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Data from the national dairy cow recording systems during 1997 were used to calculate lactation-specific cumulative risk of mastitis treatments and cumulative risk of removal from the herds in Denmark, Finland Norway and Sweden. Sweden had the lowest risk of recorded mastitis treatments during 305 days of lactation and Norway had the highest risk. The incidence risk of recorded mastitis treatments during 305 days of lactation in Denmark, Finland, Norway and Sweden was 0.177, 0.139, 0.215 and 0.127 for first parity cows and 0.228, 0.215, 0.358 and 0.204 for parities higher than three, respectively. The risk of a first parity cow being treated for mastitis was almost 3 times higher at calving in Norway than in Sweden. The period with the highest risk for mastitis treatments was from 2 days before calving until 14 days after calving and the highest risk for removal was from calving to 10 days after calving in all countries. The study clearly demonstrated differences in bovine mastitis treatment patterns among the Nordic countries. The most important findings were the differences in treatment risks during different lactations within each country, as well as differences in strategies with respect to the time during lactation mastitis was treated.

Control of infectious diseases in livestock has often been motivated by food safety concerns and the economic impact on livestock production. However, diseases may also affect animal welfare. We present an approach to quantify the effect of five infectious diseases on animal welfare in cattle (three diseases) and pigs (two diseases). We grouped clinical manifestations that often occur together into lists of clinical entities for each disease based on literature reviews, and subsequently estimated "suffering scores" based on an aggregation of duration, frequency, and severity. The duration and severity were based on literature reviews and expert knowledge elicitation, while frequency was based mainly on estimates from the literature. The resulting suffering scores were compared to scores from common welfare hazards found under Danish conditions. Most notably, the suffering scores for cattle diseases were ranked as: bovine viral diarrhoea and infection with Mycobacterium avium subsp. paratuberculosis > infectious bovine rhinotracheitis, and for pigs as: porcine respiratory and reproductive syndrome > Aujeszky's disease. The approach has limitations due to the limited data available in literature and uncertainties associated with expert knowledge, but it can provide decision makers with a tool to quantify the impact of infections on animal welfare given these uncertainties.

Pre-weaning diarrhea in mink kits (PWD), also known as "sticky kits" is a multifactorial syndrome of considerable concern in the mink production. Evidence based treatment protocols are not available, and treatment is therefore empirical and often based on the use of antimicrobials. The purpose of the study was to test the effect of 3 alternative treatments to a standard antibiotic treatment, to characterize the study groups microbiologically, and finally to compare the intestinal microbiota of the different treatment groups at the age of 42 days. In total, 226 one to three week old mink kits with PWD from 36 litters were treated with either 1) Lactobacillus reuteri, 2) benzylpenicillin, 3) Ringer lactate or 4) amoxicillin (controls). Effects of the treatments were measured as weight gain from day 0 to day 15 and mortality. Multivariable linear mixed model regression showed no significant difference in weight gain between probiotic-, penicillin or fluid-treated mink kits and the amoxicillin treated controls. There was also no significant difference in mortality risk between the treatment groups. Bacterial culture and next generation sequencing of the viral contents showed that the study groups were uniform with a high frequency of Staphylococcus intermedius group (SIG) bacteria, Escherichia coli, Enterococcus hirae, Mamastrovirus and Sapovirus which were representative for mink kits with PWD. 16S sequencing results of the bacterial microbiota, when the kits were 42 days old were dominated by clostridia in all groups and showed no clear differences in the bacterial composition between the different treatment groups., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

Treatment of mink kits with pre-weaning diarrhea (PWD) can be time-consuming and expensive for the farmer, and the efficacy of the treatment procedure may be questioned. Evidence-based treatment protocols for application on affected animals at farms with outbreaks of PWD are lacking. In Denmark, the dams are sometimes treated with amoxicillin, however, it is unknown if it is passed on to the mink kits via the milk. The aim of the present study was to investigate if amoxicillin is transferred via the milk to the kits after oral (PO) and intramuscular (IM) treatment, respectively, of the dam. Moreover, we estimated the concentrations of amoxicillin continuously in serum from the kits up to 8 h after administration. The concentration of amoxicillin was not affected by the route of administration (P = .64) and serum reached the highest level after 8 h (34 ng/mL, CI 95%  = [24.3-47.7]). The serum concentrations of amoxicillin in the mink kits achieved within 8 h were judged too low to exert antimicrobial impact on relevant bacterial species., (Copyright © 2018 Elsevier Ltd. All rights reserved.)

Background: Pre-weaning diarrhea (PWD) in mink, also known as "sticky kits", is a frequently occurring syndrome in suckling mink kits on commercial mink farms. Outbreaks of PWD result in weakened kits, increased mortality and reduced growth and welfare as well as considerable economic losses for the farmers. The syndrome is regarded as multifactorial with a complex etiology, and studies have focused on associations with environment, management and dam characteristics. The present study was conducted from May to June 2015 and included 70 dams with mink litters with and without PWD. The aims were to examine associations between PWD and mastitis (bacterial infection and histological signs of inflammation or other lesions in the mammary gland), and to examine associations between PWD and other dam-related characteristics (age, litter size, body mass index, and weight and number of active mammary glands of the dam)., Results: Using multivariable mixed logistic regression analyses with farm id as a random intercept, we found that the odds for PWD in the litter were significantly higher in 1 year old dams versus > 1 year old (OR = 13.3, CI 2.0-90.2, P = 0.01), higher if litter size observed after birth was > 5 kits versus ≤ 5 kits (OR = 16.5, CI 2.2-123.7, P = 0.01), higher if the number of active mammary glands per kit was ≤ 1.5 versus > 1.5 glands per kit (OR = 6.5, CI 1.2-36.0), P = 0.03), and higher in farms with high prevalence of PWD versus low prevalence (OR = 16.8, CI 2.9-97.6, P = 0.002). There were no significant associations between PWD and bacterial infection, histological signs of inflammation or other lesions of the mammary gland, body mass index or weight of mammary gland per kit., Conclusion: Pre-weaning diarrhea had a statistically significant association with age of the dam, litter size and the number of active mammary glands per kit. However, PWD was not associated with mastitis, body mass index and weight of mammary gland tissue per kit.

Pre-weaning diarrhea (PWD) in mink kits is a common multifactorial syndrome on commercial mink farms. Several potential pathogens such as astroviruses, caliciviruses, Escherichia coli and Staphylococcus delphini have been studied, but the etiology of the syndrome seems complex. In pooled samples from 38 diarrheic and 42 non-diarrheic litters, each comprising of intestinal contents from 2-3 mink kits from the same litter, the bacterial populations were studied using Illumina Next Generation Sequencing technology and targeted 16S amplicon sequencing. In addition, we used deep sequencing to determine and compare the viral intestinal content in 31 healthy non-diarrheic and 30 diarrheic pooled samples (2-3 mink kits from the same litter per pool). The results showed high variations in composition of the bacterial species between the pools. Enterococci, staphylococci and streptococci dominated in both diarrheic and non-diarrheic pools. However, enterococci accounted for 70% of the reads in the diarrheic group compared to 50% in the non-diarrheic group and this increase was at the expense of staphylococci and streptococci which together accounted for 45% and 17% of the reads in the non-diarrheic and diarrheic group, respectively. Moreover, in the diarrheic pools there were more reads assigned to Clostridia, Escherichia-Shigella and Enterobacter compared to the non-diarrheic pools. The taxonomically categorized sequences from the virome showed that the most prevalent viruses in all pools were caliciviruses and mamastroviruses (almost exclusively type 10). However, the numbers of reads assigned to caliciviruses were almost 3 times higher in the diarrheic pools compared the non-diarrheic pools and Sapporo-like caliciviruses were more abundant than the Norwalk-like caliciviruses. The results from this study have contributed to the insight into the changes in the intestinal microbiota associated with the PWD syndrome of mink., Competing Interests: The authors have declared that no competing interests exist. Tina Struve (TS) is employed by Kopenhagen Fur as diagnostic veterinarian and coordinator for more PhD studies. This does not alter our adherence to PLOS ONE policies on sharing data and materials.

Background: Pre-weaning diarrhea (PWD) is a syndrome affecting farm-raised neonatal mink kits. Apart from diarrhea it causes greasy skin exudation, dehydration, and distressed behavior and can ultimately lead to death. No specific causative agents have been identified and the syndrome is regarded as multifactorial. The aim of the present study was to investigate a possible inflammatory state in mink kits with PWD, as indicated by raised serum concentrations of the acute phase protein serum amyloid A (SAA) and by changes in intestinal pathomorphology and intestinal contents of bacteria. Samples collected from 20 diarrheic mink kits with PWD and 20 age-matched non-diarrheic control mink kits from two commercial Danish farms during the pre-weaning period (April-May) in 2016 were analyzed., Results: Concentrations of SAA in serum samples from mink kits with PWD were significantly higher (up to 1000-fold) compared to non-diarrheic control mink kits. Significant features of enterocytic vacuolization, atrophy and fusion of villi in jejunum and mucosal atrophy of the colon of kits with PWD were found. Moreover, attachment of coccoid bacteria to enterocytes was more often found in kits suffering from PWD, while intra-cytoplasmic eosinophil bodies were more frequently observed in control kits. Cellular infiltrations with mononuclear and neutrophil leukocytes were not associated with disease status. Bacteria from the Staphylococcus intermedius group, such as Staphylococcus delphini, were more frequently cultivated from control mink kits, whereas Enterococcus spp. dominated in mink kits with PWD. Escherichia coli was cultivated from both control and mink kits with PWD, but with a higher frequency from mink kits with PWD., Conclusion: A significant increase in circulating concentrations of SAA was found in PWD affected mink kits from 6 to 23 days old compared to controls. The histopathological changes in PWD mink kits suggest that the type of diarrhea is secretory. Attachment of coccoid bacteria, therefore, might be responsible for an enterotoxic effect causing a loss of balance in movements of ions and water leading to the vacuolization and swelling of the enterocytes. The slight to moderate infiltrations of neutrophils irrespectively of diarrheic status and the attachment of coccoid bacteria to enterocytes are comparable to observations found in piglets suffering from New Neonatal Porcine Diarrhea Syndrome. Mechanisms behind the correlation between increased SAA levels and the observed pathological intestinal features remain obscure.

Background: Pre-weaning diarrhea in mink, also known as "sticky kits", is a syndrome and outbreaks occur every year on commercial mink farms in all mink producing countries. Morbidity and mortality can be considerable on a farm with huge economic consequences for the farmer as well as compromised welfare for the mink kits. Although efforts have been taken to identify etiologic agents involved in outbreaks, the syndrome is still regarded as multifactorial and recurring problems on the same farms draw attention to management and environmental risk factors. In the pre-weaning period from May to June 2015, a case control study was carried out on 30 Danish mink farms. Data concerning management, biosecurity, hygiene, feed consumption, antibacterial prescription and production efficiency were analyzed., Results: The proportion of 1-year old females, farm size (total number of females), energy supply per female in the late gestation period, and dogs accessing the farm area were significantly associated with being a case farm. Case farms were prescribed almost twice the amount of antibacterials per gestational unit (female and litter) as in control farms. Farmers on case farms spent significantly more time nursing and treating the animals and experienced more females with mastitis compared to farmers on control farms. No significant differences in cleaning practices or hygienic measures between case and control farms were found and there were no differences in drinking water quality, bedding material, composition neither of color types nor in management regarding litter equalization., Conclusions: Results from this study showed an association between the occurrence of pre-weaning diarrhea on mink farms and parity profile, farm size and feeding intensity in the gestational period. The access of dogs to the farm area was a significant risk factor, but needs further clarification.

Background: Individual differences of mink, including color type, are speculated to affect the course of wound healing, thereby impacting wound assessment and management on the farms, as well as the assessment of wounds in forensic cases. In this study, we examined the effect of color type on early wound healing in farmed mink. Full thickness excisional wounds (2 × 2 cm) were made on the back in 18 mink of the color types Brown, Silverblue and Blue Iris. Gross and microscopic pathology of the wounds was evaluated 2 days post-wounding together with degree of wound size reduction, presence of bacteria and blood analyses., Results: Pathological examination on day 2 showed the greatest mean wound size reduction in Brown mink (11.0%) followed by Blue Iris (7.9%) and Silverblue (1.6%). Bacteria were cultured from all wounds, and predominantly Staphylococcus species were recovered in mixed or pure culture. Histopathology from day 2 wounds showed a scab overlying necrotic wound edges, which were separated from underlying vital tissue by a demarcation zone rich in polymorphonuclear leukocytes. Fibroblasts and plump endothelial cells were more numerous in the deeper tissues. Complete blood count parameters were within normal ranges in most cases, however, the mink showed mildly to markedly decreased hematocrit and six mink of the color types Silverblue and Blue Iris showed moderately elevated numbers of circulating segmented neutrophils on day 2. There was a marked increase in concentration of serum amyloid A from day 0 to day 2 in all color types., Conclusions: We have described differences in early wound healing between mink of the color types Brown, Silverblue and Blue Iris by use of an experimental wound model in farmed mink. The most pronounced difference pertained to the degree of wound size reduction which was greatest in Brown mink, followed by Blue Iris and Silverblue, respectively.

Background: Bacterial endocarditis is a recognised disease in humans and animals. In humans, infection with Coxiella burnetii can cause endocarditis, but this has not been investigated thoroughly in animals. Endocarditis in cattle is a common post-mortem finding in abattoirs and studies have identified Trueperella pyogenes as a major cause. Despite exposure of cattle to C. burnetii, the significance of this particular bacterium for development and progression of endocarditis has not been studied in detail. Cardiac valves of cattle affected with endocarditis (n = 100) were examined by histology, fluorescence in situ hybridization (FISH) and real time quantitative polymerase chain reaction (PCR). Serum was examined for anti-C. burnetii antibodies by enzyme-linked immunosorbent assay (ELISA)., Results: Serology revealed that 70% of the cattle were positive for antibodies to C. burnetii, while PCR analysis identified 25% of endocarditis valve samples as being positive. C. burnetii was not detected by FISH, probably due to the low infection levels. Most cattle had chronic valvular vegetative endocarditis with lesions being characterised by a core of fibrous tissue covered by significant amounts of fibrin, sometimes with areas of liquefaction, and with a coagulum covering the surface. In a few cases, including the case with the highest infection level, lesions were characterized by extensive fibrosis and calcification. Histologically, bacteria other than C. burnetii were observed in most cases., Conclusions: The presence of C. burnetii DNA is relatively common in cattle affected with valvular endocarditis. The role of C. burnetii remains however unknown as lesions did not differ between C. burnetii infected and non-infected cattle and because T. pyogenes-like bacteria were present in the inflamed valves; a bacterium able to induce the observed lesions. Heart valves of normal cattle should be investigated to assess if C. burnetii may be present without preexisting lesions.

Background: Human inflicted bruises in slaughter pigs are hampering animal welfare, are an infringement of the animal protection act, and are a focus of public attention. The aim of the present study was to evaluate the gross appearance of human inflicted bruises in slaughter pigs and to compare the inflammatory changes in two lesions as a basis for estimating the age of lesions in the same pig. Pigs with human inflicted bruises slaughtered at two major slaughterhouses in Denmark from November 2013 to May 2014 were evaluated. After slaughter, the bruises were examined grossly and skin and underlying muscle tissue from two similar but separate bruises (a and b) on each pig were sampled for histology., Results: Skin and muscle tissue from 101 slaughter pigs were subjected to gross evaluation. Eighty-one of these were also subjected to histological evaluation. Most frequently (51 out of 101 pigs, 50 %), bruises had a tram-line pattern due to blunt trauma inflicted with long objects such as sticks. Other bruises reflected the use of tattoo-hammers, plastic paddles, double U profiles and chains. Histological evaluation of two bruises from a pig with multiple lesions was found insufficient to assess the overall age of the lesions as substantial variation in the inflammatory response between bruises was present., Conclusions: Grossly, the pattern of bruises often reflected the shape of the object used for inflicting the lesions. When determining the age of multiple bruises on a pig more than two lesions should be evaluated histologically.

The aim of this study was to evaluate gross and histologic lesions and epidemiologic factors of foot lesions in farmed mink. The feet of 1159 mink from 4 Danish farms were examined and lesions described. Swabs from the lesions were taken from 27 mink for microbiology, and tissue samples from a representative spectrum of feet with and without lesions (n= 22) were examined histologically. Feet were grouped according to gross inspection: no lesions (55.1%), hair loss (7.1%), hyperkeratosis (35.8%), and crusting (5.3%). Lesions were predominantly located in plantar metatarsal skin (98.1%). Staphylococci were the most prevalent microorganisms cultured from the lesions. There was a significant association between presence of lesions and sex (P< .0001), age (P< .0001), and color type (P= .023). Lesion size was significantly different between hair loss and crusts and between hyperkeratosis and crusts (P< .0001). Histologically, lesions included varying degrees of orthokeratotic to parakeratotic hyperkeratosis and granulomatous to pyogranulomatous dermatitis with trichogranulomas as a dominant feature in all mink. The gross and microscopic lesions were comparable to physically induced changes in other species that develop as a response to repetitive friction or pressure. The condition may have an impact on animal welfare in mink production., (© The Author(s) 2015.)

Background: Wounds are regarded as an indicator of reduced welfare in mink production; however, information on the occurrence and significance of wounds is sparse. To provide a basis for assessment and classification of wounds in farmed mink, the distribution pattern and characteristics of wounds in farmed mink in June and October, respectively, is described. A total of 791 and 660 mink from 6 to 12 Danish mink farms, respectively, were examined. The mink were either found dead or were euthanized due to injury or other disease. Mink included from June were kits in the pre-weaning and weaning period (1-2 months old). Mink included from October were juveniles in the late growth period (approximately 5-6 months old) or older. Macroscopic pathology and wound location was systematically recorded., Results: There was considerable variation in morphology as well as location of wounds between June and October. Wounds were primarily located on the front parts of the body and in the head in June (1-2 month old kits) and mainly on the rear parts of the body and on the tail in October (5-6 month old kits and older). Moreover, there were significantly more females than males with wounds for most wound types, and significant differences in occurrence of ear and tail base wounds between certain colour types., Conclusions: Wounds varied significantly from June to October with respect to morphology and anatomical location. Wounds in June were primarily located on the front parts of the body and in the head, while wounds in October were mainly present on the hind parts of the body and on the tail. The majority of the wounds were found in specific well defined skin areas and could therefore be grouped into categories according to anatomical location.

Background: During 8 months from July 2012 to February 2013, a major outbreak of canine distemper involving 64 mink farms occurred on the Danish peninsula of Jutland. The canine distemper outbreak was associated with exposure of farmed mink to infected wild carnivores and could represent a deficit in biosecurity on the mink farms. The aim of this study was to investigate the extent and association of specific biosecurity measures with the outbreak. The study was carried out in an epidemiological case-control design. The case group consisted of the 61 farms, which had a confirmed outbreak of canine distemper from July 2012 to February 2013. The control group included 54 farms without an outbreak of canine distemper in 2012 or 2013, selected as the closest geographical neighbour to a case farm., Results: The results showed that significantly more control than case farms had vaccinated their mink against canine distemper virus. Mortality was only assessed on the case farms, and there was a non-significantly lower mortality on vaccinated farms than on the non-vaccinated farms. Furthermore, the proportion of farms with observations of wild red foxes (Vulpes vulpes) inside the farm enclosures were larger for case farms, indicating that the control farms had a better biosecurity or were not equally exposed to canine distemper virus. Generally, all farms had very few specific precautions at the gate entrance in respect to human visitors as well as animals. The use of biosecurity measures was very variable in both case and control farms. Not using plastic boot covers, presence of dogs and cats, presence of demarcated area for changing clothes when entering and leaving the farm area and presence of hand washing facilities significantly lowered the odds of the farm having a canine distemper virus outbreak., Conclusions: The results of the study indicate that consistent use of correct vaccination strategies, implementation of biosecurity measures and limiting human and animal access to the mink farm can be important factors in reducing the risk for canine distemper outbreaks.

Objectives: To evaluate the consequences of crown shortening, focusing on the prevalence of pulp exposure and periapical pathology in Greenland sled dogs that had had their canine crowns shortened at an early age., Methods: Five cadaver heads and 54 sled dogs underwent an oral examination for dental fractures and pulp exposure of canines. All canines were radiographed and evaluated for periapical pathology., Results: The prevalence of canine pulp exposure in 12 (5 heads and 7 dogs) crown shortened dogs was 91 · 7%, and 21 · 3% in 47 not-crown shortened dogs. A significant (P < 0 · 001) risk of pulp exposure of the canines in the crown shortened group compared to the not-crown shortened group was seen with a relative risk of 4 · 3 on a dog basis and a relative risk of 12 · 2 on a tooth basis. In dogs with pulp exposure of canines (n = 51) the prevalence of periapical pathology was 82 · 4%, but only 0 · 8% in dogs without pulp exposure (n = 133) resulting in a significant (relative risk, 109 · 5; P < 0 · 001) risk of periapical pathology in teeth with pulp exposure compared to teeth without pulp exposure., Clinical Significance: The high risk of periapical pathology observed in teeth with pulp exposure confirms that these teeth should not be neglected in affected dogs., (© 2015 British Small Animal Veterinary Association.)

Skin lesions on pigs inflicted by humans compromise animal welfare and are the subject of increased public and political attention in Denmark. Systematic surveillance of such skin lesions was enforced in April 2010 at all Danish pig abattoirs, through the recording of meat inspection Code 904 for the presence of skin lesions suspected to be human inflicted. The objectives of the present study were to (a) estimate the apparent prevalence of Code 904s at the pig and herd owner level; (b) characterise the distribution of deliveries with pigs demonstrating a Code 904; (c) characterise the distribution of herd owners with repeated Code 904 recordings; and (d) determine the developments in Code 904 prevalence over time in Danish finishing pigs in the period from May 1, 2010 to September 30, 2013. Data from the 12 largest finishing pig abattoirs from Denmark were included and recordings were comprised from 65,504,021 pigs from 651,681 deliveries originating from 10,796 herd owners. Overall, 7200 (0.011%) of the pigs were recorded with a Code 904, and 21% of herd owners had a minimum of one Code 904 delivery with at least one pig with skin lesions inflicted by humans. On the pig-level, the apparent prevalence was 0.020% in 2010, which was reduced to 0.008% in 2013. In the first quarter of the study period, 17% of the herd owners had a Code 904 delivery, while 7% had one in the last quarter. Nine per cent of the herds had more than one Code 904 recording, with up to 16 Code 904 deliveries from one herd owner. Most deliveries included one single pig with a Code 904, but up to 102 Code 904 recordings were made in a single delivery. The apparent prevalence at the four smallest and four middle sized abattoirs decreased from the first to the second quarter, while the apparent prevalence decreased more substantially in the largest four abattoirs; with significant decreases from both the first to the second, and from the second to the third quarter. The study showed that recorded skin lesions suspected to be inflicted by humans are prevalent, but the apparent prevalence decreased from 2010 to 2012 and 2013. The development in Code 904 over time could be due to a real decrease or be due to other factors such as changes in the way the lesions were recorded, while both underestimation and overestimation appeared to be present., (Copyright © 2014 Elsevier B.V. All rights reserved.)

A study based on bulk tank milk samples from 120 randomly selected dairy cattle herds was conducted to estimate the prevalence of Coxiella burnetii seropositive dairy herds, to describe the geographical distribution, and to identify risk factors. Using the CHEKIT Q-fever Antibody ELISA Test Kit (IDEXX), the study revealed a prevalence of 79.2% seropositive herds, 18.3% seronegative herds, and 2.5% serointermediate herds based on the instructions provided by the manufacturer. Multifactorial logistic regression showed statistically significant associations (P < 0.01) between C. burnetii seropositivity and increasing herd size (OR = 1.02 per cow increment) and increasing regional average number of cattle per dairy herd (OR = 1.02 per animal increment). Herds >150 cows had 17.9 times higher odds of testing positive compared to herds <80 cows. The regional average number of cattle herds per square kilometer was borderline significantly related to the occurrence of seropositive dairy herds (P = 0.06). The results indicate an increased prevalence of seropositive dairy herds since the previous survey in 2008 and an adverse impact of increasing herd size and cattle density on the risk of seropositivity.

Antibodies to Coxiella burnetii have been found in the Danish dairy cattle population with high levels of herd and within herd seroprevalences. However, the prevalence of antibodies to C. burnetii in Danish beef cattle remains unknown. The objectives of this study were to (1) estimate the prevalence and (2) identify risk factors associated with C. burnetii seropositivity in Danish beef and dairy cattle based on sampling at slaughter. Eight hundred blood samples from slaughtered cattle were collected from six Danish slaughter houses from August to October 2012 following a random sampling procedure. Blood samples were tested by a commercially available C. burnetii antibody ELISA kit. A sample was defined positive if the sample-to-positive ratio was greater than or equal to 40. Animal and herd information were extracted from the Danish Cattle Database. Apparent (AP) and true prevalences (TPs) specific for breed, breed groups, gender and herd type; and breed-specific true prevalences with a random effect of breed was estimated in a Bayesian framework. A Bayesian logistic regression model was used to identify risk factors of C. burnetii seropositivity. Test sensitivity and specificity estimates from a previous study involving Danish dairy cattle were used to generate prior information. The prevalence was significantly higher in dairy breeds (AP=9.11%; TP=9.45%) than in beef breeds (AP=4.32%; TP=3.54%), in females (AP=9.10%; TP=9.40%) than in males (AP=3.62%; TP=2.61%) and in dairy herds (AP=15.10%; TP=16.67%) compared to beef herds (AP=4.54%; TP=3.66%). The Bayesian logistic regression model identified breed group along with age, and number of movements as contributors for C. burnetii seropositivity. The risk of seropositivity increased with age and increasing number of movements between herds. Results indicate that seroprevalence of C. burnetii is lower in cattle sent for slaughter than in Danish dairy cows in production units. A greater proportion of this prevalence is attributed to slaughtered cattle of dairy breeds or cattle raised in dairy herds rather than beef breeds., (Copyright © 2014 Elsevier B.V. All rights reserved.)

The aim was to identify risk factors associated with Coxiella burnetii antibody positivity in bulk tank milk (BTM) samples from 100 randomly selected Danish dairy cattle herds. Antibody levels were measured by an enzyme-linked immuno-sorbent assay. Before testing the herds, the farm managers were interviewed about hired labour, biosecurity, housing and herd health during the 12 months prior to the study. Variables considered important for C. burnetii antibody positivity in multivariable logistic regression analysis included the sharing of machines between farms (OR = 3.6), human contacts (OR = 4.2), artificial insemination by other people than artificial insemination technicians (OR = 7.7), routine herd health contract with the veterinarian (OR = 4.3) and hygiene precautions taken by veterinarians (OR = 5). In addition, herd size, hired labour, trading of cattle between farms, quarantine and use of calving and disease pens also showed significant association in univariable analysis. This study demonstrates that strict biosecurity is important for the prevention of infections with C. burnetii.

Serological tests for Coxiella burnetii (the causative agent of Q fever) antibodies are usually based on enzyme linked immunosorbent assay (ELISA) although this method is not thoroughly evaluated. The objective of this study was to determine the sensitivity and specificity of an ELISA for detection of C. burnetii antibodies in milk and blood samples, using latent class models in a Bayesian analysis. Blood and milk samples of 568 lactating cows from 17 Danish dairy cattle herds collected in 2008 were used. The best combination of sensitivity and specificity estimates was revealed at a sample to positive (S/P) cut-off of 40 for both blood and milk ELISAs. At this cut-off, sensitivity of milk ELISA was 0.86 (95% posterior credibility interval [PCI] [0.76; 0.96]). This was slightly but insignificantly higher than sensitivity of blood ELISA (0.84; 95% PCI [0.75; 0.93]). The specificity estimates of the ELISA methods on milk and blood were equal at 0.99. No conditional dependence was observed between the specificity estimates of the two test methods. However, the sensitivity estimates of both tests were significantly reduced when conditional covariances ≥ 40 were used. Collection of milk samples from lactating cows is relatively easy, non-invasive and inexpensive and hence milk ELISA may be a better option for screening lactating cows. But, blood ELISA is an option for screening non-lactating cattle., (Copyright © 2012 Elsevier B.V. All rights reserved.)

Eradication of Aleutian disease was initiated in Denmark in 1976. The prevalence of positive farms has since then been reduced from 100% to only being continuously present in the region of Vendsyssel, Northern Denmark since 2004. In this study, we attempted to identify risk factors for the infection in this region based on logistic regression of spatial (environmental, neighbourhood) variables and biosecurity measures. Information on potential biosecurity (management) risk factors in the region was obtained from interviews in 342 registered farms in the region using a structured questionnaire. A total of 279 questionnaires were completed (response rate 82%). Additional spatial variables were included in the analysis. The study shows that farm size (the number of animals in the farm) and proportion of infected neighbouring farms were significant risk factors for infection with Aleutian Mink Disease Virus. These factors account for 35% of the variation of the infection status of mink farms located in Vendsyssel during 2009. These results indicate that only a coordinated effort from the farmers in the area will succeed in eradicating the disease from Denmark, because individual farms that have eradicated the disease will be at risk of re-infection from test-positive neighbours., (Copyright © 2012 Elsevier B.V. All rights reserved.)

The aim of the study was to identify associations between the level of Coxiella burnetii (C. burnetii) antibodies in individual milk samples and cow and herd level factors in Danish dairy cows. The study, designed as a prospective cross sectional study with follow up, included 24 herds identified by a stratified random sampling procedure according to the level of C. burnetii antibodies in one bulk tank milk (BTM) sample at the beginning of the study. Ten herds were BTM positive, ten herds were BTM negative and four herds had an intermediate level. The samples were tested with an ELISA and results determined as S/P (sample to positive control) values. Three cross sectional studies of all lactating cows within each herd were then conducted during an 11 months follow up period with collection of a total of 5829 milk samples from 3116 cows. Each sample was tested with the same ELISA as used for BTM testing, and cows were considered test positive for S/P values ≥ 40, and otherwise negative. Individual cow information was extracted from the Danish Cattle Database and herd information was obtained from a telephone interview with each farmer. From multivariable logistic regression analysis accounting for hierarchical structures in the data it was concluded that odds for seropositivity increased with Danish Holstein breed, increasing number of parity and high milk protein contents, but decreased with increasing milk yield and high milk fat contents. Cows were at a higher risk during summer than other seasons. Among the herd level factors, herd size, tie stall housing system, quarantine of newly purchased animals and good hygienic precautions taken by the veterinarian before entering into the stable were also significantly associated with reduced odds of C. burnetii antibody positivity. The prevalence of test positive cows was almost constant during the study period in herds which were initially BTM positive and BTM intermediate, whilst the prevalence of positive cows in a few of the initial BTM negative herds changed from almost zero to higher than 60%. This indicates that herd infections last quite long and that test negative herds may convert to positive due to a few latently infected cows or due to transmissions from other herds., (Copyright © 2012 Elsevier B.V. All rights reserved.)

Background: Coxiella burnetii is a well-known cause of placentitis and subsequent abortion in ruminants, but there are no reports on the relationship with perinatal mortality. The study was performed to determine the influence of level and change of bulk tank milk (BTM) antibodies to C. burnetii on two outcomes associated with parturition in cattle: a) stillbirth; and b) stillbirth and neonatal mortality combined (perinatal death)., Methods: Twenty-four Danish dairy herds were tested repeatedly for antibodies to C. burnetii in BTM using a commercial ELISA. Samples were collected monthly from July 2008 to July 2009. Information on the 2,362 calvings occurring in the study period was obtained from the Danish Cattle Database. Two multilevel logistic regression models were created for the two outcomes stillbirth and perinatal mortality. One model included the level of BTM antibodies in a specified period before or after the outcome had occurred. The other model included the change in antibodies over time. These predictors were included both at herd and animal level. Furthermore, all models included parity and breed., Results: The individual monthly BTM antibody levels were highly correlated within herds. Consequently, changes in BTM antibody levels were not found to be associated with neither risk of stillbirth nor the risk of perinatal mortality. However, the risk of stillborn calves and perinatal death was higher with high level of BTM antibodies 8 to 9 months after the incident, but not outside this period., Conclusion: We conclude that the level of antibodies to C. burnetii in BTM may be associated with perinatal mortality, but the association was not persistent and should be investigated further.

Milk samples of 12 Danish dairy herds were collected 3 times during an 11-mo period and tested for Coxiella burnetii DNA by real-time PCR, detecting the IS1111 element, and for the presence of antibodies against the bacterium by ELISA. On average, 25% of 1,514 samples were seropositive and 32% were positive for C. burnetii DNA. Among the 485 DNA-positive samples, quantification cycle values ranging from 15.8 to 37.8 were found. Test sensitivity did not increase after DNA extraction from the cream fraction compared with full milk. The relationship between antibody levels and bacterial shedding was investigated among 166 cows from 9 herds. The prevalence levels of C. burnetii DNA and antibodies in the herds were found to be rather stable for 6 of the herds. The test results were highly influenced by results obtained 3 to 7 mo earlier. A significant association between the antibody titer and the DNA shedding level at the same and the preceding visit was found. In addition, a significant association between the antibody titer and the antibody titers 3 to 11 mo earlier was found. A multivariable analysis identified a significant increase in C. burnetii DNA shedding with increasing parity and increasing protein concentration in milk. The antibody levels in bulk tank milk and prevalence levels of C. burnetii DNA and antibodies in individual cow milk samples were correlated. A significant correlation was also found between the quantification cycle values of the cow samples (weighted according to milk yield) and the C. burnetii concentration in bulk tank milk., (Copyright © 2011 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.)

Cotyledons (n=170) from dairy cattle were analysed for Coxiella burnetii by real-time (rt) PCR targeting the IS1111a and icd genes. Positive cases (n=90) and a random selection of negative cases (n=20) were examined by histology, immunohistochemistry and, if infection level was high, by fluorescence in situ hybridisation. PCR results were compared to bulk tank milk (BTM) antibody levels. Placental infection was detected in cows from herds at all BTM antibody levels. However the likelihood of placental infection was generally higher in herds with intermediate or high BMT antibody levels than in herds with low antibody levels. Histological examination revealed a range of mostly mild cotyledonary changes; C. burnetii infection was only rarely associated with inflammation. This may explain why bovine Q fever is usually not clinically apparent. Nevertheless, infected cattle will shed C. burnetii at calving and this can occur even in herds without BTM antibodies., (Copyright © 2010 Elsevier Ltd. All rights reserved.)

During recent years in Denmark higher rates of antibodies to Coxiella burnetii have been detected in animals and humans than previously reported. A study based on bulk tank milk samples from 100 randomly selected dairy herds was performed to estimate the prevalence and geographical distribution of antibody positive dairy herds. Using the CHEKIT Q-Fever Antibody ELISA Test Kit (IDEXX), the study demonstrated a prevalence of 59% antibody positive herds, 11% antibody intermediate herds and 30% antibody negative herds based on the instructions provided by the manufacturer. The geographical distribution does not indicate a relationship between the regional density of dairy farms and the prevalence of antibody positive dairy farms. The result supports the hypothesis of an increase in the prevalence of positive dairy herds compared to previous years.

Background: Several management and environmental factors are known as contributory causes of clinical mastitis in dairy herd. The study objectives were to describe the structure of herd-specific mastitis management and environmental factors and to assess the relevance of these herd-specific indicators to mastitis incidence rate., Methods: Disease reports from the Danish Cattle Data Base and a management questionnaire from 2,146 herds in three Danish regions were analyzed to identify and characterize risk factors of clinical mastitis. A total of 94 (18 continuous and 76 discrete) management and production variables were screened in separate bivariate regression models. Variables associated with mastitis incidence rate at a p-value < 0.10 were examined with a factor analysis to assess the construct of data. Separately, a multivariable regression model was used to estimate the association of management variables with herd mastitis rate., Results: Three latent factors (quality of labor, region of Denmark and claw trimming, and quality of outdoor holding area) were identified from 14 variables. Daily milk production per cow, claw disease, quality of labor and region of Denmark were found to be significantly associated with mastitis incidence rate. A common multiple regression analysis with backward and forward selection procedures indicated there were 9 herd-specific risk factors., Conclusion: Though risk factors ascertained by farmer-completed surveys explained a small percentage of the among-herd variability in crude herd-specific mastitis rates, the study suggested that farmer attitudes toward mastitis and lameness treatment were important determinants for mastitis incidence rate. Our factor analysis identified one significant latent factor, which was related to labor quality on the farm.

Relationships of various reproductive disorders and milk production performance of Danish dairy farms were investigated. A stochastic frontier production function was estimated using data collected in 1998 from 514 Danish dairy farms. Measures of farm-level milk production efficiency relative to this production frontier were obtained, and relationships between milk production efficiency and the incidence risk of reproductive disorders were examined. There were moderate positive relationships between milk production efficiency and retained placenta, induction of estrus, uterine infections, ovarian cysts, and induction of birth. Inclusion of reproductive management variables showed that these moderate relationships disappeared, but directions of coefficients for almost all those variables remained the same. Dystocia showed a weak negative correlation with milk production efficiency. Farms that were mainly managed by young farmers had the highest average efficiency scores. The estimated milk losses due to inefficiency averaged 1142, 488, and 256 kg of energy-corrected milk per cow, respectively, for low-, medium-, and high-efficiency herds. It is concluded that the availability of younger cows, which enabled farmers to replace cows with reproductive disorders, contributed to high cow productivity in efficient farms. Thus, a high replacement rate more than compensates for the possible negative effect of reproductive disorders. The use of frontier production and efficiency/inefficiency functions to analyze herd data may enable dairy advisors to identify inefficient herds and to simulate the effect of alternative management procedures on the individual herd's efficiency.

The accuracy of three diagnostic tests for paratuberculosis was evaluated using maximum-likelihood estimation of sensitivity and specificity. We also explored the variety of estimates that can be obtained if the tests are to be used in populations of different composition with regard to infection and disease states. Two enzyme-linked immunosorbent assays (ELISAs) were evaluated separately with the faecal culture (FC). The study was carried out as a cross-sectional field study to cover all likely states of infection with Mycobacterium avium subsp. paratuberculosis.The three basic assumptions for the maximum-likelihood technique were evaluated to validate the results. Our accuracy estimates for the ELISAs were not very different from those previously published, but those for faecal culture differed if a different cut-off value was chosen for the ELISA. If faecal culture was used for screening in a Danish dairy region where the median ELISA reading was a measure of the general disease situation, the sensitivity of the faecal culture was 20-25%. If faecal culture was used as a confirmatory test on cows with a high ELISA reading (and thus high level of antibodies), the sensitivity of the faecal culture would be in the range 60-70%. These results emphasise the importance of the composition of a target population before selecting a specific diagnostic test for a given purpose. We concluded that faecal culture is useful for confirmation but not for screening purposes.

The objective of this study was to examine transmission of paratuberculosis in dairy cattle attributable to the dam. Milk samples were collected from 8131 cows in 110 Danish dairy herds. The level of antibodies to Mycobacterium avium subspecies paratuberculosis was determined by use of an ELISA. Information on dam and sire was obtained from the Danish Cattle database. The following two data sets were analyzed: Data set A contained all cows < or = 400 days in milk (n = 7410); data set B contained 1056 dam-daughter pairs present simultaneously in herds at the day of sampling. Cows > 400 days in milk were excluded. Linear mixed models were used to obtain variance components for the effect of sire in data set A and the effect of sire and dam-daughter pairs in data set B. Models for both data sets A and B included information previously shown to confound antibody level and information of the relative prevalence of paratuberculosis in the herd. In data set A, the effect explained by sire was 1.9%, whereas it was 6.3% in data set B. The effect from dam-daughter pairs was 7.7%. Those effects were all significant. It was concluded that the parental contribution was significant, and both heritability of susceptibility and vertical transmission should be considered in any control programs on paratuberculosis in dairy cattle.

Dairy herds from three counties in Denmark (n=2144) were monitored for a 1-year period to measure the incidence rate (incidence-density) of clinical mastitis. Two different screening methods were evaluated to remove herds from the database for which the herdsman and veterinarian were suspected of under-reporting the mastitis cases which had occurred. One method was based upon agreement between clinical mastitis reports and measures of somatic cell counts of >1 million cells per ml. A second method was based upon agreement between cases reported through the regular disease-reporting system and cases reported on a management questionnaire. Depending upon the method of calculation and screening method used, rates of clinical mastitis varied between 36 and 48 cases per 100 cow-years at risk. The exclusion of herds because of documented non-reporting behavior (screening) resulted in a preponderance of herds with zero or very low incidence of mastitis being removed from the database. Following screening, the frequency distribution of herd mastitis incidence rates became decidedly more symmetrically and normally distributed.

The present review analyses the documentation on incidence, diagnosis, risk factors and effects of milk fever and subclinical hypocalcaemia. It is hereby evaluated whether the existing documentation seems sufficient for further modelling in a decision support system for selection of a control strategy. Several studies have been carried out revealing an incidence of milk fever most often in the level of 5-10%. Few studies indicate that the incidence of subclinical hypocalcaemia is several times higher than milk fever. The diagnosis based on clinical or laboratory methods or based on presence of risk factors is outlined. The clinical symptoms of milk fever are highly specific and the disease level may thus be determined from recording of treatments. Diagnosis of subclinical hypocalcaemia needs to include laboratory examinations or it may be determined by multiplying the incidence of milk fever by a certain factor. From the documentation on risk factors, it is very complex to predict the incidence from the exposure level of the risk factors. Due to uncertainty, sensitivity analyses over a wide range of values for each parameter are needed. The documentation of cow characteristics, nutrition, environment and management as risk factors are described. Among cow characteristics, parity or age, body condition and production level were found to be important. Risk factors associated with nutrition included most importantly dietary cation-anion difference and calcium level whereas the importance of general feeding related factors like type of feed stuff and feeding level were less clear. Environment and management included season, climate, housing, pasturing, exercise, length of dry period and prepartum milking. Several of the parameters on environment and management were confounded among each other and therefore firm conclusions on the importance were difficult. The documentation of the effect of milk fever includes the downer cows, reproductive disorders, occurrence of other diseases and the effect on milk production, body weight and culling. The reproductive disorders included most importantly dystocia, uterine prolapse, retained placenta, metritis and repeat breeding, and occurrence of other diseases included ketosis, displaced abomasum and mastitis. The documentation was substantial and often quantifiable within certain limits. Overall it is concluded that the present documentation on milk fever concerning incidence, diagnosis, risk factors and effects seems sufficient for a systematic inclusion in a decision support system. A model on milk fever should take into consideration the variation in biological data and individual herd characteristics. The inclusion of subclinical hypocalcaemia would be more uncertain and probably should await further documentation on possibilities of determining the herd level incidence and also the effect of this condition on production.

A competitive environment forces the farmer constantly to adopt new and more-intensive production methods aiming at lowering costs and increasing yields. At debate is whether this intensification of production has an adverse impact on animal health and welfare. We investigated this issue by using cointegration analysis (a new tool used in time series analysis). We introduce cointegration analysis by applying the method in an epidemiological study of dairy-cow mortality. Two long-run epidemiological relations are identified:(i) a physiological relation (where increasing consumption of concentrates corresponded to increasing milk yield and mortality) and (ii) a physical relation (which illustrated that higher mortality was closely related to a higher growth rate of the average herd size, current investments in dairy farming, and higher milk yield). We concluded that a higher level of physiological stress due to higher yield and concentrate consumption has led to increased mortality. Furthermore, changes in the physical environment due to increased mechanisation and larger herd sizes have contributed to less attention per cow and increased mortality.

Diagnostic findings in 218 aborted bovine foetuses are reported. The materials were examined in a matched case-control study of 69 Danish dairy herds with a sudden increase in the number of abortions and a corresponding 69 control herds. Foetuses aborted during the subsequent 6-month period were examined to identify the cause of abortion if possible. A total of 186 specimens were submitted from case herds and 32 from control herds. A likely cause of abortion was diagnosed in 73 foetuses. The most common cause was bovine viral diarrhoea virus (BVDV: 13%) followed by Neospora caninum infection (10%), mycosis (5%) and Bacillus licheniformis infection (4%). Foetal and/or placental lesions were found in a further 27 cases. Only BVDV infection and neosporosis were diagnosed in more than one foetus per herd and only protozoal associated abortions occurred significantly more frequently in the case, rather than in the control, herds.

This paper presents the first part of a questionnaire survey carried out in 2148 Danish dairy herds during 1994, as well as results from a similar survey carried out in 1983. The welfare status in Danish dairy herds with respect to disease management routines currently applied is discussed. In detail this was: recording of mastitis incidents, use of veterinarian for milk fever cases, farmer's effort in reducing incidence of mastitis, milk fever, ketosis, calving problems, and lameness, as well as frequency of claw trimming, reasons for culling, and way of replacing cullings. Furthermore, trends during the 11 year period are discussed. The results show that the Danish dairy farmers in 1994 in general have a substantial knowledge of prevention and treatment of disease. However, adjustments in the following areas would be appropriate: 1) farmers should avoid making intravenous infusions, 2) they should be encouraged to use calving boxes for parturitions, 3) there should be more attention on claw health, and 4) to comply with the new Danish legislation, antibiotic dry cow treatment should only be carried out on the individual cow if pathogenic microorganisms have been isolated within 35 days prior to drying off.

This paper presents the second part of a questionnaire survey carried out in 2148 Danish dairy herds during 1994, as well as results from a similar survey carried out in 1983. The welfare status and trends during the 11 year period are discussed with respect to cattle housing systems and grazing procedures. Generally speaking, the results show that Danish dairy farmers in 1994 followed the common recommendations, i.e. 1) there are partitions between stalls in almost all tie stall houses, 2) feeding cubicles are seldom seen in cubicle houses, 3) bedding is provided for most cows, 4) saw dust as bedding for cows is not commonly used, and 5) the majority of cows and heifers are pastured during summer. However, adjustments in the following areas would be appropriate: 1) tie systems which restrict the cow's natural rising and lying should be phased out, and 2) loose housed heifers in boxes should have access to a bedded resting area.

This paper presents the third part of descriptive results of questionnaire surveys in 152 Danish dairy herds in 1983 and in 2148 dairy herds in 1994. Focus is on working routines related to health management and the close environment of the cows. The variables are grouped in 6 categories as man power, bedding, water supply, manure handling, health management routines, and the farmers' age and their opinion about health and welfare of the dairy cows. The results show that the husbands did the major parts of the job in the herds. Permanent laborers were mainly hired in cubicle and deep bed farms, while it was more common to hire a relief man (short term basis) in tie stall herds-i.e. in the generally smaller herds. The average time spent on milking and feeding per cow per day ranged from 5.2 min in cubicle houses and 5.4 min in deep bed houses to 9.9 min in tie stall houses. The time per cow per day seemed to have been reduced by approximately 43% during the 11 year period. Straw was the primary choice of bedding, and the use varied much among the herds. In tie stall houses with open dung channel and concrete floor the daily average use of straw was 1.74 kg per cow. Only 37.0% of the farmers used bedding for the heifers. Water supply seemed to be well installed in all houses, and dung removal was highly automated. Apart from milking and feeding times the farmers looked after the cows on average twice a day. The farmers primarily looked for cows in heat, signs of disease, calving, and abnormal lying and raising patterns. At night 87.7% of tie stall farmers and 80.8% of cubicle house farmers were likely to check the cows, particularly with respect to calving. In deep bed systems only 58.5% would check the cows at night. Contrary to this, farmers looked after pastured heifers less frequently. Farmers were generally concerned that the cows had a dry period. The average length stated was 6.6 weeks. Farmers were generally satisfied with the health and welfare of the cows. The answers also indicated that farmers differentiated between the 2 concepts, as the correlation between welfare and health was only r = 0.34 (p < 0.001).

Various new developments in livestock production confront the veterinarian. In addition to Integrated Food Chain Quality Control, certification of farms for animal health status and also for production methods is becoming increasingly important. Certification for veterinary practices is forthcoming. In order to optimize national herd health, quantitative information is needed and certain methods have to be improved. The veterinarian must be able to apply new techniques adequately and to interpret disease- and environment-related data properly. Problem areas are highlighted and different ways of dealing with them are elaborated upon. It is concluded that the veterinarian is strategically positioned to solve these problems, but that suitable, complementary training is needed, as well as new quantitative research.

A group of 152 Danish dairy herds infected with Streptococcus agalactiae during 1992 was compared with 177 randomly selected control herds in order to identify factors of importance for the transmission of this bacteria between herds. The diagnosis was based on a laboratory microbiological test on a bulk tank milk sample, and management information was collected by telephone interviews with the farmers. Results from logistic regression clearly indicate that purchase of cows or heifers increases the risk of a new Streptococcus agalactiae herd infection. Hygiene management risk factors inside the farm were also identified.

A total of 578 slaughter pigs from 2 Danish conventional farrow-to-finish operations (Herds a and B) were followed from an age of 14 days to slaughter. Pigs were weighted at 3 weeks intervals and at slaughter and extended post mortem examination of the plucks was done. Regression models with second and third order interaction terms demonstrated that Mycoplasma-like pneumonia, complicated pneumonia, anterior-ventral pleuritis, pericarditis, fissures and atrophic rhinitis, separately and through interactions with other lesions, significantly reduced mean daily gains during specific intervals of the growth period in 2 conventional swine herds. It is likely that the periods of reduced growth reflect the times when the diseases were in the acute and early recovery stages. Maximum estimated reductions in daily gains associated with the combined lesions were 82 grams and 283 grams during the interval 120-140 days in Herds A and B, respectively. Although dorso-caudal pleuritis and parietal pleuritis had minor negative effects during 2 intervals neither had a significant adverse effect on total growth rate in either herd (Paisley et al. 1993). R2 values for the regression models were less than 0.27 showing that the lesions present at slaughter explained less than 27% of the variation in herd mean daily gains during any interval.

A total of 578 slaughter pigs from 2 Danish conventional farrow-to-finish operations (Herds A and B) were followed from an age of 14 days to slaughter. Pigs were weighted at 3 weeks intervals and at slaughter and an extended post mortem examination of the plucks was done. Comparison of growth rates in pigs with and without specific types of lesions by the t-test and those with multiple lesions with regression models demonstrated that Mycoplasma-like pneumonia, complicated pneumonia, anterio-ventral pleuritis, fissures and atrophic rhinitis significantly reduced mean daily gain and increased the time required to reach slaughter weight. The total impact of the lesions in Herd A was an estimated reduction in mean daily gain of 27 grams and a 2 day increase in the interval from 14 days of age until slaughter (MDG14). Decreases in MDG14 in Herd B were more substantial, 98 grams and 16.7 days. Reductions in mean daily gains during the interval from the fourth weighing until slaughter were 31 grams in Herd A and 137 grams in Herd B. Chronic dorso-caudal and parietal pleuritis, without other lesions present, had no significant adverse effects on growth rates in either herd. Interactions between lesions did not significantly alter the estimates. The R2 values obtained for the regression models showed that the presence, absence or extent of lesions at slaughter explained only 13-27% of the variations in growth rates in the 2 herds.