Background
In breeding beef herds that produce genetically high merit
breeding animals, it is necessary to use artificial insemination
(AI) to import new genetic material from progeny
tested bulls. Oestrus detection may, however, often be
fairly problematic. Animals are usually kept in big herds
and they are more difficult to approach and manage than
dairy cattle. It may be difficult to identify a single animal
from a big herd since in many beef breeds all animals are
coloured similarly. Also, time spent with beef animals is
much less than with dairy cattle. In some cases, catching a
single animal for AI may be problematic. Because of these
reasons, the use of AI after oestrus detection in some beef
herds is either impossible or at least results in a poor pregnancy
rate. According to Geary et al. [1], it is estimated
that less than 5% of beef cows in the United States are arti artificially
inseminated each year. Perhaps the biggest reason
that so few beef cattle are artificially inseminated is the
problem of accurate detection of oestrus.