Improving beef calf health: frequency of disease syndromes, uptake of management practices following calving, and potential for antimicrobial use reduction in western Canadian herds

Abstract

Bovine respiratory disease (BRD), calf diarrhea (CD), and navel infections are the most commonly reported diseases of western Canadian beef calves. The objectives of this study were to estimate the frequency of treatment for these diseases for specific age cohorts and identify potential opportunities for reducing antimicrobial use. Producers representing 89 western Canadian cow-calf herds completed a survey describing calfhood diseases and management. The most common reason for calf treatment before weaning was BRD (4.9%), and BRD treatment was described in 51% of reporting herds before 2 months of age. Calf diarrhea (2.9%) and navel infection (2.0%) were the second and third most common reasons for treatment. Most calves were treated for CD between 6 days and 1 month of age. Almost 1 in 5 herds reported routinely administering antimicrobials at birth. Calving heifers and cows together were all associated with an increased treatment risk for BRD in calves from birth to 2 months (OR 3.55, 95%CI 2.13-5.94, P<0.0001), CD from 1 month to weaning (OR 3.94, 95%CI 1.29-12.0, P=0.02), and navel infection (OR 4.55, 95%CI 1.78-11.6, P=0.002). Failure to sort cow-calf pairs out of the calving area was also associated with an increased treatment risk for BRD from 4 months to weaning (OR 4.89, 95%CI 1.96-12.2, P=0.0006) and CD from 24 hours to 5 days (OR 2.82, 95%CI 1.03-7.75, P=0.04), and not using the Sandhills system was associated with an increased treatment risk for navel infection (OR 4.55, 95%CI 1.78-11.6, P=0.002). Other potentially modifiable factors associated with an increased risk of BRD in calves from birth to 2 months were winter feeding and calving in one area (P<0.0001), heifers calving in a higher density area (P=0.01), and an increasing number of times cow-calf pairs were gathered before turn out to summer pasture (P=0.0005). The purchase of any cows during the calving or prebreeding period was associated with an increased risk of BRD from birth to 2 months (P<0.0001) and from 2 to 4 months (P<0.0001). A history of respiratory bacterin vaccines administered to the dams was associated with a decreased risk of BRD in calves from 4 months to weaning (P=0.01). Cows calving in a higher density area was associated with an increased risk of CD from 1 month to weaning (P=0.02). These practices present opportunities for investigation of approaches to disease management that could support the judicious use of antimicrobials.

Antimicrobial Use in Canadian Cow–Calf Herds

“…The reason for this association could be that, typically, calves are separated from their mother and comingled with other calves while producers process the cows, temporarily increasing animal stress and density, thereby potentially increasing the risk of pathogen transmission. This finding is consistent with previous reports from other studies [ 13 , 15 , 16 ] that identified the increasing number of times cow–calf pairs were gathered before turning out to summer pasture and estrus synchronization as risk factors for respiratory disease in calves before weaning.…”

“…For evaluating risk factors for AMU for cow lameness, herds were classified depending on whether they purchased more cattle than the median value for all herds throughout the year. Potential risk factors were selected based on previous publications [ 6 , 13 ] and expert opinion.…”

The Canadian Cow-Calf Surveillance Network – productivity and health summary 2018 to 2022

“…In the present study, the use of larger pastures for calving was associated with fewer calves treated for navel or joint infection, and calves in herds from the west had a lower risk of treatment and death from diarrhea than herds from the east where barn use and shelters are more common. The risks associated with not using large pastures was consistent with a recent paper examining data from the WCCCSN ( 25 ) that showed using high-density calving areas, such as pens or barns vs. pasture, or failure to use the Sandhills or similar calving management systems were associated with higher risks of calf diarrhea in specific age groups and navel ill. Previous reports also describe the impact of more crowded conditions on opportunities for direct transmission from infected animals or indirect transmission through environmental contamination and the associated value of the Sandhills calving management system ( 28 , 29 ).…”

“…Previous postmortem examination studies with information on the age of calf death between 24 h and weaning reported 68% of calf deaths in the first 30 days after calving ( 23 , 24 ). Another more recent study based on questionnaire data also found that most calf death loss occurred within the first month ( 25 ). While the WCCCSN did not collect data on when calf deaths occurred from birth to weaning, the current study asked producers to report losses between 24 h and 30 days after birth, which was at or before the time most spring calving herds would have been moving their herds to summer pastures.…”

Vaccine use in Canadian cow-calf herds and opportunities for improvement

“…Annual Campylobacter and Leptospira revaccination are not considered core vaccines by the American Association of Bovine Practitioners, but are recommended for herds considered to be at high risk for either of these infections due to biosecurity challenges, comingling on community pastures or geographic location ( 19 , 20 ). Waldner et al reported similar vaccination trends for BVDV in cows, but higher levels of bacterial respiratory vaccines in cows ( 39 ).…”