Cattle Sera Research Articles

Characterization and reverse genetic establishment of cattle derived Akabane virus in China

BackgroundAkabane virus (AKAV) is an important insect-borne virus which is widely distributed throughout the world except the Europe and is considered as a great threat to herbivore health.ResultsAn AKAV strain defined as TJ2016 was firstly isolated from the bovine sera in China in 2016. Sequence analysis of the S and M segments suggested that the isolated AKAV strain was closely related to the AKAV strains JaGAr39 and JaLAB39, which belonged to AKAV genogroup II. To further study the pathogenic mechanism of AKAV, the full-length cDNA clone of TJ2016 S, M, and L segment was constructed separately into the TVT7R plasmid at the downsteam of T7 promoter and named as TVT7R-S, TVT7R-M, and TVT7R-L, respectively. The above three plasmids were further transfected into the BSR-T7/5 cells simultaneously with a ratio of 1:1:1 to produce the rescued virus AKAV. Compared with the parental wild type AKAV (wtAKAV), the rescued virus (rAKAV) was proved to be with similar cytopathic effects (CPE), plaque sizes and growth kinetics in BHK-21 cells.ConclusionWe successfully isolated a AKAV strain TJ2016 from the sera of cattle and established a reverse genetic platform for AKAV genome manipulation. The established reverse genetic system is also a powerful tool for further research on AKAV pathogenesis and even vaccine studies.

Comparing Trace Element Concentrations in Serum and Claw Tissue Samples of Buffaloes and Brown Swiss Cattle

The aim of this study was to compare some trace elements in serum and hoof tissues of healthy Brown Swiss and Anatolian buffaloes raised in Turkey. Thus, the data generated in this study may have some potentials to contribute to future studies in this field. A total of 20 animals, 10 Anatolian buffalo cows and 10 Brown Swiss dairy cattle, were included in the study. The health status of all animals was examined and those without any systemic disease and lameness were enrolled in the study. Hoof tissue samples were taken from the dorsal hooves (paries ungulae) and solear hooves (solea ungulae) of the lateral of the right hind feet of all animals for trace element analysis. Cr, Mn, Fe, Cu, and Zn levels were determined by ICP-MS in all claw samples. Paries ungulae Cu and Zn levels were significantly higher than in the solea ungulae in both groups (P<0.05). In solear hoof samples, a positive correlation between Cr and Fe, Cr and Cu, and Cr and Zn levels in buffalo group was observed but not statistically significant. In conclusion, Cu and Zn levels in paries ungulae are higher than solea ungulae in both species; however, more comprehensive studies should be performed to determine trace element levels in hooves of buffaloes and cattle with claw lesions.

Half-lives of several polyfluoroalkyl substances (PFAS) in cattle serum and tissues

ABSTRACT Cattle that were at steady-state serum polyfluoroalkyl substances (PFAS) concentrations due to several years of exposure to water contaminated by residues of Aqueous Film-Forming (AFFF) firefighting foam had perfluorooctane sulphonate (PFOS) isomers, perfluoroheptane sulphonate (PFHpS), perfluorohexane sulphonate (PFHxS), perfluorononanoic acid (PFNA) and perfluorodecanoic acid (PFDA) in serum. Elimination serum half-lives were determined in five heifers from serial blood sampling over 215 days. Eleven additional animals that had blood sampled on day 19 (d19) were euthanised on d63. PFAS half-life estimates from the serial blood sampling and from d19/d63 data were not significantly different. The combined (n = 16) serum half-lives (in days) were: total PFOS (tPFOS, 74.1 ± 13.4), PFHpS (45.7 ± 9.4), PFHxS (9.3 ± 1.3), PFNA (12.3 ± 3.2) and PFDA (60.4 ± 10.4). The half-lives of linear PFOS (L-PFOS, 69.4 ± 11.6) and mono branched PFOS isomers (m-PFOS, 83.6 ± 19) were not significantly different from tPFOS, but for the di-branched isomers (di-PFOS), the serum half-life was significantly lower (29.9 ± 5.8). Animal age (1.4–12.3 years old) and serum concentration at the start of depuration did not influence half-lives, and there was no difference between steers and heifers. Consideration of serum and tissue PFAS concentrations at d63 and d215 indicated there was no difference in tPFOS depuration from serum or muscle, but elimination from liver and kidney may be slightly longer. Depuration of PFHpS is essentially the same in serum, kidney and liver, and it is expected depletion from muscle would be comparable. The short half-life of di-PFOS, PFHxS and PFNA did not allow an assessment of clearance from tissues because they were not measurable at d215 but based on the results for PFOS and PFHpS, elimination of PFHxS from tissues is expected to mirror that from serum. Human health risk assessment implications are discussed.

Development of a recombinant ELISA for ovine herpesvirus 2, suitable for use in sheep

The minor capsid protein of ovine herpesvirus 2, identified as a potential antigen for serological testing, was over-expressed and purified to allow its assessment in ELISA. The corresponding gene sequence (OvHV-2 orf65, Ov65) was modified to incorporate epitope tags and internal restriction enzyme sites in an E. coli codon-optimised version of the gene. This codon-optimised gene was then subject to internal deletions to identify regions of the protein that could be removed while maintaining protein solubility and antigenicity. It was found that a derivative with deletion of the conserved 5’-end of the gene (Ov65delB) expressed a polypeptide that was soluble when over-expressed in bacteria and was detected by OvHV-2 specific sera. Proteomic analysis of the affinity purified Ov65delB showed that it contained multiple predicted Ov65 tryptic peptides but also showed contamination by co-purifying E. coli proteins.An indirect ELISA, based on this affinity-purified OV65delB, was optimised for use with sheep and cattle samples and cut-off values were established based on known negative serum samples. Analysis of groups of samples that were either presumed infected (UK sheep) or tested OvHV-2 positive or negative by PCR (cattle MCF diagnostic samples) showed that the assay had 95 % sensitivity and 96 % specificity for sheep serum; and 80 % sensitivity and 95 % specificity for cattle serum. The lower sensitivity with cattle samples appeared to be due to a lack of serological response in some MCF-affected cattle.This recombinant antigen therefore shows promise as the basis of an inexpensive, simple and reliable test that can be used to detect OvHV-2-specific antibody responses in both MCF-affected animals and in OvHV-2 reservoir hosts.

Comparative Evaluation of Four Potent Neospora caninum Diagnostic Antigens Using Immunochromatographic Assay for Detection of Specific Antibody in Cattle.

Neospora caninum is an intracellular protozoan parasite responsible for numerous abortion outbreaks and neonatal abnormalities in cattle. Rapid and accurate diagnosis is critical for N. caninum control owing to the lack of vaccine or drug-based control strategies. Herein, we evaluated the performance of four frequently used antigens in the diagnosis of N. caninum infection using immunochromatographic tests (ICTs) as a rapid, affordable, and field applicable tool. These antigens included recombinant proteins of N. caninum surface antigen 1 (NcSAG1), dense granule proteins 7 (NcGRA7) and 6 (NcGRA6), in addition to native Neospora lysate antigen (NLA). Our study revealed the utility of all antigen-based ICTs for detection of specific antibodies to N. caninum. However, the NcSAG1-based ICT was the best for detection of all control N. caninum-infected mouse or cattle sera, while NcGRA7 and NcGRA6-based ICTs exhibited specific ability to detect samples from acute and sub-acute infection in mice and cattle, respectively. Analyses of the NcSAG1-based ICT against enzyme-linked immunosorbent assays (ELISAs) of the same antigen revealed its efficiency in detection of field cattle samples as observed in high sensitivity (84.2%), specificity (93.5%), agreement (90%), and kappa value (0.78). The current knowledge provides an efficient platform for N. caninum control through on-site diagnosis of infected cattle.

PSI-B-27 Association of multiple SNP in the LRP4 gene with features of the cattle elemental status

Abstract Bovine syndactyly is an autosomal monogenic recessive trait associated with multiple mutations in the LRP4 gene encoding low-density lipoprotein receptor-related protein 4. This protein is a specific facilitator of sclerostin-mediated inhibition of both Wnt1/ β-catenin signaling and osteocyte-secreted bone formation. It is assumed that sclerostin induces a decrease in extracellular pH and promotes the release of calcium ions from mineralized substrates. Therefore, mutations in the LRP4 gene might be associated with changes in the elemental status. The aim of this research was to evaluate the elemental composition of serum in cattle carrying multiple SNP in the LRP4 gene (16 trial animals) compared to animals without such mutations (62 control animals). DNA samples from 78 Black Pied cattle were sequenced with a TruSeq Bovine Parentage Sequencing Panel (Illumina, USA) on a MiSeq Illumina platform following by SNP analysis. The elemental composition of the serum was determined using ICP-AES and ICP-MS. The levels of Ca and P, crucial bone elements, were higher in trial cattle than in control group by 12.9% (P = 0.004) and 22.5% (P = 0.008), respectively. The level of V affecting the uniform distribution of calcium salts in bones, was higher in trial group than in control one by 34.5% (P = 0.001). The concentrations of Mn and Mg were higher in trial group than in control one by 23.6% (P = 0.026) and 10.0% (P = 0.044), respectively. The Sr level in trial cattle was higher by 18.8% (P = 0.04) that may indicate the rickets-like state. A similar trend was observed for toxic metals As and Li. This study demonstrates the association of the LRP4 multiple SNP and the changes in cattle elemental status. Moreover, such heterozygous animals have a higher risk of mineral metabolism disorders. This research was supported by The Ministry of Science and Higher Education of the Russian Federation (Project No. 0526-2019-0001).

Are infectious reproductive pathogens of large ruminants a threat to improving food security? An investigation from Cambodia.

In Cambodia, information on common pathogens causing reproductive losses in cattle and buffalo are lacking, despite there being a need to address livestock health to enhance food security. We analysed stored buffalo (n = 29) and cattle (n = 471) serum samples collected in 2016 using commercially available enzyme-linked immunosorbent assay kits. Antibodies to Neospora caninum, bovine viral diarrhoea virus (BVDV), Leptospira interrogans serovar Hardjo and Brucella abortus were detected in buffalo samples at 79.3% (95% CI 64.6-94.0), 3.4% (95% CI 0-10.0), 0% and 0%, respectively, and in cattle at 4.2% (95% CI 2.4-6.0), 6.4% (95% CI 4.2-8.6), 8.1% (95% CI 5.6-10.6) and 0%, respectively. The high N. caninum seroprevalence in buffalo was associated with increasing age, with buffalo having a 13.1% chance of being seropositive at birth, increasing to 99.4% by age 7 (p = 0.045). This suggests a predominance of horizontal transmission, possibly from exposure to faeces from free-roaming village dogs. Cattle L. interrogans serovar Hardjo seroprevalence was highest in Tbong Khmum province (20.4%) compared to other provinces (p < 0.001), and may be compromising bovine fertility and creating a zoonotic risk for smallholders who may contract leptospirosis from farm work. These high infection rates prompt further research to determine: to what extent these pathogens are linked to the low reproductive efficiency observed in large ruminants in Cambodia, the risk factors to pathogen exposure and appropriate strategies to reduce these risks. Low BVDV and B. abortus exposure is an important observation. Increasing large ruminant livestock trade into the country will require improved biosecurity and disease surveillance to prevent their emergence. An enhanced understanding of the status of infectious reproductive livestock pathogens in Cambodia can assist development projects to make evidence-based strategies to enhance cattle and buffalo health and improve food security.

Livestock Presence Influences the Seroprevalence of Crimean Congo Hemorrhagic Fever Virus on Sympatric Wildlife in Kenya.

Crimean Congo Hemorrhagic Fever (CCHF) is an emerging tick-borne zoonotic viral disease with the potential of causing public health emergencies. However, less is known about the role of wildlife and livestock in spreading the virus. Therefore, we aimed to assess how the interactions between African buffalo (Syncerus caffer) and cattle may influence the seroprevalence of CCHF across livestock-wildlife management systems in Kenya. The study included archived sera samples from buffalo and cattle from wildlife only habitats (Lake Nakuru National Park and Solio conservancy), open wildlife-livestock integrated habitats (Maasai Mara ecosystem and Meru National Park), and closed wildlife-livestock habitats (Ol Pejeta Conservancy) in Kenya. We analyzed 191 buffalo and 139 cattle sera using IDvet multispecies, double-antigen IgG enzyme-linked immunosorbent assay (ELISA). The seroprevalence toward Crimean Congo hemorrhagic fever virus (CCHFV) was significantly higher for buffalo compared to cattle (75.3% and 28.1%, respectively, p < 0.001). We obtained the highest seroprevalence among buffalo of 92.1% in closed wildlife only systems compared to 28.8% and 46.1% prevalence in closed-integrated and open-integrated systems, respectively. The regression coefficients were all negative for cattle compared to buffalo in both closed-integrated and open-integrated compared to wildlife only system. Our results show that CCHFV circulates among the diverse animal community in Kenya in spatially disconnected foci. The habitat overlap between cattle and buffalo makes cattle a "bridge species" or superspreader host for CCHFV and increases transmission risks to humans. The effect of animal management system on prevalence is depended on tick control on the cattle and not the animal per se. We conclude that buffalo, a host with a longer life span than livestock, is a reservoir and may serve as a sentinel population for longitudinal surveillance of CCHFV.

Rift Valley fever and Brucella spp. in ruminants, Somalia

BackgroundFourteen-years after the last Rift Valley fever (RVF) virus (RVFV) outbreak, Somalia still suffers from preventable transboundary diseases. The tradition of unheated milk consumption and handling of aborted materials poses a public health risk for zoonotic diseases. Limited data are available on RVF and Brucella spp. in Somali people and their animals. Hence, this study has evaluated the occurrence of RVFV and Brucella spp. antibodies in cattle, goats and sheep sera from Afgoye and Jowhar districts of Somalia.MethodsSerum samples from 609 ruminants (201 cattle, 203 goats and 205 sheep), were serologically screened for RVF by a commercial cELISA, and Brucella species by modified Rose Bengal Plate Test (mRBPT) and a commercial iELISA.ResultsTwo out of 609 (0.3 %; 95 %CI: 0.04–1.2 %) ruminants were RVF seropositive, both were female cattle from both districts. Anti-Brucella spp. antibodies were detected in 64/609 (10.5 %; 95 %CI: 8.2–13.2 %) ruminants by mRBPT, which were 39/201 (19.4 %) cattle, 16/203 (7.9 %) goats and 9/205 (4.4 %) sheep. Cattle were 5.2 and 2.8 times more likely to be Brucella-seropositive than sheep (p = 0.000003) and goats (p = 0.001), respectively. When mRBPT-positive samples were tested by iELISA, 29/64 (45.3 %; 95 %CI: 32.8–58.3 %) ruminant sera were positive for Brucella spp. Only 23/39 (58.9 %) cattle sera and 6/16 (37.5 %) goat sera were positive to Brucella spp. by iELISA.ConclusionsThe present study showed the serological evidence of RVF and brucellosis in ruminants from Afgoye and Jowhar districts of Somalia. Considering the negligence of the zoonotic diseases at the human-animal interface in Somali communities, a One Health approach is needed to protect public health.

Large-Scale International Validation of an Indirect ELISA Based on Recombinant Nucleocapsid Protein of Rift Valley Fever Virus for the Detection of IgG Antibody in Domestic Ruminants.

Diagnostic performance of an indirect enzyme-linked immunosorbent assay (I-ELISA) based on a recombinant nucleocapsid protein (rNP) of the Rift Valley fever virus (RVFV) was validated for the detection of the IgG antibody in sheep (n = 3367), goat (n = 2632), and cattle (n = 3819) sera. Validation data sets were dichotomized according to the results of a virus neutralization test in sera obtained from RVF-endemic (Burkina Faso, Democratic Republic of Congo, Mozambique, Senegal, Uganda, and Yemen) and RVF-free countries (France, Poland, and the USA). Cut-off values were defined using the two-graph receiver operating characteristic analysis. Estimates of the diagnostic specificity of the RVFV rNP I-ELISA in animals from RVF-endemic countries ranged from 98.6% (cattle) to 99.5% (sheep) while in those originating from RVF-free countries, they ranged from 97.7% (sheep) to 98.1% (goats). Estimates of the diagnostic sensitivity in ruminants from RVF-endemic countries ranged from 90.7% (cattle) to 100% (goats). The results of this large-scale international validation study demonstrate the high diagnostic accuracy of the RVFV rNP I-ELISA. Standard incubation and inactivation procedures evaluated did not have an adverse effect on the detectable levels of the anti-RVFV IgG in ruminant sera and thus, together with recombinant antigen-based I-ELISA, provide a simple, safe, and robust diagnostic platform that can be automated and carried out outside expensive bio-containment facilities. These advantages are particularly important for less-resourced countries where there is a need to accelerate and improve RVF surveillance and research on epidemiology as well as to advance disease control measures.

Serological survey and isolation of Mycoplasma mycoides subspecies mycoides from cattle slaughtered at Katsina state central abattoir, Nigeria

serological survey for the detection of antibodies to Mycoplasma mycoides subspecies mycoides (Mmm) from cattle slaughtered at Katsina Central Abattoir was conducted from March to October 2012 using competitive ELISA (CIRAD) version: P05410/04 antibody detection kit. A total of 300 cattle sera were screened for Mmm antibodies out of which 22 (7.3%) obtained from 15 (68.2%) cows and 7 (31.8%) bulls were positive. Age distribution indicated that 3 (13.6%) were less than 2 years, 11 (50%) were between 2 and 4 years of age, while 8 (36.4%) were above 4 years. The study confirmed the susceptibility of some cattle breeds from all ages and sexes to Mmm. However, middle-aged cows were shown to be more associated with the infections though not statistically significant (P˃0.01). Similarly, a total of 130 pneumonic lung tissues were used for isolation and biochemical characterization of Mmm out of which 2 (1.5%) samples one each from adult White Fulani and Red Bororo cows were found to be positive. The study established baseline information on the status of Mmm infection in Katsina State. Continuous disease surveillance and annual mass vaccination programme using effective vaccines were recommended.

Correlation Between Serology Test Result of Leptospira sp. With The Representation of Histopathological Lesions on The Cattle Kidneys

Leptospirosis is an eminent diseases among human and animal health. As a zoonosis disease, the occurrence of leptospirosis is not clearly understood in animal. Furthermore, the lesion caused by Leptospira sp. is not well demonstrated. This study aimed to analyze the correlation between the result of serological test using microscopic agglutination test (MAT) and the representation of histopathological lesion in kidney from the cattle. This study used 28 samples consist of cattle serum and kidney organs. The serum was tested using MAT and kidney was tested using histopathology. The data was reported semi quantitatively and tested using Spearman test. The result showed that there is no correlation between the result of serological test to the representation of histopathological lesion from the kidney of cattle. It is supported by the coefficient correlation (0,05) and probability value p=0,78 (p≥0,05). In conclusion, the result of Leptospira sp. serological test either seropositive or seronegative uncorrelated to the representation of histopathological lesion from the cattle kidney.

Immunodiagnosis of cattle fascioliasis using a 27 kDa Fasciola gigantica antigen

Background and Aim:Diagnosis of fascioliasis depends on clinical symptoms and routine laboratory tests. Recently, antibodies and circulating antigens of Fasciola were used for detecting active infections. Therefore, this study aimed to identify Fasciola gigantica antigens in the sera of infected cattle using Western blotting and enzyme-linked immunosorbent assay (ELISA) for an accurate diagnosis of cattle infected with F. gigantica.Materials and Methods:Serum samples were obtained from 108, 23, and 19 cattle infected with Fasciola gigantica, Paramphistomum cervi, and Strongylids, respectively, including 57 non-infected cattle that were used as healthy cattle for the study. Western blotting and ELISA were then used to detect circulating Fasciola antigens at 27 kDa.Results:The target epitope was detected in an F. gigantica adult-worm antigen preparation, excretory/secretory products, and serum from cattle infected with F. gigantica. However, it was absent in sera from P. cervi, Strongylids, and healthy cattle. The purified 27 kDa F. gigantica (FPA-27) antigen was also detected in cattle serum using ELISA with high degrees of sensitivity and specificity (94% and 82%, respectively), and the area under the receiver operating characteristic curve was 0.89 with a highly significant correlation of p<0.0001.Conclusion:The FPA-27 is proposed to be a promising candidate for the serodiagnosis of fascioliasis in cattle.

Evaluation of chimeric proteins for serological diagnosis of brucellosis in cattle.

Background and Aim:An accurate diagnosis of Brucella-infected animals is one of the critical measures in eradication programs. Conventional serological tests based on whole-cell (WC) antigens and detecting antibodies against pathogen-associated lipopolysaccharide might give false-positive results due to the cross-reactivity with other closely related bacteria. This study evaluated the serological potential of Brucella spp. chimeric outer membrane proteins (Omps) as antigens in an indirect enzyme-linked immunosorbent assay (i-ELISA).Materials and Methods:The chimeric gene constructs of the most immunodominant regions of Brucella Omps 25+31, 25+19, and 19+31 were cloned into the pET28a expression vectors and transformed into Escherichia coli BL21 (DE3). The serological potential of chimeric proteins compared with single recombinant Omps (rOmps)19, 25, and/or 31 were studied on blood serum samples of (i) a rabbit immunized with killed Brucella abortus 19WC, (ii) mice immunized with single rOmps, (iii) cows seropositive for brucellosis by rose Bengal test, and (iv) cattle naturally and/or experimentally infected with brucellosis.Results:E. coli BL21 actively produced Brucella chimeric rOmps, the concentration of which reached a maximum level at 6 h after isopropyl-b-D-1-thiogalactopyranoside stimulation. Target proteins were antigenic and expressed in an active state, as recognized by rabbit anti-B. abortus antibodies in an i-ELISA and western blotting. Murine antibodies against the single rOmps reacted with chimeric antigens, and conversely, antichimeric antibodies found their epitopes in single proteins. Brucella chimeric rOmps showed higher antigenicity in blood sera of seropositive cattle kept in the hotbed of the infection and/or experimentally challenged with brucellosis than single proteins.Conclusion:Brucella chimeric recombinant outer membrane proteins could be a potential antigen candidate for developing an ELISA test for accurate diagnosis of bovine brucellosis.

Accumulation of PFAS by livestock – determination of transfer factors from water to serum for cattle and sheep in Australia

ABSTRACT In this study accumulation has been determined of several per- and polyfluoroalkyl substances (PFAS) from ingested water to steady state serum concentration for adult beef cattle and sheep raised on a hobby farm impacted by PFAS contamination. PFAS concentrations in stock water were stable for more than a year, they were non-measurable in grass but present at very low levels in soil which equated to just 1% of the intake from water. Prior to quantifying PFAS in cattle serum there had been no breeding for 18 months. Although there were high concentrations of several PFAS in the water, only perfluorooctane sulphonate (PFOS) and perfluorohexane sulphonate (PFHxS) were in cattle serum in appreciable amounts; perfluoroheptane sulphonate (PFHpS), perfluorononanoic acid (PFNA) and perfluorodecanoic acid (PFDA) were much lower. Transfer factors (TFs) for cattle were calculated by dividing steady state serum concentration (ng PFAS/mL) by water concentration (µg PFAS/L). Average and upper estimate TF values for cattle were calculated; the former were 140 (total PFOS, i.e. tPFOS), 130 (PFHpS), 65 (PFHxS), 170 (PFNA), and 120 (PFDA). Previous investigation campaigns at the farm provided relative steady state serum PFAS concentrations for sheep and cattle that allowed adjustment of the cattle TFs. The resulting average estimate TFs for ewes (non-pregnant and not lactating) were 20 (tPFOS) and 30 (PFHxS), other PFAS were not measurable in sheep serum. Discussion on using these TFs in human health risk assessments is provided. With certain assumptions/caveats the TFs allow estimations of PFAS steady state serum concentrations for use in preliminary human health risk assessments (HHRAs) when only PFAS in stock water is known.

Quantification of zinc concentrations in serum, milk and faeces of dairy cattle as a measure of effective zinc supplementation for management of facial eczema

Aims: To investigate the relationship between Zn concentrations in serum and those in milk or faeces, and to assess the ability of the Zn concentrations in milk, serum and faeces to predict intake of ZnO in dairy cattle. Method Seventy cows from one commercial farm in the Waikato region of New Zealand received one of seven dose rates (0, 1.0, 1.5, 2.0, 2.5, 3.0, 3.5 g/100 kg bodyweight (BW)) of ZnO given by oral drench, every morning, for 7 consecutive days. Every afternoon, milk and blood samples were collected from all cows. Free-catch faecal samples were collected during the afternoon milking on 3 days throughout the trial. Linear mixed models were used to assess the relationship between the concentration of Zn in serum and that in milk, and in faeces, respectively, and the relationship between dose rate of ZnO and concentrations of Zn in serum, faeces and milk, respectively. Receiver operating characteristic curve analysis was used to determine the ability of the Zn concentration in serum, milk and faeces to predict that a cow had been treated with a dose of ZnO ≥2.5 g/100 kg, the industry-recommended dose rate needed to protect against facial eczema. Results: A 1-µmol/L increase in Zn concentration in milk was associated with a 0.14 (95% CI=0.11–0.17) µmol/L increase in Zn concentration in serum. Zn concentration in faeces was scaled by its SD; a 1 SD increase was associated with a 1.83 (95% CI=0.54–3.12) µmol/L increase in zinc concentration in serum. Zn concentrations in serum and faeces increased with increasing dose rates of ZnO. No differences in Zn concentrations in milk were noted between animals dosed with 1.5–3.5 g ZnO/100 kg BW, inclusive. At the optimal threshold for Zn concentration in serum, 22 µmol/L, the sensitivity was 0.76 (95% CI=0.69–0.82) and specificity 0.85 (95% CI=0.80–0.89). For the concentration of Zn in faeces, the optimal threshold was defined as 17.36 mmol/kg, with a corresponding sensitivity of 0.84 (95% CI=0.84–0.85) and specificity of 0.85 (95% CI=0.73–0.94). At the optimal threshold for the Zn concentration in milk (76.6 µmol/L), the sensitivity was lower than the other two sample types at 0.59 (95% CI=0.52–0.67), but with a similar specificity of 0.84 (95% CI=0.79–0.88). Conclusions and clinical relevance: The concentration of Zn in milk shows promise as an initial screening test to identify dairy farms that do not provide adequate zinc to provide protection against FE.

The efficacy of both locally prepared vaccines against foot and mouth disease in cattle in Monofeia governorate

Vaccination was the main approach to control spreading of FMD disease in Egypt. This study was carried out for evaluation of vaccination by governmental and prevailing local vaccines in cattle sera in menofia governorate during the period from October 2018 to May 2019. A total 130 serum samples were collected to evaluate the antibodies against FMDV. 30 samples were used as control, 50 samples collected from animals received local governmental vaccine and 50 samples from animals received local prevailing vaccine. 49 out of 100 serum samples (37.7%) were positive and 81 out of 130 serum samples (62.3%) were negative for NSP. Results were (0.0), 3(3.7%) pre-vaccination and 27(33.33%), 18(22.22%) 1st MPV- 25(30.86%), 18(22.22%) 2nd MPV-15(18.52%), 13(16.05%) 3rd MPV and (0.0), 9(11.11%) 4th MPV for serotype A. For serotype (O): 9(11.1%), 10(12.4%) pre-vaccination- 36(44.44%), 28(34.56%) 1st MPV-33(40.74%), 27 (33.33%) 2nd MPV-24(29.63%), 20(24.7%) 3rd MPV-14(17.3%), 12(14.80%) 4th MPV. For serotype (SAT2): 4(4.9%), 24(4.93%) pre-vaccination-30 (37.03%), 21(25.93%) 1st MPV-27(33.33%), 21(25.93%) 2nd MPV- 18 (22.22%), 14(17.3%) 3rd MPV-3 (3.71%), 4(4.93%) 4th MPV. In Conclusion. FMD controlling requires vaccines that will supply disparity of infected from vaccinated animals.

SEROPREVALENCE OF INFECTIOUS BOVINE RHINOTRACHEITIS (IBR) IN NORTH EASTERN (NE) STATES OF INDIA

Infectious bovine rhinotracheitis (IBR) is an infectious disease caused by BoHV-1 and belongs to the Herpesviridae family. IBR is endemic in India including north eastern states of the country. Hence the study was undertaken to understand the seroprevalence of IBR in north eastern parts of the country. A total of 3125 cattle (Holstein Friesian crossbred) serum samples from 35 districts of five north eastern states (Assam, Manipur, Meghalaya, Mizoram, and Sikkim) of India were screened for infectious bovine rhinotracheitis (IBR) virus antibodies using Avidin biotin ELISA. A two-stage random sampling methodology was followed for the collection of samples. Results from the present study revealed that the overall seropositivity was reported around 29.50% while the highest and lowest seropositivity of 43.39% and 16.66% were reported in the states of Sikkim and Assam respectively, followed by Mizoram (42.16%), Manipur (29.86%) and Meghalaya (27.40%). Cattle of higher age groups showed the highest seropositivity compared to younger ones. A higher percent of IBR antibodies in cattle of NE states is a cause of concern and a detailed study on IBR prevalence comprising of a large number of the bovine population need to be undertaken.

An observational study on the relationship between zinc concentrations in bulk tank milk and in serum and farmer-reported zinc supplementation of dairy cattle for facial eczema prophylaxis

ABSTRACT Aims To describe the concentration of Zn in bulk tank milk (BTM) in a sample of New Zealand dairy farms, investigate the association between the method of Zn administration for facial eczema prophylaxis and Zn concentrations in BTM and investigate the relationship between the concentration of Zn in serum and that in BTM. Methods Multiple BTM samples (n = 3,330) collected during milk pick-up by the milk tanker driver were stored and tested for 121 farms, in Northland (n = 50), Waikato (n = 51) and Southland (n = 20) from February to May 2017. Enrolled farms provided retrospective information on the type of Zn supplementation (if any) used for the prevention of facial eczema and the timeframe over which supplementation occurred. In addition, the concentration of Zn in serum was measured in blood samples collected from ≥15 cattle per farm for 22 farms from Northland (n = 11) and Waikato (n = 11), and compared against the concentrations of Zn in BTM on the day of blood sampling. A linear mixed model was used to model log Zn concentrations in BTM using method of Zn supplementation, region, milk fat and protein percentage, volume of milk, and frequency of milk pick-up as risk factors. A mixed logistic regression model was used to assess the relationship between Zn concentrations in BTM and the presence of cows with a concentration of Zn in serum of ≥20 µmol/L. Results The median Zn concentration in BTM was 67.9 (min 38.9, max 146.6) µmol/L. The median range of Zn concentrations for repeated samples of BTM within farm was 22.6 µmol/L. In comparison to farms that did not use any form of Zn supplementation, farms that supplemented Zn through a slow-release capsule, oral drench, in feed or a combination of in-feed and water were associated with increased concentrations of Zn in BTM (p < 0.001). There was no difference in Zn concentrations in BTM between farms that administered Zn through the water only and farms that did not administer Zn (p = 0.22). Every 15.3 μmol/L increase in Zn concentration in BTM was associated with 2.2 times (95% CI=1.7–2.9) the odds of a cow having Zn concentration in serum ≥20 μmol/L. Conclusion and clinical relevance Zn concentration in BTM is highly variable between farms, days and Zn administration method. Zn concentration in BTM content has modest potential as a way to signal whether a herd has achieved the high Zn status considered to be protective against FE.

Seroprevalence of Bovine Viral Diarrhea Virus in Local Borana Cattle Breed and Camels (Camelus dromedarius) in Ethiopia

BackgroundBovine viral diarrhea, caused by bovine viral diarrhea virus (BVDV), has been considered a disease of cattle but is now emerging in camels. In Ethiopia it has been detected in exotic and cross-bred dairy cattle but no information is available on its occurrence in indigenous cattle breeds and camels. This study was, therefore, conducted to estimate the prevalence of BVDV infection in indigenous Borana cattle and camels (Camelus dromedarius) in Moyale and Miesso pastoral districts.MethodologySerological investigation was carried out on 219 cattle from 44 herds and 137 camels from 11 herds in contact with the selected cattle herds in Boranara zone and 348 camels from 41 herds in Shinille zone. The sera samples were tested using a competitive enzyme lnked immunosorbent assay (c-ELISA) to detect antibodies against p80 protein of BVDV. In addition, all of the cattle sera were tested using antigen detection ELISA for identification of persistent infection.ResultsAmong the 219 cattle tested, 177 (80.82%; 95% CI: 74.97–85.81) were found to be positive for antibodies against BVDV in Moyale district, Borena Zone. The prevalence varied among different age groups and parity. The highest prevalence was observed in cattle aged 8 years and older (84.0%; 95% CI: 69.6–98.4) and in primiparous cattle (85.5%; 95% CI: 76.2–94.8). Two of the 219 cattle tested (0.05%; 95% CI: 0.02–0.08) were found to be positive with antigen detection ELISA. In addition, out of a total of 137 camels tested, two (1.46%; 95% CI: 0.18–5.17) were found to be positive in this district. Among the 348 camels tested, eight (2.29%; 95% CI: 0.99–4.485) were found to be positive for antibodies against BVDV. In conclusion, this study revealed a high prevalence of infection in Borana cattle. In addition, it recorded the occurrence of infection with BVDV in camel herds. None of the camels tested positive for the antigen of BVDV using antigen ELISA.