Avoiding Disease in Dairy Calves

Geof Smith, DVM, MS, PhDDiplomate, ACVIM, ECBHM

Dept. Population Health & Pathobiology North Carolina State University

Neonatal Calves

Overall focus should be on management – NOT products or interventions

The vast majority of disease and/or calf health problems stem from improper calf management

There is no magic bullet to overcome a poor colostrum program or bad housing/hygiene

Calf Mortality

We still have a preweaned heifer calf mortality rate of 7.8% (USDA dairy 2007 study)

Only 40% of farms can supply their own replacement heifers

The major diseases remain diarrhea (60%), pneumonia (24%), and septicemia

Many farms still doing a poor job of colostrum management

Disease Incidence – Dairy Calves

1991 1996 2002 2007 2014*Pre-weaned calf mortality

8.4% 10.8% 10.5% 7.8% 6.4%

% of deaths caused by diarrhea

52.2% 60.5% 62.1% 56.5% 56.4%

% of deaths caused by pneumonia

21.3% 24.5% 21.3% 22.5% 24.0%

Weaned calf mortality

2.2% 2.4% 2.8% 1.8% 1.9%

NAHMS Survey data*2014 estimates are preliminary – Dr. Jason Lombard, USDA/APHIS Veterinary Services)

Goals

Mortality rates in pre-weaned calves should be less than 4%

Morbidity or treatment rates in preweaned calves should be less than 25%

Use calf records to identify problems when possible

Vital for troubleshooting colostrum and disease problems

Disease Control

Key Principles of Disease Control1) Removing the source of infection from the

calf’s environment2) Remove the calf from a contaminated

environment3) Increase immunity of the calf4) Reduce stress

Colostrum Management

A good colostrum management program – ensuring that all calves get

an adequate volume of quality colostrum within the first 2-4 hours -

is the single most important aspect of neonatal calf management

ColostrumKeys to Success

1) Time of feeding – the sooner the better2) Volume – 3-4 liters to every calf3) Clean colostrum (harvest & storage important)4) Don’t pool colostrum5) Test calves periodically6) Have colostrum storage (CR available)7) Make this a priority on your farm!

Control Points

1) Calving area Calves are frequently exposed to disease from

the dam at birth Must minimize contamination of calving area –

provide good bedding material and remove calf promptly after birth

Control Points

2) Colostrum Colostrum has been identified contaminated

colostrum as a source of infection (especially with S. dublin)

Pooling increases risk of transmission Make sure colostrum is harvested

cleanly and rapidly cooled Consider using a colostrum replacer or

pasteurizing colostrum

Control Points

3) Housing House calves in a clean, dry environment with

good drainage Make sure calves are not exposed to manure

or runoff from adult cows Move hutches to clean ground between calves In group housing systems – keep groups small

and make sure calves are of similar ages Minimize temperature stress

Housing

Calf Density Calf to calf contact increases the risk of

pathogen exposure (fecal-oral) Distancing calves is important Also consider creating barriers to avoid licking,

sucking, and manure contact

Housing Density

Housing Density

Ventilation

Studies have linked respiratory disease in dairy calves to poorly ventilated housing

Important to realize that microenvironments exists within calf barns as well

Need to examine air quality at the calf’s level Key factors include:

– Sufficient bedding for calves to “nest”– Solid panel between calves– Low airborne bacteria count in calf pens

Ventilation

Ventilation

Ventilation

Ventilation

Ventilation

Julian, NC dairy

Ventilation - Winter

Ventilation

Statesville, NC dairy

Ventilation

Control Points

4) Nutrition Good nutrition is necessary to maximize host immunity Starving calves are more likely to die Must factor in seasonal conditions (heat/cold stress) Minimize the manure contamination of feed

and/or water If feeding whole milk consider a pasteurizer

Control Points

Minimize use of calf warmers, temporary holding pens, and trailers used for transporting calves (or disinfect frequently)

Turn hutches upside down after use Remove manure frequently

(pens) Clean bedding material and feed/water

buckets

Control Points

5) Stress Dietary changes, transportation, movement,

weather, anorexia, weaning, overcrowding, and parturition have been shown to ↑ diarrhea

Poultry and swine also ↑ fecal pathogen shedding during stress (transport, molting)

Some evidence that bacteria can detect “stress” in the host and multiply (quorom sensing)

Control Point Summary

1) Make sure colostrum management is good2) Clean maternity area3) Good nutrition4) Appropriate housing – all types will work but cleanliness

& disinfection is key5) Minimize manure contact between calves and older

cattle at all stages6) Sanitation of feeding equipment7) Avoid stress as much as possible

Other Risk Factors

Humidity Climate Water availability Bacterial contamination of milk/MR Feed and feeding schedules

Keys to Treatment

1) Learn to identify “sick” calves early Most calves will response well when

treatments are started early in the course of disease

2) Work with your veterinarian to have treatment protocols in place

3) Monitor response to treatment regularly (records) – don’t change drugs on a daily basis

Neonatal Calves

Overall focus should be on management – NOT products or interventions

The vast majority of disease and/or calf health problems stem from improper calf management

There is no magic bullet to overcome a poor colostrum program or bad housing/hygiene