Bovine Viral Diarrhea Virus Antibodies Research Articles

155 Impact of Ambient Temperature on Bovine Viral Diarrhea Virus and Infectious Bovine Rhinotracheitis Vaccination Response

Abstract Vaccines are created to help the immune system fight pathogens faster and more effectively, but little is known on how season of the year impacts the immune system response to vaccination. This research was conducted to evaluate how ambient temperature (summer vs fall) impacted antibody production and immune cell type changes in Brahman and Brahman-influenced cows. Cows (n = 18) were immunized (2 mL I.M.) with a combination Modified Live Vaccine for Bovine Viral Diarrhea Virus (BVDV) and Infectious Bovine Rhinotracheitis Virus (IBR) on d 0 in either July 2022 (Summer; n = 12) or November 2022 (Fall; n = 6). Blood samples (30 mL/cow) were collected on d -3, 0, 2, 4, 6, 8, 10, 14 post vaccination and transferred to 50 mL conical tubes containing EDTA to separate plasma and peripheral blood mononuclear cells (PBMC). Density gradient centrifugation was used to isolate PBMC. Serum samples were also collected (10 mL/cow) on d -3, 0, 14. Cells were incubated with propidium iodide and antibody surface cell markers for CD4, CD8, CD25, CD14, CD86, and CD335. An Amnis FlowSight flow cytometer was used to determine the percentage of each cell type in the PBMC. Concentrations of antibodies for BVDV and IBR were determined in serum samples collected pre-vaccination (d -3 and 0) and on d 14. Differences in antibody titers and leukocyte populations were analyzed as repeated measures using the MIXED model procedure in SAS. There were no differences in IBR (P = 0.2) or BVDV (P = 0.47) antibody concentrations between seasons. Percentage of antigen presenting cells (CD14+) was greater in the Summer compared with the Fall (P = 0.01; Summer=11.7 ± 1%; Fall = 7.3 ± 1.1%), but natural killer cells (CD335+) were greater in the Fall compared with the Summer (P = 0.002; Summer = 0.6 ± 0.6%; Fall = 4.4±0.7%). There was a significant treatment by time interaction for antigen presenting cells (P = 0.04), T-helper cells (CD4+; P = 0.01), activated T-helper cells (CD4+CD25+; P ≤ 0.0001), activated cytotoxic T-cells (CD8+CD25+; P = 0.03), activated T-cells (CD25+; P ≤ 0.0001), and natural killer cells (P ≤ 0.0001), but there was no difference between seasons in activated antigen presenting cells (CD14+CD86+; P = 0.19). From pre-vaccination to d 14, natural killer cells were elevated during the Fall compared with the Summer on all days (P = 0.04). Antigen presenting cells were greater in the Summer compared with the Fall on d 4, 10 and 14 (P < 0.02). T-helper cells, activated T-helper cells, activated cytotoxic T-cells, and activated T-cells increased post-vaccination in the Fall, but did not change during the Summer. Thus, ambient temperature (summer vs fall) did not directly impact production of antibodies for IBR or BVDV but did induce changes in specific immune cells following vaccination.

A longitudinal study of bovine viral diarrhea virus in a semi-closed management dairy cattle herd, 2020-2022.

Bovine viral diarrhea virus (BVDV) brings great economic loss to the cattle industry worldwide. Developing a control/prevention strategy requires the prior assessment of certain epidemiological parameters. To determine the BVD incidence rate and associated risk factors, a dairy cattle herd in the eastern region of Saudi Arabia was monitored between 2020 and 2022. Nasal swabs (n = 190), rectal swabs (n = 190), and sera (n = 190) were collected from 79 cows in this herd. Collected sera and swabs were tested using the commercially available ELISAs for the BVDV antibodies and antigens, respectively. Collected sera were also tested for the presence of BVDV nucleic acids using commercial real-time RT-PCR kits. Our data show BVDV seroprevalence (18.8%, 15%, and 8.2%) in the tested animals in 2020-2022, respectively. None of the collected nasal swabs, rectal swabs, or sera tested positive for the BVDV antigen, whereas 10.1%, 10%, and 18.1% of the tested sera were positive for BVDV nucleic acid in 2020-2022, respectively. The incidence rate was estimated at 0.02446 new cases/year despite the detection of BVDV in seronegative animals on single or two occasions at ≥6-month intervals. Young calves and bulls remained apparently unexposed to BVDV despite their presence with BVDV-infected females, with no significant physical separation. Both seropositivity and nucleic acid detectability showed significant positive and negative correlations, respectively, with reproductive performance. Collectively, the present study provides useful clues about the transmissibility of BVDV in the presence of possibly persistently infected animals. To the best of our knowledge, this is the first longitudinal study of BVDV in the Eastern Region of Saudi Arabia. Further detailed characterization of the circulating BVDVs is encouraged.

Bovine Viral Diarrhea Virus Antibody Level Variation in Newborn Calves after Vaccination of Late-Gestational Cows.

This study was conducted to confirm variation in bovine viral diarrhea virus (BVDV) antibody levels transferred to calves from their mother's colostrum after vaccination of late-gestational cows. Blood samples were drawn from 60 pregnant cows that had been vaccinated more than one year and less than two years previously. The samples were collected six weeks prior to the expected date of delivery. After sample collection, the cows were divided into two groups of 30. One group received 2 mL of BVDV vaccine, and a control group received 2 mL of phosphate-buffered saline (PBS). Blood was collected from the cows three weeks post-administration. Additional blood samples were taken from calves at 1, 4, 8, 12, 16, and 20 weeks after birth. The serum was separated from the collected blood, and BVDV antibody changes were confirmed by enzyme-linked immunosorbent assays. BVDV antibody levels were higher from 8 to 20 weeks of age in calves born to late-gestational BVDV-vaccinated cows than in calves born to control cows (p < 0.0083). Further analysis confirmed a slow decline in BVDV maternal antibodies in calves born to pregnant cows that produced high levels of BVDV antibodies following pre-calving BVDV vaccination. These results suggest that BVDV vaccination of cattle in late pregnancy may help to extend the duration of protection against BVDV infection in newborn calves.

Detection of emerging HoBi-like Pestivirus (BVD-3) during an epidemiological investigation of bovine viral diarrhea virus in Xinjiang: a first-of-its-kind report.

Xinjiang pastoral area is the second largest pastoral area in China, accounting for 26.8% of the available grassland area in the country, and the geographical advantage of cattle breeding industry is very obvious. Bovine viral diarrhea virus (BVDV) has always been one of the important viral diseases that have plagued the development of cattle farming industry in the world. As one of the main pastoral areas of China's cattle farming industry, the Xinjiang pastoral area has also been deeply affected. In this study, 6,153 bovine serum samples were collected from 18 large-scale cattle farms in 13 cities in Xinjiang. The antibodies and antigens of 6,153 and 588 serum samples were detected by serological detection methods, respectively. Ten serum samples, which were antigen-positive by ELISA, were randomly selected for RT-PCR detection, sequencing, and phylogenetic analysis of suspected HoBi-like Pestivirus (HoBiPeV) strains. The results showed that the positive rates of BVDV antibodies and antigens were 53.68% (3,303/6,153) and 6.12% (36/588), respectively. One of the 10 randomly selected seropositive samples was infected with the HoBiPeV strain. HoBiPeV, also referred to as BVDV-3, is an emerging atypical Pestivirus that occurs in cattle and small ruminants, and its clinical signs are similar to those of BVDV infection. Based on the whole genome of the BVDV-3 reference strain (JS12/01) on the GenBank, the homology of the detected strain was 96.02%. The whole genome nucleotide sequence was submitted to the GenBank database, and the gene accession number was obtained: OP210314. The whole genome of isolate OP210314 was 12.239 nucleotides and contained a 5'-UTR of 340 nucleotides, a 3'-UTR of 199 nucleotides, and a large open reading frame (ORF) encoding a polyprotein consisting of 3,899 amino acids. In conclusion, the prevalence rate of BVDV infection in Xinjiang dairy cows is high, and the genetic diversity is increasing. This study successfully identified and isolated HoBiPeV in Xinjiang for the first time, posing a potential threat to the cattle industry in Xinjiang.

Prevalence of bovine viral diarrhea virus from Korean native cattle farms in Jeju

Bovine viral diarrhea virus (BVDV) is an RNA virus belonging to Pestivirus in the family Flaviviridae. BVDV has economic significance for the livestock industry because of its association with acute disease, fetal loss, and birth of persistently infected (PI) animals. This study aimed to investigate the BVDV infection rates in Korean native cattle farms in Jeju for further planning of a BVDV control program in the Jeju Province. BVDV antibodies and antigens were tested in 15,842 sera collected from 302 Korean native cattle herds between January 2014 and June 2017 using enzyme-linked immunosorbent assay (ELISA). Viral antigen was detected by reverse transcription-polymerase chain reaction from 60 sera that were antigen ELISA-positive. BVDV antibodies were found in 90.7% (274/302) herds and 61.1% (9,678/15,842) cows. BVDV antigens were found in 13.2% (40/302) herds and 0.4% (61/15,842) cows. The oldest animal group (&gt; 8 years) exhibited the highest sero-positive rates (91%), while the youngest animal group (&lt; 1 years) had the highest antigen positivity rates (0.52%). Of the 60 antigen-positive sera, BVDV types 1 and 2 were found in 36 and 12 sera, respectively. Additionally, six animals were considered to be PI as BVDV was continually detected in annual examination.

Development and application of an indirect ELISA for the serological detection of bovine viral diarrhea virus infection based on the protein E2 antigen.

Bovine viral diarrhea virus (BVDV) causes continuous economic losses to the livestock industry. Monitoring antibodies with enzyme-linked immunosorbent assay (ELISA) is a valuable tool to ensure the purification of BVDV in cattle. However, currently available ELISA kits based on the whole BVDV virion are both costly and time-consuming. The E2 protein has good immunogenicity, induces the secretion of neutralizing antibodies and is an essential immunogen for serological detection. We developed a novel recombinant E2 protein-based indirect ELISA (rE2-iELISA) and conducted a serological survey for BVDV antibodies in 2021-2022 in Beijing, China. The results showed that E2 protein was successfully expressed with high immunogenicity and the optimal rE2-iELISA displayed high sensitivity, reproducibility and specificity. Clinical testing of 566 serum specimens indicated that 318 BVDV positive samples and 194 BVDV negative samples were tested by rE2-iELISA and the IDEXX BVDV ELISA-Ab kit, with a positive coincidence rate of 93.3%, a negative coincidence rate of 86.3%, and an overall coincidence rate of 90.5%. This study established an rE2-iELISA method, which is a highly sensitive, specific and robust ELISA-test validated to detect anti-BVDV antibodies. These findings indicate that the newly developed rE2-iELISA method has the potential to be used as a rapid, reliable and cost-effective screening tool for BVDV infection and provides technical support for the evaluation of vaccine efficacy in cattle herds in the future.

Seroprevalence of Bovine Viral Diarrhea Virus and Factors Associated with the Serological Status in Dairy Cattle in Western Region of Thailand

Background: Bovine viral diarrhea virus (BVDV) causes productive losses and reproductive failure in dairy farms. This study defined the seroprevalence and determined the factors associated with BVDV infection in dairy cows in the western region of Thailand. Methods: Blood samples were collected from 732 cows in 30 randomly selected dairy herds. The BVDV antibody was detected using a commercial indirect ELISA kit (IDEXX®BVDV Total Ab, IDEXX Laboratories Inc., Maine, USA). A questionnaire about the herd management was used to collect data via interviews with farm owners. The variables identified by Fisher’s Exact Test (p less than 0.20) were then analyzed using multivariate logistic regression. Result: Individual prevalence of BVDV infection was 36.89% (270/732), while herd prevalence was 93.33% (28/30). Significant risk factors of BVDV based on the univariate analysis were identified as area, herd size, feeding type, history of abortion, pen of calving, biosecurity and pet on farm (p less than 0.05). Biosecurity using no disinfectant (p=0.02) (OR, 1.32; CI 95%, 1.038-1.669), pet on farm (p=0.03) (OR, 4.72; CI 95%, 1.142-19.501) and history of abortion (p=0.00) (OR, 0.02; CI 95%, 0.004-0.140) were significant, based on multivariate regression analysis. Pen of calving (p=0.01) (OR, 0.24; CI 95%, 0.084-0.667) was a protective factor for BVDV infection. BVDV infection in dairy cattle herds was distributed throughout the western region of Thailand.

Risk-associated factors associated with the bovine viral diarrhea virus in dromedary camels, sheep, and goats in abattoir surveillance and semi-closed herd system.

Background and Aim:Bovine viral diarrhea virus (BVDV) is one of the most important viral pathogens causing high economic losses in cattle of all ages. Despite the active vaccination campaigns against BVDV, many outbreaks are still detected in various populations of cattle worldwide. Other species of animals such as dromedary camels, sheep, and goats may harbor BVDV infection and cause variable clinical syndromes. Thus, they may act as a source of infection to the cattle population around them. However, little is still known about the roles of these animals in the viral transmission and sustainability of BVDV in the environment. This study aimed to explore if the dromedary camels, sheep, and goats may seroconvert against BVDV and to study some associated risk factors for BVDV in these species of animals.Materials and Methods:We tested 1012 serum samples from dromedary camels, 84 from goats, and 21 from sheep for BVDV antibodies using commercial enzyme-linked immunosorbent assay (ELISA) kits. Meanwhile, we selected 211 serum samples from dromedary camels to be tested for the BVDV antigen using the commercial ELISA kits.Results:Our results show that 49/1117 serum samples were positive for the BVDV antibodies in dromedary camels (46/1012), goats (3/84), and none of the tested sheep samples were positive. However, none of the collected serum samples tested positive for the BVDV antigen.Conclusion:Seroconversion of some dromedary camels, sheep, and goats to the BVDV with no history of vaccination against BVDV strongly suggests the potential roles of these species of animals in the virus transmission cycle. The main limitations of the current study are (1) the lack of samples from other species of animals that lived close by these animals, particularly cattle. (2) lack of follow-up samples from the same animal over a long period. We believe the long-term longitudinal study of BVDV in various species of animals, particularly dromedary camels, goats, and sheep, is one of our future research directions. This will provide more information about the dynamics of BVDV antibodies in these species of animals.

Development of an in-house Indirect ELISA for detection of bovine viral diarrhoea virus antibodies in bovine sera

Bovine viral diarrhoea virus (BVDV) infection is a worldwide distributed animal disease. BVDV is the causal agent of congenital defects, diarrhea, reproductive failure, and contaminating biological products. Virus Neutralization test (VNT) as a gold standard method is used for detection of BVDV. Although this assay is very sensitive and specific, it has disadvantages including requires to an experienced person and cell culture facilities. VNT is time-consuming. It is important to design a method that does not have the mentioned disadvantages. So, in-house indirect enzyme linked immunosorbent assay (i-ELISA) was developed for laboratories where it is not possible to perform VNT. The system was made using NADL strain of BVDV and MDBK cell line. This ELISA system was compared with a commercial ELISA kit using 99 bovine sera. Coefficient of variation (CV) was calculated 3.9% and 4.8% for the positive and negative control, respectively for the designed i-ELISA system. The sensitivity, specificity, and accuracy of i-ELISA system was 88%, 53.6%, and 70.7% respectively. Based on our result correlation between in- house and commercial ELISA kit for detection of antibody against BVDV in bovine sera was significant (Kappa coefficient =0.41, p < 0.05). Results of the present study suggested that an in-house ELISA as an affordable and confident system for primary screening of the sera used for biological product.

Seroprevalence of bovine viral diarrhea virus antibodies and risk factors in dairy cattle from the central desert of Iran

Bovine viral diarrhea virus (BVDV) infects cattle worldwide and causes one of the most important economic diseases of the dairy industry. BVDV infection reduces reproductive efficiency, suppresses the immune system, and causes gastrointestinal and respiratory diseases. A first cross-sectional study was conducted in the central desert of Iran (Yazd and South Khorasan provinces) to estimate the seroprevalence and identify BVDV-related risk factors in dairy cattle. A total of 800 cows were randomly selected of 76 herds, and their serum samples were tested by the indirect enzyme-linked immunosorbent assay (ELISA) method for BVDV antibody detection. Data were analyzed using the logistic regression model. The serum prevalence of BVDV at animal and herd levels was 66.83% and 91.6%, respectively. Traditional housing system (OR = 3.22; 95% CI = 1.20-9.09) and cattle introduction to the herd (OR = 2.12; 95% CI = 1.21-3.70) were the important risk factors for BVDV seropositivity (p < 0.05). Increasing of age per year caused adding in 0.33 log (odds) of BVDV seropositivity (p < 0.05). It is necessary to implement control and eradication programs because of the high seroprevalence at the individual level and at the herd in the central desert of Iran.

The epidemiology of bovine viral diarrhea virus infection on a dairy farm - clinical signs, seroprevalence, virus detection and genotyping

In this study we investigated the presence of Bovine Viral Diarrhoea Virus (BVDV) antibodies and antigens in a dairy cow herd that had reported clinical signs related to BVDV infection. The aim of the study was to confirm BVDV infection on the dairy farm with 1500 Holstein-Friesian cattles, and genetically analyse the BVDV type/s circulating in the herd. Serum samples (n=233) were collected from clinically infected cattles and tested for the presence of BVDV antibodies and antigens. The virus neutralization test showed that 194 out of 233 sera of the tested cows were positive (83.26%), and by Ab-ELISA 203 sera samples of the tested cows were shown to be positive (87.12%). The presence of antigens was proven with the Ag-ELISA test in 2 out of 233 samples (0.86%). After RT-PCR and phylogenetic analysis of two BVD virus isolates, it was found that both isolates belonged to genotype 1, subtype BVDV-1d. This is the first time that the BVDV-1d subtype has been confirmed in Croatia, although the BVDV-1b and BVDV-1f subtypes have been detected previously on Croatian dairy farms.

143 The Effects of Vaccination Strategies on Bovine Viral Diarrhea Virus Antibody Titers and Body Weight Performance in Pre- and Post-weaned Beef Calves

Abstract The Oklahoma Quality Beef Network utilizes three health protocols for producer choice based on vaccine timing and viral components. The study objective was to examine the effects of vaccine type and timing on animal performance, and immune response pre-and post-weaning. A total of 151 Angus, Angus x Hereford, or Angus x Charolais calves were randomly assigned to one of three health protocols stratified by breed of sire, sex, and date of birth. Vaccination treatments were 1) KV/MLV – multivalent inactivated BRD vaccine (KV) administered on d 0 and revaccination with a pentavalent modified-live virus on d 125; 2) MLV/MLV – pentavalent modified-live virus on d 0 and d 125; or 3) WEAN – pentavalent modified-live virus on d 125 and 139. Virus-specific antibody (Ab) titer data was determined using serum-neutralization from serum collected at six time points. Antibody titers, BW, and ADG variables were evaluated following vaccination. Results indicated there was no treatment effect on BW. Bovine viral diarrhea virus (BVD) also displayed significance for treatment x date interaction. The MLV/MLV provided greatest response from d 0 (branding) to d 125 (weaning) than the other two treatments. There was no difference between the KV/MLV group and the WEAN group from d 0 to d 125. By d 167 the KV/MLV group had a greater immune response than the MLV/MLV and WEAN groups. The MLV/MLV provided the greatest protection from branding to weaning. Providing a KV at branding had minimal effect on BVD titers but responded well to MLV vaccine at weaning by d 167. The WEAN group generated the least number of titers overall. Further investigation is needed to determine the long-term protection of vaccination strategies.

Diagnóstico e análise filogenética do vírus da diarreia viral bovina em bovinos (Bos taurus) e búfalos (Bubalus bubalis) da região amazônica e Sudeste do Brasil

ABSTRACT: Bovine viral diarrhea virus (BVDV) is a highly infectious pathogen that affects bovines worldwide leading to great economic impact. Although Brazil has the largest commercial cattle population throughout the world and an increasing buffalo breeding industry, the country has no control or eradication program for BVDV. In this perspective, the aim of this study was to evaluate the occurrence of BVDV in cattle and buffaloes from two Brazilian states. Four different ELISA tests were performed and confirmed by virus neutralization testing (VNT). The presence of BVDV antibodies in the serum or plasma from 77 cattle from six herds (ELISA-1 and ELISA-4) and from 89 buffaloes from three herds (ELISA-1 through ELISA-4) was detected. Extraction of viral RNA was performed from the serum or plasma samples for the detection of BVDV by RT-PCR analysis. Amplified nucleotide sequences were used to construct a phylogenetic tree. In cattle, ELISA-1 detected 49.4% of seropositive animals, while ELISA-4 detected 37.7%. In buffaloes, ELISA-1 failed to detect any seropositive animals, while ELISA-2 and ELISA-3 detected 20.2% of seropositive animals, and ELISA-4 detected 21.3%. Eight of the nine herds tested had seropositive animals. The rate of PCR positive animals was 6.5% in cattle and 9% in buffaloes. Subtype 1d was found in cattle, and subtypes 1d and 1f were found in buffaloes. This is the first-time subtype 1f has been reported in Brazil. The absence of a control and eradication program seems to be favoring the spread of BVDV in the Brazilian herds. In addition, the improvement of diagnostic strategies for BVDV in buffaloes are required.

BVDV, BHV-1 and BLV antibodies in dromedary camels of Turkey kept without and with ruminants.

Camels are the only animals bred to sustain the tradition of wrestling in Turkey and are reared within a limited set of geographic areas. Farmers of such animals may also be engaged in ruminant breeding. The current research was aimed at documenting bovine viral diarrhoea virus (BVDV), bovine herpesvirus-1 (BHV-1), and bovine leukaemia virus (BLV) infections in sera collected from dromedary camels in four different geographical regions of Turkey during the years 2019-2021. All samples were tested for BVDV, BHV-1 and BLV antibodies as well as BVDV antigen by ELISA. Antibodies against BVDV were found in 16.8% of the camel sera tested. However, none of the camels sampled were positive in terms of BHV-1 and BLV antibodies as well as BVDV antigen. The prevalence was observed higher in the herds in whichruminants were raised in addition to camels (OR = 4.583, 95% CI, 1.298-16.182), (p = 0.018), while the prevalence was observed lower in the herds in which only camels were raised. This study showed that BVDV infection was more prevalent than BHV-1 and BLV infections in Turkish dromedary camels. Herewith, the camels, being a susceptible species to numerous viral ruminant diseases, may also serve as an important source of BVDV infection for other ruminant animals in the same flock.

Seroprevalence and risk factors of Neospora caninum and Bovine Viral Diarrhoea Virus in smallholder dairy cattle in Kenya

Little is known of the risk factors associated with occurrence of Neospora caninum and Bovine Viral Diarrhoea Virus (BVDV) infection in Kenya. This cross-sectional study hypothesized that there are significant biosecurity measures associated with N. caninum and BVDV infections on smallholder dairy farms in Kenya that could be adopted to reduce seroprevalence and impacts. From 158 randomly selected farms in Meru County, Kenya, 470 serum samples were collected from dairy cattle (over six months of age and unvaccinated for these two pathogens). Sera were analyzed for antibodies to N. caninum and antibodies and antigens to BVDV. Data on risk factors were obtained through face-to-face interviews with the farmers. Multivariable logistic regression models were used to identify significant risk factors associated with seropositivity for the pathogens. The apparent seroprevalence of N. caninum, BVDV antibody, BVDV antigen, and co-infection with N. caninum and BVDV antibody and/or antigen were 35.1%, 47.1%, 36.2% and 18.5%, respectively. Risk factors associated with N. caninum antibody included: introducing milking cows into the farm, lending of cattle between farms, farm dogs having access to bovine aborted fetuses, and dogs whelping in the farm compound, with an interaction between the last two variables. BVDV antigen was associated with cattle having contact with pigs, and an interaction between cattle age and whether farms introduced new calves onto farms, and cattle age and whether visiting dairy farmers have access to the cow shed. Cows had higher odds of having BVDV antibodies compared to heifers. Factors associated with co-infection included cow parity, direct contact between dairy cattle, dogs and goats, and introducing new milking cows into the farms. Antibody and antigen results may be partly a function of classical swine fever virus or border disease virus interactions. Farmer education on these biosecurity measures is recommended, along with introduction of BVDV vaccination.

Seroprevalence of Bovine Viral Diarrhoea Virus, Bovine Herpesvirus Type 1 and Bovine Herpesvirus Type 4 infections in cattle in Ağrı Province, Eastern Anatolia Region, Turkey

This research was carried out to determine the seroprevalence of Bovine Viral Diarrhoea Virus (BVDV), Bovine Herpes Virus 1 (BoHV-1), and Bovine Herpes Virus 4 (BoHV-4) in cattle (n = 188) in Ağrı province of Eastern Anatolia Region, Turkey. The presence of BVDV, BoHV-1, and BoHV-4 antibodies in sera samples were determined by an ELISA test kit. It was determined that the highest seropositivity for BoHV-1 in Tutak disrict (9.9%), in ≤ 3 years age groups (3.39%), and in Simmental cattle (14.28%); for BoHV-4 in Doğubeyazıt disrict (4.16%), %), in ≤ 3 years age groups (1.70%), and in Simmental cross breed cattle (4.54%); for BVDV in Diyadin disrict (8.33%), in ≤ 3 years age groups (3.39%), and in Eastern Anatolian Red cattle (11.11%); for BoHV-1 + BoHV-4 in Hamur disrict (14.28%), in ≤ 3 years age groups (10.17%), and in Simmental cattle (14.28%); for BoHV-1 + BVDV in Tutak disrict (30.30%), in 6 > years age groups (18.46%), and in Holstein cross-breed cattle (25%); for BoHV-4 + BVDV in Patnos disrict (12.5%), in ? 3 years age groups (5.08%), and in Holstein cross-breed cattle (25%); for BoHV-1 + BoHV-4 + BVDV in Ağrı center (83.87%), in >3- 6 ≤ years age groups (71.78%), and in Anatolian Black cross-breed cattle (100%) were found in the studied population. Rhinotracheitis and conjunctivitis were determined as the most common clinical signs in seropositive animals. In conclusion, the data obtained in this study showed that exposure to BoHV-1, BVDV and BoHV-4 agents were common among cattle in Ağrı province in the Eastern Anatolia Region of Turkey. Additionally, the highest positivity was determined in BoHV-1 + BoHV-4 + BVDV.

Vitamin E supplementation strategies for newly received feedlot cattle

Increasing doses (0, 150, 500, or 1,000 IU/d) of supplemental vitamin E (VE) fed to newly received steers linearly increased VE status and 150 IU/steer/d was adequate to prevent a decline in VE status over the 26-d trial. Although feedlot performance was not affected by supplemental VE treatments, the highest VE dose (1,000 IU/d) resulted in greater Bovine Viral Diarrhea Virus antibody titers 20 d after receiving a booster vaccine. The positive effects of VE on antibody titers in the current study, suggest supplemental VE is an effective nutritional strategy for supporting immune system function. Further research is needed to determine the optimal dose and timing of VE supplementation for newly received cattle with specific emphasis on resiliency to, and recovery from, stressful events.

Seroprevalence and association of bovine viral diarrhea virus (BVDV) serostatus with reproductive problems in dairy cattle in central and southern Ethiopia

Bovine viral diarrhea (BVD) is an economically important cattle disease with worldwide distribution and characterized mainly by suboptimal fertility in the affected herds. The objectives of this study were to estimate the seroprevalence of BVDV within dairy cattle, to identify potential risk factors, and to assess the association with occurrence of reproductive problems. Sera (n = 954) collected from dairy cattle from 98 herds in southern and central Ethiopia were tested for BVDV antibodies using a commercial ELISA. Among screened sera samples, 20.9% (95% CI, 18.4, 23.6) tested positive to BVDV antibodies. The herd prevalence was 50% (95% CI, 40.1, 59.9) and the intra-herd prevalence ranged between 2.6 and 100% (mean = 31.4%) in positive herds. Geographic region, herd size, and animal arrangement in the farm had significant association with serostatus (p < 0.05). Cattle from southern Ethiopia and herds of large size had 2.8 (95% CI, 1.9, 4.2) and 2.6 (95% CI, 1.5, 4.6) times higher odds of being seropositive compared to their counterparts, respectively. Serostatus to BVDV was associated with history of anestrus, repeat breeding (RB), mastitis, and extended calving interval (CI) (p < 0.05). Animals with history of extended CI and mastitis were 1.7 (95% CI, 1.0, 2.7) and 2.2 (95% CI, 1.5, 3.2) times more likely to be seropositive compared with those with normal CI and no history of mastitis, respectively. On the other hand, animals with history of anestrus and RB were less likely to be seropositive to BVDV compared to cattle with no such history. Sera from 26 selected cattle were also examined using reverse transcription (RT)-PCR for detection of BVDV RNA; however, all samples tested were negative for the presence of BVDV nucleic acid. Our study highlights the variation in BVDV status within Ethiopian dairy herds, and association with some important reproductive performance traits and potential risk factors.

The Principles of the Voluntary Programme for the Control and Elimination of Bovine Viral Diarrhoea Virus (BVDV) From Infected Herds in Slovenia.

In Slovenia, the control of bovine viral diarrhoea virus (BVDV) infections started in 1994. Since 2014, a voluntary programme has been running according to the national rules that prescribe the conditions for recognising, acquiring, and maintaining a BVDV-free status for an individual herd. The principle is based on periodical laboratory testing and preventive measures that need to be strictly implemented in a herd. Between 2014 and 2020, a total of 348 herds were included in BVDV antibody testing, and 25.0% of tested herds were detected to be BVDV antibody positive. To recognise the BVDV-free status of the herd, the breeder should provide two consecutive tests with intervals of at least 6 months in all animals in the age from 7 to 13 months, with negative results for BVDV antibodies in ELISA. The BVDV-free status of the herd can be maintained by implementing preventive measures and can be renewed each year with one laboratory test in the age group of animals from 7 to 13 months for antibodies in ELISA. During the 7 years of the voluntary programme, 236 herds were included in the detection of BVDV in individual herds by real-time RT-PCR method and the elimination of positive animals from herds. In 71 (31.3%) herds, at least one BVDV-positive animal was detected, with the identification of a total of 267 persistently infected (PI) animals, representing an average of 2.9% of tested animals. The cost of testing for an average herd, recognised as BVDV-negative, and maintaining its BVDV-free status within the implemented voluntary programme, was €97.64/year, while for the average positive herd, the laboratory costs for elimination of BVDV were €189.59/year. Only limited progress towards eradication at the national level has been achieved in Slovenia since 2014.

Prevalence of bovine viral diarrhea virus antibodies and risk factors in dairy cattle in Gondar city, Northwest Ethiopia

Bovine viral diarrhea (BVD) is a disease that affects cattle and other ruminants worldwide and causes considerable economic losses. A cross-sectional study was carried out between December 2017 and July 2018 with the aim to estimate the prevalence of Bovine Viral Diarrhea virus (BVDV) antibodies and to identify potential risk factors associated with the occurrence of the disease in dairy cattle in peri-urban areas of Gondar city, Northwest Ethiopia. A total of 339 serum samples obtained from randomly selected dairy cattle aged 6 months and older were assayed using a BVDV antibody competitive-Enzyme Linked Immunosorbent Assay (c-ELISA) kit. Descriptive statistics were used to estimate antibody prevalence of BVDV at animal and herd-level and logistic regression was used to identify potential risk factors. The study findings showed that the animal-level antibody prevalence of BVDV in the study area was 26.84 % (95 % CI: 22.1 %–31.6 %) and the herd-level seroprevalence was 68.3 % (95 % CI: 56.2 %–80.4 %). Logistic regression model demonstrated that age >2 years (OR = 4.75, 95 % CI: 2.20−10.26), herd size >11 (OR = 7.28, 95 % CI: 2.50−21.22), and poor farm hygiene (OR = 3.69, 95 % CI: 1.94−7.02), are potential risk factors associated with BVDV infection (P < 0.05). However, sex, faecal consistency and housing system were not associated with BVDV serostatus. The animal- and herd-level seroprevalence reports in Northwest Ethiopia can serve as a baseline finding for future BVD epidemiological investigations and to inform future control programs in the study region.