Bovine Respiratory Disease in Calves – What is it Costing You?
Preweaning pneumonia in dairy calves continues to be a struggle for many producers. A recent study in 2022 by Uyama et al of 147 dairy farms and almost 8000 dairy calves across 5 provinces in Canada demonstrated that nearly 1/3 (29.6%) of calves received treatment of some kind, with over 50% (53.7%) of that being for respiratory disease. While we often see the direct cost of treatment for the cost of the antibiotic or supportive treatment, the hidden costs or future costs are often less obvious.
Dr. Renaud and his group from OVC who some of you may have had the opportunity to hear speak had tried to quantify some of those hidden costs. His group evaluated the impact of respiratory disease on mortality, feed efficiency and growth in 1100 dairy calves for 77 days after arrival to a dairy research facility. Calves were scored daily using the UC Davis scoring system for bovine respiratory disease in pre-weaned dairy calves (see below). They found that calves not diagnosed with respiratory disease had an average daily gain of 1037 g/d while calves diagnosed with resp disease for 1-4 days during that 77-day period had an average decrease of -88 g/d. Calves with respiratory disease for >5 days, had a -227 g/d difference in growth. Feed efficiency showed similar results with a 1.98 kg feed/kg gain for healthy calves, but +0.19 kg feed/kg gain for calves with 1-4 days or respiratory disease, and +0.74 kg feed/kg gain if respiratory disease was >5 days.
Finally, mortality averaged 3% for the non-respiratory disease calves but was +9% and +20% for calves 1-4 and >5 days respiratory disease respectively.
Other groups (Schaffer et al 2016 and Abuelo et al 2021) have evaluated the impact of bovine respiratory disease (BRD) with future milk production and culling. Survival to first lactation was decreased -14% (66% vs 84%) for calves < 120 days with BRD vs no BRD. Milk production was decreased -233 to 525 kg based on 305ME for BRD and non BRD calves.
It’s obvious from the above information that prevention and early detection/treatment of BRD to prevent chronic disease is very important to maximize calf health, growth and future production. A new studier by Morrison et al 2022 has shown that there are ways to detect pneumonia early using some simple but keen observation. His group measured that both volume of milk consumption and speed of drinking cold be shown to be slightly decreased up to 7 days prior to calves being typically “diagnosed” with respiratory disease compared with age and sex matched healthy control calves.
Dr. Renaud has proposed a modification to the UC Davis scoring system to increase the sensitivity at diagnosing calves with respiratory disease earlier.
Presence of dyspnea
Temp > 39.2 C
Eye discharge
Nasal discharge
Ear drop / Head tilt
Spontaneous cough
Maximal score
Threshold
UC DAVIS
SCORE
2
2
2
4
5
2
17
>5
MODIFIED SCORING RULE
20
7
1
10
16
16
70
>10
The take home messages are that:
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Respiratory disease in early life is very detrimental to calf health and future productivity;
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There is a need to identify disease earlier to prevent chronic cases;
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It is critical to evaluate feeding behaviour in calves as an early indicator;
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Think about the key symptoms in respiratory disease diagnosis;