Category: Beef Case Studies

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)


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.


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.


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


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


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.


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

Data:  University of Missouri Grow Safe Application Dr. Kerley

60 crossbred Angus steers were placed on an 84 day trial to determine influence of ENDOVAC-Beef ® with Immune Plus ® on steer performance.  Intake results from Growsafe ® feed system.


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Studies:  Field Experience With Cross-Protective Anti-Endotoxin Antiserum in Neonatal Calves


Seventeen neonatal calves comprised the ill group for Phase 1 of this study. Phase 2 was comprised of 246 head of normal neonatal calves. Twelve of the 17 ill calves received 0.8 to 1.0 ml/lb of antiserum for treatment of gram-negative diarrhea; 8 of the 12 calves received antibiotics, oral electrolytes, and anti-diarrheal treatment in addition to the antiserum; 3 of the 12 calves received antiserum only; and 1 of the 12 calves received antiserum plus oral electrolyte therapy without concomitant antibiotic therapy.
The death rate in the antiserum-treated calves was significantly (P < 0.025) lower than in the non-antiserum-treated group. No deaths subsequently occurred in the healthy, Phase 2 neonatal calves administered 0.7 ml/lb of antiserum as a precautionary measure.



Field Experience With Cross-Protective Anti-Endotoxin Antiserum in Neonatal Calves

Leroy E. Ensley, DVM
Steve M. Ensley, DVM

2nd and Prospect
Onaga, Kansas 66521


Neonatal calves suffering from the consequences of gram-negative diarrhea have historically been treated with antimicrobials, electrolytes, and other support modes of therapy. Results of such established therapies are often frustrating because they do not neutralize the precise problem. Recent studies have confirmed that endotoxins from various sources such as Salmonella sp. and Escherichia coli may cause death in calves exhibiting the signs of diarrhea.1,2 The common denominator of all gram negative bacteria is the core lipopolysaccharide cell wall structure (endotoxin). This portion of the gram-negative cell wall is also referred to as the common-core-antigen.3
Historically, homologous antiserums produced in response to gram-negative bacterins made from organisms with complete “O” side chains have been effective in blocking specific endotoxins. These homologous antiserums have not provided cross-protective antibodies because they have contained antibodies against only one serotype. Provision of broad-spectrum protection would have required the combination of many homologous antiserums. Obviously, it would have been advantageous if a given antiserum could provide cross-protection against several gram-negative endotoxins. Therefore, the search for cross-protective immune strategies that could be used to actively immunize, treat, or passively immunize individuals against several pathogenic endotoxins is important.
The mutated Salmonella typhimurium (R17) along with the addition of an immune stimulant, toxoid (E3), has resulted in the development of a cross-protective antiserum and vaccine that are now available to veterinarians.4,5 Removal of the “O” side chains, which give the many gram-negative organisms their individual characteristics (serotype), was accomplished through mutation exposing the core-antigen of the cell wall. This core-antigen stimulates the host’s immune system to produce antibodies against it thereby providing cross-protective immunity against many of the gram-negative endotoxins.
Classification of the “O” side chains to describe the relative absence of oligosaccharides was accomplished by assigning the letters Ra through Re, with Re designating complete removal. The S. typhimurium used in the study reported here is an Re mutant (“O” side chains completely removed), while the J-5 mutant of E. coli, also cited in this report, is an Rc mutant (“O” side chains partially removed).3,5A vaccine containing such mutant bacterins used to hyperimmunize donor animals produces serum or plasma containing high levels of anti-endotoxin antibodies. These antibodies passively immunize the recipient against many gram-negative endotoxins.
Laboratory-derived evidence that antiserum provides cross-protective, passive immunity against several gram-negative bacterial endotoxins in calves1 and horses4 has recently been reported. The results of these studies suggest that calves passively immunized with plasma derived from hyperimmunized donors vaccinated with mutant gram-negative bacterins were cross-protected from various endotoxin challenges.1 Equids passively immunized with anti-core-antigen antibody antiserum and challenged under experimental conditions with a specific dose of heterologous endotoxin were also protected.4
The commercially available antiserum (Endoserum®: IMMVAC, Inc., Columbia, MO) is harvested from donor horses hyperimmunized with a mutant S. typhimurium bacterin-toxoid [Endovac-Equi®: IMMVAC, Inc.] and contains USDA standardized levels of anti-endotoxin and total IgG antibodies. Endoserum has been successfully used to treat and prevent endotoxemia in foals and horses for more than 2 years. However the effectiveness of passively immunizing calves using a mutant S. typhimurium antiserum as the source of cross-protective, anti-endotoxin antibodies has not been definitively confirmed under field conditions.
The purposes of reporting the results of this field study are:

  • To describe the results of using the cross-protective antiserum, equine origin, in neonatal calves exhibiting the signs of E. coli diarrhea/septicemia from one dairy and one beef herd; and
  • To show the results of prophylactically administering antiserum to newborn dairy and beef calves to prevent E. coli diarrhea/septicemia.

Materials and Methods


The animals in Phase 1 of the study consisted of 17 head of ill neonatal calves (3 male and 6 female cross-bred calves weighing from 70-90 lbs, and 1 male and 7 Jersey calves weighing from 35-55 lbs). In Phase 2 of the study, 248 head of normal neonatal calves were studied. The group consisted of 167 cross-bred beef and 79 Jersey calves.


All the fecal samples collected from four ill beef and three ill Jersey calves in Phase 1 of the study tested positive for E. coli (K-99 Test Kit®: Synbiotics Corp., San Diego). All 17 of the ill calves exhibited signs of diarrhea, varying degrees of central nervous system depression, and dehydration.


In Phase 1 of the study, 12 of the 17 ill calves were subcutaneously administered 0.8 to 1.0 ml/lb (1.75-2.2 ml/kg) of antiserum (Endoserum). Eight calves received antibiotics (Gentocin®: Schering-Plough Animal Health, Kenilworth, NJ; Naxcel®: The Upjohn Co., Animal Health Division, Kalamazoo, MI); oral electrolytes (Life-Guard®: Smith-Kline Beecham Animal Health, Exton, PA); and/or intravenous-administered electrolytes, and antidiarrhea (Deliver™: Haver/Diamond Scientific, Animal Health Division, Shawnee, KS) treatment in addition to the antiserum. Three of the calves received antiserum only, while one received antiserum, oral electrolyte therapy, and no antidiarrheal treatment. Five ill calves were treated with antibiotics, oral fluids, and antidiarrheal compounds without receiving antiserum.
In Phase 2 of the study, 246 neonatal calves received 0.7 ml/lb of antiserum at birth.


Either gentamicin (Gentocin) or ceftioufur sodium (Naxcel) was the antibiotic used for treating the calves, either concurrently with antiserum therapy or upon exhibition of signs of diarrhea following prophylactic administration of antiserum.


Life-Guard, lactated Ringer’s solution, and Deliver were used to treat dehydration and diarrhea.


Data from Phase 1 of the study were submitted to Chi-square analysis utilizing Fischer’s exact test with the predetermined probability level of 0.05 or less used for determining significant differences.


In Phase 1, the death rate in the non-antiserum-treated group was significantly (P < 0.025) higher that in the antiserum-treated group. Three (60%) of the five non-antiserum-treated calves died while none (0%) of the 12 antiserum-treated calves succumbed. Four of the acutely ill neonatal beef calves received antiserum and electrolyte therapy without antibiotics and survived.

In Phase 2 of the study, 167 cross-bred beef calves and 79 Jersey calves from the same two herds involved in Phase 1 were subsequently prophylactically administered 0.7 ml/lb of antiserum at birth. No deaths occurred in either the beef or dairy neonates that received antiserum. A few of the calves developed signs of diarrhea at various times following the prophylactic administration of the antiserum but responded quickly to routine antibiotic (Gentocin, Naxcel) therapy.
The results of both phases of the study are further illustrated in Table 1.

TABLE 1 Comparison of Escherichia coli Neonatal Calf Study Treatment Groups a

[wpcol_1half id=”” class=”” style=””]Treatment Group
[/wpcol_1half][wpcol_1quarter id=”” class=”” style=””]Survived
[/wpcol_1quarter][wpcol_1quarter_end id=”” class=”” style=””]Died
[wpcol_1half id=”” class=”” style=””]Ill Calves (Phase 1)
[/wpcol_1half][wpcol_1quarter id=”” class=”” style=””] 
[/wpcol_1quarter][wpcol_1quarter_end id=”” class=”” style=””] 
[wpcol_1half id=”” class=”” style=””]No antiserum given
[/wpcol_1half][wpcol_1quarter id=”” class=”” style=””]2
[/wpcol_1quarter][wpcol_1quarter_end id=”” class=”” style=””]3
[wpcol_1half id=”” class=”” style=””]0.8-1.0 ml/lb body weight antiserum b
[/wpcol_1half][wpcol_1quarter id=”” class=”” style=””]12
[/wpcol_1quarter][wpcol_1quarter_end id=”” class=”” style=””]0
[wpcol_1half id=”” class=”” style=””]Healthy Calves (Phase 2)
[/wpcol_1half][wpcol_1quarter id=”” class=”” style=””] 
[/wpcol_1quarter][wpcol_1quarter_end id=”” class=”” style=””] 
[wpcol_1half id=”” class=”” style=””]0.7 ml/lb body weight antiserum b
[/wpcol_1half][wpcol_1quarter id=”” class=”” style=””]246
[/wpcol_1quarter][wpcol_1quarter_end id=”” class=”” style=””]0
a Chi square probability = P < 0.025
b Endoserum®: IMMVAC, Inc., Columbia, MO


The endemic colibacillosis diarrhea problems in one beef and one dairy herd were apparently brought under control with anti-endotoxin antiserum treatment. Calves with feces testing positive for pathogenic E. coli (K-99) organisms and exhibiting signs of septicemia/endotoxemia responded positively to antiserum treatment, and their subsequently calved herdmates were prevented from developing serious colibacillosis diarrhea by administration of antiserum at birth.
Neonatal calves that received antiserum prophylactically and later developed clinical signs of diarrhea responded quickly to antibiotic therapy and required very little supportive therapy. These observations suggest that E. coli endotoxins were blocked by the anti-core-antigen antibodies contained in the antiserum.
The use of antiserum as a source of cross-protective anti-endotoxin antibodies is important from the aspect that a definitive gram-negative serotype diagnosis is not required and if there are several gram-negative organisms producing endotoxins, they can be neutralized with one product. As far as the safety of equine antiserum administered to calves was concerned, there were no allergic responses observed in any of the calves. Anaphylactic shock would not be expected if repeat administrations were accomplished within 7 or 8 days following the initial administration.6 A second dose should not be administered after 7 days because the chances for anaphylactic shock will have greatly increased.6 If an allergic response occurs, administration of antiserum should be immediately ceased and epinephrine along with other modes of supportive therapy initiated.
The minimum dosage administered for treatment and control of E. coli septicemia/endotoxemia in these two groups of neonatal calves was 0.7 ml/lb. This dosage level is consistent with previously published recommendations for administering antiserum for the purposes of attenuating the clinical signs exhibited by equids challenged with a specific dose of E. coli endotoxin. Repeat administration is indicated if the ill individual does not respond or experiences a relapse of clinical signs.
In summary, the successful prevention and treatment of endemic E. coli diarrhea problems in newborn calves from two cattle herds suggested that antiserum could be used to control colibacillosis diarrhea/septicemia in other herds. Because the antiserum is cross-protective, it also suggests that the antiserum may be effective in the medical management of the devastating effects of neonatal diarrhea due to gram-negative endotoxins from various sources.


1. Cullor JS, Fenwick BW, Smith BP, et al: Decreased Mortality and Severity of Infection from Salmonellosis in Calves Immunized with E. coli (Strain J5) (Abstr No. 352). Chicago, Proceedings of the 66th Annual Conference of Research Workers in Animal Disease, 1985.
2. Sprouse RF, Garner HE, Lager K: Cross-protection of Calves From E. coli and P. multocida Endotoxin Challenges Via Salmonella typhimurium Mutant Bacterin-toxoid. Agri Pract 11:29-37, 1990.
3. Tyler JW, Cullor JS, Spier SJ: Immunity Targeting Common Core Antigens of Gram-negative Bacteria. J Vet Int Med 4:17-25, 1990.
4. Garner HE, Sprouse RF, Lager K: Cross-protection of Ponies From Sublethal E. coli Endotoxemia by Salmonella typhimurium Antiserum. Eq Pract 10:10-17, 1988.
5. Sprouse RF, Garner HE, Lager K: Protection of Ponies From Heterologous and Homologous Endotoxin Challenges Via Salmonella typhimurium Bacterin-toxoid. Eq Pract 11:45-49, 1989.
6. Tizard I: Veterinary Immunology, ed. 3. Philadelphia, WB Saunders Co, 1987, p. 4.

Studies:  Gram-Negative Bacterial Protection in Beef and Dairy Production Systems

New Vaccine Technology Provides Cross-Protection With Immune Enhancement.

David F. Calabotta, Ph.D. and Thomas J. Worthington, DVM


In today’s intensive beef and dairy production systems, one must recognize and address the potential negative impact of management practices which stress the animal. These stresses can predispose animals to gram-negative, opportunistic challenges resulting in severe losses in performance, morbidity and death. Housing animals under close quarters, extreme climatic conditions, abrupt nutritional changes, feed toxins, and other typical stresses associated with shipping of animals to the feedlot, can all result in a predisposition to opportunistic diseases. In the intensive dairy system, high producing cows may be more susceptible to gram-negative associated mastitis and/or salmonella and E.Coli infections. Opportunistic diseases may also be initially manifested as viral challenges. In the majority of these viral disease situations, the establishment of secondary gram negative infections and associated endotoxemias may result in reduced performance and death.

New Technology Provides Economically Viable Options For Gram-Negative Cross-Protection:

To prevent the above described disease conditions, the producer has in the past relied upon vaccination programs to protect against viral and bacterial infections and the use of antibiotic programs to ward off and/or eliminate bacterial insults already established. However, to effectively protect against all viral and bacterial challenges and the many thousands of different bacterial serotypes, one would have to literally administer thousands of vaccinations and utilize a very intensive antibiotic program. Even under the above described intensive health management practices, complete protection would not be assured due to a myrad of bacterial culprits and constantly mutating serotypes. However, new technology has been recently invented and developed which may in fact provide complete protection from the typical gram negative secondary bacterial infections associated with viral disease development while stimulating the overall protection fighting capacity of the animal’s immune system.

The concept involves the development of a proprietary, recombinantly produced Re-17 mutant bacterin coupled with an immune stimulation system comprised of an antitoxoid antigen. This vaccine cocktail stimulates and jump starts the animal’s immune system such that both humoral (antibody production) and cellurlar (cellular killing) immunity may be successfully achieved, while cross protecting the animal against essentially all gram negative diseases.

The production of the Re-17 mutant bacterin involves the removal of the bacteria’s oligosacharride side chains which results in the production of a bacteria with a naked outer core. (Figure 1.)

In a non-mutant bacteria, the antigenic response is normally targeted specifically at the O-side chains, and while this process results in specific protection, the protection is only limited to a specific bacterial serotype. By producing a mutant bacterin devoid of the O-side chains, scientists at IMMVAC, Incorporated, in conjunction with scientists at the University Of Missouri School of Human Medicine and The School Of Veterinary Medicine, have succeeded in removing those antigenic sites responsible for a specific antibody production. The result is a bacterin which contains a naked core (cell wall) which is common to all gram negative bacteria and their many thousands of serotypes. The antigenicity of this recombinantly produced bacterin is now focused upon sites within the naked core which results in the bacterin stimulating universal cross-protection against essentially all gram negative bacteria and their serotypes. In addition, by combining an immune stimulation component to the system, the animal’s immune system is enhanced and more efficient in providing both humoral and cellular immunity. Finally, since the system is comprised of an inactivated or killed vaccine, the herd veterinarian may administer herd health antibiotic programs, without compromising immunity development to the vaccine. Thus, maximum herd health management flexibility is achieved.

Scientific Evaluations Confirm Both Physiological Potency and Practical Effectiveness Of ENDOVAC-Bovi® With IMMUNE Plus:

Figure 2. depicts the effectiveness of this novel vaccination system, particularly the E3 immune system enhancing component in stimulating the overall immune response.

Insert Figure 2

Peripheral circulation of both B and T lymphocytes are enhanced with the bacterin plus anti-toxoid (E3 stimulation is administered). As predicted, antibody production is also increased (Figure 3).

Insert Figure 3

Using this novel vaccination system, a producer can achieve herd health protection as never before, while delivering significant profits to his bottomline. In controlled field studies1 conducted at a major beef feedlot in the southwestern United States, 351 beef steers receiving ENDOVAC-Bovi were compared to a similar control group receiving their normal vaccination and herd health management schedule. (Figure 4.)

Insert Figure 4

summarizes the results of the study. Total weight gain of the vaccinates was increased by 5183 lbs, although this was not statistically significant. In addition, morbidity in the herd was significantly reduced as evidenced by a significant reduction in 1st and 2nd pulled calves requiring treatment. Of the five respiratory deaths that occurred due to bovine respiratory disease complex (BRDC), only one was a vaccinate animal. When the producer evaluated the cost of the herd health program associated with sick calves and pulled calves, it was concluded that herd health costs were significantly reduced in steers receiving ENDOVAC-Bovi compared to the control group receiving their normal vaccination program and herd health management program. Total cost improvement was $12.50/head in those animals who received ENDOVAC-Bovi. These results were confirmed by Kennedy2, 1995 (Figure 5).

Insert Figure 5

He concluded that the Re-17 mutant Salmonella typhimurium bacterin toxoid significantly decreased the respiratory disease morbidity and severity in vaccinated steers. Also, fewer deaths occurred (p = 0.11), fewer first and second pulls requiring medical treatment (p<0.005) and overall herd health costs were reduced (p<0.005) in the vaccinated group.

In studies conducted in dairy cows3, significant reduction in mastitis was observed in those cows who received ENDOVAC-Bovi. In addition recurrence of mastitis in specific cows who had previously suffered a bout of mastitis was significantly reduced in those animals who had received ENDOVAC-Bovi.

In calves headed for the feedlot and/or replacement heifers4, those animals who received an early vaccination with ENDOVAC-Bovi, had significantly fewer bouts with gram-negative associated bacterial challenges and were overall healthier as evidenced by improved performance and a significant reduction in mortality and morbidity. In addition, significant reductions in herd health management costs were noted.

Recommended Vaccination Schedules:

Beef Cows, Dairy Cows & Their Calves:

For maximum, efficient protection, it is recommended that all beef cows be vaccinated 7-10 days prior to shipping to a feedlot with a 2 ml dose of ENDOVAC-Bovi. If logistics permit, a booster 10-14 days following the first injection is advised, however very good results and herd protection have been achieved with only one vaccination. Your herd veterinarian should be consulted to assist you in determining the best course of action.

In pregnant cows (beef or dairy), it is recommended that the dam be vaccinated with a 2 ml dose of ENDOVAC-Bovi 4 weeks prior to parturition with a 2 ml booster dose being administered one week prior to parturition. This practice will provide maximum immunity to the dam while providing significant passive immunity to the new-born calf. In the case of the dairy cow, significantly less mastitis will result.

The calf should be vaccinated with the following vaccination program4

* Day 1: 1 ml injection IM*
* Day 4: 1 ml injection IM*
* Day 10: 1 ml injection IM*

An additional injection is suggested to provide protection against Pasteurella moltocida and hemolytica:

* 3-5 weeks: 2 ml injection IM*


Summary and Conclusions:

In today’s intensive beef and dairy production systems, the use of a new, proprietary, universal, cross-protective vaccine, effective against all gram negative bacteria may significantly protect the beef cow from secondary gram-negative challenges associated with environmental stress conditions and/or viral disease situations. When used as directed, the producer can save significant dollars by significantly reducing performance and mortality associated losses resulting from the above described disease challenges. In dairy animals, significant reduction in gram-negative associated diseases, including mastitis related challenges have been demonstrated when animals are properly vaccinated with ENDOVAC-Bovi. When used as directed by the manufacturer, the beef or dairy producer can achieve maximum health protection in their cows, calves and feedlot cattle while saving significant dollars on herd health costs and increasing profits through performance improvements derived from this vaccination system.

About the Authors:

Dr. Thomas J. Worthington is a doctor of veterinary medicine and owner and president of Chino Corona Veterinary Services, a consultant group serving the beef and dairy cattle industry in the western United States. Dr. David F. Calabotta has a Ph.D. in animal science and is the owner and president of Anitech, Inc., a business development firm specializing in the late stage commercial development of emerging, proprietary animal technologies.

References Cited:

1. Oliphant, R. 1994. Effect Of Re-17 Mutant Salmonella typhimurium Bacterin Toxoid on Respiratory Disease and Production. Agri-Practice, 15 (4): April.
2. Kennedy, J.A. 1995. The Effects of Re-17 Mutant Salmonella typhimurium Bacterin Toxoid on Bovine Respiratory Disease in Feedlot Heifers. Agri-Practice, 16(3).
3. McClure, A.M.; E.E. Christopher, W.A. Wolff, W.H. Fales, G.F. Krause, and J. Miramont. 1994. Effect of Re-17 Mutant Salmonella typhimurium Bacterin Toxoid on Clinical Coliform Mastitis. J. Dairy Sci 77:2272-2280.
4. Worthington, Thomas J. 1996. The Rationale Of Mass Treatment Of Gram-Negative Scours In Large Calf Ranches. American Association of Bovine Practitioners 29th Annual Conference: September 12-14; San Diego, California.