Exploratory cohort study to determine if dry cow vaccination with a Salmonella Newport bacterin can protect dairy calves against oral Salmonella challenge.

Abstract

BACKGROUND:

Salmonellosis is a major cause of morbidity and mortality in neonatal calves, often occurring before preventative vaccines can be administered.

HYPOTHESIS/OBJECTIVE:

To evaluate the protective effect on calves of colostrum from cows vaccinated with a commercially available Salmonella Newport bacterin against a Salmonella Typhimurium challenge.

ANIMALS:

Twenty Holstein bull calves from a university dairy farm.

METHODS:

Nonrandomized placebo-controlled trial in which colostrum was harvested from 30 cows that received 2 doses of either Salmonella bacterin or saline before calving. Colostrum collected from each group was pooled and fed to 2 groups of 10 calves at birth. At approximately 2 weeks of age, calves were challenged with Salmonella Typhimurium. Clinical, hematologic, microbiological, and postmortem findings were compared between the 2 groups.

RESULTS:

No differences in mortality, clinical findings, hematology results, blood and fecal cultures, or necropsy findings between the 2 groups were observed. Vaccinated cows had higher colostral titers, and calves fed this colostrum had higher serum titers (mean difference, 0.429; mean [SE], 0.852 [0.02] for vaccinated versus 0.423 [0.02] for control calves).

CONCLUSIONS AND CLINICAL IMPORTANCE:

Transfer of colostral immunoglobulins from Salmonella enterica serotype Newport bacterin to neonatal calves was not sufficient to decrease mortality, clinical signs, sepsis, intestinal damage, or fecal shedding when exposed to a highly pathogenic Salmonella isolate. A large-scale randomized controlled clinical trial is needed to evaluate the efficacy of this bacterin when administered in the dry period for prevention of salmonellosis in neonatal calves.

• Authors: Derek Foster, Megan Jacob, Devorah Stowe, Geof Smith
• Journal: Journal of veterinary internal medicine (J Vet Intern Med) Vol. 33 Issue 4 Pg. 1796-1806 (Jul 2019) ISSN: 1939-1676 [Electronic] United States
• PMID: 31134697 (Publication Type: Clinical Trial, Veterinary, Journal Article)
• Copyright: © 2019 The Authors. Journal of Veterinary Internal Medicine published by Wiley Periodicals, Inc. on behalf of the American College of Veterinary Internal Medicine.

Chemical References

• Bacterial Vaccines
• Salmonella Vaccines

Topics

• Animals
• Animals, Newborn (immunology)
• Bacterial Vaccines (administration & dosage)
• Cattle
• Cattle Diseases (immunology, microbiology, prevention & control)
• Cohort Studies
• Colostrum
• Female
• Immunity, Maternally-Acquired
• Male
• Salmonella Infections, Animal (immunology, prevention & control)
• Salmonella Vaccines (administration & dosage)
• Salmonella enterica (immunology)
• Salmonella typhimurium (physiology)
• Vaccination (veterinary)