First, it is dark, meaning that it is not in the form of stars and planets that we see. Observations show that there is far too little visible matter in the Universe to make up the 27% required by the observations. Second, it is not in the form of dark clouds of normal matter, matter made up of particles called baryons.
Livestock[edit] The raising of livestock, sheep (the traditional mainstay for generations of Icelandic farmers) and cattle (the latter grew rapidly in the 20th century), is the main occupation, but pigs and poultry are also reared; Iceland is self-sufficient in the production of meat, dairy products and eggs.
Exotic cattle were first introduced into this region by colonial farmers. Thus, the origin of exotic cattle is generally traced back to Europe. The most common exotic dairy breeds in the region are Friesian, Holstein, Ayrshire, Jersey, Guernsey and Sahiwal. However, the Friesian breed predominates.