Posts by Endovac

Event:  $250,000 to be Donated to Cattle Producers of the Plains Wildfires

 

 

IMMVAC, Inc., customers and allied industry foundations proudly give to cattlemen in need.

 

We are blown away by the success of our recent wildfire donation program.  The sales for the last two weeks of March, which we promised to donate, far exceeded our expectations.  We had faith that we would get to $100,000 in gross sales and already cut checks to 4 organizations for that amount.  While we set that as a minimum, we had no idea that with our customers help, we were going to be able to more than double that.  We have decided to round up and donate an even $250,000 in wildfire relief donations.  A big thank you goes out to all of our customers, we know many of you put money out for vaccine in advance of when you would normally purchase it, and we thank you. As a small family owned business, we could never have been able to do so much without the assistance of our customers.

 

Where the first $100,000 was donated.

 

Our minimum amount of $100,000 has already been distributed across 4 organizations. Earlier in the month we were able to get checks out to the Kansas Livestock Foundation Disaster Relief, Oklahoma Cattlemen’s Foundation Fire Relief Fund, Texas & Southwestern Cattle Raisers Association Foundation, and the Colorado Farm Bureau Foundation Disaster Fund. We chose an organization in each state affected by the wildfires. We invite you to check out each of their websites below.

 

https://www.kla.org/wildfirerelief.aspx

https://www.okcattlemen.org/firerelieffund.aspx

http://tscra.org/panhandle-wildfires/

https://www.coloradofarmbureau.com/disasterfund

 

Multiplying our customers giving power with the remaining donation.

 

We still have $150,000 of our $250,000 total to donate. Late last week, a great foundation was started that will allow our customers dollars to go twice as far. We have reached out to this organization and decided to pledge the rest of our donation dollars to the Farm Journal Foundation.

 

Drovers, a Farm Journal Media franchise, and the Farm Journal Foundation proudly announced last week the acceptance of a historic challenge by global philanthropist and American farmer-rancher Howard G. Buffett to raise at least $2 million to help ranching victims of the devastating wildfires that burned 1.6 million acres in Kansas, Texas, Oklahoma and Colorado last month. Starting today, all monetary donations to the new Drovers/Farm Journal Foundation Million Dollar Wildfire Relief Challenge will be matched, dollar-for-dollar, by the Howard G. Buffett Foundation, up to $1 million.

 

Ways the funds will be used.

 

While the agricultural community rallied around those impacted by delivering hay and other in-kind contributions, the more protracted—and expensive—job of rebuilding has just begun. For example, an estimated 18,000 miles of fencing needs to be replaced at a cost of up to $10,000 a mile.

 

All donations will be administered through the Working Ranch Cowboys Association, a respected national nonprofit dedicated to assisting working ranch cowboys and their families in times of need. To learn more visit http://www.WildfireReliefFund.org, a special website launched today to help you track wildfire relief efforts and keep up to date on the ranchers’ continuing story.

 

Studies:  E. coli and P. multocida Endotoxin Challenge Study

AGRI-PRACTICE – COW/CALF – DISEASE CONTROL

 

At 14-day intervals, 12 calves were vaccinated twice with a S. typhimurium bacterin-toxoid, and 12 control calves each received two injections of dialuminum trioxide/saline placebo. Two weeks following the vaccination booster, or the second placebo injection, ten calves – five vaccinated and five treated with placebo – were challenged with 100 ng/kg of E. coli 055:B5 endotoxin. Similarly, another 14 calves – seven vaccinated and seven placebo-treated – were challenged with 50 ng/kg of P. multocida endotoxin. There was a significant difference (P < 0.05) between the clinical responses of the vaccinated and placebo-treated group challenged with either E. coli 055:B5 or P. multocida endotoxin as measured by the endotoxin colic index, mean anorexia time intervals, and IgG(t) serum antibody titers.

 

Cross-Protection of Calves from

AGRI-PRACTICE – COW/CALF – DISEASE CONTROL

 

At 14-day intervals, 12 calves were vaccinated twice with a S. typhimurium bacterin-toxoid, and 12 control calves each received two injections of dialuminum trioxide/saline placebo. Two weeks following the vaccination booster, or the second placebo injection, ten calves – five vaccinated and five treated with placebo – were challenged with 100 ng/kg of E. coli 055:B5 endotoxin. Similarly, another 14 calves – seven vaccinated and seven placebo-treated – were challenged with 50 ng/kg of P. multocida endotoxin. There was a significant difference (P < 0.05) between the clinical responses of the vaccinated and placebo-treated group challenged with either E. coli 055:B5 or P. multocida endotoxin as measured by the endotoxin colic index, mean anorexia time intervals, and IgG(t) serum antibody titers.

 

Cross-Protection of Calves from E. coli and P. multocida Endotoxin Challenges Via S. typhimurium Mutant Bacterin-Toxoid*

 


Ronald F. Sprouse, Ph.D.

Department of Pathology

School of Medicine

University of Missouri

Columbia, Missouri 65201

 

Harold E. Garner, D.V.M., Ph.D.

Kris Lager, B.S., M.S.

Department of Veterinary Medicine and Surgery

College of Veterinary Medicine

University of Missouri

Columbia, Missouri 65201

 

Introduction

 

Some of the most common and devastating diseases encountered by the bovine practitioner are those associated with endotoxins. Gram-negative diarrheas and pneumonias are often complicated by endotoxins.1,2 Failure of passive transfer of uniformity is the primary predisposing factor to neonatal septicemia, which is caused most frequently by gram-negative bacteria.1 The host’s biological responses to endotoxins result in many of the recognizable clinical signs exhibited, and often culminate in death.3-6 An active immunization strategy aimed at host inactivation of gram-negative endotoxins represents a rational approach for preventing the devastating effects of endotoxemia.

Immune strategies that would aid cattle by providing cross-protection from the overwhelming effects of various gram-negative endotoxemias have been difficult to develop.7 In a case of endotoxemia, the specific serotype sources of endotoxin involved may be from one or more members of the large gram-negative family, Enterobacteriaceae. Because there are hundreds of gram-negative serotypes, it would be impractical to combine sufficient autogenous vaccines to provide broad-spectrum protection. Thus, a single source bacterin that provides cross-protection against virtually all gram-negative endotoxins is needed.

The fact that almost all species of gram-negative bacteria possess analogous cell wall characteristics has provided the basis for many immunological studies conducted over the past 20 years.7-15 R-mutants of Salmonella sp. and Escherichia coli have been the focus of many of these studies.8,10

R-mutants are “rough”-appearing cell colonies of mutant gram-negative bacteria. These mutants are biochemically characterized by their relative absence of oligosaccharides (“O”) side chain attachments. The relative degree of “O” side chain absence is designated by the capital letter “R” accompanied by the lowercase letters “a” through “e” with Re completely lacing “O” side chains.8,10,11 The J5 E. coli mutant previously studied by us and others is characterized as Rc and thus possesses “O” side chains.

Removal of these “O” side chains via mutation allowed the core antigen of the cell wall to be presented to the immune system for the subsequent production of cross-protective antibodies,15,16 thereby, circumventing problems associated with specific serotype characteristics. Antibodies formed in response to these core antigens devoid of the “O” side chains can cross-protect an animal from many, and possibly all, gram-negative endotoxins.

An Re-type mutant bacterial strain from a parent Salmonella typhimurium was engineered to form an Re-type mutant that possesses no “O” side chains. This naked core Re-mutant was combined with a toxoid and dialuminum trioxide to make a cross-protective vaccine.16 The results of Heterologous efficacy testing in calves immunized with this vaccine are presented.

 

Materials and Methods

 

 

The vaccine used in these experiments contained a killed bacterial Re mutant of S. typhimurium (bacterin), and immune modulator (endotoxin), a protein/lipid binding carrier/adjuvant (dialuminum trioxide), and oil. Each calf was vaccinated and boostered within 2 weeks either with the vaccine or a dialuminum trioxide/saline placebo. Each calf was intravenously challenged with endotoxin 2 weeks post-booster injection.

Twenty-four healthy calves ranging from 3 to 4 months in age and 79 kg to 200 kg in body weight were used in this study. The 22 bulls and two heifers were divided as evenly as possible into two groups of 14 and 10, respectively, on the basis of sex and then randomized into two groups of seven and two groups of five. One group of seven and one group of five were administered two 1.6 ml doses of the vaccine into the cervical musculature 14 days apart. The United States Department of Agriculture required 80%, or 1.6 ml doses of a 50% dialuminum trioxide/50% saline placebo intramuscularly 14 days apart. This experimental design allowed each group that received the vaccine to be compared with a group that received placebo when all were challenged with endotoxin.

Ten calves, five vaccinated with the bacterin-toxoid and five injected with the placebo, were challenged with an intravenous bolus of 100 ng/kg of E. coli 055:B5 endotoxin. The other 14 calves, seven vaccinated with the bacterin-toxoid and seven injected with the placebo, were challenged with an intravenous bolus of 50 ng/kg of Pasteurella multocida endotoxin. Each calf was fasted for 12 hours prior to endotoxin challenges but was allowed free access to water until tied in a box stall for observation. Each calf was observed 60 minutes prior to endotoxin injection to establish control behavior and was then allowed free choice of alfalfa and observed for 1 hour following endotoxin injection to observe clinical responses. Responses were continuously recorded. In addition, during the second hour following endotoxin administration, each calf was turned loose in a box stall and allowed free choice of alfalfa, hay, and water and closely observed to determine whether or not it was anorexic.

The endotoxin colic index scoring method used to generate the data in Figures 1 and 2 was established prior to the present study by statistically analyzing the observations of three individuals recording the clinical signs exhibited by 30 head of tied calves for 1 hour prior to and 1 hour following intravenous bolus administration of varying dosage levels of either Pasteurella or E. coli endotoxin.12 Kicking, leg flexing, stretching, bowing-stretches, looking at flank, hyperpnea, and dyspnea along with CNS depression progressing to comatosis were all included as signs used to describe the progression of behavior, which ranged from Level 1.0 to Level 6.0 of the endotoxic colic index. During efficacy studies, the assessment of the observations was accomplished via a blinded scorer. All of the calves, whether they possessed protective levels of anticore-antigen antibodies or not exhibited signs that approached Level 2.0 when they were scored. The unprotected animals developed sufficient clinical signs to progress through level 2.0 and higher, while those that were protected exhibited colic index score levels of less than 2.0.

Serum samples collected from each calf before and 4 weeks following the first injection of vaccine or placebo were analyzed for the present study by an ELISA assay adapted from a previously developed radioimmunoassay (RIA) for specific IgG(t) antiendotoxin antibody levels.17,18 The technician that analyzed the pre- and post-vaccination serum samples for anticore-antigen antibody levels was not aware of any animal’s category.

Data were analyzed via analysis of variance statistical techniques. The predetermined acceptable probability level was 0.05 or less.

 

Results

 

When challenged with endotoxin, calves vaccinated with the S. typhimurium bacterin-toxoid compared with those injected with the placebo were significantly (P < 0.05) different in terms of the mean endotoxin colic index scores reflecting colicky pain, dyspnea and somnolence, mean IgG(t) antibody levels, and anorexia time intervals (Tables 1 & 2; Figs. 1, 2, 3, & 4). The line 2.0 represents the previously established threshold that divided those with protective levels of anticore-antigen antibodies from those without.12 The mean endotoxin colic respiratory index scores of immunized vs. placebo-injected groups heterologously challenged with E. coli 055:B5 endotoxin were significantly (P < 0.001) different (Table 1; Figs. 1 & 2).

The differences between these groups (Table 2; Fig. 4) in terms of either mean IgG(t) antibody titers (P < 0.001) or mean anorexia time intervals (P < 0.05) were significant. Similarly, the mean endotoxin colic index scores of immunized vs. placebo-injected groups heterologously challenged with P. multocida endotoxin were significantly (P < 0.001) different (Table 1; Fig. 1). The differences between these groups in terms of either mean IgG(t) antibody tiers (P < 0.05) (Table 2; Figs. 3 & 4) or mean anorexia time intervals (P < 0.05) (Table 3) were also significant. In this study, 90% of the calves that received the vaccine exhibited a transient palpable 1-cm diameter swelling in the cervical musculature injection site 2 to 4 days postinjection, which was nonpalpable 2 weeks following injection. None required treatment or went off feed.

 

Discussion

 

The increase in serum IgG(t) antibody levels in the vaccinated calf groups apparently provided the active immunity responsible for protection against the outward clinical effects of the heterologous endotoxin challenges. It is interesting that these results confirmed the results of other laboratories when various species were vaccinated with similar gram-negative mutant bacterins and challenged with Heterologous endotoxins.9-11,19 It is also important to note that the protection provided by the antibodies produced in response to the core antigen of the Re-mutant S. typhimurium bacterin-toxoid cross-protected the calves from the heterologous E. coli 055:B5 endotoxin challenge as well as from the heterologous P. multocida endotoxin challenge.

The dialuminum trioxide adjuvant in this vaccine stimulated the localization of macrophages in the muscular tissue at the injection site. The macrophage-processed antigen then slowly leaked out of the localized macrophages providing a prolonged antigenic stimulus.20 Therefore, a local response was expected following injection of the vaccine and was indicative of a viable hose immunization. Dialuminum trioxide influenced the primary immune response and helped maintain the other two vaccine components in suspension.

The toxoid portion of the combination cross-protective vaccine stimulate the B-lymphocytes to divide and produce antibodies directed against the naked core determinant while the killed Re-mutant bacterial cells (bacterin) provided the naked core determinant to serve as antigen for antibody production.

Since conducting these efficacy studies, results of field study observations, including a rise in body temperature and/or generalized muscular soreness, were not detected in any calves or cows. In accordance with USDA recommendations, any animal that suffers an allergic response following vaccination should be treated immediately with epinephrine or its equivalent. No allergic responses were discerned during the efficacy and subsequent field studies.

 

Conclusion

 

The anticore-antigen antibody efficacy demonstrated in this study offers new possibilities for aiding in the control of end-stage consequences of such gram-negative diseases as E. coli sp. diarrhea, Salmonella sp. diarrhea, and Pasteurella sp. pneumonia. Because of the cross-protectiveness of the antibodies demonstrated in this study, it is suspected that cattle can also be protected from endotoxins arising from other gram-negative bacteria such as Klebsiella sp., Enterobacterieae sp. Proteus sp., and others. Application of this technology may add a new dimension to immunologic control of economically important gram-negative bovine diseases.

 

ACKNOWLEDGEMENTS

The authors extend their gratitude to Dorothy Brandon, Dan Hatfield, Joe Miramonti, Anne Sears, Kelly Lager, Bill Starke, Patsy McClenahan, and Carol Skinner for their expert technical assistance.

This study was funded in part by the University of Missouri College of Veterinary Medicine, School of Medicine, and IMMVAC, Inc., Columbia, Missouri.

 

REFERENCES

  1. Carter GK, Martens RJ: Septicemia in the Neonatal Foal. Comp Cont Ed Pract Vet 8:5256-5271, 1986.
  2. Sprouse RF, Garner HE, Green EM: Plasma Endotoxin Levels in Horses Subjected to Carbohydrate Induced Laminitis. Eq Vet J 19:25-28, 1987.
  3. McCarty DO, Kluger MJ, et al: The Role of Fever in Appetite Suppression After Endotoxic Administration. Am J Clin Nutr. 40:310-316, 1984.
  4. Moldawer LL, Georgiett M, Lanholm K: Interleukin 1, Tumor Necrosis Factor-alfa (Cachetin) and the Pathogenesis of Cancer Cachexia. Clin Phys 7:263-274, 1987.
  5. Movat HZ, Cybulsky MI, Golditz IG, et al: Acute Inflammation in Gram-Negative Infection: Endotoxins, Interleukin 1, Tumor Necrosis Factor and Neutrophils. Fed Proc 46:97-104, 1987.
  6. Hart BL: Animal Behavior and the Fever Response: Theoretical Considerations. J Am Vet Med Assoc 187:998-1001, 1985.
  7. Morris DD, Cullor JS, Whitlock RH: Endotoxemia in Horses: Protection Provided by Antiserum to Core Lipopolysaccharide. Am J Vet Res 47:544-550, 1986.
  8. McCabe WR, Kreger M, Johns MA: Type-Specific and Cross-Reaction Antibodies in Gram-Negative Bacteremia. New Engl J Med 287:262, 1972.
  9. Ng AK, Chan LH, Chang CM, et al: Relationship of Structure to Function in Bacterial Endotoxins: Serologically Cross-Reactive Components and Their Effect on Protection of Mice Against Some Gram-Negative Infections. J Gen Mic 94:107-116, 1976.
  10. Braude AI: Endotoxic Immunity. Adv Intern Med 26:427-445, 1980.
  11. Cullor JS, Fenwick BW, Williams MR, et al: Protection from Endotoxic Shock in Calves by Antibodies Against Common LPS Core Antigens Induced by Immunization with E. coli (J5). Conf Res Work (An Dis abstr) #48, 1984.
  12. Lager KL: Development and Application of Behavioral Indices for Evaluation of Equine and Bovine Responses to Low Level Endotoxin Challenges. Master’s Thesis, University of Missouri, 1989.
  13. Marget W, Mar PJ, Jaspers L, et al: Preliminary Study on Administration of High-Titer Lipid A Antibody Serum in Sepsis and Septic Shock Patients. Infection 13:120-124, 1985.
  14. Young LS, Stevens P, Ingram J: Functional Role of Antibody Against ‘Core’ Glycolipid of Enterobacteriaceae. J Clin Invest 56:850-861, 1975.
  15. Sprouse RF, Garner HE, Lager KS: Protection of Ponies from Heterologous and Homologous Endotoxin Challenges Via Salmonella Typhimurium Bacterin Toxoid. Eq Pract 11:34-40, 1988.
  16. Garner HE, Sprouse RF, Green EM: Active and Passive Immunization for Blockade of Endotoxemia. Am Assoc Eq Pract 31:525-532, 1985.
  17. Garner HE, Sprouse RF, Lager KS: Cross Protection of Ponies from Sublethal Escherichia Coli Endotoxemia by Salmonella Typhimurium Antiserum. Eq Pract 10(4):10-17, 1988.
  18. Reardon TP, Sprouse RF, Garner HE: Radioimmunoassay for the Detection of Antigen-Specific IgM, IgG, and IgA in Equine Sera. Am J Vet Res 43:294-298, 1982.
  19. Cullor JS, Spier SJ, Tyler JW, Smith BP: Antibodies that Recognize Gram-Negative Core Antigens: How Important Are They. Proc of ACVIM 1988, pp 503-508.
  20. Tizard, Ian: Veterinary Immunology: An Introduction. 3rd Ed. Philadelphia, WB Saunders Co., 1987.

 

TABLE 1
Comparison of Mean Endotoxin Respiratory Colic Index Scores and Serum IgG Antibody Titers of E. coli

Endotoxin-Challenged, Placebo-Treated, and Vaccinated Calves

 
Endotoxin-Challenged Calves
Parameter Placebo (control); N = 5 Vaccinate; N = 5
Mean Endotoxin Colic Respiratory Index Scorea
Mean 2.31 0.32c
SD ± 2.40 ± 0.64
SEM ± 1.20 ± 0.30
Range 0.60-3.6 0.0-1.0
Mean Serum IgG Titer (Log 2)b        
  Pre- Post- Pre- Post
Mean 8.60 9.00d 9.80 12.20c
SD ± 1.20 ± 1.55 ± 1.47 ± 1.17
SEM ± 0.60 ± 0.77 ± 0.74 ± 0.59
Range 8-11 8-12 8-11 11-14

a Endotoxin respiratory colic index scores were analyzed via three-factor analysis of variance with repeated measures on one factor.

b Serum IgG antibody measurements were analyzed via two-factor analysis of variance techniques with repeated measures on one factor.

c Mean value significantly (p < 0.05) different from control or pretreatment values.

d Mean value not significantly (p > 0.05) different from pretreatment values.

SE = Standard deviation; SEM = Standard error of the mean.

 

TABLE 2
Comparison of Mean Endotoxin Respiratory Colic Index Scores and Serum IgG Antibody Titers of Pasteurella

Endotoxin-Challenged, Placebo-Treated, and Vaccinated Calves

 
Endotoxin-Challenged Calves
Parameter Placebo (control); N = 7 Vaccinate; N = 7
Mean Endotoxin Colic Respiratory Index Scorea
Mean 2.35 0.64c
SD ± 2.26 ± 1.17
SEM ± 0.92 ± 0.48
Range 1.0-3.7 0.10-2.1
Mean Serum IgG Titer (Log2)b        
  Pre- Post- Pre- Post
Mean 9.29 9.71d 8.29 13.10c
SD ± 1.28 ± 1.03 ± 0.45 ± 1.36
SEM ± 0.52 ± 0.42 ± 0.18 ± 0.56
Range 8-11 8-11 8-9 11-15

a Endotoxin respiratory colic index scores were analyzed via three-factor analysis of variance with repeated measures on one factor.

b Serum IgG antibody measurements were analyzed via two-factor analysis of variance techniques with repeated measures on one factor.

c Mean value significantly (p < 0.05) different from control or pretreatment values.

d Mean value not significantly (p > 0.05) different from pretreatment values.

SE = Standard deviation; SEM = Standard error of the mean.

 

 

 

TABLE 3
Comparison of Combined Anorexia Time Intervals of E. coli and

Pasteurella Endotoxin-Challenged, Placebo-Treated, and Vaccinated Calves

 
Endotoxin-Challenged Calves
Parameter Placebo (control); N = 12 Vaccinate; N = 12
Mean Anorexia Time Interval (minutes)a
Mean 98.1 63.0b
SD ± 22.2 28.8
SEM ± 6.4 ± 8.31
Range 48-112 29-102

a Anorexia time interval measurements were analyzed via two-factor analysis of variance techniques with repeated measures on one factor.

b Mean value significantly (p < 0.05) different from control values.

SE = Standard deviation; SEM = Standard error of the mean.s Via S. typhimurium Mutant Bacterin-Toxoid*

 


Ronald F. Sprouse, Ph.D.

Department of Pathology

School of Medicine

University of Missouri

Columbia, Missouri 65201

 

Harold E. Garner, D.V.M., Ph.D.

Kris Lager, B.S., M.S.

Department of Veterinary Medicine and Surgery

College of Veterinary Medicine

University of Missouri

Columbia, Missouri 65201

 

Introduction

 

Some of the most common and devastating diseases encountered by the bovine practitioner are those associated with endotoxins. Gram-negative diarrheas and pneumonias are often complicated by endotoxins.1,2 Failure of passive transfer of uniformity is the primary predisposing factor to neonatal septicemia, which is caused most frequently by gram-negative bacteria.1 The host’s biological responses to endotoxins result in many of the recognizable clinical signs exhibited, and often culminate in death.3-6 An active immunization strategy aimed at host inactivation of gram-negative endotoxins represents a rational approach for preventing the devastating effects of endotoxemia.

Immune strategies that would aid cattle by providing cross-protection from the overwhelming effects of various gram-negative endotoxemias have been difficult to develop.7 In a case of endotoxemia, the specific serotype sources of endotoxin involved may be from one or more members of the large gram-negative family, Enterobacteriaceae. Because there are hundreds of gram-negative serotypes, it would be impractical to combine sufficient autogenous vaccines to provide broad-spectrum protection. Thus, a single source bacterin that provides cross-protection against virtually all gram-negative endotoxins is needed.

The fact that almost all species of gram-negative bacteria possess analogous cell wall characteristics has provided the basis for many immunological studies conducted over the past 20 years.7-15 R-mutants of Salmonella sp. and Escherichia coli have been the focus of many of these studies.8,10

R-mutants are “rough”-appearing cell colonies of mutant gram-negative bacteria. These mutants are biochemically characterized by their relative absence of oligosaccharides (“O”) side chain attachments. The relative degree of “O” side chain absence is designated by the capital letter “R” accompanied by the lowercase letters “a” through “e” with Re completely lacing “O” side chains.8,10,11 The J5 E. coli mutant previously studied by us and others is characterized as Rc and thus possesses “O” side chains.

Removal of these “O” side chains via mutation allowed the core antigen of the cell wall to be presented to the immune system for the subsequent production of cross-protective antibodies,15,16 thereby, circumventing problems associated with specific serotype characteristics. Antibodies formed in response to these core antigens devoid of the “O” side chains can cross-protect an animal from many, and possibly all, gram-negative endotoxins.

An Re-type mutant bacterial strain from a parent Salmonella typhimurium was engineered to form an Re-type mutant that possesses no “O” side chains. This naked core Re-mutant was combined with a toxoid and dialuminum trioxide to make a cross-protective vaccine.16 The results of Heterologous efficacy testing in calves immunized with this vaccine are presented.

 

Materials and Methods

 

 

The vaccine used in these experiments contained a killed bacterial Re mutant of S. typhimurium (bacterin), and immune modulator (endotoxin), a protein/lipid binding carrier/adjuvant (dialuminum trioxide), and oil. Each calf was vaccinated and boostered within 2 weeks either with the vaccine or a dialuminum trioxide/saline placebo. Each calf was intravenously challenged with endotoxin 2 weeks post-booster injection.

Twenty-four healthy calves ranging from 3 to 4 months in age and 79 kg to 200 kg in body weight were used in this study. The 22 bulls and two heifers were divided as evenly as possible into two groups of 14 and 10, respectively, on the basis of sex and then randomized into two groups of seven and two groups of five. One group of seven and one group of five were administered two 1.6 ml doses of the vaccine into the cervical musculature 14 days apart. The United States Department of Agriculture required 80%, or 1.6 ml doses of a 50% dialuminum trioxide/50% saline placebo intramuscularly 14 days apart. This experimental design allowed each group that received the vaccine to be compared with a group that received placebo when all were challenged with endotoxin.

Ten calves, five vaccinated with the bacterin-toxoid and five injected with the placebo, were challenged with an intravenous bolus of 100 ng/kg of E. coli 055:B5 endotoxin. The other 14 calves, seven vaccinated with the bacterin-toxoid and seven injected with the placebo, were challenged with an intravenous bolus of 50 ng/kg of Pasteurella multocida endotoxin. Each calf was fasted for 12 hours prior to endotoxin challenges but was allowed free access to water until tied in a box stall for observation. Each calf was observed 60 minutes prior to endotoxin injection to establish control behavior and was then allowed free choice of alfalfa and observed for 1 hour following endotoxin injection to observe clinical responses. Responses were continuously recorded. In addition, during the second hour following endotoxin administration, each calf was turned loose in a box stall and allowed free choice of alfalfa, hay, and water and closely observed to determine whether or not it was anorexic.

The endotoxin colic index scoring method used to generate the data in Figures 1 and 2 was established prior to the present study by statistically analyzing the observations of three individuals recording the clinical signs exhibited by 30 head of tied calves for 1 hour prior to and 1 hour following intravenous bolus administration of varying dosage levels of either Pasteurella or E. coli endotoxin.12 Kicking, leg flexing, stretching, bowing-stretches, looking at flank, hyperpnea, and dyspnea along with CNS depression progressing to comatosis were all included as signs used to describe the progression of behavior, which ranged from Level 1.0 to Level 6.0 of the endotoxic colic index. During efficacy studies, the assessment of the observations was accomplished via a blinded scorer. All of the calves, whether they possessed protective levels of anticore-antigen antibodies or not exhibited signs that approached Level 2.0 when they were scored. The unprotected animals developed sufficient clinical signs to progress through level 2.0 and higher, while those that were protected exhibited colic index score levels of less than 2.0.

Serum samples collected from each calf before and 4 weeks following the first injection of vaccine or placebo were analyzed for the present study by an ELISA assay adapted from a previously developed radioimmunoassay (RIA) for specific IgG(t) antiendotoxin antibody levels.17,18 The technician that analyzed the pre- and post-vaccination serum samples for anticore-antigen antibody levels was not aware of any animal’s category.

Data were analyzed via analysis of variance statistical techniques. The predetermined acceptable probability level was 0.05 or less.

 

Results

 

When challenged with endotoxin, calves vaccinated with the S. typhimurium bacterin-toxoid compared with those injected with the placebo were significantly (P < 0.05) different in terms of the mean endotoxin colic index scores reflecting colicky pain, dyspnea and somnolence, mean IgG(t) antibody levels, and anorexia time intervals (Tables 1 & 2; Figs. 1, 2, 3, & 4). The line 2.0 represents the previously established threshold that divided those with protective levels of anticore-antigen antibodies from those without.12 The mean endotoxin colic respiratory index scores of immunized vs. placebo-injected groups heterologously challenged with E. coli 055:B5 endotoxin were significantly (P < 0.001) different (Table 1; Figs. 1 & 2).

The differences between these groups (Table 2; Fig. 4) in terms of either mean IgG(t) antibody titers (P < 0.001) or mean anorexia time intervals (P < 0.05) were significant. Similarly, the mean endotoxin colic index scores of immunized vs. placebo-injected groups heterologously challenged with P. multocida endotoxin were significantly (P < 0.001) different (Table 1; Fig. 1). The differences between these groups in terms of either mean IgG(t) antibody tiers (P < 0.05) (Table 2; Figs. 3 & 4) or mean anorexia time intervals (P < 0.05) (Table 3) were also significant. In this study, 90% of the calves that received the vaccine exhibited a transient palpable 1-cm diameter swelling in the cervical musculature injection site 2 to 4 days postinjection, which was nonpalpable 2 weeks following injection. None required treatment or went off feed.

 

Discussion

 

The increase in serum IgG(t) antibody levels in the vaccinated calf groups apparently provided the active immunity responsible for protection against the outward clinical effects of the heterologous endotoxin challenges. It is interesting that these results confirmed the results of other laboratories when various species were vaccinated with similar gram-negative mutant bacterins and challenged with Heterologous endotoxins.9-11,19 It is also important to note that the protection provided by the antibodies produced in response to the core antigen of the Re-mutant S. typhimurium bacterin-toxoid cross-protected the calves from the heterologous E. coli 055:B5 endotoxin challenge as well as from the heterologous P. multocida endotoxin challenge.

The dialuminum trioxide adjuvant in this vaccine stimulated the localization of macrophages in the muscular tissue at the injection site. The macrophage-processed antigen then slowly leaked out of the localized macrophages providing a prolonged antigenic stimulus.20 Therefore, a local response was expected following injection of the vaccine and was indicative of a viable hose immunization. Dialuminum trioxide influenced the primary immune response and helped maintain the other two vaccine components in suspension.

The toxoid portion of the combination cross-protective vaccine stimulate the B-lymphocytes to divide and produce antibodies directed against the naked core determinant while the killed Re-mutant bacterial cells (bacterin) provided the naked core determinant to serve as antigen for antibody production.

Since conducting these efficacy studies, results of field study observations, including a rise in body temperature and/or generalized muscular soreness, were not detected in any calves or cows. In accordance with USDA recommendations, any animal that suffers an allergic response following vaccination should be treated immediately with epinephrine or its equivalent. No allergic responses were discerned during the efficacy and subsequent field studies.

 

Conclusion

 

The anticore-antigen antibody efficacy demonstrated in this study offers new possibilities for aiding in the control of end-stage consequences of such gram-negative diseases as E. coli sp. diarrhea, Salmonella sp. diarrhea, and Pasteurella sp. pneumonia. Because of the cross-protectiveness of the antibodies demonstrated in this study, it is suspected that cattle can also be protected from endotoxins arising from other gram-negative bacteria such as Klebsiella sp., Enterobacterieae sp. Proteus sp., and others. Application of this technology may add a new dimension to immunologic control of economically important gram-negative bovine diseases.

 

ACKNOWLEDGEMENTS

The authors extend their gratitude to Dorothy Brandon, Dan Hatfield, Joe Miramonti, Anne Sears, Kelly Lager, Bill Starke, Patsy McClenahan, and Carol Skinner for their expert technical assistance.

This study was funded in part by the University of Missouri College of Veterinary Medicine, School of Medicine, and IMMVAC, Inc., Columbia, Missouri.

 

REFERENCES

  1. Carter GK, Martens RJ: Septicemia in the Neonatal Foal. Comp Cont Ed Pract Vet 8:5256-5271, 1986.
  2. Sprouse RF, Garner HE, Green EM: Plasma Endotoxin Levels in Horses Subjected to Carbohydrate Induced Laminitis. Eq Vet J 19:25-28, 1987.
  3. McCarty DO, Kluger MJ, et al: The Role of Fever in Appetite Suppression After Endotoxic Administration. Am J Clin Nutr. 40:310-316, 1984.
  4. Moldawer LL, Georgiett M, Lanholm K: Interleukin 1, Tumor Necrosis Factor-alfa (Cachetin) and the Pathogenesis of Cancer Cachexia. Clin Phys 7:263-274, 1987.
  5. Movat HZ, Cybulsky MI, Golditz IG, et al: Acute Inflammation in Gram-Negative Infection: Endotoxins, Interleukin 1, Tumor Necrosis Factor and Neutrophils. Fed Proc 46:97-104, 1987.
  6. Hart BL: Animal Behavior and the Fever Response: Theoretical Considerations. J Am Vet Med Assoc 187:998-1001, 1985.
  7. Morris DD, Cullor JS, Whitlock RH: Endotoxemia in Horses: Protection Provided by Antiserum to Core Lipopolysaccharide. Am J Vet Res 47:544-550, 1986.
  8. McCabe WR, Kreger M, Johns MA: Type-Specific and Cross-Reaction Antibodies in Gram-Negative Bacteremia. New Engl J Med 287:262, 1972.
  9. Ng AK, Chan LH, Chang CM, et al: Relationship of Structure to Function in Bacterial Endotoxins: Serologically Cross-Reactive Components and Their Effect on Protection of Mice Against Some Gram-Negative Infections. J Gen Mic 94:107-116, 1976.
  10. Braude AI: Endotoxic Immunity. Adv Intern Med 26:427-445, 1980.
  11. Cullor JS, Fenwick BW, Williams MR, et al: Protection from Endotoxic Shock in Calves by Antibodies Against Common LPS Core Antigens Induced by Immunization with E. coli (J5). Conf Res Work (An Dis abstr) #48, 1984.
  12. Lager KL: Development and Application of Behavioral Indices for Evaluation of Equine and Bovine Responses to Low Level Endotoxin Challenges. Master’s Thesis, University of Missouri, 1989.
  13. Marget W, Mar PJ, Jaspers L, et al: Preliminary Study on Administration of High-Titer Lipid A Antibody Serum in Sepsis and Septic Shock Patients. Infection 13:120-124, 1985.
  14. Young LS, Stevens P, Ingram J: Functional Role of Antibody Against ‘Core’ Glycolipid of Enterobacteriaceae. J Clin Invest 56:850-861, 1975.
  15. Sprouse RF, Garner HE, Lager KS: Protection of Ponies from Heterologous and Homologous Endotoxin Challenges Via Salmonella Typhimurium Bacterin Toxoid. Eq Pract 11:34-40, 1988.
  16. Garner HE, Sprouse RF, Green EM: Active and Passive Immunization for Blockade of Endotoxemia. Am Assoc Eq Pract 31:525-532, 1985.
  17. Garner HE, Sprouse RF, Lager KS: Cross Protection of Ponies from Sublethal Escherichia Coli Endotoxemia by Salmonella Typhimurium Antiserum. Eq Pract 10(4):10-17, 1988.
  18. Reardon TP, Sprouse RF, Garner HE: Radioimmunoassay for the Detection of Antigen-Specific IgM, IgG, and IgA in Equine Sera. Am J Vet Res 43:294-298, 1982.
  19. Cullor JS, Spier SJ, Tyler JW, Smith BP: Antibodies that Recognize Gram-Negative Core Antigens: How Important Are They. Proc of ACVIM 1988, pp 503-508.
  20. Tizard, Ian: Veterinary Immunology: An Introduction. 3rd Ed. Philadelphia, WB Saunders Co., 1987.

 

TABLE 1
Comparison of Mean Endotoxin Respiratory Colic Index Scores and Serum IgG Antibody Titers of E. coli

Endotoxin-Challenged, Placebo-Treated, and Vaccinated Calves

 
Endotoxin-Challenged Calves
Parameter Placebo (control); N = 5 Vaccinate; N = 5
Mean Endotoxin Colic Respiratory Index Scorea
Mean 2.31 0.32c
SD ± 2.40 ± 0.64
SEM ± 1.20 ± 0.30
Range 0.60-3.6 0.0-1.0
Mean Serum IgG Titer (Log 2)b        
  Pre- Post- Pre- Post
Mean 8.60 9.00d 9.80 12.20c
SD ± 1.20 ± 1.55 ± 1.47 ± 1.17
SEM ± 0.60 ± 0.77 ± 0.74 ± 0.59
Range 8-11 8-12 8-11 11-14

a Endotoxin respiratory colic index scores were analyzed via three-factor analysis of variance with repeated measures on one factor.

b Serum IgG antibody measurements were analyzed via two-factor analysis of variance techniques with repeated measures on one factor.

c Mean value significantly (p < 0.05) different from control or pretreatment values.

d Mean value not significantly (p > 0.05) different from pretreatment values.

SE = Standard deviation; SEM = Standard error of the mean.

 

TABLE 2
Comparison of Mean Endotoxin Respiratory Colic Index Scores and Serum IgG Antibody Titers of Pasteurella

Endotoxin-Challenged, Placebo-Treated, and Vaccinated Calves

 
Endotoxin-Challenged Calves
Parameter Placebo (control); N = 7 Vaccinate; N = 7
Mean Endotoxin Colic Respiratory Index Scorea
Mean 2.35 0.64c
SD ± 2.26 ± 1.17
SEM ± 0.92 ± 0.48
Range 1.0-3.7 0.10-2.1
Mean Serum IgG Titer (Log2)b        
  Pre- Post- Pre- Post
Mean 9.29 9.71d 8.29 13.10c
SD ± 1.28 ± 1.03 ± 0.45 ± 1.36
SEM ± 0.52 ± 0.42 ± 0.18 ± 0.56
Range 8-11 8-11 8-9 11-15

a Endotoxin respiratory colic index scores were analyzed via three-factor analysis of variance with repeated measures on one factor.

b Serum IgG antibody measurements were analyzed via two-factor analysis of variance techniques with repeated measures on one factor.

c Mean value significantly (p < 0.05) different from control or pretreatment values.

d Mean value not significantly (p > 0.05) different from pretreatment values.

SE = Standard deviation; SEM = Standard error of the mean.

 

 

 

TABLE 3
Comparison of Combined Anorexia Time Intervals of E. coli and

Pasteurella Endotoxin-Challenged, Placebo-Treated, and Vaccinated Calves

 
Endotoxin-Challenged Calves
Parameter Placebo (control); N = 12 Vaccinate; N = 12
Mean Anorexia Time Interval (minutes)a
Mean 98.1 63.0b
SD ± 22.2 28.8
SEM ± 6.4 ± 8.31
Range 48-112 29-102

a Anorexia time interval measurements were analyzed via two-factor analysis of variance techniques with repeated measures on one factor.

b Mean value significantly (p < 0.05) different from control values.

SE = Standard deviation; SEM = Standard error of the mean.

Wildfire Revenue Donation Program

 

Purchase Endovac & Help The Cause

You may not have heard about it in the National Media, but Texas, Oklahoma, Kansas, & Colorado Ranchers have been devastated by Wildfires.  Thousands of cattle lost, more injured, forages destroyed, homes burned, & rancher lives lost.

We have seen many of our friends in the industry trucking hay, fencing supplies, and essentials to those in need.  We asked ourselves what we could do with our resources to help. While none of these affected producers are thinking about giving vaccines right now, many across the country are.  So, we are donating Endovac revenue the rest of March directly to organizations helping these ranchers.

Can I use Endovac in my Operation?

All Cattlemen who vaccinate can use Endovac in their protocols. Vaccinate with Endovac this year, save some money, & make a difference.  Plan on vaccinating in the next few months?  Purchase now to make sure your vaccine dollars help the cause. 

For questions on vaccine use and sourcing call: Jesse Brown (208)-559-8852

Where will the funds go?

We will make all our final donations public for our customer’s benefit.  Some of the organizations we plan to donate to include the Kansas Livestock Foundation, the Oklahoma Cattlemen’s Foundation, as well as several CO and TX organizations.  Have Suggestions, give Kourtney a call.

Can I donate funds in addition to purchasing Endovac?

 

 

 

 

 

The MORE Endovac Vaccine You Buy…the MORE financial aid we can give!

Now through the end of March, IMMVAC       (Makers of Endovac) is donating revenue from Endovac Sales to Cattlemen recovering from Wildfires.

 

Our Employee project Point Person:

Kourtney Neuharth

(TX, OK, & Southwest Rep)

Contact:

(480)-322-1583

kneuharth@immvac.com

Protecting the Calf by Vaccinating the Cow

A calf cannot produce its own antibodies for one to two months, so the passive immunity  a calf receives from a cow’s colostrum is critical to its health and development according to Vigortone. In order to be effective, the colostrum must be consumed by the calf as soon as possible and definitely within the first 24 hours.

Colostrum can be frozen and used at a later date without a loss of quality. However, it is important to follow necessary guidelines, found on the Beef Site, when collecting and storing the colostrum.

Vaccinations boost the antibodies in the cow, which in turn will affect the calf when it consumes colostrum. As always, follow proper handling and storage techniques of vaccines to ensure effectiveness and safety according to MSU.

Get Ready to Protect Against Pink Eye

As the warm and wet summer weather heats up you will find that fly season is in full force. Face flies are a major cause of pink eye as they carry the main causal virus of the condition, Moraxella bovis. South Dakota State University says the spring season, before an outbreak, is the best time to be thinking about fly season and pink eye.

According to Merck Animal Health, a three-pronged education and prevention plan is most effective against flies and pink eye. The plan includes the education and monitoring of fly control, vaccination, and environmental management. Because pink eye is extremely contagious, initial prevention methods are particularly important in reducing your herd’s susceptibility.

Studies:  ENDOVAC-Bovi® in Lactating Dairy in Cows

(Summer 2007 Horton Research Center, Oxford Mountain Dairy)
Dr. David Hutcheson, Animal Nutritionist and Bovine Consultant, Animal Agricultural Consulting, Inc., P.O. Box 50367, Amarillo, TX  79159

Objective

Evaluate the effects of four bacterins’ administration on daily milk production, dry matter intake and somatic cell counts.

Introduction

Mastitis occurs in 10% to 12% of all lactating cows in the United States, with 30% to 40% of mastitis cows have inflammation due to Escherichia coli. Mastitis costs U.S. dairy producers more than $1 billion annually. Diminished milk production, discarded milk, the need for replacement cows, the decreased sale value of cows, cost of drugs, veterinary services, and additional labor all contribute to the economic losses.

Endotoxemia results from the release of endotoxins through the death of Gram-negative bacteria, such as E. coli.  This occurs during phagocytosis by udder leukocytes or by the action of antimicrobials used in treatment. The clinical signs of coliform mastitis include serous secretion in the affected quarter or quarters, pyrexia, depression, anorexia, swelling and firmness of the affected quarter or quarters, ruminal hypomotility, muscle fasciculations, cold skin temperature, and diarrhea–all signs of endotoxemia.

Traditionally, treatment of coliform mastitis has been initiated only after the development of clinical illness. Therapy has been met with varying success.

The chief disadvantage of treatment initiated after clinical illness has developed is that the disease has frequently advanced to an irreversible state. Moreover, this treatment requires withholding the cow’s milk from market for days to weeks, depending on the type and amount of drug used to counter the infection. And even with successful treatment, only 20% of mastitis cows ever return to normal production; most are culled for agalactia. Also of recent concern is the development of drug-resistant salmonellae with the potential for entry into the food chain.

Two methods are currently available for decreasing the prevalence of coliform mastitis. First, better management of bedding and teat sanitation techniques decreases the exposure of teat ends to bacteria. Second, vaccination enhances the cow’s immunologic resistance to environmental bacteria.

Previously, vaccines were limited to three types: autogenous bacterial isolates expressing various specific antigens (K antigens or O-carbohydrate side chains), live vaccines composed of attenuated or deletion-modified bacteria, and polyvalent vaccines composed of the serotypes sometimes associated with mastitis.

Cross-protective vaccines have been manufactured using genetically engineered mutants such as the patented R/17 strain of Salmonella typhimurium and the J-5 strain of E. coli. A combination vaccine, ENDOVAC-Bovi® (IMMVAC), manufactured with the R/17 mutant and combined with an immune-potentiating adjuvant (IMMUNEPlus®), significantly reduces the devastating diseases caused by Gram-negative bacteria producing various endotoxins.

The use of ENDOVAC-Bovi® is the only core-antigen vaccine with a unique and effective immune stimulant. The patented IMMNEPlus® in combination with the mutant Re-17 bacterin protects against E. coli Mastitis and other endotoxin-mediated diseases caused by E. coli, Salmonella, Pasteurella multocida, and Pasteurella (mannheimia) hemolytica.

Procedures

Mature dairy cows at least 60 days in milk were indentified and allotted to 4 milking groups. The four groups were randomly allotted to the bacterins:

  1. ENDOVAC-Bovi®
  2. J-5
  3. J-Vac
  4. Negative Controls

Cows were randomly allotted to the treatment groups by the last 2 digits of the cows ear tags number. Three hundred and fourteen cows were allotted to four treatment groups of 80 (ENDOVAC-Bovi®), 78 (J-5), 79 (J-Vac) and 77 (Negative Control) cows per group. The cows were penned in separate pens by treatment groups. The cows were fed from 1 to 26 days with the same ration to all treatment groups.  The ration fed was the standard ration being fed at the dairy for milking cows. The treatments were administered on day 8 by manufactures label dose for all treatments. The treatments were administered as shown in Table 1.

Table 1 Treatments and Mode of Administration

Treatment Vaccine Administration
1 ENDOVAC-Bovi® 2cc (IM)
2 J-5 5cc (SC)
3 J-Vac 2cc (IM)
4 Negative Control None

 

Daily milk records and dry matter feed records were collected from each cow during the 26 day experimental period and somatic cell counts (SCC).

Results and Discussion

Table 2 shows the means and standard deviations for dry matter consumption by treatments and pre and post vaccination. There were no significant differences in dry matter consumption among the treatments either pre to or post vaccination.

Table 2. Dry matter consumption, Pre and Post Vaccination

Treatments ENDOVAC-Bovi® J-5 J-Vac Negative Control P value

Pre to Vaccination (7 days)

Mean 58.2 56.2 58.5 57.1 0.34
STD 2.8 1.9 3.4 1.8  
 

Post Vaccination (19 days)

Mean 59.3 59.3 60.1 58.5 0.50
STD 2.5 3.3 3.8 2.7  

Milk production was significantly higher for the cows to be administered J-5 and negative control pre test, Table 3. However no differences in milk production were detected after vaccination for any treatments.

Table 3. Milk Production, Pre and Post Vaccination.

Treatments ENDOVAC-Bovi® J-5 J-Vac Negative Control P value

Pre to Vaccination (7 days)

Mean 98.9b 101.2a 98.9b 100.5a 0.01
STD 1.7 1.3 1.2 1.0  
 

Post Vaccination (19 days)

Mean 99.6 100.6 99.9 100.1 0.62
STD 1.9 2.2 2.5 1.8  

Somatic Cell Counts were significantly higher for the group to be administered ENDOVAC-Bovi® than the J-Vac group pre vaccination. The J-5 was the lowest SCC but was not different from J-5 and Negative control pre vaccination. After vaccination the ENDOVAC-Bovi® group was significantly lower than other vaccination groups or negative control (Table 4).The ENDOVAC-Bovi® group proved to be the most effective control of mastitis as measured by SCC.

Table 4. Somatic Cell Counts (SCC), Pre and Post Vaccination.

Treatments ENDOVAC-Bovi® J-5 J-Vac Negative Control P value

Pre to Vaccination (7 days)

Mean 121.1a 94.9a,b 64.5b 89.4a,b 0.03
STD 48.3 41.4 10.4 9.2  
 

Post Vaccination (19 days)

Mean 81.8a 126.3b 118.7b 136.0b 0.01
STD 25.2 44.7 35.2 40.03  

Conclusions

  • ENDOVAC-Bovi® significantly lower somatic cell counts thereby decreasing mastitis in lactating dairy cow.
  • ENDOVAC-Bovi® had no effect on milk production in lactating dairy cows.
  • ENDOVAC-Bovi® had no effect on dry matter intake in the lactating dairy cow.

Studies:  ENDOVAC-BEEF® in Feedlot Beef Steers

Dr. David Hutcheson, Animal Nutritionist and Bovine Consultant, Animal Agricultural Consulting, Inc., P.O. Box 50367, Amarillo, TX 79159

(The 2007-2008 trials were conducted at the Knight Feedlot, Inc., 1768 Ave. J, Lyons, KS 67554)

Objective

To evaluate the effects of ENDOVAC-Beef® bacterin-toxoid (manufactured by IMMVAC INCORPORATED, 6080 Bass Lane, Columbia, Missouri 65201) administration to feedlot steers on feedlot performance and carcass quality.

Introduction

Gram-negative endotoxemia contributes to the signs associated with diarrheal septicemias, and pneumonias in cattle. The classic signs of endotoxemia are depression of the central nervous system, hypernea, dyspnea, anorexia, pyrexia, and leukopenia followed by leukocytosis; recent studies have confirmed that these signs are consistent in response to sub lethal doses of endotoxins.

So a logical approach to formulating an efficacious vaccine would be to use a single vaccine that induces the immune system to produce antibodies that cross- protect against Gram-negative bacteria and their endotoxins. Specific R-mutants of Salmonella and E. coli , although generally poor quality antigens per se, have been found to provide such cross-protection against septicemias from various Gram-negative infections. The antibodies produced by these mutant bacterin vaccines have provided cross-protection to cows, either naturally challenged or arbitrarily challenged in the laboratory. This is especially true when the mutant bacterin is coupled with an effective immune-stimulant such as IMMUNEPlus® incorporated in ENDOVAC-Beef®, that enhances the level of antibodies produced in the host.

An enzyme-linked immunosorbent assay (ELISA) of sera from control and vaccinated calves showed that antibodies produced in response to ENDOVAC-Beef®, a mutant Salmonella typhimurium bacterin-toxoid significantly attenuated the clinical responses to Escherichia coli, Pasteurella multocida, and Mannheimia (formerly Pasteurella) hemolytica endotoxins (Agri. Practice 11:29-34, 1990; Agri. Practice 12:1-4, 1991).

Many clinically evident endotoxemias are associated with Gram-negative septicemias arising from E. coli and Salmonella diarrheas; and/or Pasteurella multocida and Mannheimia hemolytica pneumonias. Veterinarians and Nutritionists have suspected for years that sub-clinical endotoxemia in beef cattle in feedlots on high carbohydrate rations have elevated endotoxins in their blood which somehow hamper maximal feed conversion and optimal weight gain.

Procedures

Two field trials were conducted with steers from the same source each year. In 2007, there were 300 steers used in 2 pens for the trial and in 2008 there were 128 steers used in the trial. Each year the steers were allotted to two groups, either those vaccinated with two doses of ENDOVAC-Beef® (1-2mL dose at conditioning, and a 2nd -2mL dose on entering the feedlot), or those that did not receive ENDOVAC-Beef® (non-vaccinated). The steers were co-mingled both in the conditioning and feedlot phases of both trials, and fed standard feedlot rations for the duration of the trial. In 2008 carcass data was also collected. Data was collected at the end of each feeding period by pens. Performance and carcass data was analyzed by Analysis of Variance techniques. Performance data was analyzed by pens. Carcass data was analyzed by individual carcasses. Chi Square analysis was used to analyze carcass count data.

Results and Discussion

Data was pooled for the performance data over two years. Table 1 shows the individual years and the pooled means for the field trial.

Table 1 Performance Data 2007-2008

Year Number Days On Feed Weight In, Pounds Weight Out Pounds Dry Matter Intake Average Daily Gain Feed to Gain

Vaccinates

             
2007 147 97 789 1293 26.9 5.19 5.19
2008 91 164 660 1435 24.3 4.38 5.54
Means 119 130 724 1364 25.4 4.76 5.36

Non Vaccinates

             
2007 153 97 741 1107 22.6 3.77 5.98
2008 37 164 660 1335 24.6 4.11 5.98
Means 95 130 700 1221 23.6 3.84 5.98

Summary

             
Vaccinates 119 130 724 1364 25.4 4.76 5.36
Non Vaccinates 95 130 700 1221 23.6 3.84 5.98
P Value     0.78 0.40 0.40 0.21 0.07

Cattle administer ENDOVAC-Beef® had the best feed to gain ratio (5.36 pounds of dry matter feed per pound of gain) and is significantly different at P =0.07 than the non-vaccinates (5.98). The ENDOVAC-Beef® vaccinates average daily gain was higher (4.76 lbs per day) compared to non- vaccinates (3.84 lbs per day), P=0.21.

Table 2 shows carcass data for the cattle fed in2008.
(Carcass Data for 2008 Trial)

Item Vaccinate Mean Non Vaccinate Mean P Value
Number 90 126  
Stun Weight 1409 1324 0.001
Carcass Weight 915 861 0.001
Dressing Percent 64.9 % 65.1% 0.49
Fat Thickness 0.54 0.52 0.38
Ribeye Square Inches 14.5 13.9 0.005
Yield Grade 3.33 3.26 0.42
  Chi Square analysis    
Prime 3 (3.33%) 8 (6.35%) 0.32
Mid Choice Plus 40 (44.44%) 71 (56.35%) 0.08
Choice 35 (38.89 %) 38 (30.16%) 0.18
       
Choice and Prime 78 (86.67 %) 117 (92.86%) 0.13
       
Select 10 (11.11%) 9 (7.14%) 0.31
Standard 2 (2.22%) 0 (0.00%) 0.09

The carcass weight were significantly (P= 0.001) higher for ENDOVAC-Beef® vaccinates by 54 pounds. The ribeye area was significantly larger for ENDOVAC-Beef® vaccinated cattle by 0.6 square inches. The increase in ribeye area may have been due to the significant higher carcass weight for ENDOVAC-Beef® vaccinated cattle.

Conclusions

1. ENDOVAC-Beef® improves feed to gain ratio in finishing steers
2. ENDOVAC-Beef® improves average daily gains in finishing steers
3. ENDOVAC-Beef® vaccinated steers showed increased carcass weights
4. ENDOVAC-Beef® suppressed endotoxemias and improved overall performance

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