Zubron
Encyclopedia
Żubroń is a hybrid of domestic cattle
Cattle
Cattle are the most common type of large domesticated ungulates. They are a prominent modern member of the subfamily Bovinae, are the most widespread species of the genus Bos, and are most commonly classified collectively as Bos primigenius...

 and wisent
Wisent
The wisent , Bison bonasus, also known as the European bison or European wood bison, is a species of Eurasian bison. It is the heaviest surviving land animal in Europe; a typical wisent is about long, not counting a tail of long, and tall. Weight typically can range from , with an occasional big...

. The wisent (żubr in Polish) is the European bison; hence, the żubroń is analogous to the American beefalo
Beefalo
Beefalo are a fertile hybrid offspring of domestic cattle, Bos taurus, and the American bison, Bison bison...

. The name żubroń was officially chosen from hundreds of proposals sent to the Polish weekly magazine Przekrój
Przekrój
Przekrój is the oldest Polish weekly newsmagazine, established in 1945 in Krakow and since 2001 published in Warsaw. Przekrój was created by M. Eile who, until 1969, was the first editor-in-chief of the magazine...

during a contest organised in 1969.

History

The żubroń was first created by Leopold Walicki in 1847, although the hybrid may also have appeared at an earlier time. After World War I
World War I
World War I , which was predominantly called the World War or the Great War from its occurrence until 1939, and the First World War or World War I thereafter, was a major war centred in Europe that began on 28 July 1914 and lasted until 11 November 1918...

, various scientists considered żubroń a possible replacement for domestic cattle
Cattle
Cattle are the most common type of large domesticated ungulates. They are a prominent modern member of the subfamily Bovinae, are the most widespread species of the genus Bos, and are most commonly classified collectively as Bos primigenius...

. Żubroń turned out to be more durable and less susceptible to disease. In addition, the animal could be bred on marginal grazing land with no farm infrastructure and with minimal husbandry
Animal husbandry
Animal husbandry is the agricultural practice of breeding and raising livestock.- History :Animal husbandry has been practiced for thousands of years, since the first domestication of animals....

 in huge state agricultural farms (SAFs). From 1958, the work on żubroń herds was continued by the Polish Academy of Sciences
Polish Academy of Sciences
The Polish Academy of Sciences, headquartered in Warsaw, is one of two Polish institutions having the nature of an academy of sciences.-History:...

 in various laboratories, most notably in Białowieża and Młodzikowo. During the first 16 years of experiments, a total of 71 animals were born, including Filon, the first żubroń born to a żubroń mother (August 6, 1960). The animal was intended to become a hardy and cheap alternative to cattle.

The experiment was continued until the late 1980s, when the results of the breeding programmes were deemed unsatisfactory. Various factors contributed to this decision, including the severe economic difficulties of the Polish socialist economy in the 1980s, a lack of interest from the notoriously ineffective SAFs, and fears that żubroń would crossbreed
Crossbreed
A crossbreed or crossbred usually refers to an animal with purebred parents of two different breeds, varieties, or populations. Crossbreeding refers to the process of breeding such an animal, often with the intention to create offspring that share the traits of both parent lineages, or producing...

 with the endangered wild wisent, contaminating
Genetic pollution
Genetic pollution is a controversial term for uncontrolled gene flow into wild populations. This gene flow is undesirable according to some environmentalists and conservationists, including groups such as Greenpeace, TRAFFIC, and GeneWatch UK.-Usage:...

 their gene pool
Gene pool
In population genetics, a gene pool is the complete set of unique alleles in a species or population.- Description :A large gene pool indicates extensive genetic diversity, which is associated with robust populations that can survive bouts of intense selection...

. The two notable centres for experiments on the species were Łękno (391 animals altogether) and Popielno (121 animals), while limited experiments were also held in the reserve of Askania Nova in the USSR. This was discontinued, and the sole surviving herd consists of several animals only, kept at Bialowieski National Park. As of 2007, however, there are press releases suggesting the breeding and experiments are continuing in Karolewo in Greater Poland
Greater Poland
Greater Poland or Great Poland, often known by its Polish name Wielkopolska is a historical region of west-central Poland. Its chief city is Poznań.The boundaries of Greater Poland have varied somewhat throughout history...

.

Description

Żubroń are heavy animals, with males weighing up to 1200 kilograms (2,645.5 lb) and females up to 810 kilograms (1,785.7 lb). They are strong, resistant to disease and tolerant of harsh weather conditions. The first-cross calves have to be born by caesarean section
Caesarean section
A Caesarean section, is a surgical procedure in which one or more incisions are made through a mother's abdomen and uterus to deliver one or more babies, or, rarely, to remove a dead fetus...

, because although they may be carried successfully to full term, parturition never occurs. Males are infertile
Infertility
Infertility primarily refers to the biological inability of a person to contribute to conception. Infertility may also refer to the state of a woman who is unable to carry a pregnancy to full term...

in the first generation. Females are fertile and can be crossbred with either parent species, i.e. with cattle or wisent, and males from these backcrosses are fertile.
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