Brief Summary of Minutes of Annual Meeting

Meeting Minutes

Room 214 New Orleans Convention Center, New Orleans, Louisiana

September 16, 2015

Attendees:

Amelia Woolums

Chris Chase

Terry Lehenbauer

Roberto Palomares

Tom Inzana

Danielle Doyle

Dave Smith

Neal Merchen

Brian Vander Ley

8:00-8:15: Attendees were welcomed to the meeting, introductions were made, and Dr. Neal Merchen, our administrative assistant introduced himself to the group.

8:15-10:00, 10:15-12:00: The NC 1192 project is set to expire next September. To continue the project, a renewal application will have to be filed. Dr. Vander Ley submitted the request to renew the project along with the issues and justification for the project in the NIMMs system by the September 15, 2015 deadline. The committee discussed the following timeline:

• September 15: Request to renew along with Issues and Justification due.
• October 15: Project Objectives due.
• November 1: Appendix E information completed and submitted by participating stations
• December 1: Completed project due to be uploaded in NIMMs.

Following a review of the timeline, committee members elected to request a change in number to NC 107 if possible. This is the original number assigned to the project. Dr. Vander Ley will contact Chris Hamilton to see if the change can be made.

Committee members discussed possibilities for recruiting new members to the committee. Several ideas including reaching outside the veterinary community, holding committee meetings in more convenient places for animal scientists/other disciplines to meet, and using current members’ networks to find new, interested committee members were discussed.

The objectives from the previous project were reviewed and the decision was made to consolidate objectives 2 and 3 as well as objectives 5 and 6. Objectives 1 and 4 were discusses and significantly amended. A new objective was constructed to address the need for research investigating forces and circumstances that prevent preconditioning and other practices at the cow/calf level that are known to drastically reduce BRD occurrence at the feedlot level. This objective was designed to address systems and epidemiology of BRD. In the revisions, statements to directly address topics of vaccination, judicious antimicrobial use, genetics, and environment were added.

New and revised objectives were compiled and will be emailed to the full committee for review, comment, and revision.

12:00-1:30: Lunch Break

1:30-4:30: Station Reports from attending committee members including reports from:

• South Dakota-Chris Chase
• California-Terry Lehenbauer
• Georgia-Amelia Woolums
• Mississippi-Dave Smith
• Missouri-Brian Vander Ley
• Virginia Tech-Tom Inzana

4:30-5:00: Business Meeting

Because of an institutional promotion, the secretary position was vacant. Dr. Vander Ley volunteered to fill both the roles of Chair and Secretary until the meeting in 2016. Drs. Vander Ley and Chase will continue to serve on the renewal writing committee.

A list of action items was developed for committee members desiring to participate in the new project.

1. Review, revise, and comment on objectives by October 1, 2015.
2. Contact your experiment station director and begin the process of completing the appendix E. Invitations should be sent automatically by email to existing members of NC-1192 requesting participation.
3. Contact potential new members of the committee and encourage them to participate in the new project.
4. Generate a word document detailing the materials and methods relating to objectives you plan to work on. Please turn send this to Dr. Vander Ley by November 1, 2015.

Objective 1: To aid the rapid identification and subsequent management of BRD by developing, validating and guiding the application of new state-of-the-art diagnostic tools.

University of Georgia

Comparison of 4 methods to identify respiratory pathogens in dairy calves with acute undifferentiated BRD.  In collaboration with CA, we recently completed a project to determine the sensitivity of the nasal swab (NS), deep guarded nasopharyngeal swab (NPS), and bronchoalveolar lavage (BAL), as compared to the gold standard of transtracheal aspirate (TTA), for the diagnosis of viral and bacterial respiratory pathogens in dairy calves with acute undifferentiated BRD.  One hundred dairy calves with undifferentiated BRD were sampled sequentially by NS, NPS, TTA, and BAL. Calves that had ever been treated for respiratory disease, or that had received intranasal modified live viral respiratory vaccine in the previous 30 days, were excluded.  Samples were submitted for aerobic culture to identify M. haemolytica, P. multocida, H. somni, and Mycoplasma sp., and RT-PCR to identify BHV-1, BRSV, BVDV, and coronavirus.  Mycoplasma sp. isolates were tested by PCR to determine if they were M. bovis.  Agreement between the TTA and the NS, NPS, or BAL was determined by calculation of the kappa statistic.  Values of kappa were categorized according to these levels of agreement: 0.20 = poor; 0.21 – 0.40 = fair; 0.41 – 0.6 = moderate; 0.61 – 0.80 = good, and 0.81 – 1.00 = very good.  One hundred calves were enrolled.  Relative to the TTA, all sampling methods showed very good agreement for identification of Pasteurella multocida or Mannheimia haemolytica.  In contrast, for identification of bovine respiratory syncytial virus and relative to TTA, agreement was moderate for NS, good for NPS, and very good for BAL.  For identification of BCV and relative to TTA, agreement was moderate for the NS and NPS, and good for BAL.  Agreement between TTA and other sampling methods differed for different pathogens; results of BAL agreed best with the TTA for all pathogens. 

Oklahoma State University

Enteric Disease in Post –Weaned Calves Associated with a Recently Identified Clade of Bovine Coronavirus.

Bovine coronavirus (BoCV) infections are associated with varied clinical presentations including neonatal diarrhea, winter dysentery in dairy cattle, and respiratory disease in various ages of cattle. This report presents information on BoCV infections associated with enteric disease of postweaned beef cattle in our region. In three separate accessions, one in 2012 and two in 2013 calves were observed with bloody diarrhea. One herd had the clinic cases in both 2012 and 2013. One calf in 2012 died and was necropsied and two calves from this herd died in 2013 and were necropsied. A third calf from another herd died and was necropsied. The gross and histopathologic diagnosis was acute, hemorrhagic colitis in all four cattle. Colonic tissues from all four animals were positive by fluorescent antibody and/or immunohistochemistry for BoCV antigen. BoCV was isolated in human rectal tumor cells from swabs of colon surfaces of all animals. The genomic information from a region of the S envelope region revealed BoCV clade 2. Detection of BoCV clade 2 in beef cattle in our region is consistent with recovery of BoCV clade 2 from the respiratory tract of postweaned beef calves that had respiratory disease signs or were healthy. Further investigations on the ecology of BoCV in cattle are important as the BoCV may be an emerging disease beyond the initial descriptions. Challenge studies are important to determine pathogenicity of these strains. Also there are implications to determine if current BoCV vaccines are efficacious against the BoCV clade 2 strains.

Diverse Outcomes of Bovine Viral Diarrhea Virus Infections in a Herd Naturally Infected During Pregnancy- A Case Study.

A beef producer purchased Angus crossbred cattle that were pregnant with nursing calves. The purchased cattle, their nursing calves, and subsequent born calves were not initially tested for BVDV.  Bovine viral diarrhea virus subtype 2a (BVDV2a) was isolated from an aborted bovine fetus, 6.5 months,  with multiple congenital malformations including arthrogryposis, kyphosis, scoliosis, polydactylism, and  cardiac over riding aorta. Testing by immunohistochemistry and virus isolation resulted in the detection of a persistently infected (PI) yearling cohort, and a PI calf born during the same calving season. The viruses isolated from the fetus, the yearling cohort, and a PI calf born during the same calving season were identical. These malformations observed in the fetus were similar to arthrogryposis multiplexa (AM) and contractural arachnodactyly (CA) diseases with association with genetic defects in the Angus breed. The fetal tissue of the malformed fetus was negative for genetic material for AM and CA. The owner had purchased cattle that were pregnant and nursing calves, but were not tested for BVDV and with an unknown vaccination history. This case illustrates that suspect malformations should also be tested for BVDV. Also the case underscores the potential for disease after failed or inadequate biosecurity.

Bovine Herpesvirus-1: Evaluation of Genetic Diversity of Subtypes Derived from Field Strains of Varied Clinical Syndromes and their Relationship to Vaccine Strains.

Bovine herpesvirus-1 (BoHV-1) causes significant disease in cattle. Control programs in North America incorporate vaccination with modified live viral (MLV) or killed (KV) vaccine.  BoHV-1 strains are isolated from diseased animals or fetuses after vaccination. There are markers for differentiating MLV from field strains using whole-genome sequencing and analysis identifying single nucleotide polymorphisms (SNPs). Using multiple primer sets and sequencing of products permits association of BoHV-1 isolates with vaccines. To determine association between vaccine virus and strains isolated from clinical cases following vaccination, we analyzed 12 BoHV-1 isolates from animals with various clinical syndromes; 9 corresponded to BoHV-1.1 respiratory group. The remaining three corresponded to BoHV-1.2b, typically found in genital tracts of cattle.  Four BoHV-1 isolates were identical to a vaccine strain; three were from post-vaccination abortion episodes with typical herpetic lesions whose dams had received MLV vaccine during pregnancy, and one from a heifer given a related MLV vaccine; Sequences of   two respiratory isolates perfectly matched mutations characterizing RLB106 strain, a temperature sensitive mutant used in intranasal and parenteral vaccines. The last three respiratory strains clearly appeared related group of MLV vaccines. Previously the MLV vaccines were grouped into four groups based on SNPs patterns. In contrast with  above-mentioned isolates that  closely matched  SNP patterns of their respective MLV vaccine virus, these 3 strains both lacked some and possessed a number of additional mutations  compared to  a group  of MLV vaccine viral genome. Finding BoHV-1.2b in respiratory cases indicates   focus should be given BoHV-1.2b as an emerging virus or a virus not recognized nor fully characterized in BRD.

South Dakota State University

1. Diagnostic findings: The infectious agents associated with bovine respiratory disease complex were monitored by bacterial culture, virus isolation, and fluorescent antibody techniques.
2. Bacteriology: Bacterial agents isolated from bovine pneumonic lungs, tracheal swabs, and nasal swabs are as follows (July 1, 2013-June 30, 2014):

Organism                    Isolations

1. haemolytica            220
2. multicida         163
3. somnus 151
4. trehalosi 45

2. Virology: Viral agents from bovine pneumonic lungs are as follows (July 1, 2013-June 30, 2014). There were 574 respiratory tract virus isolation attempts and 35 isolations:

Virus                Virus Isolations                 Fluorescent Antibody

BVDV -NCP                13                   

BVDV-CP                   12

BHV-1                         2                                            

BRSV                                                  9 positive

BHV-4 (DN-599)                     12

3. Individual Serum Ear notch-Immunohistochemistry (IHC) or ELISA: ELISA ear notch BVDV tests were conducted on 6770 samples and there were 61 positives (0.9%).
4. Molecular Diagnostics: PCR tests were done for BVDV, BHV-1, BCV, BRSV and Mycoplasma. Pooled ear notch was done on 1424 submissions with 75 positive samples, 5.3% case positive.  BVDV PCR was also done on nasal swabs, tissue, whole blood/serum /milk samples (223 submissions 18 positives, 8.0% positive).  BHV-1 PCR was also done on nasal swabs, tissue, whole blood/serum (224 submissions 11 positive).  BCV PCR was also done on nasal swabs and tissue (345 submissions 90 positive, 26%).  BRSV PCR was also done on nasal swabs and tissue (345 submissions 56 positive 16%).  There was 1 Mycoplasma bovis PCR positive samples (25 of 52, 48%).
5. Characterization of BHV-1 Field isolates. Sequencing of reproductive isolates indicated that they are almost exclusively vaccine strains.  Case Histories Case 1 occurred in a herd of 106 first-calf beef heifers. The animals were vaccinated twice with Vaccine A, a MLV vaccine containing BHV-1, once at weaning in the fall of 2012 and again in February 2013. The animals were bred in June 2013 and confirmed pregnant by rectal palpation. The animals were vaccinated with an oil adjuvanted scours vaccine and treated with an anthelmintic in January 2014. Five days later the animals began to abort. Case 2 occurred in a herd of ~100 Holstein heifers. The normal vaccination protocol was animals were vaccinated with 2 to 3 doses of MLV vaccine prior to breeding and another dose of MLV was given at pregnancy confirmation. In this group animals had not been pregnancy checked for over 8 months so no vaccine had been administered to these animals in 8-12 months. The entire herd was vaccinated with either Vaccine B or Vaccine C; both vaccines were MLV vaccines that contained BHV-1. Two weeks post vaccination 8 abortions were found in the pen. Case 3 occurred in a herd of beef cows with a poor vaccination history. The animals received a single dose of inactivated multivalent viral vaccine containing BHV-1 as heifer calves. Annual revaccination with the same inactivated vaccine was infrequent. In August 2014, calves nursing these cows were given a single dose of MLV multivalent Vaccine C containing BHV-1. Beginning in January 2015, the cows began aborting.  Case 4 occurred in a herd of 350 crossbred beef cattle.  These cattle were vaccinated by a veterinarian following the manufacturer’s instructions (i.e., the cows had all been vaccinated a year prior with a similar product from the same company; heifers vaccinated twice with similar product prior to breeding). These animals were at between 5-6 months gestation and had been vaccinated with Vaccine C about 15-20 days prior to the abortions occurring. Three 3 aborted fetuses from heifers and 1 mummified fetus from a cow were recovered over the course of 2 weeks.  Results Case 1: Forty-four of the 106 calves were aborted, delivered dead, or were born alive but died within the first 24 hours. BHV-1 was isolated from 4 of the fetuses on two separate submissions. The viruses were submitted for genetic analysis to the Animal Disease Research and Diagnostic laboratory at SDSU. Single nucleotide polymorphisms (SNP) analysis indicated that the SNP pattern of the viruses isolated from the fetuses was identical to Vaccine A. Case 2: Two fetuses were submitted and virus isolation and genetic SNP analysis was performed. The SNP pattern indicated that the SNP pattern of the two isolates were identical with Vaccine C. Case 3: Two fetuses were submitted and virus isolation and genetic SNP analysis was performed. The SNP patterns of the two isolates were identical with Vaccine C.  Case 4: All fetuses from the heifers had typical histological lesions of herpesviral abortion (multiple foci of necrosis in multiple organs, some with herpetic inclusions). 3/3 were FA positive for BHV-1, while virus was isolated from 2/3. The mummified fetus was a typical mummified fetus—tissues were too autolyzed for meaningful histopathology, and all viral assays for BHV-1 were negative (FA and VI negative). One isolate was submitted for genetic SNP analysis. The SNP pattern of the isolate was identical with Vaccine C. 

Virginia Tech

Novel diagnostic tests to detect the presence of H. somni DNA in clinical samples without PCR and to detect the presence of antibodies to the biofilm EPS have been developed.  Details of this work have been presented in previous reports and have now been published or are in preparation for publication.

University of Wisconsin

The Wisconsin Veterinary Diagnostic Laboratory (WVDL) Virology Service (Dr. Kurth) evaluated 737 samples for respiratory viruses and mycoplasmas (Table 1 below). The greatest percentage of positive were for Mycoplasma bovis (21.2%) or Bovine respiratory corona virus (15.9%). The Bacteriology Service (Dr. Okwumabua) evaluated 1173 samples (Table 2 below). The greatest percentage of positive cultures were for Pasteurella multocida (15.8%) or Mannheimia haemolytica (11.7%).

Objective 2: To elucidate key steps in the dynamic interactions between pathogens, host immunity and the environment, and to determine how manipulation of these factors can reduce the risk of BRD.

University of Georgia

Comparison of 4 methods to identify respiratory pathogens in dairy calves with acute undifferentiated BRD.  In collaboration with CA, we recently completed a project to determine the sensitivity of the nasal swab (NS), deep guarded nasopharyngeal swab (NPS), and bronchoalveolar lavage (BAL), as compared to the gold standard of transtracheal aspirate (TTA), for the diagnosis of viral and bacterial respiratory pathogens in dairy calves with acute undifferentiated BRD.  One hundred dairy calves with undifferentiated BRD were sampled sequentially by NS, NPS, TTA, and BAL. Calves that had ever been treated for respiratory disease, or that had received intranasal modified live viral respiratory vaccine in the previous 30 days, were excluded.  Samples were submitted for aerobic culture to identify M. haemolytica, P. multocida, H. somni, and Mycoplasma sp., and RT-PCR to identify BHV-1, BRSV, BVDV, and coronavirus.  Mycoplasma sp. isolates were tested by PCR to determine if they were M. bovis.  Agreement between the TTA and the NS, NPS, or BAL was determined by calculation of the kappa statistic.  Values of kappa were categorized according to these levels of agreement: 0.20 = poor; 0.21 – 0.40 = fair; 0.41 – 0.6 = moderate; 0.61 – 0.80 = good, and 0.81 – 1.00 = very good.  One hundred calves were enrolled.  Relative to the TTA, all sampling methods showed very good agreement for identification of Pasteurella multocida or Mannheimia haemolytica.  In contrast, for identification of bovine respiratory syncytial virus and relative to TTA, agreement was moderate for NS, good for NPS, and very good for BAL.  For identification of BCV and relative to TTA, agreement was moderate for the NS and NPS, and good for BAL.  Agreement between TTA and other sampling methods differed for different pathogens; results of BAL agreed best with the TTA for all pathogens. 

Acute infection with BVDV of low or high virulence leads to depletion and redistribution of WC1+ gamma delta cells ( in lymphoid tissues of beef calves.  Previous studies have shown that T lymphocytes proliferate significantly in cattle following infection or vaccination with BVDV.  However, the number, distribution, and function of these cells in the response to BVDV infection are not completely understood.   The objective of this study was to compare the abundance and distribution of T lymphocytes in lymphoid tissue during acute infection with ncp BVDV of low or high virulence.  Spleen and mesenteric lymph node (MLN) were collected from cattle at postmortem on day 5 after they were inoculated with either BVDV-1a SD-1 (low virulence; LV), BVDV-2 1373 (high virulence; HV) or control exposure (sham exposure with tissue culture medium) A higher proportion of calves challenged with BVDV showed apoptosis and cytophagy in MLN and spleen, relative to controls.  A significantly lower number of T cells was observed in spleen and MLN from calves in HV and LV groups than in controls.  Acute infection with HV or LV BVDV resulted in depletion of WC1+ T cells in mucosal and systemic lymphoid tissues at 5 days after challenge. 

Oklahoma State University

Pulmonary Lesions and Clinical Disease in Calves Challenged with Histophilus somni Five Days after Tildipirosin or Tulathromycin Treatment.

The objective of this study was to compare in calves the efficacy of two macrolide antimicrobials, tildipirosin and tulathromycin, in a metaphylaxis model of experimentally induced Histophilus somni respiratory infection. Twenty-four Holstein and Holstein - crossbreed steers, approximately 4 months of age that had low to no anti-H. somni antibodies were enrolled in the study. On day 0, 8 calves each were treated by subcutaneous injection:  Group 1 - tildipirosin   at 4 mg/kg, Group 2 - tulathromycin at 2.5 mg/kg, and Group 3 (Control) - isotonic saline. On day 5, all calves were inoculated intrabronchially with 1.6 x 109 CFU/ml of H. somni strain 7735. Clinical evaluations were done on days 5-8. On day 8, calves were humanely killed, and lungs evaluated for pneumonia and bacterial isolation.  Twelve hours after challenge, clinical scores for each group significantly increased compared to scores at challenge. On days 6, 7, and 8, clinical scores for the tildipirosin-treated group were significantly lower compared to the tulathromycin-treated and Control calves. On days 6 and 7, clinical scores for tulathromycin-treated calves were significantly lower than for the Control calves. Percentage of pneumonic lung was significantly lower for the tildipirosin-treated group (6.0 ± 2.3) than for tulathromycin (30.9 ± 21.5%) and Control groups (26.3 ± 17.6%). H. somni was reisolated from tulathromycin-treated and Control groups. Within the parameters of this metaphylaxis model, tildipirosin was generally more efficacious than tulathromycin in minimizing clinical disease.

Objective 3: To investigate the mechanisms by which infectious agents work singly or in combination to evade, suppress, or misdirect the host immune response, or to directly induce cellular or molecular pathology, in BRD.

South Dakota State University

Neutrophils are the predominant white blood cells in peripheral blood activate the innate as well as adaptive immune response. In the current study, the effect of bovine viral diarrhea virus (BVDV) infection viability, surface marker expression such as CD14, CD18 and L-selectin, neutrophil’s migration and phagocytosis ability was investigated. Isolated neutrophils (CD14+, CD18+ and L-selectin+.) were infected with homologues pair of BVDV [e.g. cytopathic (cp) BVDV1b-TGAC or non- cytopathic (ncp) BVDV1b-TGAN] at 3 MOI.  Neutrophils were examined for apoptosis and CD14, CD18 or L-selectin expression at 1 hr and 6 hrs post infection (PI). Neutrophil migration was measured through transwell assay with BVDV or LPS treated bovine macrophages in lower chamber and freshly collected neutrophils in the upper chamber. To measure the effect of BVDV on phagocytosis ability of neutrophils, neutrophils were infected with cpBVDV1b-TGAC or ncpBVDV1b-TGAN at 3 M.O.I for one hour and phagocytosis ability was measured through 0.2µm florescent beats. Both biotypes of BVDV induced the apoptosis in neutrophils. The cp BVDV1b-TGAC induced more apoptosis than its homologues ncp BVDV1b-TGAN at 1 and 6 hrs PI. Similarly, both biotypes and LPS down regulated the L-selectin expression on bovine neutrophils with course of infection. The LPS up regulated the CD14 expression while down regulates the CD18 expression on neutrophils. Whereas both biotypes of BVDV down regulated the CD14 expression and upregulate the CD18 expression on bovine neutrophils. BVDV infection significantly reduced the neutrophils migration and phagocytosis ability (p < 0.05). The cp BVDV1b-TGAC significantly reduced neutrophil’s migration and phagocytosis ability as compare to its homologues ncp BVDV1b-TGAN (p <0.05).

Virginia Tech

The biofilm formed by P. multocida has been characterized. Strains that are the most highly encapsulated, and are often isolated from acute cases of bovine respiratory disease, produce the most capsule, but make the least amount of, most rough, and least dense biofilm.  However, even highly encapsulated, poor biofilm forming strains can reside in an H. somni biofilm.  After 2-3 days incubation, H. somni is difficult to isolate and P. multocida becomes prominent or the sole agent of the biofilm. The amount of polysaccharide also diminishes over time in P. multocida mono-biofilms or in polymicrobial biofilms, but continues to increase in H. somni mono-biofilms.

Objective 4: To develop management practices, including rationally applied therapeutic and preventative interventions that minimize the impact of BRD on cattle health, welfare and productivity

University of Georgia

Evaluation of the effect of an injectable trace mineral (ITM) supplement on the immune response of dairy calves to viral vaccines.  Previous studies demonstrated that administering injectable trace minerals (ITM; Zn, Mn, Cu, and Se) improved humoral immune response to BHV-1 following administration of a MLV vaccine in cattle (Arthington and Havenga, 2012). The objective of this study was to evaluate the effect of an ITM supplement containing zinc, manganese, selenium, and copper on the humoral and cell mediated immune (CMI) responses to individual vaccine antigens in dairy calves receiving a modified-live viral (MLV) vaccine containing BVDV, BHV1, PI3V and BRSV. Thirty dairy calves (3 months of age) were administered 2 mL of a 5-way MLV vaccine and 2 mL of an attenuated-live M. haemolytica and P. multocida bacterin subcutaneously (SC). Calves were randomly assigned to 1 of 2 groups:  (1) Subcutaneous administration of ITM (1 mL/100 lb BW, ITM; MultiMin 90, Fort Collins, CO; n = 15) or (2) Subcutaneous injection of sterile saline (2 mL, Control; n = 15). Three weeks after initial vaccination, calves received a booster of 2 mL of the 5-way MLV vaccine, and 2 mL of the attenuated-live bacterin SC. Concurrently with the vaccine booster, a second administration of injectable trace minerals or sterile saline SC was given to calves in ITM and control group, respectively. Blood samples were collected on days 0, 7, 14, 21, 28, 42, 56, and 90 relative to prime vaccination for antibody titer determination, antigen-induced in vitro IFN-γ production by peripheral blood mononuclear cell (PBMC), and antigen-induced PBMC proliferation.   Administration of ITM concurrently with MLV vaccination resulted in higher antibody titer to BVDV-1 on day 28 post prime vaccination compared to the control group (P=0.03). There was a tendency of a higher PBMC proliferation response to BVDV (P=0.08) on day 14 post prime vaccination in calves treated with ITM than in the control group. Additionally, calves treated with ITM showed an earlier and more consistently increased PBMC proliferation to BVDV following MLV vaccination (on days 14, 21, and 42 relative to day 0), compared to the control group (only on day 28). There was a significantly higher PBMC proliferation upon BRSV stimulation on day 7 post prime vaccination in the ITM group than the control group (P=0.01). Calves treated with ITM showed a significantly augmented PBMC proliferation upon stimulation with BRSV on days 7, 14, and 42 after prime vaccination relative to day 0 (P <0.05). Proliferation of PBMC was increased upon BHV1 recall in both ITM and control groups on days 14, 21 28 and 42 post vaccination compared with day 0 (P<0.05). Significant differences were not found in the production of IFN-γ by PBMC after stimulation with BVDV, BHV1, and BRSV between calves treated or not with ITM. In conclusion, administration of ITM concurrently with vaccination in dairy calves resulted in increased antibody titer to BVDV1 (on day 28 after prime vaccination) and PBMC proliferation after BVDV and BRSV stimulation compared to the control group.

Case-control study of herd-level and calf-level risk factors for nursing (preweaning) calf BRD in cow-calf herds.  In collaboration with KS, SD, ND, and MS, we have completed a case-control study of herd-level risk factors for pneumonia in nursing beef calves.  Herds were enrolled in NE, SD, and ND. Case herds treated at least 5% of their nursing calves for BRD, while control herds selected randomly from the same veterinary practice treated no more than 0.5% of their nursing calves for BRD.  A total of 84 herds were enrolled in the study: 30 case herds and 54 matched control herds.  Fifty-two of the herds were enrolled in 2012, 24 were enrolled in 2013, and eight were enrolled in 2014.  Twenty-nine of the herds were located in Nebraska, 23 were located in North Dakota, and 32 were located in South Dakota.  In the multivariable analysis, three variables were significantly associated with calf BRD: herd size; the use of intensive grazing; and synchronizing cows and heifers after calving.  Compared to herds with fewer than 150 cows, the odds of having > 5% incidence of calf BRD were 7.9 times higher for herds with 150-499 cows, and 12 times higher for herds with 500 cows or more.  Compared to herds that did not use intensive grazing, the odds of having > 5% incidence of calf BRD were 3.3 times higher for herds that did use intensive grazing.  And compared to herds that did not use a synchronization program after calving, the odds of having > 5% incidence of calf BRD were 4.5 times higher for herds that did use a synchronization program.

Immune response to subcutaneous and intranasal vaccination in young beef calves.  In this study we compared the serum neutralizing antibody (SNA) titers to BHV1 and BRSV and nasal mucosal BHV1-specific IgA levels following IN or SC MLV booster 60 days after IN MLV priming in young beef calves. The objective was to determine whether IN or SC booster following IN priming induced different immune responses.  We used 24 Angus calves (1-3 weeks of age) that received an IN prime vaccine containing BHV1, BRSV and PI3 (Inforce-3^®) and 60 days later were boostered with 2ml of the same vaccine either IN (n=12) or SC (n=12). Calves had high SNA titers to BRSV and BHV1 at 1-3 weeks of age, likely due to maternal antibody.  A significant decrease in SNA titers to BRSV and BHV1 was observed 2 and 8 weeks after IN prime vaccination. Booster vaccination 60 days after priming (IN or SC) did not cause increase in SNA titers against BHV1. Intranasal booster vaccination induced a significant SNA response to BSRV 2-4 weeks after booster. On the other hand, calves that received SC booster vaccine did not show increase in SNA to BRSV.   A sustained increase in BHV1 specific IgA titers in nasal secretions was observed in both (IN & SC) groups post prime and booster vaccination.   By comparing the fold change in IgA in nasal secretions on day 21 relative to the day of booster vaccination, two patterns of response were observed in the calves that received IN booster. The calves with strongly enhanced nasal IgA to BHV1 after priming did not show clear recall response to IN booster vaccine, but those with low nasal IgA to BHV1 at the time of booster showed a strong (≥8 fold changes) recall titer on 3 or 4 weeks post IN booster.  In contrast, a significant BHV1 nasal IgA response (>8 fold increase) was observed in six calves that received a SC booster regardless the level of BHV1-specific IgA in nasal secretions by the time of booster. In summary, in this study calves primed by IN vaccination had significantly higher SNA titers to BRSV following IN booster, but not SC booster.  In contrast, BHV1 SNA titers did not increase following either IN or SC booster. However, nasal BHV1-specific IgA concentration was significantly increased following IN booster of calves if their IgA titers after priming were not high; SC booster also increased nasal BHV1-specific IgA titers.  The results of this study, which is scheduled to be repeated in fall 2015, suggest that booster route influences the immune response in primed cattle, but the response may not be the same for all pathogens.  More work will be needed to clarify the significance of these results. 

University of Missouri

We, along with collaborators from the University of California-Davis and Auburn University, have determined that orally administered iodine may be used in the respiratory tract of cattle to inactivate pathogens commonly associated with bovine respiratory disease. With further research, these findings may translate into alternative treatment and preventative therapies that can reduce the use of conventional antimicrobials.

Mississippi State University

Evaluation of the effect of on-arrival vaccination and deworming on stocker cattle health and growth performance:  High risk stocker cattle are commonly vaccinated and treated with anthelmintics at arrival; however, little research has been published which provides evidence that these practices are beneficial.  It is possible that vaccination of cattle that may be ill, such as some newly arrived high risk cattle, could be beneficial.  We wished to evaluate the effect of two common management practices, vaccination and deworming, on health and growth of high risk stocker cattle over an 84-day conditioning period.  Sera were also collected for measurement of SN titers to BHV-1, BRSV, and BVDV at multiple points over time; those results will be reported later.  Auction market derived calves (n=80) received from an order-buyer were stratified by d-3 weight and fecal egg count into 20 pens of 4 animals each. Pens were randomly assigned to treatments in a 2x2 factorial design to test vaccination at arrival (d0 modified-live BRD and clostridial vaccine or not) and deworming (d0 oral fenbendazole and levamisole or not). Body weight and blood was collected days 0, 14, 28, 42, 56, 70 and 85.  Fecal egg counts were measured days -3, 28, 56, and 85. Clinical signs of BRD were monitored daily. Treatment effects on BRD incidence, mortality, and growth were tested using Poisson, logistic, or linear regression, respectively (α≤0.05). BRD incidence was greater for calves with d0 vaccination (RR=3.2), high (≥104F) fever at day 0 and higher d-3 FEC. Mortality was greater for d0 vaccination and high fever.  Growth was lower for d0 vaccination (-10.3 lbs), moderate (103-103.9F) and high fever (-24.1 lbs and -16 lbs, respectively), and number of times treated for BRD (-17.5 lbs/treatment). Deworming at arrival decreased fecal egg counts in treated cattle but was not found to be significantly associated with BRD morbidity, mortality, or weight gain.

South Dakota State University

The Genetics of Feedlot Health This station along with Texas, Illinois, Missouri, New York and Colorado are involved in the Genetics of Feedlot Health Project the project was performed in 2009 and 2010.  This study looks at behavior, genetics, nutrition along with microbiology and immunology on respiratory disease and carcass quality. We have continued to analyze the immunological data and are analyzing cortisol and it relationship to overall antibody level and proinflammatory responses.

Objective 5: To promote open scientific exchange and dialogue among scientists, veterinarians, allied industry professionals and cattlemen to advance BRD research initiatives.

University of Georgia

With SD and CA, GA worked with the publisher of Animal Health Research Reviews to publish the proceedings of the 2014 BRD Symposium.  This means that the Symposium proceedings are now identifiable by searches on PubMed, and anyone at an institution with a subscription to the journal will be able to access the papers.  Thus the information presented at the 2014 BRD Symposium will be widely available. 

University of Missouri

Our findings have been presented at the Merial Veterinary Research Scholars Symposium and have been accepted for presentation at the annual Conference of Research Workers in Animal Diseases. In addition, a manuscript detailing our findings is being prepared.

South Dakota State University

The 2014 BRD symposium was held in Denver CO in July-August 2014.  With attendance of over 300 including producers, veterinarians, government officials and animal health industry professionals, the meeting was a success.   The 6th BVDV-Pestivirus meeting held in October 2015 in Kansas City MO.  This international conference had over 125 attendees. SD provided BRSV isolates toCA & GA and BHV-1 isolates to OK.

Objective 6: To facilitate the translation of research findings to practical field application by developing and integrating BRD educational programming for national veterinary and producer organizations focused on cattle health and management.

Oklahoma State University

Impact of Species and Subgenotypes of Bovine Viral Diarrhea Viruses on Control by Vaccination.

  Bovine viral diarrhea viruses (BVDV) are diverse genetically and antigenically. This diversity impacts both diagnostic testing and vaccination. In North America there are two BVDV species, 1 and 2 with 3 subgentoypes, BVDV1a, BVDV1b and BVDV2a. Initially U.S. vaccines contained BVDV1a cytopathic (CP) strains. With the reporting of BVDV2 severe disease in Canada and the U.S. there was focus on protection by BVDV1a vaccines on BVDV2 disease. Also emphasis of controlling persistently infected (PI) cattle resulted in studies for fetal protection afforded by BVDV1a vaccines. Initially, studies indicated that some BVDV1a vaccines gave less than 100% protection against BVDV2 challenge for fetal infection. Eventually vaccines in North America added BVDV2a to modified live virus (MLV) and killed BVDV1a vaccines. Ideally vaccines should stimulate complete immunity providing 100% protection against disease, viremias, shedding, and 100% fetal protection in vaccinates when challenged with a range of diverse antigenic viruses (subgenotypes).  There should be a long duration of immunity stimulated by vaccines, especially for fetal protection. MLV vaccines should be safe when given according to the label and free of other pathogens. While vaccines have now included BVDV1a and BVDV2a, the discovery of the predominate subgenotype of BVDV in the U.S. to be BVDV1b, approximately 75% or greater in prevalence, protection in acute challenge and fetal protection studies became more apparent for BVDV1b. Thus many published studies examined protection by BVDV1a and BVDV2a vaccines against BVDV1b in acute challenge and fetal protection studies. There are no current BVDV1b vaccines in the U.S. There are now more regulations on BVDV reproductive effects by the USDA Center for Veterinary Biologics (CVB) regarding label claims for protection against abortion, persistently infected calves, and fetal infections, including expectations for studies regarding those claims. Also USDA CVB has a memorandum providing guidance for exemption of the warning label statement against the use of the MLV BVDV in pregnant cows and calves nursing pregnant cows. In reviews of published studies in the U.S, the results of acute challenge and fetal protection studies are described including subgenotypes in vaccines and challenge strains and the results in vaccinates and the vaccinates fetuses/newborns. In general vaccines provide protection against heterologous strains, ranging from 100% to partial but statistically significant protection. In recent studies, the duration of immunity afforded by vaccines was investigated and reported. Issues of contamination remain, especially since fetal bovine serums may be contaminated with noncytopathic BVDV. In addition, the potential for immunosuppression by MLV vaccines exists, and new vaccines will be assessed in the future to prove those MLV components are not immunosuppressive by experimental studies. As new subgenotypes are found, the efficacy of the current vaccines should be evaluated for these new strains.

South Dakota State University

Classes specific on bovine respiratory disease were taught to the advanced group of the United States Dairy Education Consortium at Clovis NM in June 2015.

Palomares RA, Sakamoto K, Walz HL, Brock KV, Hurley DJ.  Acute infection with bovine viral diarrhea virus of low or high virulence leads to depletion and redistribution of WC1+ cells in lymphoid tissue of beef calves.  Vet Immunol Immunopathol, 2015.  In press. 

Palomares RA, Hurley DJ, Woolums AR, Parrish JE, Brock KV.  Analysis of mRNA expression for genes associated with regulatory T lymphocytes (CD25, FoxP3, CTLA4, and IDO) after experimental infection with bovine viral diarrhea virus of low or high virulence in beef calves.  Comp Immunol Microbiol Infect Dis. 2014. 37:331-338.

Palomares RA, Parrish J, Woolums AR, Brock KV, Hurley DJ.  Expression of toll-like receptors and co-stimulatory molecules in lymphoid tissue during experimental infection of beef calves with bovine viral diarrhea virus of low and high virulence.  Vet Res Commun. 2014 38:329-335. 

Klingenberg M.A., Shoemake B.M., Nolan R.A., Heller M.C., Newcomer B.W., Meyer A.M., Vander Ley B.L. “Iodine secretion in airway fluid following a single bolus of sodium iodide.” Poster for the Merial Veterinary Scholars Symposium. August 2015.

Heller M.C., Clothier K.A., Newcomer B.W., and Vander Ley B.L. “Sodium iodide inactivates Mannheimia haemolytica and Bibersteinia trehalosi in vitro.” Abstract for the Conference for Research Workers in Animal Diseases. December 2015.

Newcomer B.W., Vander Ley B.L., Galik P., and Heller M.C. “In vitro inactivation of bovine viral respiratory pathogens using an iodine-based antimicrobial system.” Abstract for the Conference for Research Workers in Animal Diseases. December 2015.

Shoemake B.M., Vander Ley B.L., Klingenberg M.A., Nolan R.A., Meyer A.M., Schultz L.G., Newcomer B.W., and Heller M.C. “Iodine Secretion in airway surface fluid following a single oral bolus of sodium iodide in calves.” Abstract for the Conference for Research Workers in Animal Diseases. December 2015.

Fulton, R.W., Rezabek, G.B., Grant, R., Ridpath. J.F., Burge.L.J.: Diverse Outcomes of Bovine Viral Diarrhea Virus Infections in a Herd Naturally Infected During Pregnancy- a Case Study.. Bovine Practitioner, 48: 95-98, 2014.

Fulton, R.W., Herd, H.R., Sorensen, N.J., Confer, A.W., Ritchey, J.W., Ridpath, J.F., Burge.L.J.: Enteric Disease in Postweaned Beef Calves Associated with  Bovine Coronavirus Clade 2. Journal of Veterinary Disease Investigation, 27: 97-101, 2015.

Fulton, R.W., d’Offay J.M., Eberle,R., Moeller, R.B., Van Campen, H., O’Toole, D., Chase, C., Miller. M.M., Sprowls, R., Nydam, D.V.: Bovine Herpesvirus-1: Evaluation of Genetic Diversity  of Subtypes Derived from Field Strains of Varied Clinical Syndromes and Their Relationship to Vaccine Strains. Vaccine, 31: 549-558, 2015.

Fulton, R.W.: Impact of Species and Subgenotypes of Bovine Viral Diarrhea Virus on Control by Vaccination. Animal Health Research Reviews, 16: 40-54, 2015.

Holbrook T, Gilliam L, Stein F, Morgan S,  Avery A, Confer AW, Panciera RJ. Lathyrus hirsutus (Caley Pea) Intoxication in a Herd of Horses. J Vet Intern Med 29 :294-298, 2015.

Taylor JD, Holland B, Step DL, Payton ME, Confer AW. Nasal isolation of Mannheimia haemolytica  and Pasteurella multocida as predictors of respiratory disease in shipped calves. Res Vet Sci 99:41-45, 2015.

Confer AW, Snider TA, Taylor JD, Montelongo M, Sorensen NJ. Pulmonary lesions and clinical disease in calves challenged with Histophilus somni five days after tildipirosin or tulathromycin treatment. AJVR, in press 2015.

Pan, Y., T. Fisher, C. Olk, and T. J. Inzana. 2014. Detection of antibodies to the biofilm exopolysaccharide of Histophilus somni following infection in cattle by enzyme-linked immunosorbent assay.  Clin. Vac. Immunol.  21:1463-1467.

Shah, N., A.B. Bandara, I. Sandal, and T.J. Inzana.  2014. Natural Competence in Histophilus somni strain 2336.  Vet. Microbiol. 173:371-378.

Petruzzi, B., R.E. Briggs, W.E. Swords, C. De Castro, A. Molinaro, T. J. Inzana. 2014.  Polymicrobial Biofilm formation by Pasteurella multocida and Histophilus somni.  Abst. 14.  1^st ASM Conference on Polymicrobial Infections.  Nov. 13-16, 2014. Washington, DC.

Petruzzi, B.L., R.E. Briggs, C. De Castro, A. Molinaro, T. Inzana^. Characterization of Biofilm Formation by Pasteurella multocida.  Oral Pres. 018. Conf. Res. Workers Anim. Dis. 2014 Ann. Meet. Dec. 7-9, 2014. Chicago, IL.

Petruzzi, B., W.E. Swords, R. Briggs, and T.J. Inzana. 2015. Characterization of biofilm formation in Pasteurella multocida. Mid-Atlantic Microbial Pathogenesis Meeting 2015. Jan. 25-27, 2015.Wintergreen, VA.

Section 7. Scientific and Outreach Oral Presentations.

Palomares, RA, Sakamoto, K, Waltz, H, Brock, KV, Hurley, DJ. Acute infection with        bovine viral diarrhea virus causes depletion of  WC1⁺ γδ T cells in lymphoid tissues in     beef calves. 95^th Annual CRWAD meeting, December 7-9, 2014 Chicago, IL. Abstract

Woolums A.  Review of Immunity in the Calf, and Vaccination to Control BRD.  Northwest Women Veterinarians’ Meeting, Walla Walla WA.  July 29, 2015.

Woolums A.  The Impact of Vaccination and Maternal Immunity on Respiratory Disease in Calves.  XV. Middle European Buiatric Congress and 10^th European College of Bovine Health Management Symposium.  Maribor, Slovenia.  June 10-13, 2015. 

Woolums A.  BRD Diagnostic Testing in Stocker Cattle. Meeting the Stocker Challenge.  Starkville MS.  December 9-10, 2014.

Woolums A.  Bovine Respiratory Vaccinations: When, Why, and How?  University of Georgia Continuing Education Conference for Veterinary Technicians.  Athens GA.  October 18, 2014.

Griffin CM; Karisch B; Woolums AR; Blanton J; Kaplan RM; Epperson W; Smith DR. Evaluation of on-arrival vaccination and deworming on stocker cattle health and growth performance.  Mississippi State University College of Veterinary Medicine Research Day, August 13, 2015. 

T.J. Braud, B.B. Karisch, D.R. Smith, C.L. Huston, S.G. Genova. 2015.  Effect of crude protein levels and metaphylaxis during the stocker receiving phase on feedlot and carcass performance. ASAS Southern Section.

 Smith DR. 2015. Stocker cattle receiving programs.  Mississippi Veterinary Medical Association, Summer Meeting. Orange Beach, AL. July 2015.

Smith DR. 2015. Pneumonia in calves prior to weaning.  Mississippi Veterinary Medical Association, Summer Meeting. Orange Beach, AL. July 2015.

 Schneider LG, Smith DR. 2015. The effect of morbidity on weaning weight of beef calves.  Conference of Research Workers in Animal Diseases.  Chicago.  Oral Presentation 081.  Dec 8, 2014.

Brown, J., Woolums, A.,Jones, L,McKinnon, G., Fulton, R.W., Ridpath, J.: Investigation Into an Outbreak of Respiratory Disease in Nursing Calves in a South Georgia Beef Herd. Bovine Respiratory Disease Symposium (BRDS) 2014. Denver , CO. July 30-31,2014.

Fulton, R.W.: Bovine Coronaviruses: Respiratory and Digestive Tract Infections/Disease in Post Weened Beef Calves. Academy of Veterinary Consultants Meeting. Augest 1-2,2014. Denver, CO.

Herd, H.R., Ritchey, J.W., Fulton, R.W., Ridpath, J.F.: Coronavirus-Associated Hemorrhagic Colitis in Two Young Adult Beef Cattle in Oklahoma. 57th Annual Meeting of AAVLD, October 26=22-21,2014. Kansas City, MO.

Fulton, R.W.: Impact of Species and Subgenotypes of BVDV on Control by Vaccination. Joint U.S. BVDV/ESVV Pestivirus Symposium. October 14-15,2014. Kansas City, MO.

Confer AW, Taylor JD.  Pasteurella multocida in bovine respiratory disease: What we know and what we don’t know. Summer Conference, Academy of Veterinary Consultants, Denver, CO, 2014. 

Exploring mechanisms of Histophilus somni virulence: from phase variation to biofilm formation.  2014.  University of Mississippi, College of Veterinary Medicine.

Biofilm and Exopolysaccharide Production by Histophilus somni and Pasteurella multocida individually and during Polymicrobial Interaction.  2014.  European Cooperation in Science and Technology Conference on Microbial cell surface determinants of virulence as targets for new therapeutics in Cystic Fibrosis.  Università Di Napoli Federico Ii, Naples, Italy.