Table 5.

Summary of risk factors associated with bovine respiratory disease, calf diarrhea, and navel infection in calves from birth to weaning from 89 western Canadian cow-calf operations calving in the spring of 2017

	Bovine respiratory disease (BRD)			Calf diarrhea (CD)			Navel infection
	<2 months	2 - 4 months	> 4 months	5 days	6 days - 1 month	>1 month	birth to weaning
Increased exposure and disease risk associated with:
Contamination of calving area and mixing of cows and heifers
• Winter feeding and calving in one area	↑↑↑ 1
• Cows and heifers calve together	↑↑					↑↑	↑↑
• Using high density calving area (pens or barns vs pasture)	↑↑ (Heifers)					↑↑ (Cows)
• Failure to sort pairs out of the calving area to a clean nursery pasture(s) after calving or use Sandhill’s system			↑↑	↑↑	↓		↑↑
More intensively managed herds and herds calving earlier
• Calving started in December to February or April to May vs March 2	↑↑↑	↑↑↑				↑↑↑
• Calving season checks of cows: More frequent checks vs. less frequent checks					↑↑ (Cows)		↑↑ (Heifers)
• Calving season bedding provided							↑↑↑↑
• Calves are tagged by 2 days of age	↑↑↑↑				↑↑↑↑
• Calves receive vitamin AD by 2 days					↑↑
• Calves given respiratory vaccine at or near birth	↑↑	↑↑↑				↑↑↑
Increased gathering and exposure mixing within herd
• Calves given respiratory vaccine after 1 week and before summer pasture		↑↑	↑↑↑↑
• Calves castrated at spring processing			↑↑↑↑
• Number of times pairs gathered before pasture	↑↑
Exposure from outside the herd
• Any cows or calves purchased during calving or prebreeding period	↑↑	↑↑
Immunity from dam
• Respiratory bacterins NOT administered to dams			↑↑↑
• Herd owner does NOT use body condition scoring				↑↑↑

¹ ↑ OR < 2, ↑↑OR >= 2 and < 5, ↑↑↑OR >=5 and < 10, ↑↑↑↑OR >10.

²December to February were colder than March. April and May had spring snow storms resulting in calf mortalities in much of this region severe enough to be reported in the media.