Photographer Leonhard Foeger documented the process as workers collected semen from breeding bulls at an artificial insemination centre in Hohenzell, Upper Austria. The bulls at the centre mount either an artificial cow or another bull to ejaculate so that their semen can be collected. The quality of the sperm is then checked, and the semen is diluted and preserved in tanks full of liquid nitrogen before being shipped out to clients. The breeding centre exports cattle semen to more than 52 countries worldwide and last year it sold approximately 800,000 samples. Portions of semen from bulls belonging to the Simmental breed cost between 6 and 15 euros. One bull at the centre, Wille, has produced 5 million euros worth of semen over the course of his lifetime.

Breeding Bulls

A breeding bull stands in the barn of an artificial insemination centre in the village of Hohenzell, Upper Austria April 9, 2013. The centre exports cattle semen to more than 52 countries worldwide. LEONHARD FOEGER/REUTERS

Breeding Bulls

Austrian bull keeper Josef washes Wille, a breeding bull, at an artificial insemination centre in the village of Hohenzell, Upper Austria. LEONHARD FOEGER/REUTERS

Breeding Bulls

A breeding bull stands under infrared lights, used to relax his muscles, at an artificial insemination centre in the village of Hohenzell, Upper Austria. LEONHARD FOEGER/REUTERS

Breeding Bulls

Austrian bull keeper, Johannes, walks with a breeding bull at an artificial insemination centre in Hohenzell, Upper Austria. LEONHARD FOEGER/REUTERS

Breeding Bulls

A breeding bull stands under infrared lights, used to relax his muscles, at an artificial insemination centre in the village of Hohenzell, Upper Austria. LEONHARD FOEGER/REUTERS

Breeding Bulls

Artificial vaginas are seen at an artificial insemination centre in the village of Hohenzell, Upper Austria. LEONHARD FOEGER/REUTERS

Breeding Bulls

Austrian bull keeper Johannes looks at Wille, a breeding bull, at an artificial insemination centre in the village of Hohenzell, Upper Austria. LEONHARD FOEGER/REUTERS

Breeding Bulls

Austrian veterinarian Franz looks at Wille, a breeding bull, at an artificial insemination centre in the village of Hohenzell, Upper Austria. LEONHARD FOEGER/REUTERS

Breeding Bulls

Austrian veterinarian Franz takes sperm from a breeding bull at an artificial insemination centre in the village of Hohenzell, Upper Austria. LEONHARD FOEGER/REUTERS

Breeding Bulls

Austrian veterinarian Franz takes sperm from a breeding bull at an artificial insemination centre in the village of Hohenzell, Upper Austria. LEONHARD FOEGER/REUTERS

Breeding Bulls

Bull keepers Johannes, Peter, Wolfgang and Josef look through a door at an artificial insemination centre in the village of Hohenzell, Upper Austria. LEONHARD FOEGER/REUTERS

Breeding Bulls

Austrian veterinarian Franz poses with a portion of sperm taken from a breeding bull at an artificial insemination centre in the village of Hohenzell, Upper Austria. LEONHARD FOEGER/REUTERS

Breeding Bulls

Austrian veterinarian Franz shows fresh diluted semen of breeding bull Wille at an artificial insemination centre in the village of Hohenzell, Upper Austria. LEONHARD FOEGER/REUTERS

Breeding Bulls

Austrian lab worker Georg refills a semen container with liquid nitrogen at an artificial insemination centre in the village of Hohenzell, Upper Austria. LEONHARD FOEGER/REUTERS

Breeding Bulls

Austrian lab worker Lambert checks a bull semen container at an artificial insemination centre in the village of Hohenzell, Upper Austria. LEONHARD FOEGER/REUTERS

Breeding Bulls

Containers used to store bull semen are seen at an artificial insemination centre in Hohenzell, Upper Austria. LEONHARD FOEGER/REUTERS

Breeding Bulls

Portions of semen, labeled with bulls' names, are seen in a container full of liquid nitrogen at an artificial insemination centre in the village of Hohenzell in Upper Austria. LEONHARD FOEGER/REUTERS

Breeding Bulls

A breeding bull stands in the barn of an artificial insemination centre in Hohenzell, Upper Austria. LEONHARD FOEGER/REUTERS