The implication of BLV infection in the productivity, reproductive capacity and survival rate of a dairy cow

Brenner, J.; Van-Haam, M.; Savir, D.; Trainin, Z.

doi:10.1016/0165-2427(89)90017-2

Cited by 84 publications

(53 citation statements)

References 8 publications

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“…Furthermore, other percentages of milk production losses were also described, such as 2.7% reported by Ott, Johnson and Wells (2003), or 3.5% found by Brenner et al (1989). In opposite, some studies have shown that BLV infection has no influence on milk production (KALE et al, 2007;TIWARI et al, 2007) and also in others, BLVpositive cows have even shown an increase in milk production (JACOBS et al, 1991;POLLARI et al, 1992).…”

Section: Discussionmentioning

confidence: 98%

Effects of bovine leukemia virus infection on crossbred and purebred dairy cattle productive performance in Brazil

et al. 2014

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The aim of this study was to evaluate the effects of bovine leukemia virus (BLV) infection on productive performance of dairy cattle in Brazil. A total of 158 blood samples from lactating adult cows, purebred Holstein and crossbred Holstein X Zebu, were analyzed by Agar Gel Immunodifusion Test (AGID) and leukogram. According to AGID and leukogram results, animals were grouped into three categories: seronegative, seropositive without persistent lymphocytosis, and seropositive with persistent lymphocytosis. Milk production data were compared between groups, according to breed. BLV infected females showed lower milk yield than uninfected ones, both purebred and crossbred ones. There was no difference between milk yield of seropositive cows with or without persistent lymphocytosis. These results indicate an association between BLV infection and reduction of milk production, and this study is the first one to show these effects in crossbred Holstein X Zebu cows. Key words: Bovine leukemia virus, milk production, purebred, crossbred, cow ResumoO objetivo desse estudo foi avaliar os efeitos da infecção pelo vírus da leucose bovina (VLB) na produção de vacas leiteiras no Brasil. Foram analisadas 158 amostras de sangue de vacas adultas em lactação puras da raça Holandesa e mestiças Holandês X Zebu. As amostras foram testadas pela Imunodifusão em Gel de Ágar (IDGA) e pelo leucograma. De acordo com os resultados da IDGA e do leucograma, os animais estudados foram agrupados em três categorias: soronegativos, soropositivos sem linfocitose persistente e soropositivos com linfocitose persistente. Os dados de produção leiteira foram comparados entre os grupos, de acordo com a raça. Vacas infectadas com o VLB apresentaram produção de leite inferior que de vacas não infectadas, tanto puras como mestiças. Não houve diferença na produção de leite de vacas positivas com e sem linfocitose persistente. Esses resultados indicam a associação da infecção pelo VLB com a queda na produção de leite, e esse é o primeiro estudo a mostrar tais efeitos em vacas mestiças Holandês X Zebu. Palavras-chave: Vírus da leucose bovina, produção de leite, pura, mestiça, vaca

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Section: Discussionmentioning

confidence: 98%

Effects of bovine leukemia virus infection on crossbred and purebred dairy cattle productive performance in Brazil

et al. 2014

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“…Bovine leukaemia virus (BLV) is an infectious agent of cattle that can cause lymphomas and benign disorders which, directly or indirectly, have a financial impact on the cattle industry (Ferrer, 1980 ;Brenner et al, 1989 ;Burny et al, 1990). It is estimated that more than 10 % of dairy cattle in the United States are infected with BLV.…”

Section: Introductionmentioning

confidence: 99%

Degenerate and specific PCR assays for the detection of bovine leukaemia virus and primate T cell leukaemia/lymphoma virus pol DNA and RNA: phylogenetic comparisons of amplified sequences from cattle and primates from around the world.

Dube

Bachman

Spicer

et al. 1997

Journal of General Virology

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“…How BLV affects animal reproductive performance remains unclear. Previous studies failed to find an effect of the infection on herd fertility (BRENNER et al, 1989;D'ANGELINO et al, 1998;HUBER et al, 1981;KALE et al, 2007). However, others have reported that the presence of the virus may be associated with fetal loss and presence of ovarian cysts (HEALD et al, 1992;JACOBS et al, 1991;POLLARI et al, 1992;VANLEEUWEN et al, 2010).…”

Section: Introductionmentioning

confidence: 97%

Molecular detection of Bluetongue Virus (BTV) and Bovine Leukemia Virus (BLV) in uterine biopsies of dairy cows with or without reproductive problems

Bicalho

Júnior

Oliveira

et al. 2016

SCA

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Reproductive performance of dairy cows has a direct impact on herd productivity. Infectious agents, such as Bluetongue Virus (BTV) and Bovine Leukemia Virus (BLV), are associated with reproductive failure. However, it remains unknown if these viruses are present in the uterus and cause gestational loss. This study used molecular methods to assess if BTV and BLV can be detected in the uterus of serologically positive dairy cows with a record of abortions, stillbirths and repeat breeding (n=23) and without a record of reproductive problems (n =23). The cows came from three dairy herds of the state of Minas Gerais, Brazil. BTV was not detected in any of the uterine biopsies. Proviral DNA of BLV was detected in 54.5 % of the seropositive cows, but positivity for BLV in the uterus was not associated with the existence of reproductive problems. In conclusion, this study shows that BLV, but not BTV, is present in the uterus of seropositive cows, regardless of reproductive performance. Key words: Bovines. Reproduction. Uterus. BTV. BLV. associados à ocorrência de falhas reprodutivas. Entretanto, não se sabe se estes vírus poderiam estar presentes no útero resultando nas perdas gestacionais. Este estudo utilizou métodos moleculares para investigar se os vírus BTV e BLV estão presentes no úterio de vacas leiteiras sorologicamente positivas com histórico de abortos, natimortos e repetição de cio (n=23) e em vacas sem histórico de problema reprodutivos (n =23) provenientes de três rebanhos leiteiros localizados no estado de Minas Gerais, Brasil. Não foi detectado BTV em nenhuma amostra de biópsia uterina. Por outro lado, o DNA proviral de BLV foi detectado no útero de 54.5 % das vacas soropositivas, independentemente da ocorrência de problemas reprodutivos. Conclui-se que o vírus BLV, ao contrário do BTV está presente no útero de vacas soropositivas, entretanto, sem associação com o desempenho reprodutivo. Palavras-chave: Bovinos. Reprodução. Útero. BTV. BLV. Resumo

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The implication of BLV infection in the productivity, reproductive capacity and survival rate of a dairy cow

Cited by 84 publications

References 8 publications

Effects of bovine leukemia virus infection on crossbred and purebred dairy cattle productive performance in Brazil

Effects of bovine leukemia virus infection on crossbred and purebred dairy cattle productive performance in Brazil

Degenerate and specific PCR assays for the detection of bovine leukaemia virus and primate T cell leukaemia/lymphoma virus pol DNA and RNA: phylogenetic comparisons of amplified sequences from cattle and primates from around the world.

Molecular detection of Bluetongue Virus (BTV) and Bovine Leukemia Virus (BLV) in uterine biopsies of dairy cows with or without reproductive problems

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