PT10 Lidia Inbreeding and livestock Aguilar BY: Wilfredo Quiroz Campana (groan)
The Lidia bovine breed has a reduced effective worldwide, estimated at less than a quarter of a million head, and it grows following management systems very traditional foster animal crossings related to each other in different herds. This increases the blood, setting emphasizing desirable traits but also many serious defects.
The population universe of the Lidia cattle breed is small, would be estimated at some 210,000 heads, of which about 175,000 are stocks in Spain and the rest is distributed in Mexico, Portugal, Colombia, Venezuela, Peru and Ecuador. This fact points out the feasibility of the presence of inbreeding in herds of Lydia, as these small herds and closed handling and orientation selection in these sites, which follow a particular genetic line or mating, further reducing the breeding population. Inbred
is the mating of animals that are more closely among themselves than the average of the breed or population to which they belong. The mating of animals associated with a particular example, to maintain or increase its characteristics in their descendants, is a form of inbreeding that is called line breeding.
factors contributing to the increase of inbreeding in a population are its size and existing subdivisions on it. In the proper management of domestic animals are created subdivisions. In the case of the Lidia cattle they are more evident because the mating of animals commonly associated with a particular example, to maintain or increase its characteristics in their descendants. Complications of working to improve a character that carries the risk of losing variability.
has traditionally been a production management system of the bull that has led to increased of inbreeding, to cause reproductive isolation. Especially as they represent the selection methods aimed at the definition of certain characters, using increasingly smaller farms and a small number of spigots, some of which have gradually reduced their presence, according to the preferences of the time.
breeders currently accepted inbreeding and rely on computers to get a control that allows them to minimize their presence and mating take consistent with their objectives. Since the studies published by academics show that statistical trend is for growth of inbreeding in herds.
The farmer oriented farming according to their phenotypic and behavioral preferences, trying to get all your bulls have a number of common characteristics in terms of the stated purposes of its holding. And to do so, according to the selection and management, incurring some degree of inbreeding. Within
benefits, is to draw attention to the fact that inbreeding has been used over the years to fix desirable traits. Based on this principle have been developed and preserved animal breeds, and this is the case of Lydia.
Alvaro Domecq y Díez, in his book El Toro Bravo, makes the following reference:
"was Joseph Vincent Vázquez, according to what he says López Martínez, back in the mid-eighteenth century, who, after gathering cattle from different herds, sought out a single, uniform rate by selection and inbreeding.
In a valuable and entertaining work entitled Perspectives the river of bravery, Dr. Alberto Ramírez Avendaño, veterinarian, teacher and farmer Venezuelan notes:
"In the case of the Lidia cattle enough to analyze the rope of a stallion in any livestock for prestige, to warn a very high rate of inbreeding compared with other breeds of cattle. The selection of herds secular family, closed few, through many generations appears to have segregated many adverse factors, which are not shown in contemporary herds, which they maintain such a high fertility in general and on the contrary, there are signs possibly related to genetic factors in disorders of locomotion and pathophysiological changes of muscle contraction. In relation to these matters, the complexity, requires serious interdisciplinary studies, since time is handled between the bull's motion, any jargon on inbreeding, degeneration, cooling blood, linking bulls, terms used most authoritative piece alleged that real knowledge ".
In his work, venturing into the unknown, notes on the fall of the bull, Juan Jose Zaldivar Ortega, says:
"A prior informed the causes must be added the most important and which, in those years of the 1950 and 1960, no one spoke, the above consanguinity. It is especially installed a factor of imbalance myoneural starring a significant reduction of cholinesterase enzymes in the blood of animals with high levels of homozygosity. In most of Portuguese farms, which livestock has played for many years within closed groups, the degree of inbreeding is high, resulting in a risk immobilize muscle relaxant drug, because they have low levels of cholinesterase in the blood are exposed to animals do not recover. "
Prof. J. Cannon et al. of UCM Madrid (Spain), research called Distribution of genetic variability in Lidia breed, placed in its findings and conclusions, inter alia, the following:
"We measured the levels of inbreeding and kinship between animals of each mating season and its contribution to global biodiversity. The spigots accounted for 20% of the total variability, 43% is attributable to genetic differences between animals and 37% to the genetic variability of animals, which implies the existence of a tendency towards homozygosity in animals of the spigots.
The existence of a population structure divided into lines or spigots and livestock has allowed an accumulation of genetic variability between the spigots, following significant process drift, and although the overall effective size of the race is reduced as a result of This division has been able to be a good strategy to maintain overall genetic variability.
should be emphasized that the spigots Miura and Paul Romero are among the largest contributors to the global diversity of the Lidia breed, because of their high genetic distance from the rest. However, other encastes which are among the biggest contributors in proportion to global diversity, they do because of the greater internal genetic variability, ie the greater genetic distance between mating animals. This is the case of Santa Coloma, Contreras, Saltillo or Concha y Sierra.
Developments in genetic studies, among them the DNA tests, to analyze and determine the origin and distribution of the spigots. Also comparison of farms and their horses and give information about their structures and levels of inbreeding (mating between individuals of a race, community or genetically isolated population), and likewise provide the dynamic of inbreeding. Interestingly
published by the weekly AplausoS.es, the July 31, 2010, in an interview entitled Concerning Bravura, by Inigo Crespo English livestock Victorino Martin, who writes:
"Our biggest enemy is the inbreeding. We have more one hundred years of blood purity, so it is important to open the livestock and find the lines. "
At this juncture, it is questionable whether Lidia cattle breeders will open in seeking to incorporate other genetic lines occurring outside their properties and leave aside the traditional management. If professional advice geneticists used to analyze the current situation your campus, crossing in use guidelines and feasible new routes that allow the controlled management of inbreeding and production of products that meet the mission and vision of what owners have to be a cattle breed. Hopefully
advances in scientific studies to guide our livestock Lydia to get increasingly better results, conserve resources and preserve the breed.