Efficient estrus detection in high-

Efficient estrus detection in high-producing dairy
cows is a permanent challenge for successful reproductive
performance. In former studies, dogs have
been trained to identify estrus-specific odor in vaginal
fluid, milk, urine, and blood samples under laboratory
conditions with an accuracy of more than 80%. For
on-farm utilization of estrus-detection dogs it would
be beneficial in terms of hygiene and safety if dogs
could identify cows from the feed alley. The objective
of this proof of concept study was to test if dogs can
be trained to detect estrus-specific scent in saliva of
cows. Saliva samples were collected from cows in estrus
and diestrus. Thirteen dogs of various breeds and both
sexes were trained in this study. Five dogs had no experience
in scent detection, whereas 8 dogs had been
formerly trained for detection of narcotics or cancer.
In the training and test situation, dogs had to detect
1 positive out of 4 samples. Dog training was based on
positive reinforcement and dogs were rewarded with a
clicker and food for indicating saliva samples of cows in
estrus. A false indication was ignored and documented
in the test situation. Dogs with and without prior
training were trained for 1 and 5 d, respectively. For
determining the accuracy of detection, the position of
the positive sample was unknown to the dog handler,
to avoid hidden cues to the dog. The overall percentage
of correct positive indications was 57.6% (175/304),
with a range from 40 (1 dog) to 75% (3 dogs). To our
knowledge, this is the first indication that dogs are able
to detect estrus-specific scent in saliva of cows.
Key words: estrus detection , saliva , detection dog