Association of Bovine Respiratory Disease during the Pre-Weaning Period with Blood Cell Counts and Circulating Concentration of Metabolites, Minerals, and Acute Phase Proteins in Dairy Calves Transported to a Calf Raising Facility

Abstract

Our objective was to investigate the association of bovine respiratory disease (BRD) occurring within the first 56 days of life with blood cell counts and the circulating concentration of metabolites, minerals, and acute phase proteins throughout the pre-weaning period in dairy calves transported to a heifer raising facility within their first week of life. Data from 305 calves transported from dairies in Minnesota to a calf raising facility in New Mexico within their first four days of life were used in this retrospective cohort study. Blood samples were collected at 7, 17, 34, and 56 days of life for the analysis of blood cell counts, biochemistry, and the concentration of acute phase proteins. Blood urea nitrogen, albumin, GLDH, CK, P, Na, K, Cl, Zn, Hp, SAA, and monocyte counts were associated with BRD status throughout or at least at one of the time points evaluated in this study. In conclusion, several hematological variables were associated with BRD status in dairy calves that underwent transportation stress in early life.

Keywords: bovine respiratory disease; calves; haptoglobin; transportation stress; white blood cells.

Figure 1

Distribution plot of bovine respiratory disease (BRD) incidence curve during the pre-weaning period.

Figure 2

Least square means by days of sampling of (A) total protein, (B) albumin, (C) glutamate dehydrogenase (GLDH), (D) blood urea nitrogen (BUN), (E) creatine kinase (CK), (F) phosphorus (P), (G) magnesium (Mg), (H) sodium (Na), (I) potassium (K), (J) chloride (Cl), (K) sodium to potassium ratio (Na/K), and (L) zinc (Zn) by bovine respiratory disease (BRD) status (NBRD = no BRD; EBRD = BRD diagnosed ≤30 days of age; LBRD = BRD diagnosed >30 days of age). Error bars represent SEM. Bovine respiratory disease was diagnosed based on a systematic scoring system [4] based on the presence of nasal and ocular discharge, abnormal respiration, cough, ear droop or head tilt, and rectal temperature ≥39.2 °C.

Figure 3

Least square means by days of sampling of (A) circulating concentration of serum amyloid A (SAA), (B) serum concentration of haptoglobin (Hp), and (C) monocyte counts by bovine respiratory disease (BRD) status (NBRD = no BRD; EBRD = BRD diagnosed ≤30 days of age; LBRD = BRD diagnosed >30 days of age). Error bars represent SEM. Bovine respiratory disease was diagnosed based on a systematic scoring system [4] based on the presence of nasal and ocular discharge, abnormal respiration, cough, ear droop or head tilt, and rectal temperature ≥39.2 °C.