Management factors associated with bovine respiratory disease in preweaned calves on California dairies: The BRD 100 study

Abstract

The objective of this cross-sectional study was to determine how management practices on California dairies may be associated with bovine respiratory disease (BRD) in preweaned calves. A convenience sample of 100 dairies throughout California, providing a study population of 4,636 calves, were visited between May 2014 and April 2016. During each farm visit, in-person interviews with the herd manager or calf caretaker were conducted to collect information about herd demographics, maternity pen, colostrum and calf management, herd vaccinations, and dust abatement. A random sample of preweaned calves was identified and evaluated for the presence of BRD using a standardized tool. A survey-adjusted generalized linear mixed model with a logit link function was fitted with calf as the unit of analysis and dairy as the random effect. Mean study herd size (±SE) was 1,718 (±189.9) cows. Survey-adjusted estimates of breed types in the sample were 81.6% (±0.6) Holstein, 13.1% (±0.4) Jersey, and 5.3% (±0.5) crossbred or other purebred breeds, and calf sex proportions were 73.8% (±1.0) female and 26.2% (±1.0) male. Overall survey-adjusted BRD prevalence in the study herds was 6.91% (±0.69). Housing factors positively associated with BRD were metal hutches compared with wood hutches [odds ratio (OR) = 11.19; 95% confidence interval (CI) = 2.80-44.78], calf-to-calf contact in calves >75 d of age (OR = 9.95, 95% CI = 1.50-65.86), feeding Holstein calves <2.84 L of milk or replacer per day (OR = 7.16, 95% CI = 1.23-41.68), and lagoon water used for flushing manure under hutches compared with no flush (OR = 12.06, 95% CI = 1. 93-75.47). Providing extra shade over hutches (OR = 0.08; 95% CI = 0.02-0.37), feeding calves at least 90% saleable milk (OR = 0.27, 95% CI = 0.13-0.54) or pasteurized milk (OR = 0.10; 95% CI = 0.03-0.36), and feeding >5.68 L of milk or replacer per day to Jersey calves (OR = 0.04; 95% CI = 0.01-0.28) were negatively associated with BRD. Our study identified management practices on California dairies with variability and that may contribute to differences in BRD prevalence, which will be incorporated into a risk-assessment tool to control and prevent BRD in preweaned dairy calves.

Human Relationships with Domestic and Other Animals: One Health, One Welfare, One Biology

“…The materials used in construction or bedding can also generate welfare problems, on the one hand for animal safety and on the other as a potential vector of diseases or parasites. Small particles forming dust can cause respiratory problems, for humans [76] but also for animals such as pigs and calves [77].…”

Analysis of lung transcriptome in calves infected with Bovine Respiratory Syncytial Virus and treated with antiviral and/or cyclooxygenase inhibitor

“…Bovine respiratory disease complex (BRDC) is a common and serious illness of both dairy and beef cattle. This multi-factorial and multi-pathogenic condition [ 1 ] is a leading cause of direct and indirect economic losses in the dairy- and especially in the beef industry [ 2 , 3 ]. One of the most common pathogens in the etiological structure of BRDC is bovine respiratory syncytial virus (BRSV) [ 4 ].…”

Microbial diversity involved in the etiology of a bovine respiratory disease outbreak in a dairy calf rearing unit

“…In the specialized heifer calf rearing units, the outbreaks of BRD in calves are commonly reported [15]. Also, adverse conditions in transportation, nutrition, temperature, and sanitary and environmental management may lead to immunosuppression and increased susceptibility to pathogens of the bovine respiratory system [19,20].…”