Immunologic response of sheep to inactivated and virulent bluetongue virus

Humoral and cellular immune responses of sheep to inactivated and virulent bluetongue virus (BTV) were studied. All sheep inoculated with inactivated BTV developed BTV group-specific nonneutralizing antibodies, as determined by agar-gel immunodiffusion. The development of group-specific, nonneutralizing, complement-fixing antibodies was variable and appeared to be dependent on immunizing BTV serotype, sheep breed, and individual variation. Virus-neutralizing antibodies were never detected after inoculation with the inactivated BTV. In vitro lymphocyte stimulation to BTV soluble antigen was observed with cells from all inoculated Warhill sheep and with cells from 1 of 3 inoculated Suffolk cross sheep. Complement-fixation titers did not appear to correlate with the degree of protection observed, ie, duration of postchallenge-exposure viremia. The development of postchallenge-exposure neutralizing antibody titer was inversely correlated to protective immunity. The development of a response to BTV antigen in the lymphocyte-stimulation test associated most closely with protection. Warhill sheep were afforded better protection, by inoculation with inactivated BTV, to live virus challenge exposure than were the Suffolk cross sheep. Approximately 30% of the inoculated Suffolk cross sheep responded to challenge exposure with intensified clinical signs of blue-tongue, compared with the challenge-exposed control sheep of the same breed.     

Nontransmission of bluetongue virus by embryos from bluetongue virus-infected sheep

Donor sheep were infected either by bites of bluetongue virus (BTV)-infected (serotype 11, "Texas Station strain") Culicoides variipennis or by inoculation with 100,000 median chicken embryo intravascular lethal doses of BTV (serotype 11) from a suspension made from infected C variipennis. Fourteen embryos from 4 BTV-infected ewes bred by rams not infected with BTV were transferred to 8 BTV-seronegative recipient ewes, and 35 embryos and 4 unfertilized eggs from 14 BTV-infected ewes bred by BTV-infected rams were transferred to 19 BTV-seronegative recipient ewes. Eleven pregnancies and 12 lambs resulted. None of the recipients or lambs seroconverted, and BTV was not isolated from the pregnant recipient ewes or their lambs at slaughter 30 days after parturition.     

Effects of ewe breed and ram exposure on estrous behavior in May and June

Two groups of purebred ewes (A and B), each consisting of 25 Dorsets and 25 Hampshires, were used to study effects of ewe breed and ram exposure on ovulation and estrus in May and June. Ewes lambed in January and February and were isolated from mature rams for at least 5 mo. From May 8 to June 11 (Period 1), Group A ewes were penned with vasectomized rams fitted with marking harnesses and Group B ewes were isolated from rams. From June 11 to July 13 (Period 2), rams were placed with Group B ewes and Group A ewes were isolated from rams. Ovulation was monitored by biweekly serum progesterone assays and crayon marks were used to detect estrus. For Group A ewes in Period 1, more Dorsets ovulated (96%) than did Hampshires (72%), and of ewes that ovulated, more Dorsets mated (83 vs 28%). Fifty-five percent of Dorsets, but only 20% of Hampshires, appeared to have been spontaneously cycling at the start of the experiment. Of ewes mated in Period 1, more Dorsets than Hampshires continued to cycle during Period 2 (65 vs 0%). For Group B ewes in Period 1, 44% of Dorsets, but only 8% of Hampshires, ovulated in the absence of rams. In Period 2, 92% of Dorsets and 84% of Hampshires ovulated. Of ewes that ovulated, more Dorset ewes mated (78 vs 52%). Of ewes that mated, more Dorsets appeared to be cycling spontaneously at ram introduction (39 vs 0%). Throughout the study, 24% of Dorsets, but no Hampshires, cycled continuously.(ABSTRACT TRUNCATED AT 250 WORDS)     

Comparison of virologic and serologic responses of lambs and calves infected with bluetongue virus serotype 10

Four lambs and 3 calves, seronegative to bluetongue virus (BTV), were inoculated intravenously with a highly plaque-purified strain of BTV Serotype 10. A single calf and lamb served as controls and were inoculated with uninfected cell culture lysate. All BTV-inoculated lambs exhibited mild clinical manifestations of bluetongue, whereas infected calves were asymptomatic. Viremia persisted in BTV-infected lambs for 35-42 days, and for 42-56 days in BTV-infected calves. Neutralizing antibodies were first detected in sera collected at Day 14 post-inoculation (PI) from 2 BTV-infected calves and all 4 infected lambs, and at Day 28 PI in the remaining calf. The appearance of neutralizing antibody in serum did not coincide with clearance of virus from blood; BTV and specific neutralizing antibody coexisted in peripheral blood of infected lambs and calves for as long as 28 days. The sequential development, specificity and intensity of virus protein-specific humoral immune responses of lambs and calves were evaluated by immunoprecipitation of [35S]-labelled proteins in BTV-infected cell lysates by sera collected from inoculated animals at bi-weekly intervals PI. Sera from infected lambs and calves reacted most consistently with BTV structural proteins VP2 and VP7, and nonstructural protein NS2, and less consistently with structural protein VP5, and nonstructural protein NS1. Lambs developed humoral immune responses to individual BTV proteins more rapidly than calves, and one calf had especially weak virus protein-specific humoral immune responses; viremia persisted longer in this calf than any other animal in the study. The clearance of virus from the peripheral blood of BTV-infected lambs and calves is not caused simply by the production of virus-specific neutralizing antibody, however the intensity of humoral immune responses to individual BTV proteins might influence the duration of viremia in different animals.     

Pathological,serological, and virological findings in sheep infected simultaneously with <Emphasis Type="Italic">Bluetongue</Emphasis>, <Emphasis Type="Italic">Peste-des-petits-ruminants</Emphasis>, and <Emphasis Type="Italic">Sheeppox viruses</Emphasis>

In this study, pathological, serological and virological examinations were performed on 15 sheep from a flock of 250 sheep and lambs that suffer from simultaneous naturally occurring BTV, PPRV and SPV outbreaks. SPV was diagnosed macroscopically and histopathologically, BTV was diagnosed by ELISA, and PPRV was diagnosed pathologically and by ELISA. Clinically fever, diarrhea, depression, polypnea, conjunctivitis, lacrimation, rhinitis, erosive stomatitis, edema of eyelids, photophobia, cutaneous eruption with erythematous areas especially noticeable in wool-free parts of the body and axilla lesions evolving into papules were observed. At necropsy, the most effected organs were lungs and gut. Subepicardial hemorrhages were also commonly seen. While typical pox lesions were observed in some lambs, usually fibrinous pleuropneumonia was more prominent lung lesion. SPV and PPRV lesions were seen at the histopathological examination of the lesioned tissues, BT lesions were mild than SPV and PPRV microscopically. Serum and leukocyte samples of 15 animals were examined for PPRV and BTV by ELISA; 5 samples were positive for PPRV and 6 BTV, 4 were positive for both PPRV and BTV simultaneously. One hundred animals died, most were lambs. Mortality rates were 100% in lambs and 80% in the herd.     

Neutralizing antibody responses to bluetongue and epizootic hemorrhagic disease virus serotypes in beef cattle

Blood samples were obtained from sentinel beef cattle at monthly intervals, and the sera were tested for antibodies, using a bluetongue virus (BTV) immunodiffusion test (IDT) and virus-neutralization test (VNT), for 5 BTV serotypes (2, 10, 11, 13, and 17) and 2 epizootic hemorrhagic disease virus (EHDV) serotypes (1 and 2). The cattle tested were transported from Tennessee to Texas in 1984 and 1985. All cattle were seronegative by the BTV IDT at the initial bleeding in Texas in 1984 and 1985. In 1984, 16 of 40 (40%) cattle seroconverted as assessed by results of the BTV IDT. In the 16 seropositive cattle in 1984, neutralizing antibodies were detected to BTV serotypes 10 (n = 7), 11 (n = 3), and 17 (n = 11), and EHDV serotypes 1 (n = 1) and 2 (n = 7). In 1984, no cattle seroconverted to BTV-2 or BTV-13. In 1985, 10 of 36 (27.8%) cattle seroconverted as assessed by results of the IDT. Of the 10 seropositive cattle in 1985, neutralizing antibodies were detected to BTV serotypes 10 (n = 10), 11 (n = 10), 13 (n = 7), and 17 (n = 5), and EHDV serotypes 1 (n = 1) and 2 (n = 7). In 1985, no cattle seroconverted to BTV-2. Clinical diseases attributable to BTV or EHDV was not detected in these cattle in 1984 or 1985.     

A competitive ELISA for detection of antibodies to the group antigen of bluetongue virus.

A competitive enzyme-linked immunosorbent assay (cELISA) was developed to detect antibodies to the group antigen of bluetongue virus (BTV). The epitope recognized by the BTV-specific monoclonal antibody was confirmed, by immunofluorescence staining of monolayers of virus-infected Vero cells, to be present on BTV serotypes 2, 10, 11, 13, and 17 but not on epizootic hemorrhagic disease virus (EHDV) serotypes 1 and 2. Sera from BTV-inoculated ruminants and rabbits were used to evaluate the cELISA and to compare its specificity and sensitivity with that of the conventional BTV-specific agar gel immunodiffusion (AGID) and serum neutralization (SN) tests. Rabbit antisera to the 5 serotypes of BTV present in the United States had cELISA titers (inverse of the final dilution of serum that gave greater than 20% inhibition) that ranged from 32 to greater than 1.024. Seroconversion of the 8 calves and lambs inoculated with BTV was detected by all 3 serologic tests (SN, AGID, cELISA) by 6 weeks after inoculation. Specificity of the cELISA test was confirmed with bovine sera that contained neutralizing antibodies to EHDV but not to the 5 serotypes of BTV present in the United States; these sera gave positive results by AGID test but were negative by cELISA. The sensitivity and specificity of the cELISA test was further confirmed by analysis of a panel of bovine test sera supplied by the National Veterinary Services Laboratories, indicating that the cELISA is a superior test for detection of BTV group-specific antibodies in sera from ruminants in the United States.     

Recovery of dual serotypes of bluetongue virus from infected sheep and cattle

Dual serotypes of bluetongue virus (BTV) were recovered from field-collected samples of sheep and cattle blood. Two sheep, each infected with both BTV serotypes 10 and 17, were found in a flock with bluetongue disease associated with these two serotypes. One sheep infected with BTV serotypes 11 and 17 was found in a second flock; it was the only viremic sheep detected and was clinically ill. Dual serotype infections of one beef and two dairy cattle were found in three geographically separate herds; mixtures recovered were of BTV serotypes 10 and 17 and serotypes 11 and 17. Clinical signs of illness were absent in the cattle in two herds, but severe conjuctivitis was seen in several cows in a third herd, including the cow with a dual serotype infection (BTV 11 and 17). Two of the cattle with dual infections had no serological evidence of BTV as determined by the agar gel precipitin test; serum was not available from the other cow with a dual serotype infection. The significance of dual infections and immune tolerance are discussed.     

Evaluation of the South African Dorper as a terminal sire breed for growth,carcass, and palatability characteristics

The South African Dorper is an important terminal meat sire breed in Africa that was recently imported into the United States. The objective of this study was to evaluate the Dorper as a terminal meat sire breed for U.S. production. Semen from purebred Dorper sires was used to artificially inseminate Columbia ewes to produce F1 crossbred lambs. Growth and carcass characteristics of F1 Dorper-Columbia lambs (n = 165), F1 Suffolk-Columbia (n = 89), and purebred Columbia lambs (n = 207) were compared based on subsets of the total number of animals. The F1 Dorper lambs grew significantly slower (313 g x d(-1)) and weighed less (29.8 kg) than F1 Suffolk- (357 g x d(-1), 33.5 kg) and Columbia-sired lambs (328 g x d(-1), 31 kg) at 77 d of age. However, at a weaning age of 118 d weaning weight and ADG did not differ (P > 0.20) among sire breed groups. Postweaning growth of F1 Dorper(239 g xd(-1)) wether lambs did not differ from that of purebred Columbia wethers (230 g x d(-1)) but was less than that of F1 Suffolk lambs (259 g x d(-1); P= 0.09). Feed efficiency did not differ among breed types. Breed types had similar dressing percentages (53%), shoulder fat depth (2.8 mm), body wall thickness (3 cm), leg conformation score (Choice), Yield grade (2.4), and Quality grade (Choice). Weight of wholesale shoulders and racks made up approximately 38% of the carcass weight in the Columbia and F1 Suffolk-Columbia type but only 33% in the F1 Dorper-Columbia lambs. However, the more expensive wholesale loins from F1 Dorpers were heavier (P < 0.01) than the other breed types. Total weights of wholesale legs were similar among F1 Dorpers and F1 Suffolks but were heavier than those for the purebred Columbia (P < 0.05). Percentages of total wholesale primal cuts were similar among breed types (P > 0.10). Chemical composition of the carcass did not differ significantly between breed types with a mean composition of 52% moisture, 30% lipid (ether extract), 17% protein, and 0.76% ash. Warner-Bratzler shear force values were less (P < 0.05) and sensory panel ratings for tenderness were significantly more favorable for lamb chops from Dorper sired lambs. Dorper rams can be used as terminal meat sires to produce lambs whose growth rate to 118 d of weaning age, postweaning ADG and feed efficiency, and carcass characteristics are similar to that of Suffolk crossbred lambs and purebred Columbia lambs but with a slight improvement in tenderness.     

滨州绵羊冷冻胚胎移植试验研究

该项成果通过引进德国肉用美利奴绵羊冷冻胚胎29枚,用山东地方良种洼地绵羊作受体,共移植受体母羊20只,二情期不返精率65％（13．20）,产出活羔11只,产羔率55％（11／20）。     

Recombinant cDNA probe from bluetongue virus genome segment 10 for identification of bluetongue virus

Genome segment 10 of bluetongue virus (BTV) serotype 11 UC8 strain was cloned and subsequently hybridized to viral double-stranded RNA extracted from 90 field isolates of BTV serotypes 10, 11, 13, and 17; the prototype strains of BTV 2, 10, 11, 13, and 17; the prototype strain epizootic hemorrhagic disease virus (EHDV) serotype 1; and 4 field isolates of EHDV serotype 2. The 90 field isolates were obtained from different counties in California, Louisiana, and Idaho during the years 1979, 1980, and 1981. The cloned genetic probe hybridized with all the BTV samples tested, showing different degrees of cross-hybridization at the stringency conditions used in this study. This indicated that BTV genome segment 10 has conserved nucleotide sequences among the BTV serotypes 2, 10, 11, 13, and 17. No cross-hybridization signals were detected between the cloned genome segment 10 of BTV 11 UC8 strain and the prototype strain of EHDV serotype 1 and the field isolates of serotype 2. This probe recognized a wide variety of BTV isolates.     

Recombinant DNA probe for serotype-specific identification of bluetongue virus 17

The double-stranded RNA genome from 117 field isolates of bluetongue virus (BTV) serotypes 10, 11, 13, and 17 was blotted onto nitrocellulose paper and hybridized with a radioactively labeled cloned copy of DNA genome segment 2 of BTV-17. Viral RNA from BTV prototype strains 2, 10, 11, 13, and 17 were used as controls. The probe hybridized only with the viral RNA from prototype BTV-17 virus and field isolates of BTV-17. There was no cross hybridization with field isolates of BTV serotypes 10, 11, and 13. A complementary DNA probe developed from genes coding for BTV serotype specificity was effectively used in a slot-blot hybridization system for efficiently characterizing the viral serotype.     

Humoral Response to 2 Inactivated Bluetongue Virus Serotype‐8 Vaccines in South American Camelids

Background: Bluetongue virus serotype 8 (BTV‐8) has caused disease in domestic ruminants in several countries of northern Europe since 2006. In 2008 a mass‐vaccination program was launched in most affected countries using whole virus inactivated vaccines. Objective: To evaluate 2 inactivated vaccines (Bovilis BTV 8; BTVPUR AlSap8) for immunogenicity and safety against BTV‐8 in South American camelids (SAC) in a field trial. Animals: Forty‐two SAC (25 Alpacas, 17 Llamas) aged between 1 and 16 years. Methods: The animals were vaccinated twice at intervals of 21 days. They were observed clinically for adverse local, systemic, or both reactions throughout the trial. Blood samples collected on days 0, 14, 21, 43, and 156 after vaccination were tested for the presence of BTV‐8 virus by real time‐polymerase chain reaction and of specific antibodies by competitive ELISA and a serum neutralization test. Results: All vaccinated animals developed antibodies to BTV‐8 after the 2nd administration of the vaccine. No adverse effects were observed except for moderate local swellings at the injection site, which disappeared within 21 days. Slightly increased body temperatures were only observed in the first 2 days after vaccination. The BTV was not detected in any of the samples analyzed. Conclusions and Clinical Importance: The administration of the 2 inactivated commercial vaccines was safe and induced seroconversion against BTV‐8 in all vaccinated animals. The results of this study suggest that 2 doses injected 3 weeks apart is a suitable vaccination regimen for SAC.     

Texel sheep are more resistant to natural nematode challenge than Suffolk sheep based on faecal egg count and nematode burden

Limited information is available on differences between sheep breeds with respect to helminth resistance under temperate conditions. The present study was designed to confirm and extend preliminary findings on observed breed differences in resistance to naturally acquired gastrointestinal nematodes in Suffolk and Texel sheep. Three trials were carried out. In trial 1 (1999-2003) lambs co-grazed from birth were faecal sampled at various time points up to 17 weeks of age. Worm burden was assessed at 17 weeks of age from a minimum of six lambs per breed in each of the 3 years. In trial 2, faecal egg count (FEC) was determined on six farms with co-grazed Suffolk and Texel purebred lambs. In trial 3 (2001-2003), ewes were faecal sampled at winter housing. In all three trials, an influence of breed on resistance to naturally acquired trichostrongyle infection was demonstrated. In trial 1, significantly higher FEC and worm burden was observed in Suffolk compared with Texel lambs following natural challenge. In trial 2, FEC recorded in lambs from six farms confirmed the breed differences previously observed. A breed difference in resistance to GI parasites was also observed in older ewes. In both breeds, an age effect on the FEC was observed with younger ewes having greater FEC than older ewes.     

IgE responses to bluetongue virus (BTV) serotype 11 after immunization with inactivated BTV and challenge infection

To test the hypothesis that development of a BTV-specific IgE response plays a role in clinical disease manifestation, the humoral immune response of cattle to inactivated and virulent BTV was studied. Three calves received three sensitizing immunizations of inactivated BTV, 3 weeks apart. The BTV-sensitized animals, two non-sensitized BTV-seropositive and 4 BTV-seronegative control cattle. were challenge-exposed with BTV-11, UC8 strain. All cattle inoculated with inactivated BTV developed group-specific non-neutralizing and serotype-specific neutralizing antibodies. The development of post-challenge-exposure neutralizing antibody titers was inversely correlated with protective immunity. None of the BTV-challenged animals showed clinical disease. The levels of IgE were greatest in the sensitized calves after virus challenge in comparison with control groups. The sequential development, specificity and intensity of virus protein-specific humoral responses were evaluated using immunostaining. After challenge exposure of BTV-sensitized and non-sensitized cattle, total and IgE antibodies reacted consistently within BTV structural proteins VP2, VP5 and VP7. Although no correlation was found between clinical disease and IgE, results add support to the hypothesis that IgE may be involved in the pathogenesis of clinical disease, since infection with BTV causes an increase in serum IgE levels. However, these results suggest that the levels of virus-specific reactivity may be an important factor in determining whether or not clinical disease manifestation occurs.     

Detection of viral antigens in bluetongue virus-infected ovine tissues, using the peroxidase-antiperoxidase technique

An indirect immunoperoxidase procedure was developed to detect viral antigens in bluetongue virus (BTV)-infected tissues. Embryonating chicken eggs were infected with BTV serotypes 10, 11, 13, or 17, and the chorioallantoic membranes were subsequently fixed in formalin and embedded in paraffin. The peroxidase-antiperoxidase (PAP) system was used to examine the infected membranes for the presence of viral antigens. Sheep antisera raised against BTV serotypes 10, 11, 13, and 17 served as the primary antibodies in the PAP procedure. Specific staining was observed when each of these antisera was applied to membranes expressing antigens of homologous and heterologous BTV serotypes. The PAP method was rapid, reliable, and specific in its detection of BTV.     

A seroepidemiological study on bluetongue virus in dairy cattle in the central valley of California

A seroepidemiological study on bluetongue virus (BTV) infection in California dairy cattle was conducted to estimate the prevalence and distribution by age and season of BTV group-reactive antibodies and to look for possible associations between the presence of antibodies and cattle age or breed and farm. Between December 1985 and March 1987, a sample of cattle was tested at approximately two-month intervals for BTV group-reactive antibodies using an enzyme-linked immunosorbent assay (ELISA). Data taken during the month of December 1986 were used to evaluate possible associations between a positive antibody test and certain intrinsic (age, breed) and extrinsic (farm) factors.Univariate and multivariate statistical analyses using the -square test for associations and multiple logistic regression, respectively, were carried out for possible associations between positive antibody tests to BTV and each factor of interest. The strengths of the associations were determined using estimates of the odds ratio.Of the 3774 serum samples tested, 238 (6.3%) were from calves, 1045 (27.6%) were from heifers and 2492 (66.0%) were from cows. Seroprevalence varied from nil in calves on two occasions to over 90% on several occasions in cows. Cows consistently had higher prevalence rates than heifers or calves across all test dates (p<0.05). The seroprevalence of BTV group-reactive antibodies also showed a seasonal fluctuation, with the highest rates occurring during the warmer months of the year. These highest prevalence rates coincided with heavy activity of the known vector of BTV, Culicoides spp. Breed and farm effects were not statistically significant (p>0.05). With the exception of one farm, all cattle were of the Holstein breed, which reduced confidence in assessing any breed effect in this study. Relative estimates of the sensitivity and specificity of BTV ELISA were 87% and 100% respectively, compared to the standard agar gel immunodiffusion (AGID) test.The observations support previous findings of seasonal distribution of BTV antibodies and suggest an age relationship, whereby older cattle are more likely to be positive to BTV group-reactive antibodies than younger cattle.     

The use of passive injectable transponders in fattening lambs from birth to slaughter: effects of injection position,age, and breed

A total of 1,159 Tiris half-duplex passive injectable transponders (PIT) of 32-mm length were used to study the electronic identification of 618 fattening lambs of two breeds used for different production purposes (Ripollesa, meat breed, n = 271, and Manchega, dairy breed, n = 347). The lambs were s.c. injected in the armpit and the retro-auricular positions at 2, 15, and 30 d of age. All lambs were also tagged with a small plastic ear tag after birth. A group of 76 lambs were injected only in the right armpit and were kept for breeding. The PIT losses, breakages, and electronic failures were evaluated at weekly weight recordings throughout the fattening period using two types of hand-held transceivers. Fattened lambs were harvested in a commercial abattoir between 3 and 4 mo of age when they reached market weight (11 to 12 kg hot carcass weight). The total number of PIT that fell or broke in the slaughtering line, the location method, and the recovery time were recorded. On the farm PIT losses were not affected (P > 0.05) by age at injection, injection position, or breed. Mean losses of PIT and ear tags during the same period were 5% and 6.3%, respectively (P > 0.05). No PIT breakages or failures were observed during the fattening period. Mean recovery of PIT in the abattoir (85.6%) was affected (P < 0.05) by breed and injection position. Losses of PIT in the abattoir were greater (P < 0.05) in the Ripollesa breed (18.4%) than in Manchega (10.0%), and for both breeds losses were greater (P < 0.05) in the retro-auricular than in the armpit positions (18.6 vs 10.8%, respectively). The percentage of PIT broken during slaughtering was low (0.3%). The mean recovery times (18 +/- 2 s) were not affected (P > 0.05) by breed, injection position, or age, thus allowing a harvesting speed of 200 lambs/h on average. In conclusion, the injection of 32-mm PIT into the armpit or the retro-auricular region is not recommended as a practice for the electronic identification of fattening lambs, even though they perform similarly to small plastic ear tags. This is partly a consequence of the PIT losses observed on the farm but mainly because of the difficulties with recovering the PIT in the abattoir. More research will determine whether the use of smaller transponders or injection in other positions could improve their performance in fattening lambs.     

Bluetongue and epizootic hemorrhagic disease in ruminants in Georgia: survey by serotest and virologic isolation

The frequencies of precipitating antibodies to bluetongue virus (BTV) and epizootic hemorrhagic disease virus (EHDV) in domestic ruminants and white-tailed deer (WTD) in Georgia were 36% and 32%, respectively (n = 2,200). The frequencies of seropositivity to BTV and EHDV were high among cattle (47% and 42%, respectively [n = 1,068]) and less so in WTD (36% and 34% [n = 414]). The frequencies among sheep were 34% for BTV and 29% for EHDV (n = 286), whereas among goats, seropositivity was 8% for BTV and 7% for EHDV (n = 433). Serum samples from northeastern Georgia (1 of the 4 regions in the survey) had the highest frequency of precipitating antibodies for BTV (45%) and EHDV (38%). The lowest frequency was in southeastern Georgia, with 29% seropositivity for BTV and 24% seropositivity for EHDV. Of the 175 farms or herds in the serosurvey, 70% included animals that had BTV-precipitating antibodies, and 67% included animals which had EHDV-precipitating antibodies. Seventeen viral isolates were obtained from individual animals on 9 different farms. Fifteen of the isolates were BTV--8 from cattle, 4 from sheep, and 3 from WTD; 8 of them were serotype 11, and 7 were serotype 17. Viral isolates from each of 2 WTD were identified as EHDV serotype 1 and serotype 2. Of the total 17 isolates, 11 were from clinically healthy ruminants, and 6 were from animals with clinical signs of BT or EHD. Five of the viral isolates originated from northeastern Georgia, 7 from the northwestern region, and 5 from the southwestern region; none was obtained from specimens from the southeastern region.