeat breeders, mostly four to eight weeks after serving. During the autumn there was a decrease in the litter size at birth and an increase in the number of stillborn and mummified piglets. Several gilts and sows showed a seroconversion against Porcine Parvovirus (PPV), determined by the Haemagglutination Inhibition test (HI-test). Characteristic pathological findings were seen in some maturely stillborn and neonatally decreased piglets (up to an age of 28 days); hepatic congestion and necrosis, accummulation of fluid in body cavities, myocarditis, and encephalitis were the most prominent features. Serological tests for antibodies in blood samples of one sow and body fluids of two stillborn piglets were suggestive of Porcine Parvovirus as the aetiological agent.     

Low reproductive performance and high sow mortality in a pig breeding herd: a case study

Sow performance is a key component of the productivity of commercial pig farms. Reproductive failure in the sow is common in pig production. For every 100 sows served, 89 should farrow. In absence of specific diseases such as porcine parvovirus, pseudo-rabies, swine fever, leptospirosis and brucellosis, management failures are the most important causes of loss. A syndrome associated with reproductive inefficiency, and post-service vaginal discharge and high sow mortality in a commercial pig farm is described. Pregnancy failures exceeded 20% and sow mortality exceeded 12% for two consecutive years. The abnormal post-service vaginal discharge rate was 1.7% during the period of investigation.An investigation involving an analysis of farm records, a review of breeding management practices, clinical examinations, laboratory analysis and examination of urogenital organs was conducted.The main contributing factors found were a sub-optimal gilt breeding management, an inadequate culling policy in combination with a sub-optimal culling rate and the presence of cystitis in more than 1% of the urogenital organs examined. The high sow mortality rate was related to an aged breeding herd.A control programme was recommended based on management changes involving oestrus detection, movement of gilts post-service, hygiene in the service area, boar exposure post-service and urinary acidification. This programme failed to increase the farrowing rate due to incomplete implementation of the recommendations made. The farrowing rate increased to 86.5% subsequent to a farm manager change in January 2005, which resulted in complete implementation of the control programme.     

Identification and control of paratuberculosis in a large goat herd

Mycobacterium paratuberculosis infection was detected in 2 goats in 1974 and in 5 goats in 1975; 5 of which were from a single herd. The magnitude of the subsequent epizootic in the goat herd was not recognized until 1977, when results of bacteriologic culture of fecal and tissue specimens, antibody determinations (agar-gel immuno-diffusion test), and histopathologic studies became available. By 1984, paratuberculosis had been diagnosed in 124 goats. Nearly all the goats were being used in antiserum production and had been given Freund complete adjuvant and human antigens. From 1974 to 1986, herd size varied from 100 to 300. The yearly incidence of paratuberculosis decreased from 13.2% (27 of 204 goats) in 1977 to 0% in 108 goats in 1985. The prevalence was higher in does. In goats that arrived on the farm in 1975 and before, 49 of 121 (40.5%) does developed paratuberculosis vs 41 of 120 (34.2%) wethers. In goats arriving on the farm in 1976 and after, 25 of 274 (8.5%) does and 9 of 216 (4.1%) wethers developed paratuberculosis. The average incubation period was approximately 4 years from arrival on the farm in every year except 1978, regardless of whether the goat was born on the farm or was purchased elsewhere.(ABSTRACT TRUNCATED AT 250 WORDS)     

猪钩端螺旋体病的诊断与防制

1　发病情况　 1 998年至 2 0 0 2年 6月底 ,我县兽医临床共诊疗 (包括尸体剖检 )猪病 1 62 8例 (次 )。其中 ,钩端螺旋体病为 5 0例 (次 ) ,分别为 :1 998年 4例 (次 ) ;1 999年 8例 (次 ) ;2 0 0 0年 1 0例 (次 ) ;2 0 0 1年 1 4例 (次 ) ;2 0 0 2年 1～ 6月 1 4例 (次 )。这 4年半 ,该病占猪病的平均发病率为 3.0 7% ,其中 1 998年占猪病的 0 .99% ,1 999年 2 .0 8% ,2 0 0 0年 2 .74% ,2 0 0 1年 4.31 % ,2 0 0 2年上半年 9.46% ;检疫站宰后检出为 1 998年 2头 ,1 999年 4头 ,2 0 0 0年 5头 ,2 0 0 1年 6头 ,2 0 0 2年 1～ 6月 6头 ,检…     

蓝狐钩端螺旋体病的诊治

钩端螺旋体病 ,是由一群致病性钩端螺旋体引起人和多种动物共患的传染病。本文所介绍的是蓝狐 (北极狐 )出血性黄疸钩端螺旋体病的诊治情况。1 990年初 ,莒县外贸公司良种场蓝狐正值春季发情配种季节 ,突发以短期发热后出现出血性黄疸、血尿、贫血、出血性素质、迅速消瘦衰竭而     

母猪子宫内膜炎的诊断与综合防制

20 0 0年 8月至 1 2月期间 ,广东某种猪场共有1 2 4头母猪发生较为严重的子宫内膜炎 ,由于母猪发情不正常甚至不发情 ,屡配不孕或流产 ,给该猪场造成巨大的经济损失。为了寻找真正的发病病因 ,我们从子宫内膜炎的患猪采取子宫炎性分泌物 ,经过病原的分离、鉴定及其致病性检验 ,     

Swine dysentery in a sow herd. I. Clinical manifestation and elimination of the disease with a combination of lincomycin and spectinomycin

An acute outbreak of swine dysentery (Doyle) on a farrowing farm is described. Besides clinical signs of enteritis a general loss of condition was seen throughout the herd. This resulted in a decreased fertility and breeding performance among sows and an increase in piglet mortality. Several dehydrated sows aborted. The outbreak was stopped by oral treatment with lincomycin/spectinomycin 1:1. In the course of the treatment all animals and buildings were washed and disinfected. The use of pharmacotherapeutics in treating swine dysentery is discussed with emphasis on the involuntary induction of carriers.     

母猪乳房炎的综合防控措施

乳房是合成与分泌乳汁并通过哺育完成母子间营养物质传递的器官。母猪泌乳期乳房合成乳汁,及时被吸吮或挤出,乳房才能继续保持泌乳的功能。在健康状态下,母猪连续3 d奶水没有被排出时,乳区的乳汁会被机体吸收,该乳区不再有泌乳功能。在病理情况下,乳汁不能被吸收利用时,乳房将会发生炎症。     

母猪子宫内膜炎的综合防控措施

子宫是孕育胎儿的器官,健康的子宫是动物繁殖功能得以实现的前提。现代化养猪场,为保证母猪的繁殖性能,不断通过育种提高产仔数、通过早期断奶降低非生产天数,使母猪子宫超负荷的工作;另一方面,为了提高产仔数,多次重复配种。这都增加了母猪罹患子宫炎的风险。子宫内膜炎严重影响母猪的繁殖性能,增加生产成本,降低养殖效益。子宫内膜炎是指细菌侵入子宫内膜而发生炎症,是繁殖母猪常见的疾病,后备母猪配种前很少发生,配种后的各生理阶段,均有可能发生子宫内膜炎。     

Progression of Coxiella burnetii infection after implementing a two-year vaccination program in a naturally infected dairy cattle herd

Background

The high prevalence of Coxiella burnetii infection in dairy cattle herds recently reported and the long survival time of the bacterium in the environment pose a risk to human and animal health that calls for the implementation of control measures at herd level. This study presents the results of a 2-year vaccination program with an inactivated phase I vaccine in a Spanish dairy herd naturally infected with C. burnetii. Calves older than 3 months and non-pregnant heifers and cows were vaccinated in April 2011 and the farm was subsequently visited at a monthly basis for vaccination of recently calved cows and calves that reached the age of 3 months. Annual booster doses were given to previous vaccinated animals as well. The effectiveness of the vaccine was assessed in terms of level of C. burnetii shedding through milk and uterine fluids and environmental contamination as determined by polymerase chain reaction (PCR).

Results

The percentage of shedder animals through uterine fluids and milk progressively decreased, and C. burnetii DNA load in bulk-tank milk samples was low at the end of the study. The average seroconversion rate in not yet vaccinated animals, which acted as control group, was 8.6% during the first year and 0% in the second year. DNA of C. burnetii was found in aerosols and dust samples taken in the calving area only at the beginning of the study, whereas slurry samples remained C. burnetii PCR positive for at least 18 months. Multiple Locus Variable number tandem-repeat Analysis identified the same genotype in all C. burnetii DNA positive samples.

Conclusions

In the absence of any changes in biosecurity, the overall reduction of C. burnetii infection in animals to 1.2% milk shedders and the reduced environment contamination found at the end of the study was ascribed to the effects of vaccination together with the culling of milk shedders. Vaccination has to be planned as a medium-long term strategy to suppress risks of re-infection.