Editing Monoculture (section)

==== Cattle ====
[[File:SOBREVVO EM RONDONIA DIA 07-08-2020 (FOTO BRUNO KELLY) (62) (50224604772).jpg|thumb|Aerial view of [[Deforestation of the Amazon rainforest|deforested area]] prepared for monoculture or [[Ranch|cattle ranching]], near Porto Velho in [[Rondônia]], Brazil, in 2020]] 
Genetic monoculture can also refer to a single breed of farm animal being raised in large-scale [[concentrated animal feeding operation]]s (CAFOs). Many [[Livestock|livestock production systems]] rely on just a small number of highly specialized breeds. Focusing heavily on a single trait (output) may come at the expense of other desirable traits{{Snd}}such as [[fecundity|fertility]], resistance to disease, [[wikt:|vigor]], and [[mothering]] instincts. In the early 1990s, a few [[Holstein cow|Holstein calves]] were observed to grow poorly and died in the first 6 months of life. They were all found to be [[homozygous]] for a mutation in the gene that caused bovine [[leukocyte adhesion deficiency]]. This mutation was found at a high frequency in Holstein populations worldwide. (15% among bulls in the US, 10% in Germany, and 16% in Japan.) Researchers studying the pedigrees of affected and carrier animals tracked the source of the mutation to a single bull that was widely used in livestock production. In 1990 there were approximately 4 million Holstein cattle in the US, making the affected population around 600,000 animals.<ref name=":17">{{cite news|url=http://albc-usa.etapwss.com/index.php/resources/internal/rare-breed-facts|title=The Value of Genome Mapping for the Genetic Conservation of Cattle|last=Williams|first=J.L.|date=2015-10-22|publisher=The [[Food and Agriculture Organization]] of the United Nations|access-date=2015-10-22|location=[[Rome]]|archive-url=https://web.archive.org/web/20160306175025/http://albc-usa.etapwss.com/index.php/resources/internal/rare-breed-facts|archive-date=6 March 2016|url-status=dead}}</ref>