Rivastigmine (sold under the trade name Exelon) is a parasympathomimetic or cholinergic agent for the treatment of mild to moderate dementia of the Alzheimer's type and dementia due to Parkinson's disease.
Quick Answer. According to the University of Washington, cows sleep for approximately 3.9 hours per day, meaning that they spend about 16.9 percent of the day sleeping. Adult humans sleep for approximately 8 hours per day, which represents 33.3 percent of the day. Human infants sleep approximately 16 hours per day.
Nobody is sure why dogs sleep so much. The amount of sleep that an animal needs depends upon its species. Horses and cows may sleep only three or four hours daily, because they require long hours of grazing to supply their bodies with sufficient food. Bats and opossums may sleep closer to 20 hours. The various breeds of dogs also seem to have different sleep requirements.