Post on 16-Apr-2017
transcript
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