Successful treatment of suckling Red Angus calves for bovine respiratory disease is not associated with increased mean pulmonary arterial pressures at weaning

• Published in: Journal of animal science Vol. 96; no. 8; pp. 3070 - 3076
• Main Authors: Neary, Joseph M, Church, Dee, Reeves, Nathan, Rathmann, Ryan J
• Format: Journal Article
• Language: English
• Published: US Oxford University Press 01-08-2018
• Subjects: Altitude; Animal diseases; Animal Health and Well Being; Animals; Arterial Pressure; Blood pressure; Body Weight; Calves; Cattle; Cattle Diseases - prevention & control; Cattle Diseases - virology; Cell number; Congestive heart failure; Female; Fibrinogen; Heart; Heart Failure - etiology; Heart Failure - veterinary; Hypertension; Hypertension, Pulmonary - etiology; Hypertension, Pulmonary - veterinary; Inflammation; Inflammation - veterinary; Leukocytes; Lung - virology; Male; Medical treatment; Mercury; Monocytes; Respiratory diseases; Respiratory Tract Diseases - prevention & control; Respiratory Tract Diseases - veterinary; Respiratory Tract Diseases - virology; Suckling behavior; Vaccination - veterinary; Weaning; Weight; heart failure; leukocytes; inflammation; calf; respiratory disease; pulmonary arterial pressure
• ISSN: 0021-8812; 1525-3163
• DOI: 10.1093/jas/sky189

Abstract
The purposes of this study were to determine if the successful treatment of bovine respiratory disease (BRD) in suckling calves was associated with a long-term increase in mean pulmonary arterial pressure (mPAP) and, to screen for associations between blood leukogram variables and mPAP. A cohort of Red Angus calves (n = 74) were followed from birth to weaning at an altitude of 975 m. Calves were weaned at 172 ± 14 d when their mPAP was measured and whole blood collected. Thirty calves that had been treated for BRD (34 to 45 d prior) and 30 calves that had not required treatment for BRD were sampled. Treatment for BRD had no effect on mPAP (P = 0.37). Mean mPAP was 48 ± 8 mm Hg (± SD) with a minimum of 34 mm Hg and a maximum at 69 mm Hg. Weaning weight and sex tended to be associated with mPAP, but they explained just 5% of the variation in mPAP (P = 0.08; Adj. r2 = 0.05). Fibrinogen (P = 0.008) and absolute lymphocyte count (P = 0.06) were negatively associated with mPAP, whereas absolute monocyte count was positively associated with mPAP (P = 0.01). The findings of this study suggest that pre-weaning treatment for BRD does not increase a calves’ post-weaning risk of congestive right heart failure. Further, components of the immune and acute phase response system may play a role in the development and progression of pulmonary hypertension.