Publications by authors named "John Vanleeuwen"

Humans and dogs commonly share the same domestic environment. Europe, and Italy specifically, have a substantial and growing dog population. Potentially zoonotic parasites may be harbored even by dogs receiving regular veterinary care.

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The Atlantic Johne's Disease Initiative (AJDI) aims to control Mycobacterium avium ssp. paratuberculosis infection by using veterinary-administered risk assessments to identify high-risk management practices and prompt changes in management behavior. Objectives for this study were to measure producer satisfaction with the veterinary-administered risk assessment and management plan (RAMP) process in a voluntary Johne's disease (JD) control program, compare RAMP-specific satisfaction results based on herd JD status, and measure knowledge transfer from certified veterinarians to producers during the RAMP.

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In food animal production medicine (FAPM), the success of control programs for infectious diseases that have serious animal health and economic consequences frequently rely on the veterinarian's effective communication and producer adherence to veterinary recommendations. However, little research has been conducted on communication skills of practicing FAPM veterinarians. During this study, we developed a communication training workshop intervention to support the Atlantic Johne's Disease Initiative.

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This trial evaluated average daily gain (ADG) effects of heifer calves (< 1 year old) from affordable housing improvements to the roof and flooring on 150 randomly allocated smallholder dairy farms. During the 16-month data collection period, bimonthly farm visits were used to measure weight and other animal- and farm-level factors on the 187 study calves. Multivariable linear regression was used to model ln ADG and ADG during pre-weaning and post-weaning periods, respectively.

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Article Synopsis
  • The study aimed to investigate the management factors influencing lamb mortality in sheep flocks in Prince Edward Island, analyzing data from 50 lambing groups across 36 farms during the 2014-15 seasons.
  • It found that the average lamb mortality rate was 10.0%, with 25 groups exceeding this figure, which is above standard productivity goals.
  • Four key management areas identified that could help decrease lamb mortality included improved flock management practices, better ewe nutrition, close veterinary collaboration, and specific health interventions for lambs.
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Subclinical Ruminal Acidosis (SARA) and Subclinical Ketosis (SCK) are two of the most prevalent metabolic diseases of dairy cows, with impacts on reproductive performance. There is scarce literature about these diseases in dairy regions in Colombia. In 29 randomly selected herds in Pasto, Colombia, 249 dairy cows were followed weekly for two months postpartum to determine: 1) incidence risk of SARA and SCK; and 2) effects of SARA and SCK on the occurrence of postpartum anestrus (PA) at two months.

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Although many studies on the frequency of endoparasites in dogs and cats in Canada have been reported, seasonal and/or annual patterns are often not evaluated. The frequency and risk factors of endoparasite infections from fecal samples of cats and dogs submitted to the Veterinary Teaching Hospital of the Atlantic Veterinary College, University of Prince Edward Island-Canada were determined, using univariable and multivariable logistic regression analyses. Investigated predictors of endoparasitism available in the 2000-2017 database included sex, age, geographic origin and seasonality.

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The aim of the study was to determine the antibody sero-prevalence of Bovine Herpesvirus-1 which cause Infectious Bovine Rhinotracheitis (IBR) and to identify risk factors associated with BHV-1 antibody seropositivity among smallholder dairy farms in Meru County, Kenya. A cross-sectional study was conducted in the Naari area of Meru County, Kenya between September-October 2016 and March-April 2017. The 149 farmers were randomly selected from members of the Naari Dairy Farmers Cooperative Society who were actively delivering milk to the society at the time of the study.

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Our study aimed to evaluate farmers' compliance in implementing recommendations of farm-specific cow comfort changes, and the effects of these changes on lying time, stall cleanliness and cow cleanliness using a randomized controlled trial carried out on 100 smallholder dairy farms in Kenya, with 62 and 11 farms remaining in the intervention and control groups, respectively. On the first farm visit, data loggers were attached on lactating cows to determine lying time and questionnaires utilized to collect baseline data. Three days later, stall design and management recommendations were given to the intervention group of farmers orally and in written form.

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This paper highlights the factors likely to influence the economic efficiency of small-scale dairy farms in Mukurweini, Nyeri County, Kenya. A total of 91 small-scale dairy farms previously involved in a nutritional training in 2013 were administered with semi-structured questionnaires. Data collected were entered into SPSS and FRONTIER 4.

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Background: No comprehensive studies have been carried out on the infectious causes of abortion in Kenyan dairy cattle herds. A survey was carried out to determine the seroprevalence of antibodies against Bovine Viral Diarrhoea Virus (BVDV), Brucella abortus (BA) and Neospora caninum (NC) among dairy cattle herds in Nakuru County, a major dairying area in Kenya. A prospective sero-epidemiological study was also undertaken to investigate the effects of BVDV, BA and NC on the occurrence of bovine abortion in dairy cattle herds, where monthly rectal palpations for pregnancy were performed, and monthly serum samples were tested for antibodies to the 3 pathogens.

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Aim: The study was to evaluate the relationship between the first service conception (FSC) and milk urea nitrogen (MUN) in smallholder dairy farms under heat and humidity stress.

Materials And Methods: Dairy cows from 43 dairy farms giving birth between November 2014 and April 2015 (n=295) contributed to the study. All cows were sampled monthly to measure milk compositions, and we collected additional farm data from farmers through a questionnaire.

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Blood samples were collected from late-gestation ewes to determine the agreement of a point-of-care (POC) Precision Xtra meter and a standard laboratory test for β-hydroxybutyrate (BHBA). Fresh whole blood samples were immediately tested with the POC instrument, and serum samples were analyzed with a standard commercial biochemical analyzer. Ewes were classified as having ketonemia if their BHBA concentrations were ≥800 µmol/L.

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Aim: The study was to determine seasonal fluctuations and non-nutritional factors associated with bulk tank milk urea nitrogen(BTMUN).

Materials And Methods: A total of 58,364 BTM testing records were collected from 2364 farms in Central Thailand during September 2014-August 2015. Using square root BTMUN as the outcome, other milk components, farm effect, and sampling time were analyzed by univariable repeated measures linear regression, and significant variables were included in multivariable repeated measures linear regression.

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Late-gestation ewes are susceptible to ketonemia resulting from high energy requirement for fetal growth during the last few weeks of pregnancy. High lamb mortality is a possible consequence of effects of ketonemia on both ewes and lambs. Determining risk factors to ketonemia is a fundamental step to identify ewes at risk, in order to avoid losses caused by ketonemia.

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Enzootic bovine leukosis (EBL) is an economically important disease of dairy cattle caused by bovine leukemia virus (BLV). The economic impacts of the infection have been debated in the literature. The present study was conducted to determine the lifetime effects of BLV infection on longevity and milk production of dairy cows in Canada.

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Aim: Gastrointestinal diseases are among the leading causes of calf morbidity and mortality in Kenya and elsewhere. This study was undertaken to determine the prevalence of Cryptosporidia, Eimeria, Giardia, and Strongyloides in calves on smallholder dairy farms (SDF) in Mukurwe-ini District, Nyeri County, Kenya. These infections have been associated with economic losses by decreased growth rates, decreased productivity, and increased susceptibility to other diseases.

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There is limited field-based research and recommendations on the effect of cattle feeding management practices on smallholder dairy farms (SDF) for the growing dairy industry in Kenya. This controlled trial aimed to determine the effect of feeding locally produced dairy meal (DM) on early lactation daily milk production (DMP) on Kenyan SDF, controlling for other factors associated with DMP. Privately owned, recently calved cows (n=111) were randomly assigned to one of three groups of feeding recommendations for DM (meeting predicted DM requirements by: (1) 100%; (2) 50%; or (3) feeding by the farmer's discretion).

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A new portable x-ray fluorescence (XRF) screening tool was evaluated for its effectiveness in arsenic (As) quantification in human finger and toe nails ([Formula: see text]). Nail samples were measured for total As concentration by XRF and inductively coupled plasma-mass spectrometry (ICP-MS). Using concordance correlation coefficient (CCC), kappa, diagnostic sensitivity (Sn) and specificity (Sp), and linear regression analyses, the concentration of As measured by XRF was compared to ICP-MS.

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Enzootic bovine leukosis (EBL) is an economically important infection of dairy cattle caused by bovine leukemia virus (BLV). Estimating the prevalence of BLV within dairy herds is a fundamental step towards pursuing efficient control programs. The objectives of this study were: (1) to determine the prevalence of BLV infection at the herd level using a bulk-tank milk (BTM) antibody ELISA in the Maritime region of Canada (3 provinces); and (2) to develop appropriate statistical models for predicting within-herd prevalence of BLV infection using BTM antibody ELISA titers.

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Enzootic bovine leukosis (EBL) is an economically important infection of dairy cattle worldwide, which is caused by bovine leukemia virus (BLV). The prevalence of infection in Canadian dairy herds is high and continues to increase; however, there has not been a national program to control BLV. This cross-sectional study was conducted to identify potentially important risk factors for BLV infection on Canadian dairy herds, which is a prerequisite to developing an effective control program.

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Aim: Cows on smallholder dairy farms (SDF) in developing countries such as Kenya typically produce volumes of milk that are well below their genetic potential. An epidemiological study was conducted to determine reasons for this low milk production, including limited use of best management practices, such as suboptimal nutritional management.

Methods: An observational cross-sectional study of 111 SDF was performed in Nyeri County, Kenya in June of 2013 determining the effect of cow factors, farmer demographics and farm management practices on the volume of milk sold per cow per year (kg milk sold/cow).

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This study investigated the overwintering survival and infectivity of free-living gastrointestinal nematode (GIN) stages on pasture. The presence of GIN larvae was assessed on 3 sheep farms in Ontario with a reported history of clinical haemonchosis, by collecting monthly pasture samples over the winter months of 2009/2010. The infectivity of GIN larvae on spring pastures was evaluated using 16 tracer lambs.

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