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Hamada R, Fereig RM, Metwally S. The influence of risk factors on bovine leukemia virus infection and proviral load in egyptian cattle. Vet Res Commun 2024; 48:191-202. [PMID: 37610507 DOI: 10.1007/s11259-023-10198-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2023] [Accepted: 08/08/2023] [Indexed: 08/24/2023]
Abstract
Bovine leukemia virus (BLV) is the etiological agent of enzootic bovine leucosis (EBL), which affects cattle globally. In Egypt, BLV control strategies have been ignored because of the shortage of BLV research studies and the silent infection in most animals. This study aimed to identify the risk factors associated with the prevalence of BLV among dairy and beef cattle from six different geographic and climatic provinces in Egypt. Additionally, risk factors affecting the BLV proviral load (PVL) among the positive cattle were targeted. The total BLV prevalence in cattle from six investigated Egyptian provinces was 24.2% (105/433), while the mean PVL (8651.6 copies /105 white blood cells) was absolutely high as estimated by the BLV-CoCoMo-quantitative polymerase chain reaction (qPCR)-2 assay. Analysis of the influence of risk factors (age, sex, breed, production type, farm size, and location) on BLV prevalence indicated that the Holstein breed (OR = 1.582, p = 0.007), beef cattle (OR = 1.088, p = 0.0001), large-size farms (OR = 1.26, p = 0.0001), and cattle from Damietta (OR = 1.43, p = 0.0001) and Cairo (OR = 1.16, p = 0.0001) were ultimately proven the most important risks for BLV infection. The risk factors were analyzed considering the BLV PVL levels in the BLV-positive cases. Significantly high PVL (HPVL) levels were observed in cattle > 5 years old (p < 0.0001), females (p = 0.0008), Holstein (p < 0.0001), dairy cows (p = 0.0053), large-size farms (p < 0.0001), and cattle from Damietta (p < 0.0001) compared to other categories. Contrary, no significant differences in PVL levels were reported between the Native and Mixed cattle breeds (p = 0.13). Ultimately, the logistic regression model indicated that the probability of carrying HPVL in cattle > 5 years is 1.27 (95% CI: 1.03-2.09, p < 0.001) times more likely compared to cattle < 2 years old. In conclusion, the findings were valuably correlating the BLV prevalence with PVL as an indicator of the risk of BLV infection.
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Affiliation(s)
- Rania Hamada
- Division of Clinical Pathology, Department of Pathology, Faculty of Veterinary Medicine, Damanhour University, 22511, Damanhour, Egypt.
| | - Ragab M Fereig
- Division of Internal Medicine, Department of Animal Medicine, Faculty of Veterinary Medicine, South Valley University, 83523, Qena City, Qena, Egypt
| | - Samy Metwally
- Division of Infectious Diseases, Department of Animal Medicine, Faculty of Veterinary Medicine, Damanhour University, 22511, Damanhour, Egypt.
- Laboratory of Global Infectious Diseases Control Science, Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, 113-8657, Tokyo, Japan.
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Kuczewski A, Adams C, Lashewicz B, van der Meer F. Alberta dairy farmers’ and veterinarians’ opinion about bovine leukemia virus control measures. Prev Vet Med 2022; 200:105590. [DOI: 10.1016/j.prevetmed.2022.105590] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2021] [Revised: 12/22/2021] [Accepted: 01/23/2022] [Indexed: 11/30/2022]
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3
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Diagnostic Measures of Disease Progression in Cattle Following Natural Infection with Bovine Leukemia Virus. Pathogens 2021; 10:pathogens10080987. [PMID: 34451451 PMCID: PMC8398158 DOI: 10.3390/pathogens10080987] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2021] [Revised: 08/02/2021] [Accepted: 08/03/2021] [Indexed: 11/17/2022] Open
Abstract
This study describes the longitudinal changes in bovine leukemia virus (BLV) ELISA antibodies, proviral load (PVL), and blood lymphocyte counts (LC) observed over a 2.5-year period in naturally infected cattle. The dataset utilized was from a BLV intervention field trial on three Midwestern dairy herds. Our analysis showed ELISA false negatives were more likely to occur in cattle with low PVL and normal LC. On average, negligible changes in LC were observed during six-month intervals. Periods of lymphocytosis, defined as >10,000 lymphocytes per uL of blood, were observed in 31.5% (68/216) of BLV test-positive cattle. In BLV test-positive cows, an average increase of 2900 to 3100 proviral copies per 100,000 cells was observed during each subsequent six-month sampling interval. The difference between the minimum and maximum PVL observed for an ELISA-positive cow with 3 or more observations ranged from 0 to 115,600 copies per 100,000 cells (median: 12,900; mean: 19,200). Therefore, following the identification of ELISA-positive cattle and the assessment of PVL and LC, subsequent semiannual tests to assess disease progression may not be needed. Further work is needed to determine how available diagnostic tests can be optimized to design cost-effective testing schemes for BLV control programs.
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Kuczewski A, Orsel K, Barkema HW, Mason S, Erskine R, van der Meer F. Invited review: Bovine leukemia virus-Transmission, control, and eradication. J Dairy Sci 2021; 104:6358-6375. [PMID: 33741150 DOI: 10.3168/jds.2020-18925] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2020] [Accepted: 11/21/2020] [Indexed: 11/19/2022]
Abstract
Bovine leukemia virus (BLV) infection, endemic in North American dairy herds, has production-limiting effects. A literature review of available papers published since 1995 concerning BLV transmission and its control was conducted. Although confirmed transmission routes were reviewed (blood, natural breeding, in utero, colostrum, and milk), there is still a lack of detailed information on other specific risks for transmission (e.g., contact transmission and hoof-trimming knives). Eradication of BLV has been achieved by combined management, segregation, and culling approaches. In contrast, although sole implementation of best management practices aimed at prevention of BLV transmission has decreased within-herd BLV prevalence, it has not eradicated BLV from a herd. Therefore, control and eradication of BLV by best management practices only should be further investigated. Additionally, the role of proviral load in infected cattle was investigated. Cattle with a high proviral load seem to be more likely to infect others, whereas those with a very low proviral load seem to have low risks of transmitting BLV. Information on proviral load could be taken into account when controlling BLV in high-prevalence herds. In conclusion, there is a need for detailed, large-scale studies investigating roles of specific transmission routes, knowing proviral load of infected individuals.
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Affiliation(s)
- Alessa Kuczewski
- Department of Ecosystem and Public Health, University of Calgary, Calgary, AB T2N 4Z6, Canada
| | - Karin Orsel
- Department of Production Animal Health, University of Calgary, Calgary, AB T2N 4Z6, Canada
| | - Herman W Barkema
- Department of Production Animal Health, University of Calgary, Calgary, AB T2N 4Z6, Canada
| | - Steve Mason
- Agromedia International Inc., Calgary, AB T2L 0T6, Canada
| | - Ron Erskine
- Large Animal Clinical Sciences, College of Veterinary Medicine, Michigan State University, East Lansing 48824
| | - Frank van der Meer
- Department of Ecosystem and Public Health, University of Calgary, Calgary, AB T2N 4Z6, Canada.
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Kuczewski A, Mason S, Orsel K, van der Meer F. Pilot implementation of a newly developed bovine leukemia virus control program on 11 Alberta dairy farms. J Dairy Sci 2021; 104:4549-4560. [PMID: 33663863 DOI: 10.3168/jds.2020-19251] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2020] [Accepted: 11/03/2020] [Indexed: 11/19/2022]
Abstract
We developed a custom bovine leukemia virus (BLV) control program for the Alberta dairy industry, consisting of a risk assessment and a comprehensive list of best management practices (BMP) aimed at prevention of BLV transmission between cattle. This control program was implemented on 11 farms for approximately 1 yr. Blood samples were collected from all cattle ≥12 mo old, and serum was tested with a commercial ELISA. Risk assessments were performed on each farm, risk-connected on-farm management was identified, and management changes expected to prevent transmission of BLV between cattle were suggested by the first author and agreed upon with each farmer. Throughout the following year, all participating farmers were visited multiple times to identify and overcome barriers to implementation and to monitor progress. After approximately 1 yr of implementing BLV control, all cattle ≥12 mo old on farm with a negative or no previous test result were sampled, and the within-herd prevalence was determined. The median number of cattle on farm that were ≥12 mo was 195 (range 110-524). The initial prevalence averaged 39% (13-66%). On average, 5 BMP (3-7) were suggested to each farmer. On average, 4 BMP (1-7) were implemented. At the second sampling, the average within-herd prevalence of all animals that tested positive (including the previous sampling) was 36% (12-62%). Eight farms reduced their within-herd BLV prevalence, within-herd prevalence stayed constant on 1 farm, and it increased on 1 farm. The remaining farm terminated their participation before the second sampling. The number of seroconversions per farm ranged from 3 to 109, highlighting the success of some producers to minimize new infections. The risk assessment was proven to be a valuable tool to identify flaws in on-farm management, although risk assessment score was unrelated to the within-herd BLV prevalence. Finally, it appeared that implementation of BMP aimed at prevention of BLV transmission between cattle could reduce within-herd BLV prevalence when farmers committed to their implementation.
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Affiliation(s)
- Alessa Kuczewski
- Department of Ecosystem and Public Health, Faculty of Veterinary Medicine, University of Calgary, Calgary, AB T2N 4Z6, Canada
| | - Steve Mason
- Agromedia International Inc., Calgary, AB T2L 0T6, Canada; Department of Production Animal Health, Faculty of Veterinary Medicine, University of Calgary, Calgary, AB T2N 4Z6, Canada
| | - Karin Orsel
- Department of Production Animal Health, Faculty of Veterinary Medicine, University of Calgary, Calgary, AB T2N 4Z6, Canada
| | - Frank van der Meer
- Department of Ecosystem and Public Health, Faculty of Veterinary Medicine, University of Calgary, Calgary, AB T2N 4Z6, Canada.
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Schambow R, Poulsen K, Bolin S, Krahn D, Norby B, Sockett D, Ruegg P. Apparent prevalence of Mycoplasma wenyonii, Candidatus Mycoplasma haemobos, and bovine leukemia virus in Wisconsin and Michigan dairy cattle herds. JDS COMMUNICATIONS 2021; 2:61-66. [PMID: 36338775 PMCID: PMC9623634 DOI: 10.3168/jdsc.2020-0033] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/28/2020] [Accepted: 11/11/2020] [Indexed: 05/18/2023]
Abstract
Mycoplasma wenyonii (formerly Eperythrozoon wenyonii) is a hemotrophic, epicellular bacterial parasite of cattle that has been associated with clinical disorders, including hemolytic anemia, decreased milk yield, and peripheral edema. Mycoplasma wenyonii and a related organism, Candidatus Mycoplasma haemobos, have been detected in both ill and apparently healthy cattle, but little is known about their prevalence in US dairy cattle. The objective of this prospective, cross-sectional study was to determine herd-level apparent prevalence of M. wenyonii and C. M. haemobos in dairy cattle located in Wisconsin and Michigan compared with seroprevalence of bovine leukemia virus (BLV) in the same herds. In summer 2018, researchers collected blood samples from 30 lactating cows per herd from randomly recruited farms in selected dairy-intensive counties in each state. During the farm visit, a brief survey was used to collect herd management information. Detection of M. wenyonii and C. M. haemobos were based on PCR testing, and ELISA was used to test for antibodies to BLV. Blood samples were collected from lactating cows located in 64 Wisconsin herds (n = 1,930 samples) and 18 Michigan herds (n = 591 samples). Herd-level apparent prevalence was 100% for both M. wenyonii and C. M. haemobos. Herd-level seroprevalence for BLV was 83 and 100% for Wisconsin and Michigan herds, respectively. Estimated within-herd apparent prevalence of M. wenyonii was 71.7% ± 1.0% (ranging from 23.3 to 93.5%) and for C. M. haemobos was 77.3% ± 1.0% (ranging from 16.7 to 100%). Within-herd prevalence of BLV positive samples was 39.8% ± 1.0% and ranged from 0 to 86.7%. About 22% of cows were concurrently positive for all 3 organisms. Parity and stage of lactation were recorded for 2,317 cows. Prevalence of positive cows for parity groups 1, 2, and ≥3 were 72.0, 73.8, and 67.7% for M. wenyonii; 80.9, 76.8, and 74.9% for C. M. haemobos; and 25.3, 39.7, and 55.5% for BLV, respectively. None or only minor differences in apparent prevalence were observed based on stage of lactation. This is the first report of the prevalence of hemotrophic mycoplasmas in Wisconsin and Michigan dairy herds and indicates that infection with these organisms is endemic. The impact of infection on cattle health and productivity remains unknown, and risk factors associated with infection warrant further study.
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Affiliation(s)
- R.A. Schambow
- Center for Animal Health and Food Safety, University of Minnesota School of Veterinary Medicine, St. Paul 55108
| | - K. Poulsen
- Wisconsin Veterinary Diagnostic Lab, Madison 53705
| | - S. Bolin
- Department of Pathobiology and Diagnostic Investigation, Michigan State University, East Lansing 48824
| | - D. Krahn
- Country Hills Animals Health Center, Fond du Lac, WI 54937
| | - B. Norby
- Department of Large Animal Clinical Sciences, Michigan State University, East Lansing 48824
| | - D. Sockett
- Wisconsin Veterinary Diagnostic Lab, Madison 53705
| | - P.L. Ruegg
- Department of Large Animal Clinical Sciences, Michigan State University, East Lansing 48824
- Corresponding author
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7
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Petersen MI, Carignano HA, Suarez Archilla G, Caffaro ME, Alvarez I, Miretti MM, Trono K. Expression-based analysis of genes related to single nucleotide polymorphism hits associated with bovine leukemia virus proviral load in Argentinean dairy cattle. J Dairy Sci 2020; 104:1993-2007. [PMID: 33246606 DOI: 10.3168/jds.2020-18924] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2020] [Accepted: 08/29/2020] [Indexed: 12/29/2022]
Abstract
In dairy cattle infected with bovine leukemia virus (BLV), the proviral load (PVL) level is directly related to the viral transmission from infected animals to their healthy herdmates. Two contrasting phenotypic groups can be identified when assessing PVL in peripheral blood of infected cows. A large number of reports point to bovine genetic variants (single nucleotide polymorphisms) as one of the key determinants underlying PVL level. However, biological mechanisms driving BLV PVL profiles and infection progression in cattle have not yet been elucidated. In this study, we evaluated whether a set of candidate genes affecting BLV PVL level according to whole genome association studies are differentially expressed in peripheral blood mononuclear cells derived from phenotypically contrasting groups of BLV-infected cows. During a 10-mo-long sampling scheme, 129 Holstein cows were phenotyped measuring anti-BLV antibody levels, PVL quantification, and white blood cell subpopulation counts. Finally, the expression of 8 genes (BOLA-DRB3, PRRC2A, ABT1, TNF, BAG6, BOLA-A, LY6G5B, and IER3) located within the bovine major histocompatibility complex region harboring whole genome association SNP hits was evaluated in 2 phenotypic groups: high PVL (n = 7) and low PVL (n = 8). The log2 initial fluorescence value (N0) transformed mean expression values for the ABT1 transcription factor were statistically different in high- and low-PVL groups, showing a higher expression of the ABT1 gene in low-PVL cows. The PRRC2A and IER3 genes had a significant positive (correlation coefficient = 0.61) and negative (correlation coefficient = -0.45) correlation with the lymphocyte counts, respectively. Additionally, the relationships between gene expression values and lymphocyte counts were modeled using linear regressions. Lymphocyte levels in infected cows were better explained (coefficient of determination = 0.56) when fitted a multiple linear regression model using both PRRC2A and IER3 expression values as independent variables. The present study showed evidence of differential gene expression between contrasting BLV infection phenotypes. These genes have not been previously related to BLV pathobiology. This valuable information represents a step forward in understanding the BLV biology and the immune response of naturally infected cows under a commercial milk production system. Efforts to elucidate biological mechanisms leading to BLV infection progression in cows are valuable for BLV control programs. Further studies integrating genotypic data, global transcriptome analysis, and BLV progression phenotypes are needed to better understand the BLV-host interaction.
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Affiliation(s)
- M I Petersen
- Instituto de Virología e Innovaciones Tecnológicas, Instituto Nacional de Tecnología Agropecuaria - Consejo Nacional de Investigaciones Científicas y Técnicas, B1686 Hurlingham, Argentina; Consejo Nacional de Investigaciones Científicas y Técnicas, C1033AAJ Ciudad Autónoma de Buenos Aires, Argentina; Consejo Nacional de Investigaciones Científicas y Técnicas, C1033AAJ Ciudad Autónoma de Buenos Aires, Argentina
| | - H A Carignano
- Instituto de Virología e Innovaciones Tecnológicas, Instituto Nacional de Tecnología Agropecuaria - Consejo Nacional de Investigaciones Científicas y Técnicas, B1686 Hurlingham, Argentina; Consejo Nacional de Investigaciones Científicas y Técnicas, C1033AAJ Ciudad Autónoma de Buenos Aires, Argentina; Instituto de Genética, Instituto Nacional de Tecnología Agropecuaria, B1686 Hurlingham, Argentina.
| | - G Suarez Archilla
- Estación Experimental Agropecuaria Rafaela, Instituto Nacional de Tecnología Agropecuaria, S2300 Rafaela, Argentina
| | - M E Caffaro
- Instituto de Genética, Instituto Nacional de Tecnología Agropecuaria, B1686 Hurlingham, Argentina
| | - I Alvarez
- Instituto de Virología e Innovaciones Tecnológicas, Instituto Nacional de Tecnología Agropecuaria - Consejo Nacional de Investigaciones Científicas y Técnicas, B1686 Hurlingham, Argentina; Consejo Nacional de Investigaciones Científicas y Técnicas, C1033AAJ Ciudad Autónoma de Buenos Aires, Argentina; Consejo Nacional de Investigaciones Científicas y Técnicas, C1033AAJ Ciudad Autónoma de Buenos Aires, Argentina
| | - M M Miretti
- Consejo Nacional de Investigaciones Científicas y Técnicas, C1033AAJ Ciudad Autónoma de Buenos Aires, Argentina; Grupo de Investigación en Genética Aplicada, Instituto de Biología Subtropical, FCEQyN, Universidad Nacional de Misiones, N3300 Posadas, Argentina
| | - K Trono
- Instituto de Virología e Innovaciones Tecnológicas, Instituto Nacional de Tecnología Agropecuaria - Consejo Nacional de Investigaciones Científicas y Técnicas, B1686 Hurlingham, Argentina; Consejo Nacional de Investigaciones Científicas y Técnicas, C1033AAJ Ciudad Autónoma de Buenos Aires, Argentina; Consejo Nacional de Investigaciones Científicas y Técnicas, C1033AAJ Ciudad Autónoma de Buenos Aires, Argentina
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8
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Wisnieski L, Norby B, Gandy J, Byrem TM, Sordillo LM. Changes in bovine leukemia virus serological status and lymphocyte count between dry-off and early lactation in Michigan dairy cows. J Dairy Sci 2020; 103:9473-9480. [PMID: 32773309 DOI: 10.3168/jds.2019-17839] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2019] [Accepted: 04/20/2020] [Indexed: 11/19/2022]
Abstract
This study addresses how the serological status of bovine leukemia virus (BLV) and lymphocyte count fluctuate from dry-off to early lactation in dairy cattle. Very few studies have investigated how BLV antibody status and lymphocyte count of cows changes longitudinally during the lactation cycle. Blood samples were collected from dairy cattle (n = 149) on 5 commercial dairy herds in Michigan at dry-off, close-up, and 7 to 10 d after calving. Plasma was analyzed for anti-BLV antibodies using a BLV-ELISA and whole blood was analyzed for lymphocyte counts. We found that BLV seroprevalence increased from dry-off (38.9%) to close-up (43.6%), then slightly decreased from close-up to 7 to 10 d after calving (43.0%). However, the change in seroprevalence was only significant from dry-off to close-up. Cows of third or higher parity were more likely to seroconvert than cows of lower parity and had the highest ELISA-negative prevalence of BLV. Lymphocyte counts were significantly higher in ELISA-positive animals, but only among second and third or greater parity animals. These results indicate that the use of lymphocyte counts as a disease severity monitoring tool for BLV should differ by parity group. Future studies should investigate if changes in seroprevalence are due to new infections or natural changes in antibody concentrations as the cow prepares for colostrum production. More accurate lymphocyte guidelines to be used for monitoring the progression of BLV should be created that consider parity and lactation stage.
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Affiliation(s)
- L Wisnieski
- Department of Large Animal Clinical Sciences, College of Veterinary Medicine, Michigan State University, East Lansing 48824
| | - B Norby
- Department of Large Animal Clinical Sciences, College of Veterinary Medicine, Michigan State University, East Lansing 48824.
| | - J Gandy
- Department of Large Animal Clinical Sciences, College of Veterinary Medicine, Michigan State University, East Lansing 48824
| | - T M Byrem
- CentralStar Cooperative, Lansing, MI 48909
| | - L M Sordillo
- Department of Large Animal Clinical Sciences, College of Veterinary Medicine, Michigan State University, East Lansing 48824
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9
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John EE, Keefe G, Cameron M, Stryhn H, McClure JT. Development and implementation of a risk assessment and management program for enzootic bovine leukosis in Atlantic Canada. J Dairy Sci 2020; 103:8398-8406. [PMID: 32684477 DOI: 10.3168/jds.2019-17434] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2019] [Accepted: 04/22/2020] [Indexed: 11/19/2022]
Abstract
Over the past 30 yr, the prevalence of bovine leukemia virus (BLV) infection has increased in North America, including Atlantic Canada, at both the herd and individual cow levels. This has occurred despite increased awareness of the disease and its deleterious effects and despite implementation of management practices aimed at reducing disease transmission. Our objectives were to identify risk factors associated with the within-herd prevalence of BLV-infected cows by using a risk assessment and management program workbook, as well as to determine the current level of BLV prevalence in the Atlantic Canada region. We hypothesized that previously established risk factors, including management practices associated with calf rearing and fly control, would affect within-herd BLV prevalence. Bulk tank milk (BTM) samples were collected in January and April of 2016 and again during the same months in 2017 and 2018 from all dairy farms shipping milk in the region. Samples were tested with ELISA for levels of anti-BLV antibodies to estimate within-herd prevalence. Regional BLV prevalence at the herd level was 88.39% of dairy herds infected in 2016 and 89.30% in 2018. All dairy farms shipping milk and who had BTM samples collected in 2017 (n = 605) were eligible to participate in the risk assessment and management program questionnaire (RAMP), which was developed and distributed to all bovine veterinarians in Atlantic Canada. One hundred and six RAMP were returned, with representation from all 4 provinces. The RAMP results were combined with the mean BTM ELISA results, and univariable logistic regression followed by multivariable logistic regression was performed to investigate the association between RAMP risk factors and the estimated within-herd BLV prevalence. Factors in the multivariable model significantly associated with the odds of a herd being classified as >25% estimated within-herd prevalence included history of diagnosis of clinical BLV and calves receiving colostrum from cows with unknown BLV status. Differences in within-herd prevalence were not associated with hypodermic needle and injection practices, rectal sleeve practices, or using bulls for natural breeding, based on these 106 dairy farms.
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Affiliation(s)
- E E John
- Department of Health Management, Atlantic Veterinary College, University of Prince Edward Island, Charlottetown, PE, Canada C1A 4P3.
| | - G Keefe
- Department of Health Management, Atlantic Veterinary College, University of Prince Edward Island, Charlottetown, PE, Canada C1A 4P3
| | - M Cameron
- Department of Health Management, Atlantic Veterinary College, University of Prince Edward Island, Charlottetown, PE, Canada C1A 4P3
| | - H Stryhn
- Department of Health Management, Atlantic Veterinary College, University of Prince Edward Island, Charlottetown, PE, Canada C1A 4P3
| | - J T McClure
- Department of Health Management, Atlantic Veterinary College, University of Prince Edward Island, Charlottetown, PE, Canada C1A 4P3
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Hutchinson HC, Norby B, Erskine RJ, Sporer KRB, Bartlett PC. Herd management practices associated with bovine leukemia virus incidence rate in Michigan dairy farms. Prev Vet Med 2020; 182:105084. [PMID: 32682155 DOI: 10.1016/j.prevetmed.2020.105084] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2020] [Revised: 06/28/2020] [Accepted: 06/29/2020] [Indexed: 11/28/2022]
Abstract
The objective of this study was to identify associations between herd management practices and the incidence rate of bovine leukemia virus (BLV) infections in Michigan dairy herds. Previous management risk factor studies were of antibody prevalence rather than the rate of recent infections. Milk samples were collected from cohorts of cows on 112 Michigan dairy herds and tested for BLV using an antibody capture ELISA (n = 3849 cows). Cows were subsequently followed for an average of 21 months. Cows negative for anti-BLV antibodies and still present in their respective herds were retested by the same antibody capture ELISA to estimate within-herd incidence rates. The overall crude incidence rate was 1.46 infections per 100 cow-months at risk for the 1314 retested cows in 107 herds. The average within-herd incidence rate was 2.28 infections per 100 cow-months (range: 0 to 9.76 infections per 100 cow-months). A negative binomial regression model was used to identify herd management practices associated with the within-herd incidence rate. Results of the final multivariable model identified higher herd prevalence, milking frequency, needle reuse, as well as housing post-parturient cows separately, to be associated with increased incidence rate. Utilization of sand bedding for the lactating herd was found to be associated with decreased incidence rates. Results of this study suggest potential routes of BLV transmission which should be further investigated as disease control targets in ongoing control programs.
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Affiliation(s)
- H C Hutchinson
- Department of Large Animal Clinical Sciences, Michigan State University, 784 Wilson Rd, East Lansing, MI 48824, USA
| | - B Norby
- Department of Large Animal Clinical Sciences, Michigan State University, 784 Wilson Rd, East Lansing, MI 48824, USA.
| | - R J Erskine
- Department of Large Animal Clinical Sciences, Michigan State University, 784 Wilson Rd, East Lansing, MI 48824, USA
| | - K R B Sporer
- CentralStar Cooperative, 4200 Forest Rd, Lansing, MI 48910, USA
| | - P C Bartlett
- Department of Large Animal Clinical Sciences, Michigan State University, 784 Wilson Rd, East Lansing, MI 48824, USA
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Sato H, Bai L, Borjigin L, Aida Y. Overexpression of bovine leukemia virus receptor SLC7A1/CAT1 enhances cellular susceptibility to BLV infection on luminescence syncytium induction assay (LuSIA). Virol J 2020; 17:57. [PMID: 32321527 PMCID: PMC7178733 DOI: 10.1186/s12985-020-01324-y] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2019] [Accepted: 04/08/2020] [Indexed: 11/10/2022] Open
Abstract
Bovine leukemia virus (BLV) causes enzootic bovine leukosis, the most common neoplastic disease in cattle. We previously reported the development and protocol of the luminescence syncytium induction assay (LuSIA), a method for evaluating BLV infectivity based on CC81-GREMG cells. These cells form syncytia expressing enhanced green fluorescent protein when co-cultured with BLV-infected cells. Recently, we confirmed CAT1/SLC7A1 functions as a receptor of BLV. Here, we focused on CAT1/SLC7A1 to increase the sensitivity of LuSIA. We constructed a bovine CAT1-expressing plasmid and established a new CC81-GREMG-derived reporter cell line highly expressing bovine CAT1 (CC81-GREMG-CAT1). The new LuSIA protocol using CC81-GREMG-CAT1 cells measures cell-to-cell infectivity and cell-free infectivity of BLV faster and with greater sensitivity than the previous protocol using CC81-GREMG. The new LuSIA protocol is quantitative and more sensitive than the previous assay based on CC81-GREMG cells and will facilitate the development of several new BLV assays.
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Affiliation(s)
- Hirotaka Sato
- Nakamura Laboratory, Baton Zone Program, RIKEN Cluster for Science, Technology and Innovation Hub, 2-1 Hirosawa, Wako, Saitama, 351-0198, Japan.,Virus Infectious Diseases Unit, RIKEN, 2-1 Hirosawa, Wako, Saitama, 351-0198, Japan
| | - Lanlan Bai
- Virus Infectious Diseases Unit, RIKEN, 2-1 Hirosawa, Wako, Saitama, 351-0198, Japan.,Photonics Control Technology Team, RIKEN Center for Advanced Photonics, 2-1 Hirosawa, Wako, Saitama, 351-0198, Japan
| | - Liushiqi Borjigin
- Nakamura Laboratory, Baton Zone Program, RIKEN Cluster for Science, Technology and Innovation Hub, 2-1 Hirosawa, Wako, Saitama, 351-0198, Japan.,Virus Infectious Diseases Unit, RIKEN, 2-1 Hirosawa, Wako, Saitama, 351-0198, Japan
| | - Yoko Aida
- Nakamura Laboratory, Baton Zone Program, RIKEN Cluster for Science, Technology and Innovation Hub, 2-1 Hirosawa, Wako, Saitama, 351-0198, Japan. .,Virus Infectious Diseases Unit, RIKEN, 2-1 Hirosawa, Wako, Saitama, 351-0198, Japan.
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12
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Ruggiero VJ, Norby B, Benitez OJ, Hutchinson H, Sporer KRB, Droscha C, Swenson CL, Bartlett PC. Controlling bovine leukemia virus in dairy herds by identifying and removing cows with the highest proviral load and lymphocyte counts. J Dairy Sci 2019; 102:9165-9175. [PMID: 31378496 DOI: 10.3168/jds.2018-16186] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2018] [Accepted: 06/05/2019] [Indexed: 01/30/2023]
Abstract
The objective of this field trial was to reduce bovine leukemia virus (BLV) transmission and prevalence in commercial dairy herds using proviral load (PVL) and lymphocyte count (LC) measurements as indicators of the most infectious animals for culling or segregation. Bovine leukemia virus causes lymphoma in <5% of infected cattle, and increased lymphocyte counts (lymphocytosis) in about one-third. Recent research has shown that dairy cows infected with BLV have altered immune function associated with decreases in milk production and lifespan. Recent findings show that a minority of infected cattle have PVL concentrations in blood and other body fluids of over 1,000 times that of other infected cattle. In combination with a high LC, these animals are thought to be responsible for most transmission of BLV in a herd. Milk or blood samples from adult cows in our 3 Midwestern dairy farm field trials were tested semiannually with ELISA for BLV antibodies, and ELISA-positive cattle were then retested using a blood LC and a quantitative PCR test for PVL to identify the animals presumed to be most infectious. Herd managers were encouraged to consider PVL and LC status when making cull decisions, and to segregate cows with the highest PVL and LC from their BLV ELISA-negative herd mates where possible. After 2 to 2.5 yr of this intervention, the incidence risk of new infections decreased in all 3 herds combined, from 13.8 to 2.2, and the overall herd prevalence decreased in all 3 herds combined from 62.0 to 20.7%, suggesting that this approach can efficiently reduce BLV transmission as well as prevalence. This is encouraging, because a very low prevalence of BLV infection would make it economically feasible to cull the remaining ELISA-positive cattle, as was achieved in national eradication programs in other countries decades ago.
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Affiliation(s)
- V J Ruggiero
- Department of Large Animal Clinical Sciences, College of Veterinary Medicine, Michigan State University, East Lansing 48824.
| | - B Norby
- Department of Large Animal Clinical Sciences, College of Veterinary Medicine, Michigan State University, East Lansing 48824
| | - O J Benitez
- Department of Large Animal Clinical Sciences, College of Veterinary Medicine, Michigan State University, East Lansing 48824
| | - H Hutchinson
- Department of Large Animal Clinical Sciences, College of Veterinary Medicine, Michigan State University, East Lansing 48824
| | - K R B Sporer
- Department of Large Animal Clinical Sciences, College of Veterinary Medicine, Michigan State University, East Lansing 48824; NorthStar Cooperative, Lansing, MI 48910
| | - C Droscha
- Department of Large Animal Clinical Sciences, College of Veterinary Medicine, Michigan State University, East Lansing 48824; NorthStar Cooperative, Lansing, MI 48910
| | - C L Swenson
- Department of Pathobiology and Diagnostic Investigation and Veterinary Diagnostic Laboratory, Michigan State University, East Lansing 48824
| | - P C Bartlett
- Department of Large Animal Clinical Sciences, College of Veterinary Medicine, Michigan State University, East Lansing 48824
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13
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Ruggiero VJ, Bartlett PC. Control of Bovine Leukemia Virus in Three US Dairy Herds by Culling ELISA-Positive Cows. Vet Med Int 2019; 2019:3202184. [PMID: 31341609 PMCID: PMC6614971 DOI: 10.1155/2019/3202184] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2019] [Revised: 06/03/2019] [Accepted: 06/10/2019] [Indexed: 01/12/2023] Open
Abstract
The objective of this trial was to evaluate a test-and-cull approach to controlling bovine leukemia virus (BLV) in US dairy herds with a low BLV prevalence. Despite worldwide distribution of the virus, 21 nations have eradicated BLV from their dairy cattle and are currently considered 'BLV-free.' In contrast, the US has attempted no industry-wide BLV control programs and has experienced an increase in BLV prevalence among dairy cows to about 40%. This raises concerns about production efficiency, herd health, and sustainability. In a pilot field trial with three Midwestern-US dairy herds, a test-and-cull approach using ELISA screening of milk samples was successful in reducing BLV prevalence in two herds. In the third herd, BLV prevalence increased following the introduction of infected heifers that were raised at an out-of-state calf raising facility. This trial demonstrated that a test-and-cull approach to BLV control can be successful in US dairy herds with low BLV prevalence, but ongoing surveillance is necessary to prevent reintroduction of the virus.
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Affiliation(s)
- Vickie J. Ruggiero
- Department of Large Animal Clinical Sciences, College of Veterinary Medicine, Michigan State University, East Lansing 48823, USA
| | - Paul C. Bartlett
- Department of Large Animal Clinical Sciences, College of Veterinary Medicine, Michigan State University, East Lansing 48823, USA
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14
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Evermann JF, DeAvila DM, Parish SM, Merritt CH, Noble KC, Srikanth S, Bronowski ALE. Evaluation of a serum ELISA for detection of bovine leukemia viral antibodies in milk samples. J Vet Diagn Invest 2019; 31:598-600. [PMID: 31234727 DOI: 10.1177/1040638719860487] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Bovine leukemia virus (BLV) infection has worldwide distribution in both dairy and beef herds. Our study was initiated in order to encourage control of BLV infection by using milk samples, in lieu of serum samples, to readily test lactating animals prior to dry-off and calving. Two Holstein dairy herds (A and B), with known status of BLV infection as determined by serology, were sampled by the collection of serum and fresh milk samples. Selected samples were tested using a USDA-licensed BLV antibody ELISA kit (Bovine leukemia virus antibody test kit; VMRD, Pullman, WA) for serum. Forty-one lactating cows from each herd were sampled. Herd A was confirmed to have endemic BLV infection; herd B was confirmed to be free of BLV infection. The milk ELISA results demonstrated 100% identification of positive and negative animals compared with the serum results. The correlation of the ELISA values between serum and milk samples was 97%, which supports the use of this BLV ELISA on milk samples.
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Affiliation(s)
- James F Evermann
- Washington Animal Disease Diagnostic Laboratory (Evermann, DeAvila, Merritt, Noble), Department of Veterinary Clinical Sciences (Evermann, Parish), College of Veterinary Medicine, Washington State University, Pullman, WA.,Veterinary Medical Research & Development (VMRD), Pullman, WA (Srikanth, Bronowski)
| | - David M DeAvila
- Washington Animal Disease Diagnostic Laboratory (Evermann, DeAvila, Merritt, Noble), Department of Veterinary Clinical Sciences (Evermann, Parish), College of Veterinary Medicine, Washington State University, Pullman, WA.,Veterinary Medical Research & Development (VMRD), Pullman, WA (Srikanth, Bronowski)
| | - Steven M Parish
- Washington Animal Disease Diagnostic Laboratory (Evermann, DeAvila, Merritt, Noble), Department of Veterinary Clinical Sciences (Evermann, Parish), College of Veterinary Medicine, Washington State University, Pullman, WA.,Veterinary Medical Research & Development (VMRD), Pullman, WA (Srikanth, Bronowski)
| | - Catherine H Merritt
- Washington Animal Disease Diagnostic Laboratory (Evermann, DeAvila, Merritt, Noble), Department of Veterinary Clinical Sciences (Evermann, Parish), College of Veterinary Medicine, Washington State University, Pullman, WA.,Veterinary Medical Research & Development (VMRD), Pullman, WA (Srikanth, Bronowski)
| | - Katherine C Noble
- Washington Animal Disease Diagnostic Laboratory (Evermann, DeAvila, Merritt, Noble), Department of Veterinary Clinical Sciences (Evermann, Parish), College of Veterinary Medicine, Washington State University, Pullman, WA.,Veterinary Medical Research & Development (VMRD), Pullman, WA (Srikanth, Bronowski)
| | - Sampath Srikanth
- Washington Animal Disease Diagnostic Laboratory (Evermann, DeAvila, Merritt, Noble), Department of Veterinary Clinical Sciences (Evermann, Parish), College of Veterinary Medicine, Washington State University, Pullman, WA.,Veterinary Medical Research & Development (VMRD), Pullman, WA (Srikanth, Bronowski)
| | - Amanda L E Bronowski
- Washington Animal Disease Diagnostic Laboratory (Evermann, DeAvila, Merritt, Noble), Department of Veterinary Clinical Sciences (Evermann, Parish), College of Veterinary Medicine, Washington State University, Pullman, WA.,Veterinary Medical Research & Development (VMRD), Pullman, WA (Srikanth, Bronowski)
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15
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Takeshima SN, Ohno A, Aida Y. Bovine leukemia virus proviral load is more strongly associated with bovine major histocompatibility complex class II DRB3 polymorphism than with DQA1 polymorphism in Holstein cow in Japan. Retrovirology 2019; 16:14. [PMID: 31096993 PMCID: PMC6524304 DOI: 10.1186/s12977-019-0476-z] [Citation(s) in RCA: 39] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2019] [Accepted: 05/08/2019] [Indexed: 01/14/2023] Open
Abstract
Bovine leukemia virus (BLV) causes enzootic bovine leukosis and is closely related to the human T-lymphotropic virus. Bovine major histocompatibility complex (BoLAs) are used extensively as markers of disease and immunological traits in cattle. For BLV diagnosis, proviral load is a major diagnosis index for the determination of disease progression and transmission risk. Therefore, we investigated the frequency of BoLA-DRB3 alleles, BoLA-DQA1 alleles, and haplotypes of BoLA class II isolated from the heads of 910 BLV-infected cows out of 1290 cows assessed from BLV-positive farms, in a nationwide survey from 2011 to 2014 in Japan. Our aim was to identify BoLA class II polymorphisms associated with the BLV proviral load in the Holstein cow. The study examined 569 cows with a high proviral load and 341 cows with a low proviral load. Using the highest odds ratio (OR) as a comparison index, we confirmed that BoLA-DRB3 was the best marker for determining which cow spread the BLV (OR 13.9 for BoLA-DRB3, OR 11.5 for BoLA-DQA1, and OR 6.2 for BoLA class II haplotype). In addition, DRB3*002:01, *009:02, *012:01, *014:01, and *015:01 were determined as BLV provirus associated alleles. BoLA-DRB3*002:01, *009:02, and *014:01 were determined as resistant alleles (OR > 1), and BoLA-DRB3*012:01 and *015:01 were determined as susceptible alleles (OR < 1). In this study, we showed that BoLA-DRB3 was a good marker for determining which cow spread BLV, and we found not only one resistant allele (BoLA-DRB3*009:02), but also two other disease-resistant alleles and two disease-susceptible alleles. This designation of major alleles as markers of susceptibility or resistance can allow the determination of the susceptibility or resistance of most cows to disease. Overall, the results of this study may be useful in eliminating BLV from farms without having to separate cows into several cowsheds.
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Affiliation(s)
- Shin-Nosuke Takeshima
- Viral Infectious Diseases Unit, RIKEN, Wako, Saitama, 351-0198, Japan.,Photonics Control Technology Team, RIKEN Center for Advanced Photonics, Wako, Saitama, 3510198, Japan.,Department of Food and Nutrition, Jumonji University, Niiza, Saitama, 352-8510, Japan
| | - Ayumu Ohno
- Viral Infectious Diseases Unit, RIKEN, Wako, Saitama, 351-0198, Japan
| | - Yoko Aida
- Viral Infectious Diseases Unit, RIKEN, Wako, Saitama, 351-0198, Japan. .,Nakamura Laboratory, Baton Zone Program, RIKEN Cluster for Science, Technology and Innovation Hub, Wako, Saitama, 351-0198, Japan.
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16
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Kuczewski A, Hogeveen H, Orsel K, Wolf R, Thompson J, Spackman E, van der Meer F. Economic evaluation of 4 bovine leukemia virus control strategies for Alberta dairy farms. J Dairy Sci 2019; 102:2578-2592. [PMID: 30639017 DOI: 10.3168/jds.2018-15341] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2018] [Accepted: 10/10/2018] [Indexed: 11/19/2022]
Abstract
Bovine leukemia virus (BLV) is a production-limiting disease common in North American dairy herds. To make evidence-based recommendations to Canadian dairy producers and their consultants regarding cost and financial benefits of BLV on-farm control, an economic model that takes the supply-managed milk quota system into account is necessary. Alberta-specific input variables were used for the presented analysis. A decision tree model program was used to evaluate economic aspects of decreasing a 40% BLV within-herd prevalence on dairy farms by implementing various control strategies over 10 yr. Investigated strategies were (1) all management strategies, including 3 options for colostrum management; (2) some management strategies; (3) test and cull; and (4) test and segregate. Each of these strategies was compared with a no control on-farm approach. The prevalence for this no-control approach was assumed to stay constant over time. Each control strategy incurred specific yearly cost and yielded yearly decreases in prevalence, thereby affecting yearly partial net revenue. Infection with BLV was assumed to decrease milk production, decrease cow longevity, and increase condemnation of carcasses at slaughter from cattle with enzootic bovine leukosis, thereby decreasing net revenue. Cows infected with BLV generated a yearly mean partial net revenue of Can$7,641, whereas noninfected cows generated Can$8,276. Mean cost for the control strategies ranged from Can$193 to Can$847 per animal over 10 yr in a 146-animal herd. Net benefits of controlling BLV on farm, as compared with not controlling BLV, per cow in a 146-animal herd over a 10-yr period for each strategy was: Can$1,315 for all management strategies (freezer); Can$1,243 for all management strategies (pasteurizer); Can$785 for all management strategies (powdered colostrum); Can$1,028 for some management strategies; Can$1,592 for test and cull; and Can$1,594 for test and segregate. Consequently, on-farm BLV control was financially beneficial. Even though negative net benefits were possible and expected for some iterations, our sensitivity analysis highlighted the overall robustness of our model. In summary, this model provided evidence that Canadian dairy farmers should be encouraged to control BLV on their farm.
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Affiliation(s)
- Alessa Kuczewski
- Department of Ecosystem and Public Health, University of Calgary, Calgary, AB, Canada T2N 4N1.
| | - Henk Hogeveen
- Business Economics Group, Wageningen University, Wageningen 6706 KN, the Netherlands
| | - Karin Orsel
- Department of Production Animal Health, University of Calgary, Calgary, AB, Canada T2N 4N1
| | - Robert Wolf
- Amt der Steiermärkischen Landesregierung, Graz 8010, Austria
| | - Jada Thompson
- Department of Agricultural and Resource Economics, University of Tennessee, Knoxville 37996
| | - Eldon Spackman
- Department of Community Health Sciences, University of Calgary, Calgary, AB, Canada T2N 4Z6
| | - Frank van der Meer
- Department of Ecosystem and Public Health, University of Calgary, Calgary, AB, Canada T2N 4N1
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17
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LaDronka RM, Ainsworth S, Wilkins MJ, Norby B, Byrem TM, Bartlett PC. Prevalence of Bovine Leukemia Virus Antibodies in US Dairy Cattle. Vet Med Int 2018; 2018:5831278. [PMID: 30534354 PMCID: PMC6252197 DOI: 10.1155/2018/5831278] [Citation(s) in RCA: 50] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2018] [Accepted: 10/15/2018] [Indexed: 11/29/2022] Open
Abstract
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.
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Affiliation(s)
- Rebecca M. LaDronka
- Department of Large Animal Clinical Sciences, College of Veterinary Medicine, Michigan State University, East Lansing, MI 48824, USA
| | - Samantha Ainsworth
- Department of Large Animal Clinical Sciences, College of Veterinary Medicine, Michigan State University, East Lansing, MI 48824, USA
| | - Melinda J. Wilkins
- Department of Large Animal Clinical Sciences, College of Veterinary Medicine, Michigan State University, East Lansing, MI 48824, USA
| | - Bo Norby
- Department of Large Animal Clinical Sciences, College of Veterinary Medicine, Michigan State University, East Lansing, MI 48824, USA
| | - Todd M. Byrem
- North Star Cooperative, 4200 Forest Rd., Lansing, MI 48910, USA
| | - Paul C. Bartlett
- Department of Large Animal Clinical Sciences, College of Veterinary Medicine, Michigan State University, East Lansing, MI 48824, USA
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18
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Carignano HA, Roldan DL, Beribe MJ, Raschia MA, Amadio A, Nani JP, Gutierrez G, Alvarez I, Trono K, Poli MA, Miretti MM. Genome-wide scan for commons SNPs affecting bovine leukemia virus infection level in dairy cattle. BMC Genomics 2018; 19:142. [PMID: 29439661 PMCID: PMC5812220 DOI: 10.1186/s12864-018-4523-2] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2017] [Accepted: 02/01/2018] [Indexed: 12/11/2022] Open
Abstract
BACKGROUND Bovine leukemia virus (BLV) infection is omnipresent in dairy herds causing direct economic losses due to trade restrictions and lymphosarcoma-related deaths. Milk production drops and increase in the culling rate are also relevant and usually neglected. The BLV provirus persists throughout a lifetime and an inter-individual variation is observed in the level of infection (LI) in vivo. High LI is strongly correlated with disease progression and BLV transmission among herd mates. In a context of high prevalence, classical control strategies are economically prohibitive. Alternatively, host genomics studies aiming to dissect loci associated with LI are potentially useful tools for genetic selection programs tending to abrogate the viral spreading. The LI was measured through the proviral load (PVL) set-point and white blood cells (WBC) counts. The goals of this work were to gain insight into the contribution of SNPs (bovine 50KSNP panel) on LI variability and to identify genomics regions underlying this trait. RESULTS We quantified anti-p24 response and total leukocytes count in peripheral blood from 1800 cows and used these to select 800 individuals with extreme phenotypes in WBCs and PVL. Two case-control genomic association studies using linear mixed models (LMMs) considering population stratification were performed. The proportion of the variance captured by all QC-passed SNPs represented 0.63 (SE ± 0.14) of the phenotypic variance for PVL and 0.56 (SE ± 0.15) for WBCs. Overall, significant associations (Bonferroni's corrected -log10p > 5.94) were shared for both phenotypes by 24 SNPs within the Bovine MHC. Founder haplotypes were used to measure the linkage disequilibrium (LD) extent (r2 = 0.22 ± 0.27 at inter-SNP distance of 25-50 kb). The SNPs and LD blocks indicated genes potentially associated with LI in infected cows: i.e. relevant immune response related genes (DQA1, DRB3, BOLA-A, LTA, LTB, TNF, IER3, GRP111, CRISP1), several genes involved in cell cytoskeletal reorganization (CD2AP, PKHD1, FLOT1, TUBB5) and modelling of the extracellular matrix (TRAM2, TNXB). Host transcription factors (TFs) were also highlighted (TFAP2D; ABT1, GCM1, PRRC2A). CONCLUSIONS Data obtained represent a step forward to understand the biology of BLV-bovine interaction, and provide genetic information potentially applicable to selective breeding programs.
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Affiliation(s)
- Hugo A. Carignano
- Instituto Nacional de Tecnología Agropecuaria (INTA). Centro de Investigaciones en Ciencias Veterinarias y Agronómicas (CICVyA). Instituto de Genética, B1686 Hurlingham, Argentina
| | - Dana L. Roldan
- Instituto Nacional de Tecnología Agropecuaria (INTA). Centro de Investigaciones en Ciencias Veterinarias y Agronómicas (CICVyA). Instituto de Genética, B1686 Hurlingham, Argentina
| | - María J. Beribe
- Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Pergamino, B2700 Pergamino, Argentina
| | - María A. Raschia
- Instituto Nacional de Tecnología Agropecuaria (INTA). Centro de Investigaciones en Ciencias Veterinarias y Agronómicas (CICVyA). Instituto de Genética, B1686 Hurlingham, Argentina
| | - Ariel Amadio
- Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Rafaela, S2300, Rafaela, Argentina
- Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), C1033AAJ Ciudad Autónoma de Buenos Aires, Argentina
| | - Juan P. Nani
- Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Rafaela, S2300, Rafaela, Argentina
| | - Gerónimo Gutierrez
- Instituto Nacional de Tecnología Agropecuaria (INTA). Centro de Investigaciones en Ciencias Veterinarias y Agronómicas (CICVyA). Instituto de Virología, B686 Hurlingham, Argentina
| | - Irene Alvarez
- Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), C1033AAJ Ciudad Autónoma de Buenos Aires, Argentina
- Instituto Nacional de Tecnología Agropecuaria (INTA). Centro de Investigaciones en Ciencias Veterinarias y Agronómicas (CICVyA). Instituto de Virología, B686 Hurlingham, Argentina
| | - Karina Trono
- Instituto Nacional de Tecnología Agropecuaria (INTA). Centro de Investigaciones en Ciencias Veterinarias y Agronómicas (CICVyA). Instituto de Virología, B686 Hurlingham, Argentina
| | - Mario A. Poli
- Instituto Nacional de Tecnología Agropecuaria (INTA). Centro de Investigaciones en Ciencias Veterinarias y Agronómicas (CICVyA). Instituto de Genética, B1686 Hurlingham, Argentina
| | - Marcos M. Miretti
- Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), C1033AAJ Ciudad Autónoma de Buenos Aires, Argentina
- Grupo de Investigación en Genética Aplicada, Instituto de Biología Subtropical (GIGA - IBS), Universidad Nacional de Misiones, N3300 Posadas, Argentina
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19
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Kuczewski A, Orsel K, Barkema HW, Kelton DF, Hutchins WA, van der Meer FJUM. Short communication: Evaluation of 5 different ELISA for the detection of bovine leukemia virus antibodies. J Dairy Sci 2017; 101:2433-2437. [PMID: 29274963 DOI: 10.3168/jds.2017-13626] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2017] [Accepted: 11/01/2017] [Indexed: 11/19/2022]
Abstract
Although Canadian dairy herds have been infected with bovine leukemia virus (BLV) for years, recent research has put new emphasis on the potential negative effects of this infection. Consequently, BLV control is becoming more favorable; however, BLV control cannot be successful without identifying infected animals. Bovicheck BLV (Biovet, Saint-Hyacinthe, QC, Canada) is currently the only assay licensed by the Canadian Centre for Veterinary Biologics. The first goal of this study was, therefore, to determine the reproducibility of the Bovicheck BLV assay for serum samples derived from Canadian cattle. The second goal was to evaluate and compare 5 different ELISA and determine their test characteristics using serum samples from Canadian herds. The considered ELISA were Bovicheck BLV, ID Screen BLV Competition (IDvet, Grabels, France), Idexx Leukosis Serum X2 Ab Test (Idexx Europe B.V., Hoofddorp, the Netherlands), Svanovir BLV gp51-Ab (Svanova, Uppsala, Sweden), and the Serelisa BLV Ab Mono Indirect (Synbiotics, Lyon, France). Eighty serum samples from Canadian cattle provided by Prairie Diagnostic Services (PDS; Saskatoon, SK, Canada) and an additional 80 serum samples from Canadian dairy and beef herds were used for the study. The Bovicheck BLV assay yielded the same results for all PDS-derived samples, implying a high level of reproducibility and robustness of this assay. Additionally, the comparison of the assays' results showed high agreement between assays, with Cohen's kappa values between κ = 0.91 and κ = 1. Furthermore, using original test results of the field samples as true status, relative diagnostic sensitivity and specificity were calculated. Relative diagnostic sensitivity of all tests was 100%. False-positive results were probable; therefore, the following relative diagnostic specificities were determined: 100% for Bovicheck BLV, Idexx Leukosis Serum X2, and Svanovir BLV; 95% for ID Screen BLV; and 97% for Serelisa BLV. When considering other test characteristics, ID Screen BLV is exceptional due to considerable practical advantages.
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Affiliation(s)
- Alessa Kuczewski
- Department of Ecosystem and Public Health, University of Calgary, Calgary, Alberta, Canada T2N 1N4.
| | - Karin Orsel
- Department of Production Animal Health, University of Calgary, Calgary, Alberta, Canada T2N 1N4
| | - Herman W Barkema
- Department of Production Animal Health, University of Calgary, Calgary, Alberta, Canada T2N 1N4
| | - David F Kelton
- Department of Population Medicine, University of Guelph, Guelph ON, Canada N1G 2W1
| | - Wendy A Hutchins
- Department of Microbiology, Immunology and Infectious Diseases, University of Calgary, Calgary, Alberta, Canada T2N 1N4
| | - Frank J U M van der Meer
- Department of Ecosystem and Public Health, University of Calgary, Calgary, Alberta, Canada T2N 1N4
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20
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Takeshima SN, Sasaki S, Meripet P, Sugimoto Y, Aida Y. Single nucleotide polymorphisms in the bovine MHC region of Japanese Black cattle are associated with bovine leukemia virus proviral load. Retrovirology 2017; 14:24. [PMID: 28376881 PMCID: PMC5379713 DOI: 10.1186/s12977-017-0348-3] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2017] [Accepted: 03/21/2017] [Indexed: 11/24/2022] Open
Abstract
Bovine leukemia virus (BLV) is the causative agent of enzootic bovine leukosis, a malignant B cell lymphoma that has spread worldwide and causes serious problems for the cattle industry. The BLV proviral load, which represents the BLV genome integrated into host genome, is a useful index for estimating disease progression and transmission risk. Here, we conducted a genome-wide association study to identify single nucleotide polymorphisms (SNPs) associated with BLV proviral load in Japanese Black cattle. The study examined 93 cattle with a high proviral load and 266 with a low proviral load. Three SNPs showed a significant association with proviral load. One SNP was detected in the CNTN3 gene on chromosome 22, and two (which were not in linkage disequilibrium) were detected in the bovine major histocompatibility complex region on chromosome 23. These results suggest that polymorphisms in the major histocompatibility complex region affect proviral load. This is the first report to detect SNPs associated with BLV proviral load in Japanese Black cattle using whole genome association study, and understanding host factors may provide important clues for controlling the spread of BLV in Japanese Black cattle.
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Affiliation(s)
| | - Shinji Sasaki
- Shirakawa Institute of Animal Genetics, Japan Livestock Technology Association, Odakura, Nishigo, Fukushima, 961-8061, Japan
| | - Polat Meripet
- Viral Infectious Diseases Unit, RIKEN, 2-1 Hirosawa, Wako, Saitama, 351-0198, Japan
| | - Yoshikazu Sugimoto
- Shirakawa Institute of Animal Genetics, Japan Livestock Technology Association, Odakura, Nishigo, Fukushima, 961-8061, Japan
| | - Yoko Aida
- Viral Infectious Diseases Unit, RIKEN, 2-1 Hirosawa, Wako, Saitama, 351-0198, Japan.
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Nekouei O, Durocher J, Keefe G. Diagnostic performance of an indirect enzyme-linked immunosorbent assay (ELISA) to detect bovine leukemia virus antibodies in bulk-tank milk samples. THE CANADIAN VETERINARY JOURNAL = LA REVUE VETERINAIRE CANADIENNE 2016; 57:778-780. [PMID: 27429469 PMCID: PMC4904818] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
This study assessed the diagnostic performance of a commercial ELISA for detecting bovine leukemia virus antibodies in bulk-tank milk samples from eastern Canada. Sensitivity and specificity of the test were estimated at 97.2% and 100%, respectively. The test was recommended as a cost-efficient tool for large-scale screening programs.
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Affiliation(s)
- Omid Nekouei
- Address all correspondence to Dr. Omid Nekouei; e-mail:
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Abdalla EA, Weigel KA, Byrem TM, Rosa GJM. Short communication: Genetic correlation of bovine leukosis incidence with somatic cell score and milk yield in a US Holstein population. J Dairy Sci 2016; 99:2005-2009. [PMID: 26778307 DOI: 10.3168/jds.2015-9833] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2015] [Accepted: 11/11/2015] [Indexed: 11/19/2022]
Abstract
Bovine leukosis (BL) is a retroviral disease caused by the bovine leukosis virus (BLV), which affects only cattle. Dairy cows positive for BL produce less milk and have more days open than cows negative for BL. In addition, the virus also affects the immune system and causes weaker response to vaccines. Heritability estimates of BL incidence have been reported for Jersey and Holstein populations at about 0.08, indicating an important genetic component that can potentially be exploited to reduce the prevalence of the disease. However, before BL is used in selection programs, it is important to study its genetic associations with other economically important traits such that correlated responses to selection can be predicted. Hence, this study aimed to estimate the genetic correlations of BL with milk yield (MY) and with somatic cell score (SCS). Data of a commercial assay (ELISA) used to detect BLV antibodies in milk samples were obtained from Antel BioSystems (Lansing, MI). The data included continuous milk ELISA scores and binary milk ELISA results for 11,554 cows from 112 dairy herds across 16 US states. Continuous and binary milk ELISA were analyzed with linear and threshold models, respectively, together with MY and SCS using multitrait animal models. Genetic correlations (posterior means ± standard deviations) between BL incidence and MY were 0.17 ± 0.077 and 0.14 ± 0.076 using ELISA scores and results, respectively; with SCS, such estimates were 0.20 ± 0.081 and 0.17 ± 0.079, respectively. In summary, the results indicate that selection for higher MY may lead to increased BLV prevalence in dairy herds, but that the inclusion of BL (or SCS as an indicator trait) in selection indexes may help attenuate this problem.
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Affiliation(s)
- E A Abdalla
- Department of Animal Sciences, University of Wisconsin, Madison 53706; Department of Animal Science, University of Benghazi, Benghazi, Libya 21861.
| | - K A Weigel
- Department of Dairy Science, University of Wisconsin, Madison 53706
| | - T M Byrem
- Antel BioSystems Inc., Lansing, MI 48910
| | - G J M Rosa
- Department of Animal Sciences, University of Wisconsin, Madison 53706; Department of Biostatistics and Medical Informatics, University of Wisconsin, Madison 53706
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Nekouei O, Stryhn H, VanLeeuwen J, Kelton D, Hanna P, Keefe G. Predicting within-herd prevalence of infection with bovine leukemia virus using bulk-tank milk antibody levels. Prev Vet Med 2015; 122:53-60. [DOI: 10.1016/j.prevetmed.2015.10.009] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2015] [Revised: 10/14/2015] [Accepted: 10/18/2015] [Indexed: 10/22/2022]
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Nekouei OA, Sanchez J, Keefe GP. Carryover of bovine leukemia virus antibodies in samples from shared milk meters. J Dairy Sci 2015; 98:5274-9. [PMID: 26004835 DOI: 10.3168/jds.2014-9036] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2014] [Accepted: 04/09/2015] [Indexed: 11/19/2022]
Abstract
Screening for infectious diseases of cattle using milk from the dairy herd improvement (DHI) sampling process is very convenient. However, when samples from shared milk meters are used, carryover of antibodies or other diagnostic targets can complicate the interpretation of the diagnostic test results for diseases, including bovine leukosis. The objectives of this study were (1) to assess the potential for carryover of antibodies against bovine leukemia virus (BLV) in milk samples obtained from shared meters, and (2) to determine if adjustment of the diagnostic test cut-off value would improve the test characteristics for meter-collected milk ELISA results. Eight dairy farms were randomly selected from herds with a wide range of BLV prevalence levels in Prince Edward Island, Canada. Within each chosen farm, 2 to 4milk meters were randomly selected. During the routine procedures of DHI sampling, 2 simultaneous milk samples, 1 hand-collected at the beginning of milking (after udder preparation) and the other from the corresponding milk meter, were taken from all lactating cows (n=236) that were milked at the selected meters (n=26). The sequence of cows using each meter was recorded. All samples were tested for BLV antibodies using a commercial indirect ELISA. Antibody carryover potential was assessed in meter-collected samples which were preceded by other cows using the same meters. Applying the hand-collected sample results as our reference standard, a new cut-off was defined for meter-collected samples to optimize the test characteristics. At the standard cut-off value of the diagnostic test, 110 (46.6%) of the hand-collected and 136 (57.6%) of the meter-collected samples were positive. For low-titer cows (e.g., true negatives), the likelihood of antibody carryover significantly increased as the titer of preceding cows increased, whereas this change was not substantial for high-titer cows. The odds of obtaining false diagnoses in meter-positive samples became larger with increase in the titer of preceding cows. A suspicious category for meter ELISA results was defined, and a retest was recommended for the cows falling into this category. This strategy effectively assisted in reducing the number of consequent false-positive results. When DHI-collected samples are used, carryover can affect the interpretation of dichotomous test results and may require adjustment of assay cut-off values.
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Affiliation(s)
- O A Nekouei
- Department of Health Management, Atlantic Veterinary College, University of Prince Edward Island, Charlottetown, Prince Edward Island, Canada C1A 4P3.
| | - J Sanchez
- Department of Health Management, Atlantic Veterinary College, University of Prince Edward Island, Charlottetown, Prince Edward Island, Canada C1A 4P3
| | - G P Keefe
- Department of Health Management, Atlantic Veterinary College, University of Prince Edward Island, Charlottetown, Prince Edward Island, Canada C1A 4P3
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Bartlett P, Norby B, Byrem T, Parmelee A, Ledergerber J, Erskine R. Bovine leukemia virus and cow longevity in Michigan dairy herds. J Dairy Sci 2013; 96:1591-7. [DOI: 10.3168/jds.2012-5930] [Citation(s) in RCA: 81] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2012] [Accepted: 11/23/2012] [Indexed: 11/19/2022]
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Abstract
The prevalence of bovine leukaemia virus (BLV) was determined in 113 Michigan dairy herds by ELISA testing for anti-BLV antibodies in milk. Additionally, an interview regarding management practices with cooperating herd managers identified farm-level variables thought to be associated with prevalence of BLV. Twenty-three risk factors (P ⩽ 0·1) were identified on one-way ANOVA or simple linear regression. Multivariate analysis identified several management practices whose predictive value for increased prevalence of BLV may relate to transmission among herd mates, e.g. reuse of hypodermic needles, lack of fly control, gouge dehorning and increased use of injections in dry cows. Additionally, exclusive breeding of heifers with artificial insemination was associated with decreased BLV prevalence, as compared with at least some use of natural service by a bull. Although intervention studies are needed before causal relationships can be concluded, and unaccounted variables related to transmission exist among dairy herds, these findings suggest management practices that may help dairy producers reduce the transmission of BLV within their herds.
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