scholarly journals Prevalence of Bovine Leukemia Virus Antibodies in US Dairy Cattle

2018 ◽  
Vol 2018 ◽  
pp. 1-8 ◽  
Author(s):  
Rebecca M. LaDronka ◽  
Samantha Ainsworth ◽  
Melinda J. Wilkins ◽  
Bo Norby ◽  
Todd M. Byrem ◽  
...  
Keyword(s):  
Dairy Cattle ◽  
Dairy Cows ◽  
Bovine Leukemia Virus ◽  
Leukemia Virus ◽  
Herd Size ◽  
Cross Sectional ◽  
Herd Level ◽  
Apparent Prevalence ◽  
Observational Study Design ◽  
Epidemiologic Features

Objective. To estimate current US herd-level and animal-level prevalence of bovine leukemia virus (BLV) in dairy cows and characterize epidemiologic features. Design. Cross-sectional observational study design and survey. Animals. 4120 dairy cows from 103 commercial dairy herds in 11 states across the US. Procedures. Milk samples were collected from dairy cows through routine commercial sampling and tested for anti-BLV antibodies by antibody capture ELISA. Based on the ELISA results of a sample of an average of 40 cows per herd, within-herd apparent prevalence (AP) was estimated by a directly standardized method and by a lactation-weighted method for each herd. Within-herd AP estimates were summarized to give estimates of US herd-level and animal-level AP. Differences in AP by lactation, region, state, breed, and herd size were examined to characterize basic epidemiologic features of BLV infection. Results. 94.2% of herds had at least one BLV antibody positive cow detected. The average within-herd standardized AP was 46.5%. Lactation-specific AP increased with increasing lactation number, from 29.7% in first lactation cows to 58.9% in 4th and greater lactation cows. Significant differences were not observed based on region, state, breed, or herd size. Conclusions and Clinical Relevance. These results are consistent with a historical trend of increasing prevalence of BLV among US dairy cattle. Given the findings of other studies on the negative impacts of BLV infection on milk production and cow longevity, these findings are clinically relevant for veterinarians counseling dairy clients on the risks of BLV to their herds.

scholarly journals Bayesian Estimation of the True Seroprevalence and Risk Factor Analysis of Bovine Leukemia Virus Infection in Pakistan

Animals ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 1404
Author(s):  
Ali Sakhawat ◽  
Marzena Rola-Łuszczak ◽  
Zbigniew Osiński ◽  
Nazia Bibi ◽  
Jacek Kuźmak
Keyword(s):  
Risk Factor ◽  
Dairy Cattle ◽  
Bovine Leukemia Virus ◽  
Water Buffalo ◽  
Leukemia Virus ◽  
Credible Interval ◽  
Indigenous Cattle ◽  
Herd Level ◽  
Exotic Breed ◽  
Posterior Estimate

The objective of this study was to determine the true seroprevalence of bovine leukemia virus (BLV) infection in dairy cattle from Pakistan at the animal and herd-level. We tested 1380 dairy cattle from 451 herds and 92 water buffalo. The sera were tested by ELISA and the results were analyzed using Bayesian inference. The median posterior estimate of the herd level true BLV prevalence was 1.4%, with a 95% credible interval (CI) 0.7–3.1, whereas the median posterior estimate of the within-farm true seroprevalence was 3.8% with a 95% CI 2.8–4.8. All 92 sera collected from water buffalo were negative. Several risk factors potentially associated with seropositivity to BLV infections in Pakistan were analyzed using logistic regression model based on calculation of an odds ratio (OR). The study showed an association between seropositivity and medium herd (≥50) size (OR = 23.57, 95% CI: 3.01–103.48). Common housing of indigenous cattle with exotic-breed cattle (OR = 0.67, 95% CI: 06–2.35) or housing indigenous or their crossbred cattle with exotic-breed cattle (OR = 0.95, 95% CI: 0.14–3.01) had no effect on the BLV seroprevalence. Similarly, common housing of cattle and water buffalo was not risk factor for increased BLV seropositivity (OR = 27.10, 95% CI: 0.63–119.34).

scholarly journals Mycobacterium aviumSubspeciesparatuberculosisand Bovine Leukemia Virus Seroprevalence and Associated Risk Factors in Commercial Dairy and Beef Cattle in Northern and Northeastern China

2015 ◽  
Vol 2015 ◽  
pp. 1-7 ◽  
Author(s):  
Wu-Wen Sun ◽  
Wen-Fa Lv ◽  
Wei Cong ◽  
Qing-Feng Meng ◽  
Chun-Feng Wang ◽  
...  
Keyword(s):  
Risk Factors ◽  
Beef Cattle ◽  
Bovine Leukemia Virus ◽  
Large Scale ◽  
Leukemia Virus ◽  
Herd Size ◽  
Northeastern China ◽  
Herd Level ◽  
Source Sample ◽  
Associated Risk Factors

Mycobacterium aviumsubspeciesparatuberculosis(MAP) and bovine leukemia virus (BLV) are important pathogens, commonly responsible for economical loss to cattle farms all over the world, yet their epidemiology in commercial dairy and beef cattle in China is still unknown. Thus, from September 2013 to December 2014, a large-scale seroprevalence study was conducted to determine the seroprevalence and identify herd-level risk factors associated with MAP and BLV infection. The source sample was 3674 cattle from 113 herds in northern and northeastern China. Antibodies against MAP and BLV were detected using ELISA tests. At animal-level, the seroprevalence of antibodies against MAP and BLV was 11.79% (433/3674) and 18.29% (672/3674), respectively. At herd-level, the seroprevalence of antibodies against MAP and BLV was 20.35% and 21.24% (24/113), respectively. Herd size was identified to be associated with MAP infection while herd size and presence of cattle introduced from other farms were significantly associated with BLV infection. Further research is needed to confirm these findings and improve the knowledge of the epidemiology of these two pathogens in these regions and elsewhere in China.

scholarly journals Natural Infection of Dairy Cows with Bovine Leukemia Virus Affects Immunoglobulin Levels in Saliva and Serum but Not Milk

Pathogens ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 907
Author(s):  
Monika Dziuba ◽  
Vickie J. Ruggiero ◽  
Catherine Wilson ◽  
Paul C. Bartlett ◽  
Paul M. Coussens
Keyword(s):  
Pilot Study ◽  
Dairy Cows ◽  
Bovine Leukemia Virus ◽  
Leukemia Virus ◽  
Natural Infection ◽  
Total Serum ◽  
Serum Samples ◽  
Retroviral Infection ◽  
Serum Iga ◽  
The Impact

Bovine leukemia virus (BLV) is a retroviral infection that disrupts the immune function of infected animals. It is widespread among U.S. dairy cattle. In this pilot study, the average total IgA and IgM concentrations in milk, saliva, and serum samples from BLV ELISA-positive (ELISA+) dairy cows were compared against samples from BLV ELISA-negative (ELISA−) cows using the Kruskal–Wallis test (with ties). The results from ELISA+ cows were also stratified by lymphocyte count (LC) and proviral load (PVL). In milk and saliva from ELISA+ cows, the average total IgA and IgM concentrations were decreased compared to ELISA− cows, although this was only statistically significant for saliva IgM in cows with low PVL (p = 0.0424). Numerically, the average total IgA concentrations were 33.6% lower in milk and 23.7% lower in saliva, and the average total IgM concentrations were 42.4% lower in milk and 15.5% lower in saliva. No significant differences were observed in the total serum IgA concentrations, regardless of PVL and LC. The total serum IgM from ELISA+ cows was significantly decreased (p = 0.0223), with the largest decreases occurring in the highest PVL and LC subgroups. This pilot study is a first step in investigating the impact of BLV on mucosal immunity and will require further exploration in each of the various stages of disease progression.

scholarly journals Iron and Ferritin Levels in the Serum and Milk of Bovine Leukemia Virus-Infected Dairy Cows

2015 ◽  
Vol 2 ◽  
Author(s):  
Star A. Schnell ◽  
Hiromichi Ohtsuka ◽  
Seiichi Kakinuma ◽  
Yasunaga Yoshikawa ◽  
Kiyotaka Watanabe ◽  
...  
Keyword(s):  
Dairy Cows ◽  
Bovine Leukemia Virus ◽  
Leukemia Virus

Lack of association between amino acid sequences of the bovine leukemia virus envelope and varying stages of infection in dairy cattle

2020 ◽  
Vol 278 ◽  
pp. 197866
Author(s):  
Fernando Cerón Téllez ◽  
Ana Silvia González Méndez ◽  
Jorge Luis Tórtora Pérez ◽  
Elizabeth Loza-Rubio ◽  
Hugo Ramírez Álvarez
Keyword(s):  
Amino Acid ◽  
Dairy Cattle ◽  
Bovine Leukemia Virus ◽  
Leukemia Virus ◽  
Amino Acid Sequences ◽  
Virus Envelope

scholarly journals Intracellular Reactive Oxygen Species Production by Polymorphonuclear Leukocytes in Bovine Leukemia Virus-Infected Dairy Cows

2012 ◽  
Vol 74 (2) ◽  
pp. 221-225 ◽  
Author(s):  
Fernando Nogueira de SOUZA ◽  
Maiara Garcia BLAGITZ ◽  
Andréia Oliveira LATORRE ◽  
Eduardo Milton RAMOS SANCHEZ ◽  
Camila Freitas BATISTA ◽  
...  
Keyword(s):  
Reactive Oxygen Species ◽  
Dairy Cows ◽  
Bovine Leukemia Virus ◽  
Polymorphonuclear Leukocytes ◽  
Reactive Oxygen Species Production ◽  
Leukemia Virus ◽  
Reactive Oxygen ◽  
Intracellular Reactive Oxygen Species ◽  
Oxygen Species ◽  
Species Production

Examination of the fecal microbiota in dairy cows infected with bovine leukemia virus

2020 ◽  
Vol 240 ◽  
pp. 108547 ◽  
Author(s):  
Jumpei Uchiyama ◽  
Hironobu Murakami ◽  
Reiichiro Sato ◽  
Keijiro Mizukami ◽  
Takehito Suzuki ◽  
...  
Keyword(s):  
Dairy Cows ◽  
Bovine Leukemia Virus ◽  
Leukemia Virus ◽  
Fecal Microbiota

Epidemiologic Study on Enzootic Bovine Leukemia Using Serologic Tests and Hematologic Examinations

1977 ◽  
Vol 63 (5) ◽  
pp. 407-413
Author(s):  
Domenico Rutili ◽  
Maurizio Severini ◽  
Luigi Rampichini ◽  
Francesco Titoli ◽  
Umberto Chicchini
Keyword(s):  
Dairy Cattle ◽  
Bovine Leukemia Virus ◽  
Leukemia Virus ◽  
Epidemiologic Study ◽  
Diagnostic Procedures ◽  
Blood Picture ◽  
Electron Microscopic ◽  
Serologic Tests ◽  
Epidemiologic Survey ◽  
History Of

In order to find suitable diagnostic procedures to use in an epidemiologic survey for the detection of animals infected with the bovine leukemia virus (BLV), the authors conducted an investigation on 262 Friesian dairy cattle. The results of hematologic, serologic, and electron microscopic examinations are reported. Evaluation of the results demonstrated the validity of the immunodiffusion and immunofluorescence tests and the opportunity for their use in conjunction with examination of the blood picture. From the data reported it would appear useful to extend the investigation to the herds without history of lymphosarcoma.

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