ian j.h. duncan professor of applied ethology chair in animal welfare university of guelph guelph,...
TRANSCRIPT
Ian J.H. Duncan
Professor of Applied Ethology
Chair in Animal Welfare
University of Guelph
Guelph, Ontario, Canada
The Costs and Benefits of
Tail Docking Dairy Cows
History of Tail Docking Cows
Started in New Zealand in 1970s
Claimed that benefits included :-
• Better milk hygiene
• Improved udder health
• Improved milker health (Leptospirosis)
• Increased milker comfort
Spread to the U.S. in late 1980s
Spread to Canada in 1990s
History of Tail Docking Cows
But remember :
• Dairy cattle are outside year round in N. Z.
History of Tail Docking Cows
But remember :
• Dairy cattle are outside year round in N. Z.
• Manure is much thinner
• Very mucky winter conditions in N.Z.
• Now a vaccine for leptospirosis
Canadian conditions are very different – so some benefits of tail docking may not apply.
History of Tail Docking Cows
On the other hand, the introduction of parallel parlours means that operator is at risk of being hit across the face with faeces- and urine-soaked tail.
History of Tail Docking Cows
Some recent research at UBC (Dave Fraser,
Dan Weary) questions the hygiene benefits
of tail docking :-
• No difference in somatic cell count
• No difference in cleanliness of cows
(Tucker et al., 2001. J. Dairy Sci., 84: 84-87.)
Tail Docking Cows
So, many of the benefits of tail docking seem questionable.
What about the costs to the cow?
• Acute pain?
• Chronic pain?
• Increased sensitivity of the stump?
• Increased fly nuisance?
• Loss of social signalling?
Tail Docking Cows
BENEFITS COSTS
Tail Docking Cows
Hygiene? Cleanliness?
Unmeasured costs?
Tail Docking Sheep
Prevention of fly strike
Pain of docking
Tail Docking Pigs
Prevention of tail biting
Pain of docking
Tail Docking Cows
Hygiene? Cleanliness?
Pain? Fly nuisance?
Tail Docking Cows
University of Guelph Study
Measure the acute adverse effects of tail docking cows using rubber rings with and without epidural anaesthetic.
Lennoxville Study
Measure the acute adverse effects of tail docking calves using rubber rings or a hot docking iron.
University of Guelph Study
Methods
64, lactating, mixed-parity, Holstein cows, housed in a tie-stall barn were used.
• Docked with anaesthetic (RRA)
• Docked without anaesthetic (RR)
• Control with anaesthetic (CA)
• Control without anaesthetic (C)
Four trials each with 16 cows
Docking done after morning milking
Different people to dock and to observe
Observations were done “blind”
Methods
Administration of epidural anaesthetic
Methods
Every cow in the study had its tail
bandaged . . .
Methods
. . . so that all observations were “blind”
Methods
After 7 days the lower tail was cut off
Methods
We measured on a daily basis :-
• Feed intake
• Milk production
• Somatic cell count
Tried to measure stress via saliva sampling (but this was unsuccessful)
Methods
We observed cows (especially behaviour likely to indicate pain) very intensively on first day and regularly over first week.
• Postures and posture changes
• Time spent in various activities
• Vocalizations
• Foot stamps, head turns, etc.
• Respiration rate
Methods
No significant differences between treatments in :-
• Milk production
• Feed intake
• Somatic cell count
• Respiration rate
Results
Results
No significant differences between treatments in :-
• Postures or posture changes
• Time spent standing or lying
• Time spent ruminating
• Vocalizations
• Foot stamps, head turns, etc.
Results
There were some differences in tail shaking and tail position :-
Tail Pressed Against Body
05
101520253035404550
0 1 2 3 7Day
%
Tim
e
C
CA
RR
RRA
Results
Tail shaking: We think that tail shaking was prevented by the anaesthetic and the rubber ring.
Tail position: We think that the change in tail position following removal of the dead tissue is probably a mechanical effect and not due to pain.
Conclusions
Tail-docking cows using rubber rings has minimal acute effects :
• No acute pain or distress
• Not even signs of discomfort
• No point in giving an anaesthetic