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J van den Broek

Publications and source records attributed to J van den Broek.

At least 19 recordsLinked to original sources
PubMed2006

The assessment of biomarkers in sentinel cattle for monitoring vanadium exposure.

Various potential biomarkers were sampled for vanadium every 3-4 months from Bos indicus beef cattle farmed extensively immediately adjacent (high exposure (HE) group) and two km away (low exposure (LE) group) from a vanadium processing plant, respectively. Vanadium intake (mg vanadium kg(-1) bwt d(-1)) was modelled using environmental and physiological data as inputs. The vanadium intake ranged from 0.57 to 5.44 mg vanadium kg(-1) bwt d(-1) in the HE group and 0.41 to 2.61 mg vanadium kg(-1) bwt d(-1) in the LE group over a five-year period of monitoring. Samples collected from live sentinel animals over the five-year period included caudal coccygeal vertebrae, tail-switch hair, milk, urine, faeces, rib-bone biopsies and a wide range of blood clinical pathology and haematological parameters. The data was analysed for differences in response between the HE and LE groups. Where differences were found, a linear mixed-effects regression model was fitted to model the relationship between the exposure dose and the response variable. The model included the effects of age, duration of exposure and response, and allowed the prediction of the exposure dose given these inputs. Moreover, forty-two adult cattle were slaughtered over the five years. A wide range of tissue samples, rumen content and whole blood were taken from the cattle at slaughter for vanadium determination. In live animals, a difference in response was found between the HE group and LE group with respect to serum albumin (n = 36), monocyte (n = 36) and thrombocyte (n = 36) counts, and hair (n = 2) and faeces (n = 34) vanadium concentrations. No difference in vanadium concentrations could be shown for urine (n = 36), the traditional occupational health biomarker. Regression models are described for serum albumin, monocyte counts, faeces and hair, which showed the most promise as biomarkers. Average concentrations of vanadium in the tissues of slaughtered cattle ranged from 0.08 to 2.94 mg kg(-1) (wet-weight basis) and rumen content contained 16.67 mg kg(-1). Significant correlations were found between the exposure dose (end-dose) just prior to slaughter and the concentrations of vanadium in the coccygeal vertebrae, liver, diaphragm and rib-bone in descending order of magnitude. Other tissues showed poor correlation to the end-dose. Tissue levels of vanadium in healthy cattle include a much wider range than is currently reflected in the literature. The best tissue from slaughter animals for assessing chronic vanadium exposure is probably the liver.

Animals↗
PubMed2005

Quantifying transmission of Campylobacter spp. among broilers.

Campylobacter species are frequently identified as a cause of human gastroenteritis, often from eating or mishandling contaminated poultry products. Quantitative knowledge of transmission of Campylobacter in broiler flocks is necessary, as this may help to determine the moment of introduction of Campylobacter in broiler flocks more precisely. The aim of this study was to determine the transmission rate parameter in broiler flocks. Four experiments were performed, each with four Campylobacter-inoculated chicks housed with 396 contact chicks per group. Colonization was monitored by regularly testing fecal samples for Campylobacter. A mathematical model was used to quantify the transmission rate, which was determined to be 1.04 new cases per colonized chick per day. This would imply that, for example, in a flock of 20,000 broilers, the prevalence of Campylobacter would increase from 5% to 95% within 6 days after Campylobacter introduction. The model and the estimated transmission rate parameter can be used to develop a suitable sampling scheme to determine transmission in commercial broiler flocks, to estimate whether control measures can reduce the transmission rate, or to estimate when Campylobacter was introduced into a colonized broiler flock on the basis of the time course of transmission in the flock.

Animals↗
PubMed2004

Comparative histological studies of mechanically versus manually processed sheep intestines used to make natural sausage casings.

The natural sausage casings industry is large and worldwide, and casings prepared from the small intestine of sheep form a large part of it. Food safety authorities in several countries have been concerned about the risk to consumers from the bovine spongiform encephalopathy (BSE) agent. Although this agent could enter the European small ruminant population via infected feed, there is no evidence that it has. Because the BSE agent introduced experimentally into sheep and goats has a tissue distribution very similar to that found in animals with natural cases of scrapie, the agent would likely be found in the intestine and lymph nodes of some infected sheep from an early age. When natural casings are prepared from the intestine, the ileum (known to be infected in animals with natural cases of scrapie) is removed and the intestine is cleaned such that the inner (tunica mucosa) and outer (tunica serosa and tunica muscularis) layers are removed, leaving only the submucosa. There are two main methods for cleaning the intestine: manual and mechanical. The cleaning efficiency of these two methods was examined in the commercial environment as practiced on healthy sheep considered fit for human consumption in Turkey and Great Britain. The investigation involved a qualitative and quantitative histological approach. There was no significant difference in cleaning efficiency between the two methods, although there was some variation. No Peyer's patches or residues of them were found in any part of the cleaned casings. This finding is important because in sheep infected with transmissible spongiform encephalopathies (TSEs) Peyer's patches are likely to contain a major part of the intestinal infectivity. No serosa was found in any casing, but some residual mucosa and muscularis was retained, with more of the former than the latter. The results indicate that the cleaning efficiency of the two methods was broadly equivalent, that there was significant removal of tissue that could promote TSE infection, and that TSE risk reduction likely would be achieved by both methods, although this probability could not be quantified by the methods used in this study.

Animals↗
PubMed2003

In vitro growth of mastitis-inducing Escherichia coli in milk and milk fractions of dairy cows.

The outcome of E. coli mastitis in cows ranges from mild to severe in individual animals. This study explored the hypothesis that milk from individual cows differs in its growth medium properties for E. coli, and whether possible variation could be related to specific milk constituents. To mimic the early phase of intramammary E. coli infection, a low inoculum size and a short incubation period were used. Cell-reduced, cell- and fat-free (skim) and cell- and fat-free and protein-reduced (whey) fractions were prepared from whole milk samples (n=18). Ten ml of whole milk, milk fractions and brain heart infusion broth (BHI) were inoculated with approximately 100cfu E. coli. After 6h of incubation, bacterial counts were assessed by dilution plating in triplicate. Bacterial counts in whole milk differed up to a 100-fold between cows, which was not associated with SCC. Bacterial counts were significantly higher in whey fractions than in whole milk, cell-reduced and skim fractions and variation in whey was smaller, indicating that the acid-precipitable protein fraction contains the milk constituents of major relevance for inhibition of and variation in bacterial growth. The presence of fat and cells added to bacterial growth inhibition to a lesser extent. In conclusion, in vitro growth of E. coli in milk differs substantially between individual cows within an incubation period comparable with the early phase of intramammary infection. This suggests that the growth medium properties of milk could be of importance in the pathogenesis of E. coli mastitis and subsequent outcome of disease.

Animals↗
PubMed2002

Intestinal calcium absorption in growing dogs is influenced by calcium intake and age but not by growth rate.

The effects of calcium (Ca) intake (V(I)), age and growth rate on intestinal Ca absorption were studied in growing dogs. Two breeds of dogs differing in their growth rate (67 Great Danes and 23 Miniature Poodles) were raised on diets differing only in their Ca content (range 0.33 to 3.3 g/100 g diet on a dry matter basis). Repetitive Ca balance studies were performed with the aid of (45)Ca from 6 wk (i.e., after weaning) until 6 mo of age. Several models were investigated expressing true Ca absorption (V(a)) as a function of V(I), breed and age. V(a) was directly proportional to a function close to V(I)(0.82) being a continuation of the high Ca needs for mineralization of the growing skeleton. This curvilinear relationship between V(a) and V(I) and the inverse relationship between fractional Ca absorption and V(I) indicated the presence of active and passive Ca absorption in weaned growing dogs. A model in which these two components of Ca absorption can be discerned revealed that active Ca absorption underwent age-dependent changes, whereas passive absorption remained constant and accounted for 53% absorption of the V(I). At low V(I), active absorption contributed to a significant part of the V(a), whereas at excessive V(I) active absorption was negligible and passive absorption was the driving force for causing supra positive Ca balance. Intestinal Ca handling did not differ between breeds with dramatically different mature body size and growth rates.

Aging↗
PubMed2001

Relationships of age and shape of the navicular bone to the development of navicular disease: a radiological study.

Estimating the shape of the proximal articular border of the navicular bone and grading the radiological navicular bone condition (grades 3 and 4 representing the most severe changes), the aim of this study was to assess potential age-related implications of the previously reported shape predisposition to navicular disease in 746 normal and 174 clinically affected Dutch Warmbloods age 3-19 years. A significant, age-independent, shape-grade association found in normal and affected horses emphasises the fundamental character of the shape predisposition to navicular disease. A significant age-related increase of the least susceptible shape prevalence was found in elderly normal horses. A shape-independent low grades 3 and 4 prevalence (mean 15%) was found in normal horses, vs. a high grades 3 and 4 prevalence (mean 85%) in the affected horses. Therefore, the clinical manifestation of the disease is grade-rather than shape-dependent. A significant age-related appearance of inverted flask-shaped channels and enthesophytes was found in the clinically affected horses. However, considering the significant shape-radiological features association previously reported in 3-year-old normal horses, this association may be shape- rather than age-dependent.

Animals↗
PubMed2001

Diversity and seasonal fluctuations of the dominant members of the bacterial soil community in a wheat field as determined by cultivation and molecular methods.

There is a paucity of knowledge on microbial community diversity and naturally occurring seasonal variations in agricultural soil. For this purpose the soil microbial community of a wheat field on an experimental farm in The Netherlands was studied by using both cultivation-based and molecule-based methods. Samples were taken in the different seasons over a 1-year period. Fatty acid-based typing of bacterial isolates obtained via plating revealed a diverse community of mainly gram-positive bacteria, and only a few isolates appeared to belong to the Proteobacteria and green sulfur bacteria. Some genera, such as Micrococcus, Arthrobacter, and Corynebacterium were detected throughout the year, while Bacillus was found only in July. Isolate diversity was lowest in July, and the most abundant species, Arthrobacter oxydans, and members of the genus Pseudomonas were found in reduced numbers in July. Analysis by molecular techniques showed that diversity of cloned 16S ribosomal DNA (rDNA) sequences was greater than the diversity among cultured isolates. Moreover, based on analysis of 16S rDNA sequences, there was a more even distribution among five main divisions, Acidobacterium, Proteobacteria, Nitrospira, cyanobacteria, and green sulfur bacteria. No clones were found belonging to the gram-positive bacteria, which dominated the cultured isolates. Seasonal fluctuations were assessed by denaturing gradient gel electrophoresis. Statistical analysis of the banding patterns revealed significant differences between samples taken in different seasons. Cluster analysis of the patterns revealed that the bacterial community in July clearly differed from those in the other months. Although the molecule- and cultivation-based methods allowed the detection of different parts of the bacterial community, results from both methods indicated that the community present in July showed the largest difference from the communities of the other months. Efforts were made to use the sequence data for providing insight into more general ecological relationships. Based on the distribution of 16S rDNA sequences among the bacterial divisions found in this work and in literature, it is suggested that the ratio between the number of Proteobacteria and Acidobacterium organisms might be indicative of the trophic level of the soil.

Bacteria↗
PubMed1999

Complementation of a gl-deficient feline herpesvirus recombinant by allotopic expression of truncated gl derivatives.

The alphaherpesvirus glycoproteins gE and gI form a hetero-oligomeric complex involved in cell-to-cell transmission. The gI-deficient recombinant feline herpesvirus (FHV), FHVdeltagI-LZ, produces plaques that are only 15% the size of those of wild-type FHV. Here, we have complemented FHV(delta)gI-LZ allotopically by expressing intact gI and C-terminally truncated gI derivatives from the thymidine kinase locus. The effect on gE-gI-mediated cell-to-cell spread was assessed by plaque assay employing computer-assisted image analysis (software available at http://www.androclus.vet.uu.nl/spotter/spotter.htm+ ++). Allotopic complementation with intact gI fully restored plaque size. Deletion of the C-terminal 11 residues of gI did not affect cell-to-cell spread, whereas deletion of the complete cytoplasmic tail reduced plaque size by only 35%. Mutants expressing gI166, roughly corresponding to the N-terminal half of the ectodomain, displayed a small-plaque phenotype. Nevertheless, their plaques were reproducibly larger than those of matched gI-deficient controls, indicating that the gE-gI166 hetero-oligomer, though crippled, is still able to mediate cell-to-cell spread. Our data demonstrate that plaque analysis provides a reliable and convenient tool to measure and quantitate gE-gI function in vitro.

Alphaherpesvirinae↗
PubMed1998

Flow cytometric measurement of neutrophil alkaline phosphatase before and during initiation of an induced Escherichia coli mastitis in cattle.

In 12 healthy cows, neutrophil alkaline phosphatase (NAP) activity was measured by flow cytometer before and during an experimentally induced Escherichia coli mastitis, to study the role and increase of NAP in Gram-negative bacterial infections. Percentage of neutrophils containing alkaline phosphatase and intensity of NAP activity were measured. Preinfection percentage of neutrophils with enzyme activity varied between 64.0% and 84.4% and the intensity of enzyme activity was low in all cows. After induction of infection, percentage of neutrophils with enzyme activity showed a significant decrease on day 1 followed by an significant increase on day 3. NAP intensity increased significantly on the second and third day after infection. This increase of intensity was significantly, positively correlated with the severity of infection. From this study we may conclude that variation in susceptibility to E. coli mastitis could not be explained by preinfection NAP levels. The post-infection increase of NAP activity, that was found following an induced infection was more a result of increased enzyme intensity per neutrophil, then from an increase of percentage neutrophils with enzyme activity. Furthermore, a strong correlation was found between NAP intensity and severity of inflammation. There was evidence that the more severely diseased animals showed stronger NAP intensity increase.

Alkaline Phosphatase↗
PubMed1998

Evaluation of a sustained 7-year health education campaign on leprosy in Rufiji District, Tanzania.

To assess the impact of a 7-year intensive health education campaign about leprosy delivered by workers of the Kindwitwi Leprosy Trust to schoolchildren and general public in Rufiji District. Knowledge, attitude and beliefs towards leprosy were measured in Rufiji and compared to neighbouring Kisarawe District as control. Lessons learned from this analysis may be useful for the planning and evaluating of health education campaigns. Interview of schoolchildren, general public, community leaders, traditional healers and medical staff in both districts. A stratified randomized sampling scheme was used, with stratification for urban and rural settings. A representative sample of schoolchildren, general public, community leaders, traditional healers and medical staff in Rufiji District and in the control area of Kisarawe District was interviewed. The interviews were partly structured and partly open. The results of the interviews were analysed in the context of epidemiological leprosy data from 1985 till 1995, and demographic data of both districts. Data entry and statistical analysis was done using FileMaker Pro, Stata and Excel computer packages. We did not observe positive effects of the health education campaign on the indicators regarding early diagnosis of leprosy with less disability. Leprosy case detection was declining in both districts. We found that the campaign had a favourable impact on the knowledge and the attitude of schoolchildren in Rufiji District. We could demonstrate a relationship between increased knowledge of leprosy and a positive, less stigmatizing attitude. Knowledge of leprosy was better in Rufiji as compared to Kisarawe, but only among schoolchildren. We found indications that low level of education, rural residence, older age, female gender and Moslem religion were associated with stigmatizing attitudes and beliefs towards leprosy. Knowledge about leprosy reactions among medical staff interviewed was not optimal. The exact outcome of the sustained campaign in Rufiji District was difficult to assess because no comparison could be made with the situation prior to the campaign. However, the health education campaign was associated with increased knowledge and diminished tendency to stigmatize leprosy among schoolchildren. Health education campaigns have to be sustained and have to cover a broad sector of the society in order to induce behavioural changes in the community. The focus of health education should be rural communities and schools, and pay special attention to women, religious leaders and traditional healers. Awareness of diagnosis and treatment of leprosy reactions among medical staff should be improved.

Adolescent↗
PubMed1998

Impact of human immunodeficiency virus infection on the outcome of treatment and survival of tuberculosis patients in Mwanza, Tanzania.

SETTING: Little is known about the outcome of tuberculosis (TB) treatment and subsequent survival of human immunodeficiency virus (HIV) infected patients treated under routine programme conditions in a developing country. We followed a cohort of HIV-positive and HIV-negative tuberculosis patients during therapy and assessed their vital and tuberculosis status 3 years after completion of treatment in Mwanza, Tanzania. METHODS: Newly diagnosed and relapse tuberculosis cases consecutively registered over a 6-month period were enrolled into an epidemiological study of TB/HIV. Treatment outcome was based on information in tuberculosis treatment registers. Patients surviving treatment were assessed 3 years later by personal interview. Cause of death was determined by verbal autopsy. RESULTS: Of 561 patients enrolled into the study, 505 patients alive at completion of treatment were eligible for assessment at 3 years. Except for mortality, HIV infection was not statistically associated with differing treatment outcomes. At time of follow-up, the overall mortality was 19% and was associated with HIV infection (hazard ratio [hr] 3.7, 95% confidence interval [CI] 2.6-5.2) and age 35 years and over (hr 1.5, 95% CI 1.02-2.1), but not with type of tuberculosis, gender, or initial drug resistance. By life table analysis, probability of survival at 4 years was 35% for HIV-positive patients compared to 90% for HIV-negative patients. Although no relapse cases were diagnosed, verbal autopsy suggested equivalent low rates of relapse in both groups. CONCLUSION: These results demonstrate the effectiveness of the current approach to the treatment of tuberculosis patients regardless of HIV status. However, HIV-related mortality remains high both during and following completion of treatment, and further studies are needed to determine if this mortality might be reduced by simple interventions which are feasible in developing countries.

Adolescent↗
PubMed1997

Relationship between sperm-zona pellucida binding assays and the 56-day nonreturn rate of cattle inseminated with frozen-thawed bull semen.

Assays based on sperm-zona pellucida binding have been developed as diagnostic tests to predict the fertilizing potential of mammalian spermatozoa. Recently, we reported on the development of a sperm-zona pellucida binding assay (SZBA) for bull spermatozoa. The aim of the present study was to develop a hemi-zona assay (HZA) for bull spermatozoa and to investigate the relationship between SZBA and HZA outcomes and in vivo fertility. Frozenthawed semen samples from 8 fertile Swedish Red and White bulls (one ejaculate per bull) designated as the test semen samples and a single ejaculate from a fertile Holstein-Friesian bull designated as the control semen sample were used in this study. In the SZBA, 2 groups of 20 oocytes per semen test sample and in the HZA a minimum of 6 matching pairs of hemizonae were used for comparison of sperm binding with control semen. Sperm binding to matching hemi-zonae of individual semen samples was equal, and clearly demonstrated the feasibility of the HZA for cattle. A significant correlation was found between the SZBA and the HZA indices obtained from the different semen test samples (r = 0.42, P < 0.001; n = 67). There was no significant relation between the SZBA indices and the 56-d nonreturn rate of the test samples. However, the HZA indices of the semen test samples and the 56-d nonreturn rate were significantly correlated (r = 0.46, P < 0.0001; n = 67). It is concluded that HZA can be regarded as a potential assay for predicting the fertilizing ability of bovine semen samples. However, further studies using more semen samples are necessary to confirm this view.

Journal Article↗
PubMed1997

Association between leprosy and HIV infection in Tanzania.

SETTING: An epidemiological study of the interaction of leprosy and HIV infection in Tanzania. OBJECTIVE: To establish the prevalence of HIV infection among leprosy patients, and to measure the association of HIV and leprosy by comparing the HIV prevalence in leprosy patients and blood donors. DESIGN: Testing for HIV infection in consecutively diagnosed leprosy patients (new and relapsed after MDT) in all regions in Tanzania successively for a period of 3 to 6 months during 1991, 1992 and 1993. RESULTS: Out of the total estimated eligible leprosy patients, 697 patients (69%) entered the final analysis. The HIV prevalence among these leprosy patients was 12% (83/697) as compared to 6% (8960/ 158,971) in blood donors examined in Tanzania during the same period. There were no significant differences in HIV seroprevalence by age, sex, residence or type of disease. However, the adjusted odds ratio (OR) of the presence of a BCG scar was 1.9 [95% confidence interval (CI) 1.1-3.3] among HIV-positive leprosy cases compared to HIV-negative leprosy cases. Comparing leprosy cases with blood donors as controls, the logistic regression model, controlling for sex, age group and residence, showed the OR for HIV seropositivity among leprosy patients to be 2.5 (95% CI 2.0-3.2). This association existed in all strata, but was strongest in the 15-34-year age group. No difference of HIV status between multibacillary and paucibacillary leprosy could be shown to exist. The point estimate of the population attributable risk of HIV infection for leprosy was 7%. CONCLUSION: HIV infection is associated with leprosy and might reverse the epidemiological trend of the slow decline in case notification in Tanzania if HIV infection is increasing greatly. Previous BCG vaccination loses its protection against leprosy in the presence of HIV infection. A repeated study is recommended in order to validate these findings, whereby recording of the disability grading of the cases is necessary to adjust for delay in diagnosis.

Adolescent↗
PubMed1996

Within day and between day variation of the in vitro under agarose chemotaxis assay in bovine.

The present study was conducted to determine within day variation (experiment I) and between day variation (experiment II) of the in vitro under agarose chemotaxis assay. Further, results from experiment II were used to estimate a more stable immunological parameter for the chemotactic activity. In experiment I, blood samples of eight cows were taken every 4 h starting at 0800 during a 24 h period. This procedure was replicated on three different days with peripheral white blood cells of lactating bovine. Chemotactic differential showed variation within a day. The differences between samplings were not constant over the days, but varied randomly from day to day. In experiment II, 12 cows were followed for 8 consecutive days and blood samples for chemotaxis assay were taken once a day at 0730. Differences between the days were significant. With a conditional auto regression model of the first order adjusted least squares means of each cow were estimated over the 8 consecutive days. The chemotactic value of a day was used to estimate the value of the next day. Expanding the model with more previous days did not improve the model. The results of this study indicate that blood samples for chemotaxis should be taken at the same time of the day to control for within day variation. If a sequence of chemotactic values is available we strongly suggest working with adjusted least square means of chemotactic differentials. These adjusted means show less random variation and are a more stable parameter for chemotactic activity.

Animals↗
PubMed1996

Risk of recurrence of repeat breeding in sows with a repeat breeding in the first parity.

Risk of recurrence of repeat breeding in sows with a repeat breeding in the 1st parity was investigated in 241 sow herds (1985-1990). The association between repeat breeding in the 1st and subsequent parities was examined using data on 9,120 sows. Each sow contributed only one pair of observations to the total data set. Occurrence of repeat breeding in the 1st and higher parities was presented in terms of recurrent risk rates (rRR), adjusted for different strata of herds. Sows with a repeat breeding in the 1st parity did not have a significantly higher risk rate for recurrence of a repeat breeding in the 2nd parity (rRR = 1.12, 95% confidence interval .97-1.29) and in the 3rd parity (rRR = 1.10, 95% confidence interval .86-1.41) compared to sows without a repeat breeding in the 1st parity. Sows with a repeat breeding in the 1st parity had a slightly higher risk rate for recurrence of a repeat breeding in the 4th or higher parity (rRR = 1.07, 95% confidence interval 1.03-1.10), compared to sows without a repeat breeding in the 1st parity. However, this risk is, in a biological sense, very small.

Animals↗
PubMed1995

Relation between stallion sperm binding to homologous hemizonae and fertility.

The hemizona assay (HZA) has been developed as a diagnostic test to predict the fertilisation potential of human spermatozoa. The aim of this study was to develop an HZA for stallion spermatozoa and to investigate a possible relationship between fertility and the outcome of the HZA in this species. Equine oocytes were obtained from ovaries collected at a slaughterhouse and by transvaginal, ultrasound-guided follicle aspiration. They were then denuded from cumulus cells and stored in salt solution at 4 degrees C until use. On the day of the experiments the oocytes were bisected, thus providing 2 equal matching hemizonae from each oocyte. Semen samples from Dutch Warmblood stallions with known fertility data were used to assess the number of spermatozoa bound to the outer side of the hemizona after incubation in vitro. Sperm binding to matching hemizonae of a particular stallion was similar and confirmed the feasibility of using the HZA for the horse. Sperm hemizona binding capacity of 10 pairs of stallions was compared by incubating 1 hemizona with the semen of a stallion and the matching hemizona with the semen of another stallion from the same stud farm. Five matching pairs of hemizonae were used for each pair of stallions. There was a significant relationship between the mean number of spermatozoa bound to matching hemizonae and the fertility indices of stallions from each stud farm (P < 0.0001). It is concluded that HZA can be used as a valuable parameter in stallion semen analysis.

Journal Article↗
PubMed1995

Role of navicular bone shape in the pathogenesis of navicular disease: a radiological study.

From progeny lists of 30 Dutch Warmblood sires, 586 3-year-old females by these stallions were randomly selected, each progeny group aimed at 20 animals for statistical reasons. The front feet of the sires and female progeny were examined radiographically using lateromedial and dorsopalmar upright pedal projections. The radiological features associated with navicular disease were classified 0-4 using a standardised classification, grades 3 and 4 representing the more severe changes. The shape of the proximal articular border of the navicular bone outline on the dorsopalmar view was classified 1-4; 1=concave; 2=undulating; 3=straight; 4=convex. A significant shape-grade association was found, the highest grades 3 and 4 incidence demonstrated by shape 4. In shapes 1 and 2, navicular bones grades 3 and 4 features were mainly characterised by inverted flask-shaped channels. In shape 3, navicular bones grades 3 and 4 were dominated by enthesiophytes. These findings indicate an apparent shape predisposition to radiological changes associated with navicular disease. The shape of the navicular bone in the offspring was on average the same as the sire, indicating an hereditary element in navicular bone shape.

Animals↗