Bovine respiratory disease (BRD) is a major animal health problem in feedlot cattle. Presently, BRD makes up about 65 to 80 per cent of feedlot diseases and 45 to 75 per cent of deaths in many lots. The financial toll of BRD on North America’s cattle industry is more than $1 billion per year.
Previously, the most common vaccines used to control the occurrence of BRD were administered either subcutaneously or intramuscularly. In a recent study, Dr. Philip Griebel, from the University of Saskatchewan, developed an effective vaccination strategy that begins early in the life of a calf and provides effective immunity against BRD before the cattle enter the feedlot.
During his research, he assessed the efficacy of both intranasal (nasal spray) and intramuscular (injected) routes using several commonly used commercial vaccines administered at branding and at weaning. The results showed that an intranasal vaccination at branding and weaning resulted in better protection from BRD compared to the same vaccine administered intramuscularly.
“The project data clearly shows that the intranasal vaccination at branding led to persisting immunity until calves were six to seven months old,” said Griebel in a release from the Alberta Livestock and Meat Agency that supported this research. A second intranasal vaccination at weaning resulted in complete protection against BRD. Meanwhile, the intramuscular vaccination at weaning did not prevent the disease.
The key is in circumventing the maternal antibodies present in calves. These antibodies, present in the animal’s blood, neutralize the intramuscular vaccines and reduce the animal’s immunity during booster follow-ups. However, the antibodies in the nasal cavity are cleared from calves within three to five days after birth, allowing the intranasal route to work more effectively.
Dr. Susan Novak, ALMA’s executive director, strategic initiatives says the use of intranasal route to administer vaccines at branding and weaning could reduce antibiotic usage at the feedlot and potentially reduce the cost of antibiotics to the cattle industry.
For more details contact Dr. Griebel at [email protected].