Ascariasis, respiratory diseases and production indices in selected Prince Edward Island swine herds.

The levels of production, ascarid burden and respiratory disease were measured on 15 purposively selected swine herds, and the relationships between the various measures of ascarid burden were examined. On each farm 30 randomly selected pigs were weighed and rectal fecal samples were collected at approximately 11, 15, 19 and 22 weeks of age, and at slaughter. Fecal ascarid-egg counts and duration of infection were combined to calculate a composite measure of ascarid burden called "lifetime burden". At the abattoir the carcass weight and levels of anteroventral pneumonia, atrophic rhinitis, and liver lesions were recorded for each hog. The number of ascarids in the small intestines were counted. Study hogs were marketed at an average of 189 +/- 22 days. The average dressed carcass weight was 77.0 +/- 5.9 kg and the mean average daily gain was 0.519 +/- 0.071 kg/day. The percent of hogs with ascariasis varied widely among farms, no matter what measure of ascariasis was used; the percent with intestinal ascarids at slaughter ranged from 0% to 96%, the percent that shed ascarid eggs during their lifetime ranged from 0% to 100%, and the range for hogs with liver lesions ranged from 27% to 100%. Of the hogs slaughtered, 82% had milk spot lesions, 32% shed ascarid eggs during their lifetime and 35% had intestinal ascarids. The latter had an average of 12 intestinal ascarids. Anteroventral pneumonia occurred in 55% of the slaughtered hogs and 9% had atrophic rhinitis scores of five. The percent of hogs per farm with pneumonia ranged from 17% to 96%. The percent of hogs per farm with atrophic rhinitis scores of five ranged from 0% to 57%.     

Patterns associated with season and facilities for atrophic rhinitis and pneumonia in slaughter swine.

Three slaughter checks were performed for each of 21 swine producers at 6-month intervals. Two slaughter checks were performed during the winter, and 1 slaughter check was performed during the summer. Lesions of atrophic rhinitis and pneumonia were evaluated during the slaughter checks. Two types of farrowing facilities and 4 types of grower/finisher facilities were used by the swine producers. Lesions of atrophic rhinitis and pneumonia were compared among seasons and among types of facilities. Lesions of both atrophic rhinitis and pneumonia varied with season. Lesions of atrophic rhinitis were more severe among hogs slaughtered in the summer, whereas lesions of pneumonia were more severe among hogs slaughtered in the winter. Lesions of atrophic rhinitis were more severe in hogs farrowed in central, enclosed farrowing houses and finished in enclosed, mechanically ventilated buildings than in hogs farrowed individually in sow huts and finished on dirt lots. Knowledge of disease patterns associated with season and facilities is useful for assessment of herd health status and for implementation of control programs.     

A study of air quality and respiratory infections in pigs raised in confinement

Air quality, respiratory disease, and growth rate were followed in four different farrowing and nursery systems. Ammonia levels varied with ambient air temperature, but were within normally accepted levels (25 ppm). These levels of ammonia did not appear to affect the health or performance of the pigs raised in these units. Hydrogen sulfide levels were consistently low. Counts of bacterial colony forming particles (BCFP) varied and the organisms identified were predominantly micrococci. Bordetella bronchiseptica was isolated from nasal cavities of pigs from 3 out of 4 farms. Three of the farms did not have evidence of atrophic rhinitis; pigs farrowed in the last quarter of the test year on one farm from which B. bronchiseptica was isolated developed lesions of atrophic rhinitis. The B. bronchiseptica isolates from the 3 farms were virulent for gnotobiotic piglets. Groups of pigs for slaughter inspection from one farm had lungs with 11–28% pneumonic lesions; these lesions were not typical of mycoplasmal pneumonia.     

规模化猪场传染性萎缩性鼻炎病原学调查与分析

本试验对吉林部分地区规模化猪场进行猪传染性萎缩性鼻炎病原学调查。采集吉林不同地区6个规模化猪场阳性猪鼻腔黏液148份,进行病原菌的分离与鉴定。结果表明,148头猪中有84头被支气管败血波氏杆菌感染,占56.76%;被产毒素多杀巴氏杆菌感染53头,占35.81%;混合感染的11头,占7.43%。结果提示,吉林地区规模化猪场中猪传染性萎缩性鼻炎多以支气管败血波氏杆菌感染为主,混合感染程度轻微。     

Association of growth performance with atrophic rhinitis and pneumonia detected at slaughter in a conventional pig herd in Hungary

The influence of atrophic rhinitis (AR) and pneumonia on growth performance was assessed in a conventional farrow-to-finish pig farm affected by both diseases. All tested pigs (n = 138) were individually weighed at birth, at weaning, at moving to the growing/finishing unit, and at slaughtering. The extent (grade) of turbinate atrophy and lung consolidation attributable to pneumonia was determined in each pig at slaughter. A negative correlation was found between birth weight and the prevalence of nasal lesions at slaughter, suggesting that pigs born with smaller weight may be more susceptible to AR. The growth performance of the pigs also showed a negative correlation with the degree of turbinate atrophy. In the nursery period, the average daily gain (ADG) of pigs with moderate/severe turbinate atrophy was 13.3% lower than that of animals with healthy snouts. In the finishing period, pigs with mild AR lesions had an ADG reduction of 6.2%, while pigs with severe AR lesions had a significant, 9.4% reduction in ADG as compared to the AR-free pigs. The extent of weight gain reduction over the whole life cycle was very similar (approximately 6%) in the pigs having either AR or pneumonia alone. In those pigs where both respiratory diseases were present, their effects seemed to be added up (11.5%); however, nasal lesion scores and percentage of lung consolidation did not show statistically apparent interactive effects on growth performance.     

Effect of atrophic rhinitis on growth rate in Illinois swine herds

Influence of atrophic rhinitis (AR) on mean daily weight gain (MDG) was studied in hogs randomly selected from 7 farrow-to-finish herds in Illinois. Herds were selected to obtain a wide range of clinical signs and lesions of the disease; thus, prevalence of clinical signs of AR in finishing hogs ranged from 0% to 20% among herds, and in hogs examined at slaughter the proportion of hogs with turbinate lesions ranged from 5% to 92%. None of the herds investigated had any obvious problems with pneumonia; nevertheless, hogs with moderate to severe pneumonic lesions were excluded from the study, to minimize any combined effect of AR and pneumonia. In 3 herds, MDG in AR-free pigs was 15% to 18% better than in pigs with severe AR lesions. Prevalence of clinical signs ranged from 5% to 20%, and of turbinate lesions, from 66% to 92%. In 4 herds in which MDG appeared to be unaffected by AR, prevalence of clinical signs of the disease ranged from 0% to 5%, and of turbinate lesions, from 5% to 74%. No consistent pattern of influence on AR lesions was found for bacterial infections, as determined by culturing of nasal swab specimens on MacConkey agar and blood agar.     

A critical assessment of abattoir surveillance as a screening test for swine ascariasis.

The following data on ascarid burden were collected on an individual basis for 380 hogs marketed in the fall of 1987: a series of fecal ascarid-egg counts during the growing period; the level of milk spot lesions on the liver at slaughter; and the number of ascarids in the small intestines at slaughter. The presence of milk spots had a high sensitivity, very low specificity, and a high negative predictive value as a screening test for ascariasis in individual hogs. Results were consistent whether ascariasis was measured as the presence of intestinal ascarids at slaughter (sensitivity 91%, specificity 22%, negative predictive value 82%), or by a positive fecal egg count during the hog's lifetime (sensitivity 96%, specificity 24%, negative predictive value 93%). The presence of milk spots does not necessarily indicate that an ascarid infection has been established in the small intestine. The absence of milk spots, however, is a reliable indicator of the absence of an established ascarid infection, provided that the prevalence of ascariasis is equal to or less than that observed in this study. The severity of the ascarid infection in an individual hog could not be ascertained by the number of milk spot lesions on the liver.     

Epidemiological survey of Corynebacterium equi infections on five Ontario horse farms.

Corynebacterium equi was cultured from manure or soil on five horse-breeding farms in Ontario at monthly intervals on three occasions during the summer of 1982. The organism was widespread. Contamination by C. equi of the loafing paddock and pasture areas was significantly greater in a farm established 30 years than in two established for four and six years and there was a significant correlation between the C. equi burden in stables, paddocks and pastures and the length of use of the five farms for horses. In all farms, numbers of C. equi in pasture soil exceeded numbers in fresh manure, suggesting that environmental multiplication of the organism might occur. A farm with an endemic C. equi pneumonia problem differed significantly from the other four farms, where disease was not endemic, in the larger number of C. equi isolated in the stable area. By contrast the farm with a C. equi pasture soil burden significantly heavier than on all other farms had no deaths due to C. equi pneumonia. There was a correlation (r = 0.78, p = 0.061) between the number of cases of C. equi pneumonia on the farms and numbers of C. equi in the area of the stables, but not on the paddocks or pastures. About two-thirds of randomly chosen isolates from the farms belonged to the three capsular serotypes most commonly found in pneumonic foals.     

Prevalence of respiratory diseases and their association with growth rate and space in randomly selected swine herds.

The prevalence and extent of respiratory tract lesions were measured in 1425 pigs from 27 randomly selected herds in the summer of 1982 and winter of 1983. About 75% of pigs had lesions of enzootic pneumonia, approximately 60% had atrophic rhinitis and approximately 11% had pleuropneumonia and/or pleuritis. Individual pig growth rate was recorded on two of the farms, and it was found that the correlations between growth rate and severity of enzootic pneumonia lesions were positive on one farm and negative on the other. Negative correlations between severity of turbinate atrophy and growth rate existed in one of the two herds. Extent of pneumonia and severity of turbinate atrophy were poorly related in individual pigs but herd averages were moderately and positively correlated. Prevalence of diffuse pleuritis and of pleuropneumonia were positively related, as were the extent of pneumonia and prevalence of localized pleuritis. Prevalence of pleuropneumonia was strongly correlated with increased days-to-market. A method of estimating the average days-to-market using weekly herd data (inventory) was developed.     

Epidemiological associations between Mycoplasma hyopneumoniae and Actinobacillus pleuropneumoniae antibody titers and lung lesions in Prince Edward Island swine herds.

A survey of anteroventral (AV) lung lesions, pleuritis and serology for Mycoplasma hyopneumoniae (MH) and Actinobacillus pleuropneumoniae (AP) was conducted on a minimum of 25 slaughter hogs from each of 18 randomly sampled Prince Edward Island farms (producing over 1,000 market hogs per year). The data were analyzed to evaluate the potential role of these two agents as risk factors for the two conditions, using crude and multivariable techniques, as well as individual and herd data. Anteroventral lung lesions were present in 50.5% of hogs at slaughter, and pleuritis was present in 15.4% of the hogs. Least squares multivariable regression was used to analyze the simultaneous ability of MH, AP and MH/AP interaction to predict the herd prevalence of AV lung lesions. Only MH was associated with AV lung lesions (p = 0.035). In spite of this statistical significance, MH accounted for only 53% of the herd variation in prevalence of lung lesions (R2 = 0.529). As well, some herds maintained very low levels of lung lesions despite moderate (up to 30%) prevalence of MH. Discrepancies between the analytic techniques suggested herd-level factors play an important role in the development of lung lesions. Pleuritis did not appear to be associated with either of the agents studied (p = 0.478).     

Environment, respiratory disease, and performance of pigs in three Saskatchewan grower-finisher barns

A microcomputer-based environmental monitoring system was used to monitor temperature, humidity, and ventilation rate continuously in three commercial grower-finisher swine barns in Saskatchewan. During the monitoring period, a group of pigs in each barn was examined for growth rate, amount of lung affected with pneumonia, and degree of atrophic rhinitis. In addition, the total bacterial colony forming particle count within the airspace of each barn was measured once each week.

Significant differences existed among barns for daily maximum and minimum temperature, relative humidity, ventilation rate, and average bacterial colony forming particle counts. There was no difference among farms in the average percentage of lung affected with pneumonia, average snout atrophy score, or growth rate of the test animals.

On one farm, there was a significant positive correlation between snout score and percentage of lung affected with pneumonia. On another farm, there was a significant negative correlation between percentage of lung affected with pneumonia and growth rate.

     

广东地区猪传染性萎缩性鼻炎流行病学调查

为了解广东地区猪传染性萎缩性鼻炎(AR)的流行情况,本研究采用细菌分离、鼻甲骨组织形态学测定(TPR值)等方法,对广东各区14个规模在500头母猪的养猪场随机抽样进行AR的流行病学调查。试验统计数据显示,调查的14个猪场均存在AR,平均发病率为58.58%,平均支气管败血波氏杆菌(Bb)感染率为46.74%;抽样猪场中猪的萎缩指数平均数为1.286,萎缩指数标准差为1.871。结果表明,AR在广东省广泛流行,Bb感染率高。     

Pasteurella multocida and Bordetella bronchiseptica in atrophic rhinitis and pneumonia in swine.

A total of 163 pigs from nine farrow-to-finish herds representing various levels of atrophic rhinitis (AR) were selected for postslaughter examination of AR and pneumonia. Nasal swabs and lungs were cultured for detection of Bordetella bronchiseptica and Pasteurella multocida. Seventy-three pigs were examined at eight weeks of age and 90 contemporaries at six months of age. Mean AR scores were 1.21 and 1.11 for the eight week and six month old pigs, respectively (0 = normal, 3 = severe). In individual pigs increasing AR score was related to increasing pneumonia score in eight week old pigs but not in six month old hogs. In eight week old pigs, B. bronchiseptica and P. multocida were isolated more frequently from pigs with higher AR scores. From nasal swabs of six month old hogs, Bordetella was almost never recovered while Pasteurella was frequently isolated score. Toxigenic type DP. multocida was isolated from nasal cultures of only seven (4%) pigs and from lung cultures of only one pig. Pasteurella was never isolated from lungs of the eight week old pigs and Bordetella never from the six month old hogs. The isolation rate of P. multocida, predominantly type A, from lungs of six month old pigs increased from 11% in grossly normal lungs to 86% in lungs with severe pneumonia. Pigs from one herd free from lesions of AR and pneumonia were also examined; type AP. multocida was isolated from nasal cultures of one of six eight week old pigs. Somatic antigens of P. multocida were determined for 94 nasal and 20 lung isolates. Somatic serovar 3 was found in 93% of the nasal isolates and in all lung isolates.(ABSTRACT TRUNCATED AT 250 WORDS)     

Prevalence of gastrointestinal parasitism in Oklahoma swine

The prevalence of swine gastrointestinal parasites was determined from all listed large swine operations (28) and a geographically representative sample (70) of the population of small hog farm operations in Oklahoma. Fecal samples (n = 975) were collected from 98 farms. From the 98 farms, parasites were recovered in pig feces as follows: Ascaris, 53.0%, strongyles, 53.1%, Trichuris, 35.7%, spirurids, 6.1%, Strongyloides, 19.4%, coccidia, 57.1%, and Balantidium, 55.1%. A higher percentage (16.5%) of hogs maintained on cement floors were positive for Ascaris than were those on either dirt lots (11.9%) or slatted floors (9.9%), but pigs on dirt lots were more often positive with a higher percentage of coccidia (21.0%) than those on either cement or slatted floors (8.5% and 6.0%, respectively). Prevalence of Trichuris was essentially the same (6.8% to 11.3%) in hogs from all 3 management practices.     

A serological survey of leptospirosis in Prince Edward Island swine herds and its association with infertility.

A serological survey was undertaken to determine the prevalence of leptospirosis, and to investigate associations between leptospiral antibody titers, and herd measures of reproduction. Production records and leptospirosis serology were analyzed for 25 slaughter hogs from each of eleven randomly sampled farrow-finish operations on Prince Edward Island. The effect of selected leptospiral serovars on nonproductive sow days per parity (NPSD/P) and the proportion of pigs born dead was evaluated. The four most common serovars to which antibodies were detected were Leptospira icterohaemorrhagiae, L. bratislava, L. autumnalis and L. pomona, with respective prevalences of 57.1%, 35.1%, 3.4% and 1.5% of PEI slaughter hogs. None of these serovars was associated with increased frequency of stillbirths (p greater than 0.05). However, farms with a higher prevalence of L. bratislava antibody titers tended to have more infertility, as measured by NPSD/P (r = 0.738, p = 0.036 with Bonferroni adjustment). Also, farms with L. pomona antibody titers had higher NPSD/P than farms without L. pomona antibody titers (p = 0.0008 with Bonferroni adjustment). There was no association between NPSD/P and antibodies to either L. autumnalis or L. icterohaemorrhagiae (p greater than 0.05).     

Phenotypic characterization and random amplified polymorphic DNA (RAPD) analysis of Pasteurella multocida isolated from Korean pigs

Pasteurella multocida causes various respiratory disease symptoms in pigs, including atrophic rhinitis and pneumonia. In the present study, 69 strains of P. multocida were isolated from 443 pigs with respiratory clinical symptoms at 182 farms located throughout South Korea from 2009 to 2010. A multiplex capsular PCR typing assay revealed that 69 strains of P. multocida isolated in this study had the biosynthetic locus of the capsules of either serogroup A (47 strains, 68.1%) or serogroup D (22 strains, 31.9%). The 22 strains positive for serogroup D-specific primers were divided into four clusters and the 47 strains positive for serogroup A-specific primers were divided into 12 clusters according to the results of Random Amplified Polymorphic DNA (RAPD) analysis. P. multocida strains in the present study were susceptible to most of the antimicrobial agents used. An analysis of antimicrobial resistance and virulence gene pattern combined with RAPD indicated that a certain P. multocida strain appeared to be genetically identical, implying the persistence of the strain within a single farm.     

Comparison of six different regimens for the control of atrophic rhinitis in swine

Effectiveness of six different programs of atrophic rhinitis (AR) control was evaluated under field conditions. Efficacy of treatments was recognized on the basis of--comparative evaluation of the average daily gain (ADG), morphometric examination of turbinate bones and computer conchal morphometry (TPR). Usefulness of the evaluated regimes differed significantly. TPR appeared to be the most objective method for AR evaluation. Correlation between severity of turbinate atrophy and ADG was only partial.     

Evaluation in Appalachian pasture systems of the 1996 (update 2000) National Research Council model for weaning cattle

This study was conducted to evaluate the accuracy of the National Research Council's (2000) Nutrient Requirements of Beef Cattle computer model when used to predict calf performance during on-farm pasture or dry-lot weaning and backgrounding. Calf performance was measured on 22 farms in 2002 and 8 farms in 2003 that participated in West Virginia Beef Quality Assurance Sale marketing pools. Calves were weaned on pasture (25 farms) or dry-lot (5 farms) and fed supplemental hay, haylage, ground shell corn, soybean hulls, or a commercial concentrate. Concentrates were fed at a rate of 0.0 to 1.5% of BW. The National Research Council (2000) model was used to predict ADG of each group of calves observed on each farm. The model error was measured by calculating residuals (the difference between predicted ADG minus observed ADG). Predicted animal performance was determined using level 1 of the model. Results show that, when using normal on-farm pasture sampling and forage analysis methods, the model error for ADG is high and did not accurately predict the performance of steers or heifers fed high-forage pasture-based diets; the predicted ADG was lower (P < 0.05) than the observed ADG. The estimated intake of low-producing animals was similar to the expected DMI, but for the greater-producing animals it was not. The NRC (2000) beef model may more accurately predict on-farm animal performance in pastured situations if feed analysis values reflect the energy value of the feed, account for selective grazing, and relate empty BW and shrunk BW to NDF.     

Association of soil concentrations of Rhodococcus equi and incidence of pneumonia attributable to Rhodococcus equi in foals on farms in central Kentucky

OBJECTIVE: To determine whether soil concentrations of total or virulent Rhodococcus equi differed among breeding farms with and without foals with pneumonia caused by R equi. SAMPLE POPULATION: 37 farms in central Kentucky. Procedures-During January, March, and July 2006, the total concentration of R equi and concentration of virulent R equi were determined by use of quantitative bacteriologic culture and a colony immunoblot technique, respectively, in soil specimens obtained from farms. Differences in concentrations and proportion of virulent isolates within and among time points were compared among farms. RESULTS: Soil concentrations of total or virulent R equi did not vary among farms at any time point. Virulent R equi were identified in soil samples from all farms. Greater density of mares and foals was significantly associated with farms having foals with pneumonia attributable to R equi. Among farms with affected foals, there was a significant association of increased incidence of pneumonia attributable to R equi with an increase in the proportion of virulent bacteria between samples collected in March and July. CONCLUSIONS AND CLINICAL RELEVANCE: Results indicated that virulent R equi were commonly recovered from soil of horse breeding farms in central Kentucky, regardless of the status of foals with pneumonia attributable to R equi on each farm. The incidence of foals with pneumonia attributable to R equi can be expected to be higher at farms with a greater density of mares and foals.     

Field Trials with a New Genetically Engineered Vaccine for Protection Against Progressive Atrophic Rhinitis in Pigs

Bording, A., K. Nymark, E. Smidt: Field trials with a new genetically engineered vaccine for protection against progressive atrophic rhinitis in pigs. Acta vet. scand. 1994, 35, 155-163.–Field trials were carried out testing a new genetically engineered vaccine against Progressive Atrophic Rhinitis. The vaccine contained a non-toxic recombinant derivative of the P. multocida toxin. The experimental vaccine was compared with a commercial vaccine in 4 farms and in 1 farm 2 different dose regimens were applied. A total of 825 sows were included. The primary efficacy variable was a comparison of post mortem evaluation of the degree of conchae atrophy in the 4585 pigs. The pigs were slaughtered at normal slaughter weight. The secondary efficacy variables were serological response and age at slaughter. In all farms the experimental vaccine provided significantly better protection of the progeny than the control vaccine. The serological response in sows was significantly higher in all farms than the response to the control vaccine. The serological response did not differ between farms.