首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献，搜索用时 31 毫秒
1.
Fattening-pigs carriers of Salmonella enterica are believed to be a main source of carcass and pork contamination at the later steps of the meat process. We did a prospective study in 2000-2001 in 105 French farrow-to-finish pig farms. In each farm, a batch of contemporary fattening pigs housed in the same room was followed throughout the fattening period. Salmonella shedding was assessed on environmental samples of faecal material (taken by means of pairs of gauze socks) analysed by classical bacteriological methods. 36.2% of the batches studied had at least one contaminated environmental sample and therefore were classified as Salmonella-shedding batches. Logistic regression was used to assess the association between managerial and hygiene practices and health status and the shedding risk at the end of the finishing period. Emptying the pit below the slatted floor after the previous batch of sows was removed and frequent removal of sow dung during the lactation period were protective. Presence of residual Salmonella contamination of the floor and pen partitions in the fattening rooms before loading the growing pigs also was a risk factor. The risk for Salmonella shedding at the end of the fattening period was increased when dry feed (versus wet feed) was provided during the fattening period. Lastly, Lawsonia intracellularis seroconversion and PRRSV seropositivity during the fattening period also was a risk factor for Salmonella shedding.  相似文献   

2.
The aim of this study was to evaluate the impact of the pre-slaughter process on Salmonella caecal contamination of pigs at slaughter. An observational study was carried out in 2001 on 101 conventional farrow-to-finish pig farms. On each farm, one batch of contemporary pigs was followed from the end of the fattening period until slaughter. The Salmonella bacteriological status of the batches was assessed by environmental samples of faecal material. The serological Salmonella status was obtained on 30 individually identified market-age pigs using an indirect ELISA test. At the slaughterhouse, 25 g of caecal contents were taken from 10 of the identified pigs. Faecal and caecal material were analysed according to a classical bacteriological method. A questionnaire was designed to obtain information about the type of feeding during the fattening period (dry versus wet), the duration of fasting on the farm before leaving for the slaughterhouse, the duration of transport between the farm and the slaughterhouse, the holding time in lairage at the slaughterhouse and loading and unloading conditions on the farm and at the slaughterhouse. To assess the relationships between these factors and the Salmonella caecal status of the pigs and the batches, two logistic models were fitted at the individual and at the batch level, respectively. The first analysis was performed using a random effects logistic regression model. The second analysis was based on a cumulative logit model with a positive caecal rate classified into three classes as the outcome variable. The results showed that the Salmonella status of market-age pigs assessed on the farm either by serological or bacteriological examinations and the time spent in lairage before slaughtering played a crucial role on caecal contamination. In the light of these results, actions should be considered both on the farm and at the slaughterhouse to decrease the risk of Salmonella contamination of the caecal contents.  相似文献   

3.
We did a prospective observational 9-month long study to quantify risk factors of managerial and hygiene practices, and pig-health status for Salmonella seroconversion of fattening pigs reared in subclinically infected French farrow-to-finish farms. During the fattening phase, 2,649 pigs belonging to the same batch of contemporary pigs, from 89 conventional farrow-to-finish farms were individually followed and regularly blood sampled on a monthly basis. Farm recruitment was based on the farmer's willingness to cooperate. Pig status was assessed using an indirect ELISA test. Evolution of the serological status was studied by means of survival analysis. A Cox proportional-hazards model, taking into account the clustering of animals at the farm level, was used to examine the effects of explanatory variables on the time to Salmonella seroconversion of pigs. Applying group level antibiotic treatment to the pigs during the fattening period (Hazard Ratio (HR) = 2.4; 95% CI: 1.7, 3.4) was identified as a risk factor for Salmonella seroconversion, as the presence of residual Salmonella contamination in the fattening pen before placing the pigs into the pens (HR = 1.9; 95% CI: 1.2, 2.9). Porcine reproductive and respiratory syndrome virus (PRRSV) seropositivity during the fattening period also indicated an increased hazard for seroconversion (HR = 1.6; 95% CI: 1.1, 2.5). The batch size was identified as a risk factor for Salmonella seroconversion: the higher the number of pigs was in the fattening room followed, the higher was the risk (HR(+10 pigs) = 1.05 for a 10-pig increment; 95% CI: 1.03, 1.06). The biosecurity measures of wearing specific clothes before entering the facilities (HR = 0.5; 95% CI: 0.3, 0.9) and enclosing the pig farm facilities were protective (HR = 0.4; 95% CI: 0.2, 0.8).  相似文献   

4.
The Hygiene Package and Regulation EC‐2160/2003 require information flow from farm to slaughterhouse to enhance European consumers protection in a ‘farm to fork’ approach. This obligation especially concerns food‐borne zoonotic hazards transmitted to humans through pork consumption, such as thermophilic Campylobacter spp., Listeria monocytogenes, Salmonella enterica and Yersinia enterocolitica. Prevalence estimates of these four hazards are affected by the sampling strategy and diagnostic procedure. Individual prevalence estimates for pig carriage (from digestive contents or lymph nodes collected at slaughterhouse) were higher than individual prevalence estimates for pig shedding (from faeces). Among risk factors described in the literature, poor pen cleaning and disinfection after pig departure to slaughterhouse and poor bio‐security measures are of major significance. Moreover, whereas wet feed increases the risk of pig infection by L. monocytogenes, dry feed is a risk factor for Salm. enterica. Mixing batches of pigs, notably in fattening herds, represents a risk for the transmission of Salm. enterica and Y. enterocolitica. Whereas small herds are more infected by thermophilic campylobacters and Y. enterocolitica, higher prevalence of Salmonella is observed in large herds due to a more frequent mixing of batches. Antibiotic treatment during the finishing period increases the risk of transmission of Salm. enterica. The forenamed elements should be taken into account to characterize farms in a risk assessment approach and to improve zoonotic hazard management in the pork food chain.  相似文献   

5.
Application of risk analysis to control pork-borne zoonoses on farms is a major aim of the current European food safety legislation. The prevalence, levels of contamination and variations in pig contaminations according to herds and batches must therefore be studied to define relevant methods for control of zoonoses. The aims of this exploratory study were to provide information on the prevalence and levels of infection of finisher/fattening pigs by Campylobacter spp., Clostridium perfringens, Listeria monocytogenes, Salmonella enterica and Staphylococcus aureus, and to quantify the respective effects of batches and herds. One hundred and twenty-seven pooled fresh feces samples and 120 pooled cutaneous swab samples were tested from 37 batches in 14 farrowing-to-finishing farms. Campylobacter spp. was identified in all fecal samples on farms whereas L. monocytogenes was never found. C. perfringens was identified in 48% of samples, Salmonella in 2%, and S. aureus in 48%. The decomposition of variance of on-farm prevalence and levels of contamination and a general linear model showed a systematically significant effect of herd, and an effect of batch only for levels of contamination with Campylobacter and C. perfringens and for prevalence of S. aureus. The contamination status of pigs seems to be mainly explained by herd status linked to poor biosecurity measures. Further studies are needed to explain such correlations in order to define farm indicators for food-borne zoonotic hazards.  相似文献   

6.
Salmonellosis is one of the major zoonotic, food-borne diseases, among others, caused by pig derived food products. As infected pigs are one of the main sources of the introduction of the bacterium into the food chain, scientific research in the last years has focussed on identifying risk factors for infection as well as developing mitigation strategies on this level of production. In order to update the knowledge of the German situation by incorporating recent changes in the German pig industry, a case-control study was set up to identify the key contributing risk factors for farms located in the western part of Lower Saxony, the region with the highest pig density in Germany. Based on an extensive and systematic literature search, a comprehensive questionnaire with 302 questions concerning such topics as personnel hygiene, animal management, biosecurity, feeding management as well as cleaning and disinfection routines was utilized in a face-to-face interview on 104 case and 67 control farms. Within a stepwise forward selection process the preliminary identified factors were grouped contextually, associations between variables were calculated and multivariable logistic regression models were conducted. Identified risk factors were: the moving of individual animals during the fattening period (OR 5.3, CI 95% 1.35-20.35), not having a separate transporter for different age groups (OR 11.4, CI 95% 1.94-66.18) and pigs having contact to other animals (OR 4.3, CI 95% 1.39-12.96). The following factors were identified as being protective: not cleaning the transporter (OR 0.2, CI 95% 0.05-0.72) and not having clean boots available (OR 0.2, CI 95% 0.07-0.64). While this study was able to identify some factors which influence the Salmonella-infection of a herd, overall the process of analysis showed that the control of Salmonella on farm is due to a series of individual factors and therefore remains extremely complex.  相似文献   

7.
Listeria monocytogenes is a foodborne pathogen of major concern for public health in industrialized countries. Listeria carriage by pigs at the herd level could be a primary source for carcass contamination. Forty-seven finishing pig facilities were involved in the present study designed to compare three environmental swabbing sites in order to detect Listeria spp. in piggeries. Swabs were taken from the pen walls, the perianal regions of the pigs and the trough/feeder of the piggery premises. Listeria contamination of wet or dry feed given to the pigs was also investigated. The capacity of the various sampling sites for Listeria spp. detection were compared with a maximum likelihood estimation method. Listeria spp. were recovered in 74% of the pens studied and L. monocytogenes was detected in 15% of pens. With a specificity of 99%, sensitivity estimates (and 95% CI) of the Listeria spp. detection method were 93.4% (72.7-98.7) for pen walls, 73.1% (54.9-85.9) for pigs and 66.6% (48.6-80.7) for the trough/feeder. Listeria spp. were isolated from 84% of wet feed samples and 5% of dry feed samples. Listeria monocytogenes was found in 13% of wet feed samples. The type of feeding (wet versus dry) was associated (P < 0.001) with Listeria spp. contamination of both the pen and the feed. The results of this study confirm that Listeria spp., including L. monocytogenes, are present in pig facilities. Pen wall swabbing appears to be an effective way to assess Listeria spp. status of finishing pigs. The type of feeding (wet versus dry) could play a role in pig contamination.  相似文献   

8.
Fattening pigs are frequently contaminated with salmonella bacteria. In 1983 and 1984 some 40 pig fattening farms in the Dutch province of Gelderland were examined to test the hypothesis that acidic byproducts from the dairy industry could influence the degree of contamination in groups of fattening pigs. Clear differences were observed: first salmonella was found in a lower percentage of farms using whey as part of the feed mix (40%) than on farms using only water (80%). Of the farms on which salmonella bacteria were demonstrated, the percentage of positive samples was lower for the 'whey' farms than for the 'water' farms (19.4% compared with 64.1%).  相似文献   

9.
Summary

Numerous epidemiological reports implicate foods of animal origin as vehicles of human campylobacteriosis. Pigs are probably an important reservoir of campylobacter and a potential source of human infection. In order to improve our knowledge of the epidemiology of campylobacter in pigs, the prevalence of campylobacter and its contamination of feed were monitored in eight pig farms. Faeces samples of pigs aged 11 and 22 weeks, and samples of rectal, ileal and gastric content at a slaughterhouse were collected for bacteriological examination. On 5 farms, subsequent groups of pigs housed in the same stalls was sampled, too. A selection of the campylobacter isolates was characterized with a genetic typing method (RFLP). More than 85% of the sampled porkers were shown to be intestinal carriers of campylobacter at all stages of fattening. Subsequent groups of pigs housed in the same stalls were all carriers, too. The level of campylobacters in the faeces tended to decrease as the pigs got older. There was no difference in the frequency and level of infection with campylobacter between porkers on different farms. The feeding system (wet feed versus dry pellets) did not seem to influence the prevalence of campylobacter although wet feed gave lower counts of Enterobacteriaceae in the faeces.

RFLP‐typing showed a high diversity of campylobacter strains at each sampling on the farm. Similarities were seen between strains isolated during two subsequent samplings of the same group of pigs, but not between strains isolated on the same farm from subsequent groups of pigs housed in the same stall. This suggests that the piglets were already infected at a young age on the breeding farm.  相似文献   

10.
The purpose of this study was to assess the effects of management, environmental and temporal factors of farms and batches on mortality and feed consumed per market hog. Information of management, environmental and temporal factors from 158 all-in all-out finishing batches completed in 27 integrated fattening farms in Galicia (Spain) were collected from 1999 to 2002. Multilevel random effects models were used to determine the factors associated with the mortality and the average amount of feed provided per marketed hog. The level 1 unit was the finishing batch (batch level). At the level 2 the fattening farm where the batch of pigs was developed was introduced as random effects.A bad level of care provided by the farmer to the pigs increased the risk of mortality (P = 0.03). The mortality of the fattening batch was associated with the supplier sow farm (P < 0.01). The level of mortality of the batches of piglets entered the fattening farms both between January and April and October and December was higher than for batches incorporated from May to August (P < 0.01). The year when the piglets entered the farm was significantly associated with mortality (P < 0.01). The introduction of such variables in the multilevel model for mortality reduced the total unexplained variation by 41.06%. The proportion of the variation of the mortality attributable to the fattening farms was small (3.65%). The variability of mortality was higher when the placement of piglets was from September to December (P = 0.01).Higher consumption of feed was recorded when the feed was provided in a non-pellet form (P < 0.01). The introduction of piglets between September and December was associated with a higher consumption of feed (P < 0.01). The average final weight of the hogs was positively associated with the feed consumed per hog of the fattening batch (P < 0.01). The amount of feed provided per hog was statistically different among the years and these effects were modified by the level of mortality recorded in the batch and by the average weight of the marketed hogs. After introducing all the fixed effects in the multilevel model for feed provided per hog the unexplained variation at the farm and batch level was reduced by 47.72% and 85.35%, respectively. A considerable amount of variation of feed provided per hog resided at the fattening farm (32.50%). When the piglets were placed on September–December the variability of feed consumed was higher than in the other two periods of the year (P = 0.02). In conclusion, our study shows that specific factors of the batches are the main contributors to explain mortality. On the other hand, by improving permanent farm characteristics a substantial profit is expected in the long run as a result of lower feed costs.  相似文献   

11.
In this paper, multilevel logistic models which take into account the multilevel structure of multi-site pig production were used to estimate the variances between pigs produced in Danish multi-site pig production facilities regarding seroconversion to Actinobacillus pleuropneumoniae serotype 2 (Ap2) and Mycoplasma hyopneumoniae (Mh). Based on the estimated variances, three newly described computational methods (model linearisation, simulation and linear modelling) and the standard method (latent-variable approach) were used to estimate the correlations (intra-class correlation components, ICCs) between pigs in the same production unit regarding seroconversion. Substantially different values of ICCs were obtained from the four methods. However, ICCs obtained by the simulation and the model linearisation were quite consistent. Data used for estimation were collected from 1161 pigs from 429 litters reared in 36 batches at six Danish multi-site farms chronically infected with the agents. At the farms, weaning age was 3-4.5 weeks, after which batches of pigs were reared using all-in/all-out management by room. Blood samples were collected shortly before: weaning, transfer from weaning-site to finishing-site, and sending the first pigs in the batch for slaughter (third sampling). Few pigs seroconverted at the weaning-sites, whereas considerable variation in seroconversion was observed at the finishing-sites. Multilevel logistic models (initially including four levels: farm, batch, litter, pig) were used to decompose the variation in seroconversion at the finishing-site. However, there was essentially no clustering at the litter level-leading to the use of three-level models. In the case of Ap2, clustering within batch was so high that the data eventually were reduced to two levels (farm, batch). For seroconversion to Ap2, ICC between pigs within batches was approximately 90%, whereas the ICC between pigs within batches for Mh was approximately 40%. This indicates that the possibility for Mh to spread between pigs within batches is lower than for Ap2. The diversity in seroconversion between batches within the same farm was large for Ap2 (ICC approximately 10%), whereas there was a relative strongly ICC (approximately 50%) between batches for Mh. This indicates that the transmission of Mh is more consistent within a farm, whereas the presence of Ap2 varies between batches within a farm.  相似文献   

12.
The European regulation 2160/2003 of November 17th, 2003 clearly shows the European strategy of zoonosis monitoring and control as an integrated approach, including the entire food production chain with a first application to Salmonella control in different animal species. This regulation is the consequence of a risk assessment performed with a "farm to fork" philosophy. European strategy is scarcely different from the American strategy, despite the fact that both were achieved by a quantitative risk assessment, as for instance, in the USA the control of Salmonella in eggs is supposed to be completed by refrigeration. Nevertheless, the EU will still have a final product control approach towards future regulations on microbiological criteria for foodstuffs. The final production monitoring and control with HACCP (93/43/EC) and microbiological criteria is the only one available for L. monocytogenes in foodstuffs. The purpose of this paper is to discuss alternative control strategies for L. monocytogenes in pig production including integrated risk assessment. In France, most of the food-borne outbreaks associated with L. monocytogenes in delicatessen were due to one particular group of strains belonging to serovar 4b and presenting a particular RFLP/PFGE (Restriction Fragment Length Polymorphism/Pulsed Field Gel Electrophoresis) profile. The outbreak itself is always associated with the initial contamination of a RTE ("ready to eat") product and re-contamination by inappropriate handling after cooking. Consequently, in most cases the RTE product is subject to inadequate refrigeration during an excessive shelf-life. The responsibility of the food industry and the consumer is clearly engaged during this scenario of foodborne diseases. The question is how to avoid the introduction of this particular strain of L. monocytogenes in the food chain. In a study we tried to evaluate the risk of pig carcass contamination at slaughterhouse level and to identify the main risk factors associated with the infection of live pigs. In most cases inappropriate cleaning and disinfection of surfaces were associated with the contamination of raw meat, but in some cases the introduction of epidemic strains in the food chain was also associated with primary production. Feeding with soup in piggeries seemed to select a particular microbial ecology associated to L. monocytogenes contamination of live pigs. The possible strategies that may be used to control L. monocytogenes in live pig production are not yet developed sufficiently to be included in the EC regulation but should be discussed in more detail.  相似文献   

13.
We set up a matched case-control study of potential risk factors for clinical encephalomyocarditis virus (EMCV) in 58 pig farms in West Flanders (Belgium). In total, 29 farms experienced a clinical outbreak of EMCV confirmed by EMC virus isolation. Mortality was seen only among suckling piglets (18 case farms), in piglets and other age-groups (4 case farms), or only among fattening pigs (7 case farms). Five farms had reproductive problems among the sows. Control farms were matched geographically on farm size and farm type and were selected on the absence of clinical signs. A questionnaire on potential risk factors for EMCV was developed to collect data at both case and control farms. The exploration of the data used clusters of factors associated with clinical EMCV infection: (a) rodents, (b) general farm set up and (c) general hygiene. The multivariable relationships between clinical appearance of EMCV and potential risk factors were tested with conditional logistic regression. The final model on all farms contained presence of mice (OR=8.3) as a risk factor for clinical EMCV infection while the flow of manure up through the slatted floor (OR=0.11) and movement of manure between manure pits in the pig stable (OR=0.14) were protective.  相似文献   

14.
Pigs were examined on five farms for carrier status of Yersinia enterocolitica. Yersinia enterocolitica biovar 4, serovar 3, phagovar VIII was isolated consistently from the feces of fattening pigs on one farm and sporadically from those of similar pigs on the other farms and of sows on all five farms, during a one-year period of weekly surveys. Seasonal variation was not a feature of fattening pigs on a highly contaminated farm. In other pigs, however, the organisms were not isolated during the summer months. On a highly contaminated farm, the organisms were excreted in the feces of 8 to 15-week-old pigs within 1–3 weeks of entering pens which were thought to be contaminated with the organisms. On a detailed observation of natural infection of Y. enterocolitica in eight pigs, the organism appeared in the pigs' feces within 2–7 weeks of them being moved to a pen which had been washed thoroughly after becoming contaminated, by a previous group of pigs, with feces containing 105 viable organisms per g. Thus, Y. enterocolitica is apparently transmitted from infected feces or picked up from the floor of a contaminated pen, and the regular schedule of pig movement among the pens is an important factor in the spread of Y. enterocolitica within a piggery. Intestinal colonization continues for a long time and does not occur by re-infection. The organisms were not isolated from eight pigs at the time of slaughter, and their serum O-agglutinin titers were 140 or less. Thus, circulating antibody may not inhibit intestinal colonization by Y. enterocolitica.  相似文献   

15.
Summary

Fattening pigs are frequently contaminated with salmonella bacteria. In 1983 and 1984 some 40 pig fattening farms in the Dutch province of Gelderland were examined to test the hypothesis that acidic byproducts from the dairy industry could influence the degree of contamination in groups of fattening pigs. Clear differences were observed: first salmonella was found in a lower percentage of farms using whey as part of the feed mix (40%) than on farms using only water (80%). Of the farms on which salmonella bateria were demonstrated, the percentage of positive samples was lower for the ‘whey’ farms than for the ‘water’ farms (19.4% compared with 64.1%).  相似文献   

16.
Possible sources of exogenous contamination of raw milk by Listeria monocytogenes were examined on four dairy farms of different size and type of animal housing during morning milking. Feeds, including hay and concentrates, were found to be major sources of both pathogenic and nonpathogenic species of Listeria on the barns. L. innocua was the only species isolated from the grass silage, which was of good quality on all the farms. The numbers of Listeria were below 10(2)/g in all feed samples. Fecal shedding of listeriae was detected in 11.9% of the cows and the prevalences of L. monocytogenes among farms ranged from no detections to 8.7%. The number of Listeria isolations from constructions inside the barns and from the milking environment varied between the farms. Listeriae were detected almost everywhere on one of the farms whereas on another farm the only isolations were from feed passages and floors. 13.6% of the swab samples taken from the teats before washing and drying were Listeria positive, whereas no isolations were made after cleaning the udder. Good milking and barn hygiene is considered important for diminishing the risks of exogenous contamination of raw milk by listeriae.  相似文献   

17.
[目的]通过比较2种不同配合料饲喂育肥猪的饲养效果和效益情况,筛选出适合试验猪场生产所需的饲料品种。[方法]选择体重在（47.3±2.5）kg的洋三元猪40头作为试验对象,将其分为2组,并分别饲喂2种配合料55 d,当体重达到90 kg左右后,对其生长性能进行对比分析。[结果]在试验阶段结束后,大北农饲料组的实验猪在头均末重和头均总增重上分别极显著高于金格力饲料组11.29%和16.32%（P〈0.01）,但其料肉比却极显著低于金格力饲料组13.64%（P〈0.01）。[结论]综合以上因素,并从养殖场的经济效益出发,可以认为大北农公司的配合料更适合推广应用。  相似文献   

18.
A longitudinal survey was conducted in France in a subclinically Salmonella-infected farrow-to-finish pig farm to describe the time-course of the serological response to Salmonella enterica in growing pigs. We used three batches of sows and their corresponding litters (n = 31 litters). Among these, 256 pigs randomly selected and individually identified were followed from the first week of age until slaughter. Serial individual blood samples were submitted to indirect Salmonella-ELISA testing. Salmonella shedding was investigated by bacteriological testing of faecal material regularly collected from the sows and pigs and by environment swabs taken from the pens. Caecal contamination was checked at the slaughterhouse. Information about litter composition (filiation), location of the pigs in post-weaning and fattening pens, sanitary events, sex and body weights was recorded. 11.6% of the pigs shed S. enterica; 52% of pigs seroconverted before slaughter. The age-related variation of the natural logarithm of calibrated optical densities (COD) of pigs was described with two linear mixed models. From 8 to 61 days of age, the decrease in COD with age was fitted with a model including random effects of the animal and the dam on the intercept and slope, a batch random effect on the intercept and an individual birth-weight fixed effect on the intercept. The dam random effect was explained by the parity of the sow, Salmonella shedding by the sow during the farrowing phase and the value of the optical density of colostrum collected at parturition. A second model fitting the increase in COD from 61 days of age until slaughter included the random effect on intercept of the batch and the random effects on slope and intercept of the animal, the dam and the pen in which the followed animals were located during the fattening phase and the environmental contamination as fixed effect. In this second model, no relation was found between individual slaughter-bacteriological results and increasing COD values. Considering seroconversion time between 61 days of age and slaughter, survival function were constructed using the Cox proportional-hazards model. Both methods suggested that seroconversions generally occurred during the last third of the fattening phase (from 140 days of age to slaughter), while shedding was observed during the first half of the fattening period. The fitted models suggest the existence of clusters (such as pen and litter of origin).  相似文献   

19.
The aim of this study was to investigate farm-level economic and technical factors that are associated with the use of antibiotics on pig farms. Identification of such factors, like farm size and net farm result, may help to increase epidemiological knowledge and to specify farm advice and policy making to reduce inappropriate use of antibiotics. The study used over 300 farm-year records collected during 2004 to 2007 from pig farms in the Netherlands. Data included economic and technical factors as well as antibiotic administration. Data were statistically analyzed for factors associated with antibiotic use, both for fattening pig and sow farms (piglets only), separately. The response variable was the average number of daily dosages per average pig year. Statistical analysis was performed on 16 and 19 potential explanatory factors for the fattening pig and sow farms, respectively. The results showed that, both on the fattening pig and sow farms, the average use of antibiotics increased from 2004 to 2006, but decreased during 2007, but the effect of year was not significant (P > 0.05). Use of antibiotics varied between individual farms. Large farm repeatability for the use of antibiotics in the different years was found. Factors associated (P < 0.05) with the use of antibiotics included: farm system, number of pigs, and population density in the region of the farm (for sow farms only). As these factors are easy to collect and to register, they can be used to specify farm advice and investigation, as well as for policy making. The majority of the technical and economic factors were not significantly (P > 0.05) related to the on-farm use of antibiotics. Therefore, it is recommended to focus future research on the potential role of socioeconomic factors associated with antibiotic use on pig farms.  相似文献   

20.
The present study investigated risk factors for mortality in grow-finishing pigs of 137 pig herds belonging to one integration company during a period of 2.5 years. Mortality data, expressed as the number of dead pigs divided by the number of pigs placed in the fattening unit were investigated retrospectively. The following potential risk factors were evaluated: type of pig herd, season and year of placement in the fattening unit, pig density in the municipality, management practices (density of the pigs in the barn, origin of the pigs), housing conditions and feeding practices. The overall average mortality percentage was 4.70%. Three variables in a multivariable regression model were significantly associated with mortality: season of placement in the fattening unit, origin of the piglets and duration of the fattening period. Pigs placed in October, November and December, were at higher risk than pigs placed in other months. Herds that purchased pigs from a merchant, used pigs from other herds with an excess of piglets for filling their fattening units or herds that purchased pigs from more than five origin herds also suffered higher mortality. The mortality also increased in case of longer duration of the fattening period. This study documented for the first time that in addition to seasonal effects and a longer duration of the fattening period, purchasing feeder pigs from one or a limited number of herds is of crucial importance to achieve low mortality in the grow-finishing pigs.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号