This study was conducted in order to evaluate the transmission of caprine lentivirus to sheep using different experimental groups. The first one (colostrum group) was formed by nine lambs receiving colostrum from goats positive for small ruminant lentiviruses (SRLV). The second group (milk group) was established by nine lambs that received milk of these goats. Third was a control group, consisting of lambs that suckled colostrum and milk of negative mothers. Another experimental group (contact group) was formed by eight adult sheep, confined with two naturally infected goats. The groups were monitored by immunoblotting (IB), enzyme-linked immunosorbent assay (ELISA), agar gel immunodiffusion (AGID) and nested polymerase chain reaction (nPCR). All lambs that suckled colostrum and milk of infected goats and six sheep of the contact group had positive results in the nPCR, although seroconversion was detected only in three of the exposed animals, with no clinical lentiviruses manifestation, in 720 days of observation. There was a close relationship between viral sequences obtained from infected animals and the prototype CAEV-Cork. Thus, it was concluded that SRLV can be transmitted from goats to sheep, however, the degree of adaptation of the virus strain to the host species probably interferes with the infection persistence and seroconversion rate.

Small ruminant lentiviruses, caprine arthritis encephalitis virus, and Maedi-Visna virus cause diseases that result in significant productive losses, mostly in dairy animals. These viruses belong to the Retroviridae family, Lentivirus genus, and constitute a heterogeneous group, which may generate implications for the diagnosis and control of small ruminant lentiviruses. Losses caused by them are associated with reproductive failure, short productive life, and decreased milk production by the infected animals. In addition, these viruses may reduce milk quality, affecting the production of dairy products such as cheese. Small ruminant lentiviruses lead to indirect losses, decreasing herd value and forcing the development of epidemiological trade barriers for animal germplasm. Control of small ruminant lentiviruses is important to promote optimal milk production and to reduce costs with medicine and technical assistance. This control may vary in caprine and ovine populations of each country, according to seroprevalence, variety of breeds, and peculiarities of the practiced management.

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The aim of this study was to evaluate in vitro and in vivo the effect of sodium dodecyl sulfate (SDS) on the caprine lentivirus (CLV) in colostrum and milk. This was performed to develop a practical and efficient method of blocking the lactogenic transmission of the virus. In the in vitro experiment, colostrum and milk were treated with 0.25%; 0.50% and 1% SDS. Then, somatic cells of colostrum and milk were submitted to co-culture with caprine synovial membrane cells (CSM). In the in vivo test, goats were fed with colostrum and milk provided from CLV-positive goats treated with SDS in the same concentrations used in the in vitro experiment. Animals were tested by nested polymerase chain reaction (nPCR) and Western blot (WB) assays. In the in vitro experiment, inhibitory activity against CLV without inactivation occurred in colostrum with all SDS concentrations. However, concentrations of 0.25 and 0.5% SDS presented only inhibitory activity against CLV in milk cells, and 1% concentration provided inactivation of the virus. In the in vivo tests, none of the three concentrations of SDS was effective in inactivating LVC in colostrum or goat milk, which was confirmed by seroconversion and presence of proviral DNA in animals afterwards.

This study aimed to isolate cells from the Wharton's jelly of umbilical cord (WJUC) of sheep collected during natural parturition using different culture media, in addition to reporting for the first time the permissiveness of these cells to in vitro infection by small ruminant lentiviruses. Ten umbilical cords were collected from healthy sheep. Each cord explants were grown in different media consisting of MEM, low glucose DMEM, M199, and RPMI-1640. The permissiveness of infection of sheep cells from WJUC was tested with CAEV-Cork and MVV-K1514 strains, inoculating 0.1 MOI of each viral strain. Four supernatants from each strain were obtained from WJUC sheep cell cultures infected in different media. The results demonstrated the presence of cytopathic effect after the in vitro infection by CAEV-Cork and MVV-K1514 with all of the tested culture media. Nested-PCR detected proviral DNA in all supernatants. Supernatants containing CAEV-Cork viruses had TCID50/ml titres of 105.5 in MEM, 104.0 in low glucose DMEM, 105.0 in M199, and 105.7 in RPMI-1640. Supernatants containing the MVV-K1514 virus had TCID50/ml titres of 104.3 in MEM, 103.5 in low-glucose DMEM, 104.7 in M199, and 103.5 in RPMI-1640. Sheep cells from WJUC are permissive to in vitro infection by small ruminant lentivirus.