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85-547: The South African Lipizzaners is a riding academy that operates according to the classical model in just outside of Paarl , in the Western Cape in the Western Cape province of South Africa . In contrast to other classical riding schools, only women ride and train the 40 Lipizzaner stallions. Public performances take place every week on Sundays. There is also an affiliated stud farm that provides horses for

170-559: A herd , where they may also engage in play activity and social bonding. The area where the horses are placed can be of any size, from a small pen with room to run, to wide areas covering thousands of square miles. In the United Kingdom this may range from open moorland without internal subdivision, down to small, fenced areas of grass, called pastures or paddocks in British English. A large turnout of several acres

255-455: A population bottleneck caused by purposeful ( assortative ) breeding or natural environmental factors, the deleterious inherited traits are culled. Island species are often very inbred, as their isolation from the larger group on a mainland allows natural selection to work on their population. This type of isolation may result in the formation of race or even speciation , as the inbreeding first removes many deleterious genes, and permits

340-450: A species may not be able to adapt to changes in environmental conditions. Each individual will have similar immune systems, as immune systems are genetically based. When a species becomes endangered , the population may fall below a minimum whereby the forced interbreeding between the remaining animals will result in extinction . Natural breedings include inbreeding by necessity, and most animals only migrate when necessary. In many cases,

425-436: A consistent and uniform animal model for experimental purposes and enables genetic studies in congenic and knock-out animals. In order to achieve a mouse strain that is considered inbred, a minimum of 20 sequential generations of sibling matings must occur. With each successive generation of breeding, homozygosity in the entire genome increases, eliminating heterozygous loci. With 20 generations of sibling matings, homozygosity

510-856: A degree at the College of Agriculture in Warsaw . In his dissertation, he wrote about horse breeding . After two years as an assistant manager of the Polish National Stud in Bogusławice , he finished cavalry school and went into the army. After the Second World War he took over Gestüt Lauvenburg in Rhineland for two years. Then he went to South Africa. He and Josy Hicks founded Centaur Stables in Johannesburg . This later became

595-467: A form of distant linebreeding occurs. Again it is up to the assortative breeder to know what sort of traits, both positive and negative, exist within the diversity of one breeding. This diversity of genetic expression, within even close relatives, increases the variability and diversity of viable stock. Systematic inbreeding and maintenance of inbred strains of laboratory mice and rats is of great importance for biomedical research. The inbreeding guarantees

680-577: A large portion of the day, or where additional forage is not desired, they may be turned out in to areas with no grass, to encourage activity and prevent grazing. In the USA, such spaces are called a paddock or, in the western United States, a corral, in the British Isles, a paddock, and in Australia, a pen. Sometimes the colloquialism "starvation" is prefixed to these grassless areas, though the intent

765-404: A particular recessive genetic mutation . Except in certain rare circumstances, such as new mutations or uniparental disomy , both parents of an individual with such a disorder will be carriers of the gene. These carriers do not display any signs of the mutation and may be unaware that they carry the mutated gene. Since relatives share a higher proportion of their genes than do unrelated people, it

850-470: A population through purifying selection . Inbreeding is a technique used in selective breeding . For example, in livestock breeding , breeders may use inbreeding when trying to establish a new and desirable trait in the stock and for producing distinct families within a breed, but will need to watch for undesirable characteristics in offspring, which can then be eliminated through further selective breeding or culling . Inbreeding also helps to ascertain

935-524: A population to become fixed for certain traits, like having too many bones in an area, like the vertebral column of wolves on Isle Royale or having cranial abnormalities, such as in Northern elephant seals , where their cranial bone length in the lower mandibular tooth row has changed. Having a high homozygosity rate is problematic for a population because it will unmask recessive deleterious alleles generated by mutations, reduce heterozygote advantage, and it

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1020-422: A service for horses to live on pasture only, without a space inside the stable buildings, known as "grass livery" (BrE), "agistment" (BrE), or "pasture board" (AmE). Where the stables also house a riding school or hireling operation, some operators may also offer a "working livery" (UK) or "partial lease" (US), where the horse owner pays a discounted rate (or no money at all) for their own horse's care in return for

1105-462: A severe winter weather related population crash. These studies show that inbreeding depression and ecological factors have an influence on survival. The Florida panther population was reduced to about 30 animals, so inbreeding became a problem. Several females were imported from Texas and now the population is better off genetically. A measure of inbreeding of an individual A is the probability F (A) that both alleles in one locus are derived from

1190-566: A significantly higher chance of reaching repeated results with future offspring. Additionally, consanguineous parents possess a high risk of premature birth and producing underweight and undersized infants. Viable inbred offspring are also likely to be inflicted with physical deformities and genetically inherited diseases. Studies have confirmed an increase in several genetic disorders due to inbreeding such as blindness, hearing loss, neonatal diabetes, limb malformations, disorders of sex development , schizophrenia and several others. Moreover, there

1275-485: A small building to house only one or two animals, to facilities used at agricultural shows or at race tracks , which can house hundreds of animals. Terminology relating to horse accommodation differs between American and British English , with additional regional variations of terms. The term "stables" to describe the overall building is used in most major variants of English, but in American English (AmE)

1360-499: A small colony was discovered in the Point Sur region in the 1930s. Since then, the population has grown and spread along the central Californian coast to around 2,000 individuals, a level that has remained stable for over a decade. Population growth is limited by the fact that all Californian sea otters are descended from the isolated colony, resulting in inbreeding. Cheetahs are another example of inbreeding. Thousands of years ago,

1445-478: A small population for a period of time can lead to inbreeding within that population, resulting in increased genetic relatedness between breeding individuals. Inbreeding depression can also occur in a large population if individuals tend to mate with their relatives, instead of mating randomly. Due to higher prenatal and postnatal mortality rates, some individuals in the first generation of inbreeding will not live on to reproduce. Over time, with isolation, such as

1530-467: Is a paddock in Australia, a pasture is significantly larger. In the United States, similar large spaces ranging from a few to many acres are called pastures or, for larger areas of public land or private unfenced ranch land approaching 100 acres or more, rangeland . Where the purpose of turning the horses out is to encourage activity and not for forage , for instance where a horse is stabled for

1615-488: Is also denoted as the kinship coefficient between A and B. A particular case is the self-coancestry of individual A with itself, f(A,A), which is the probability that taking one random allele from A and then, independently and with replacement, another random allele also from A, both are identical by descent. Since they can be identical by descent by sampling the same allele or by sampling both alleles that happen to be identical by descent, we have f(A,A) = 1/2 + F(A)/2. Both

1700-576: Is an increased risk for congenital heart disease depending on the inbreeding coefficient (See coefficient of inbreeding ) of the offspring, with significant risk accompanied by an F =.125 or higher. The general negative outlook and eschewal of inbreeding that is prevalent in the Western world today has roots from over 2000 years ago. Specifically, written documents such as the Bible illustrate that there have been laws and social customs that have called for

1785-473: Is detrimental to the survival of small, endangered animal populations. When deleterious recessive alleles are unmasked due to the increased homozygosity generated by inbreeding, this can cause inbreeding depression. There may also be other deleterious effects besides those caused by recessive diseases. Thus, similar immune systems may be more vulnerable to infectious diseases (see Major histocompatibility complex and sexual selection ). Inbreeding history of

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1870-613: Is discussed in the following quotation on cattle: Meanwhile, milk production per cow per lactation increased from 17,444 lbs to 25,013 lbs from 1978 to 1998 for the Holstein breed. Mean breeding values for milk of Holstein cows increased by 4,829 lbs during this period. High producing cows are increasingly difficult to breed and are subject to higher health costs than cows of lower genetic merit for production (Cassell, 2001). Intensive selection for higher yield has increased relationships among animals within breed and increased

1955-443: Is expected to increase the number of spontaneous abortions of zygotes, perinatal deaths, and postnatal offspring with birth defects. The advantages of inbreeding may be the result of a tendency to preserve the structures of alleles interacting at different loci that have been adapted together by a common selective history. Malformations or harmful traits can stay within a population due to a high homozygosity rate, and this will cause

2040-469: Is more likely that related parents will both be carriers of the same recessive allele, and therefore their children are at a higher risk of inheriting an autosomal recessive genetic disorder. The extent to which the risk increases depends on the degree of genetic relationship between the parents; the risk is greater when the parents are close relatives and lower for relationships between more distant relatives, such as second cousins, though still greater than for

2125-404: Is not as effective. Fixation of alleles most likely occurs through Muller's ratchet , when an asexual population's genome accumulates deleterious mutations that are irreversible. Despite all its disadvantages, inbreeding can also have a variety of advantages, such as ensuring a child produced from the mating contains, and will pass on, a higher percentage of its mother/father's genetics, reducing

2210-524: Is not to starve the horse, but simply to regulate diet. This also could include a space such as a riding arena, doing double-duty as a turnout area. Equine nutritionists and management specialists also recommend a grassless area, which they sometimes call a "sacrifice area," be fenced off from pastures intended for forage where horses can be placed when it is wet or muddy, to prevent the grass from being trampled, and during times of drought, to prevent or minimize overgrazing . Inbreeding Inbreeding

2295-409: Is occurring at roughly 98.7% of all loci in the genome, allowing for these offspring to serve as animal models for genetic studies. The use of inbred strains is also important for genetic studies in animal models, for example to distinguish genetic from environmental effects. The mice that are inbred typically show considerably lower survival rates. Inbreeding increases homozygosity, which can increase

2380-551: Is primarily assortative breeding (see selective breeding ). Without the sorting of individuals by trait, a breed could not be established, nor could poor genetic material be removed. Homozygosity is the case where similar or identical alleles combine to express a trait that is not otherwise expressed (recessiveness). Inbreeding exposes recessive alleles through increasing homozygosity. Breeders must avoid breeding from individuals that demonstrate either homozygosity or heterozygosity for disease causing alleles. The goal of preventing

2465-460: Is the main selective reason for outcrossing. Crossbreeding between populations sometimes has positive effects on fitness-related traits, but also sometimes leads to negative effects known as outbreeding depression . However, increased homozygosity increases the probability of fixing beneficial alleles and also slightly decreases the probability of fixing deleterious alleles in a population. Inbreeding can result in purging of deleterious alleles from

2550-494: Is the production of offspring from the mating or breeding of individuals or organisms that are closely related genetically . By analogy, the term is used in human reproduction , but more commonly refers to the genetic disorders and other consequences that may arise from expression of deleterious recessive traits resulting from incestuous sexual relationships and consanguinity . Animals avoid inbreeding only rarely. Inbreeding results in homozygosity which can increase

2635-448: Is unlikely that two unrelated partners will both be carriers of the same deleterious allele; however, because close relatives share a large fraction of their alleles, the probability that any such deleterious allele is inherited from the common ancestor through both parents is increased dramatically. For each homozygous recessive individual formed there is an equal chance of producing a homozygous dominant individual — one completely devoid of

South African Lipizzaners - Misplaced Pages Continue

2720-505: Is when the horse owner does all of the work related to the care of the horse themselves, called "do-it-yourself" (DIY) or "self-board". In the middle range, the term "full board" is used in the US to refer to several options, depending on the part of the country, from a facility that simply feeds the animals and possibly provides turnout, to one that handles all care of the horse, sometimes including exercise under saddle but not training per se . At

2805-574: The Crater lions, it is known that a population bottleneck has occurred. Researchers found far greater genetic heterozygosity than expected. In fact, predators are known for low genetic variance, along with most of the top portion of the trophic levels of an ecosystem . Additionally, the alpha males of two neighboring prides can be from the same litter; one brother may come to acquire leadership over another's pride, and subsequently mate with his 'nieces' or cousins. However, killing another male's cubs, upon

2890-538: The Haute ecole level. Later Janković-Bésán had to sell his herd, which then consisted of 6 stallions, 9 mares and 3 fillies , for financial reasons. They were purchased by Jack and Angela Irvin. About 1972, the Irvins went to Vienna and imported the stallion Maestoso Palmira to add new blood to the herd in order to prevent inbreeding . They later imported another stallion to use as an outcross , Siglavy Savona. However,

2975-629: The South American sea lion , there was concern that recent population crashes would reduce genetic diversity. Historical analysis indicated that a population expansion from just two matrilineal lines was responsible for most of the individuals within the population. Even so, the diversity within the lines allowed great variation in the gene pool that may help to protect the South American sea lion from extinction. In lions, prides are often followed by related males in bachelor groups. When

3060-696: The foundation bloodline of the same name. They also preserved an important branch of the Pluto bloodline. About 1890, the family stud farm at Terezovac (now in Croatia ), a part of the Jankovics-Bésán estate, was split up because of an inheritance issue. As a result, a second stud was founded in Cabuna , not far from Terezovac. After the resolution of yet another dispute over the Slavonian property of

3145-569: The recombination load , and allowing the expression of recessive advantageous phenotypes. Some species with a Haplodiploidy mating system depend on the ability to produce sons to mate with as a means of ensuring a mate can be found if no other male is available. It has been proposed that under circumstances when the advantages of inbreeding outweigh the disadvantages, preferential breeding within small groups could be promoted, potentially leading to speciation . Autosomal recessive disorders occur in individuals who have two copies of an allele for

3230-461: The round pen popular with natural horsemanship practitioners, which generally start at 40 to 60 feet (12 to 18 m) in diameter. Most arenas designed to allow more than one horse and rider pair to exercise safely at the same time are rectangular in shape and at the barest minimum are 50 to 60 feet (15 to 18 m) wide and at least 90 to 120 feet (27 to 37 m) long. The largest are commercial facilities designed for competitive events open to

3315-556: The British Queen Victoria or King Christian IX of Denmark . The House of Habsburg was known for its intermarriages; the Habsburg lip often cited as an ill-effect. The closely related houses of Habsburg, Bourbon , Braganza and Wittelsbach also frequently engaged in first-cousin unions as well as the occasional double-cousin and uncle–niece marriages. In ancient Egypt , royal women were believed to carry

3400-630: The Jankovics-Bésáns in the late 1920s, the horse breeding operation then moved to Öreglak in Hungary. In 1944, the owner of the stud, Count Jankovics-Bésán, was forced to flee Hungary due to the advance of the Red Army . He left with eight Lipizzans: six mares and two stallions. He first went to Sünching , Germany, where his parents' stud farm was located, and then he fled with his horses to Dorset , England, arriving at Christmas 1946 at

3485-536: The Lipizzan stallions and mares in South Africa are still direct descendants of the original six mares and two stallions. The stud now has up to 20 broodmares, and has become a genetic outcross pool for European studs, because these bloodlines were cut off for several generations from the rest of the world. Jack Irvin was also the head of the company National Chemical Products, which became the first sponsor of

South African Lipizzaners - Misplaced Pages Continue

3570-479: The Qatari population suffered from hereditary hearing loss; most were descendants of a consanguineous relationship. Inter-nobility marriage was used as a method of forming political alliances among elites. These ties were often sealed only upon the birth of progeny within the arranged marriage . Thus marriage was seen as a union of lines of nobility and not as a contract between individuals. Royal intermarriage

3655-578: The South African Lipizzaners, and the company continued its sponsorship until 1978. In the mid-1950s, George Iwanowski met Colonel Hans Handler , who at the time was second in command at the Spanish Riding School . Handler began to travel to South Africa once a year to help Iwanowski with the planning, the choreography and the training for the performance. The first public performances of the South African Lipizzaners

3740-448: The United States follows similar sizes. Stallions are sometimes kept in larger boxes, up to 14 feet (4.3 m) square, and mares about to foal or with foal at side are sometimes kept in a double-sized stall. Stables can be maintained privately for an owner's own horses or operated as a public business where a fee is charged for keeping other people's horses. In some places, stables are run as riding schools , where horses are kept for

3825-425: The abstention from inbreeding. Along with cultural taboos, parental education and awareness of inbreeding consequences have played large roles in minimizing inbreeding frequencies in areas like Europe. That being so, there are less urbanized and less populated regions across the world that have shown continuity in the practice of inbreeding. The continuity of inbreeding is often either by choice or unavoidably due to

3910-575: The academy as well as preserving a valuable genetic outcross pool for European studs. The roots of the South African Lipizzaners trace to two individuals, both immigrants to South Africa who were each born in Eastern Europe: Horse breeder Count Elemér Janković-Bésán de Pribér-Vuchin of Hungary and horse trainer Major George Iwanowski of Poland . The Jankovics-Bésán family was long known as influential breeders of Lipizzan horses. The animals they bred included Tulipan , founder of

3995-568: The animals. These buildings are normally subdivided to provide a separate stall or box for each horse, which prevents horses injuring each other, separates horses of different genders, allows for individual care regimens such as restricted or special feeding, and makes handling easier. The design of stables can vary widely, based on climate, building materials, historical period, and cultural styles of architecture. A wide range of building materials can be used, including masonry (bricks or stone), wood, and steel. Stables can range widely in size, from

4080-599: The available space, local custom, welfare concerns, and workload of the horses. In some countries, local organisations give recommendations as to the minimum size of accommodation for a horse. For instance, in Britain, the British Horse Society recommends that horses be kept only in boxes which allow freedom of movement, and that these should measure a minimum of 10 feet (3.0 m) square for ponies, and 12 feet (3.7 m) square for horses. Common practice in

4165-532: The bloodlines and so it was advantageous for a pharaoh to marry his sister or half-sister; in such cases a special combination between endogamy and polygamy is found. Normally, the old ruler's eldest son and daughter (who could be either siblings or half-siblings) became the new rulers. All rulers of the Ptolemaic dynasty uninterruptedly from Ptolemy IV ( Ptolemy II married his sister but had no issue) were married to their brothers and sisters, so as to keep

4250-517: The chance for these recessive alleles to pair and become homozygous greatly increases, leading to offspring with autosomal recessive disorders. However, these deleterious effects are common for very close relatives but not for those related on the 3rd cousin or greater level, who exhibit increased fitness. Inbreeding is especially problematic in small populations where the genetic variation is already limited. By inbreeding, individuals are further decreasing genetic variation by increasing homozygosity in

4335-477: The chances of offspring being affected by recessive traits . In extreme cases, this usually leads to at least temporarily decreased biological fitness of a population (called inbreeding depression ), which is its ability to survive and reproduce. An individual who inherits such deleterious traits is colloquially referred to as inbred . The avoidance of expression of such deleterious recessive alleles caused by inbreeding, via inbreeding avoidance mechanisms,

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4420-472: The chances of the expression of deleterious or beneficial recessive alleles and therefore has the potential to either decrease or increase the fitness of the offspring. Depending on the rate of inbreeding, natural selection may still be able to eliminate deleterious alleles. With continuous inbreeding, genetic variation is lost and homozygosity is increased, enabling the expression of recessive deleterious alleles in homozygotes. The coefficient of inbreeding , or

4505-439: The cheetah went through a population bottleneck that reduced its population dramatically so the animals that are alive today are all related to one another. A consequence from inbreeding for this species has been high juvenile mortality, low fecundity, and poor breeding success. In a study on an island population of song sparrows, individuals that were inbred showed significantly lower survival rates than outbred individuals during

4590-444: The closest available mate is a mother, sister, grandmother, father, brother, or grandfather. In all cases, the environment presents stresses to remove from the population those individuals who cannot survive because of illness. There was an assumption that wild populations do not inbreed; this is not what is observed in some cases in the wild. However, in species such as horses , animals in wild or feral conditions often drive off

4675-424: The degree of inbreeding in an individual, is an estimate of the percent of homozygous alleles in the overall genome. The more biologically related the parents are, the greater the coefficient of inbreeding, since their genomes have many similarities already. This overall homozygosity becomes an issue when there are deleterious recessive alleles in the gene pool of the family. By pairing chromosomes of similar genomes,

4760-399: The dominant male is killed or driven off by one of these bachelors, a father may be replaced by his son. There is no mechanism for preventing inbreeding or to ensure outcrossing. In the prides, most lionesses are related to one another. If there is more than one dominant male, the group of alpha males are usually related. Two lines are then being "line bred". Also, in some populations, such as

4845-405: The expression of genes that allow a population to adapt to an ecosystem . As the adaptation becomes more pronounced, the new species or race radiates from its entrance into the new space, or dies out if it cannot adapt and, most importantly, reproduce. The reduced genetic diversity , for example due to a bottleneck will unavoidably increase inbreeding for the entire population. This may mean that

4930-603: The first home of the South African Lipizzaners. The relationship between Janković-Bésán's horses and the training talents of Iwanowski began in 1951, when the two men met at the Royal Agricultural Show in Pietermaritzburg . Janković-Bésán then invited Iwanowski to his farm in Mooi River, and offered Iwanowski the Lipizzan stallion Maestoso Erdem for training. Iwanowski trained the stallion up to

5015-400: The general population. Children of parent-child or sibling-sibling unions are at an increased risk compared to cousin-cousin unions. Inbreeding may result in a greater than expected phenotypic expression of deleterious recessive alleles within a population. As a result, first-generation inbred individuals are more likely to show physical and health defects, including: The isolation of

5100-713: The general public with a performance space well over 150 by 300 feet (46 by 91 m) A riding academy or riding center is a school for instruction in equestrianism , or for hiring of horses for pleasure riding . Most feature a large indoor riding arena . At the time of the Napoleonic Wars large buildings were constructed for them, like Moscow Manege , Mikhailovsky and Konnogvardeisky maneges in St Petersburg . Many horses are turned out in to fields to graze , exercise, or exhibit other natural behaviours, either on their own or more usually as part of

5185-409: The genetic diversity of a population and cause problems related to a too-small gene pool that may include an increased prevalence of genetic disorders and inbreeding depression. Outcrossing is where two unrelated individuals are crossed to produce progeny. In outcrossing, unless there is verifiable genetic information, one may find that all individuals are distantly related to an ancient progenitor. If

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5270-411: The genomes of their offspring. Thus, the likelihood of deleterious recessive alleles to pair is significantly higher in a small inbreeding population than in a larger inbreeding population. The fitness consequences of consanguineous mating have been studied since their scientific recognition by Charles Darwin in 1839. Some of the most harmful effects known from such breeding includes its effects on

5355-412: The harmful allele. Contrary to common belief, inbreeding does not in itself alter allele frequencies, but rather increases the relative proportion of homozygotes to heterozygotes; however, because the increased proportion of deleterious homozygotes exposes the allele to natural selection , in the long run its frequency decreases more rapidly in inbred populations. In the short term, incestuous reproduction

5440-506: The inbreeding and the coancestry coefficients can be defined for specific individuals or as average population values. They can be computed from genealogies or estimated from the population size and its breeding properties, but all methods assume no selection and are limited to neutral alleles. There are several methods to compute this percentage. The two main ways are the path method and the tabular method. Typical coancestries between relatives are as follows: Breeding in domestic animals

5525-710: The limitations of the geographical area. When by choice, the rate of consanguinity is highly dependent on religion and culture. In the Western world, some Anabaptist groups are highly inbred because they originate from small founder populations that have bred as a closed population. Of the practicing regions, Middle Eastern and northern Africa territories show the greatest frequencies of consanguinity. Among these populations with high levels of inbreeding, researchers have found several disorders prevalent among inbred offspring. In Lebanon , Saudi Arabia , Egypt , and in Israel ,

5610-550: The mortality rate as well as on the general health of the offspring. Since the 1960s, there have been many studies to support such debilitating effects on the human organism. Specifically, inbreeding has been found to decrease fertility as a direct result of increasing homozygosity of deleterious recessive alleles. Fetuses produced by inbreeding also face a greater risk of spontaneous abortions due to inherent complications in development. Among mothers who experience stillbirths and early infant deaths, those that are inbreeding have

5695-473: The negative health consequences of excessive inbreeding. Linebreeding is a form of inbreeding. There is no clear distinction between the two terms, but linebreeding may encompass crosses between individuals and their descendants or two cousins. This method can be used to increase a particular animal's contribution to the population. While linebreeding is less likely to cause problems in the first generation than does inbreeding, over time, linebreeding can reduce

5780-568: The offspring of consanguineous relationships have an increased risk of congenital malformations, congenital heart defects, congenital hydrocephalus and neural tube defects . Furthermore, among inbred children in Palestine and Lebanon, there is a positive association between consanguinity and reported cleft lip/palate cases. Historically, populations of Qatar have engaged in consanguineous relationships of all kinds, leading to high risk of inheriting genetic diseases. As of 2014, around 5% of

5865-572: The population should also be considered when discussing the variation in the severity of inbreeding depression between and within species. With persistent inbreeding, there is evidence that shows that inbreeding depression becomes less severe. This is associated with the unmasking and elimination of severely deleterious recessive alleles. However, inbreeding depression is not a temporary phenomenon because this elimination of deleterious recessive alleles will never be complete. Eliminating slightly deleterious mutations through inbreeding under moderate selection

5950-438: The possible effects of inbreeding, such as congenital birth defects . The chances of such disorders are increased when the biological parents are more closely related. This is because such pairings have a 25% probability of producing homozygous zygotes, resulting in offspring with two recessive alleles , which can produce disorders when these alleles are deleterious. Because most recessive alleles are rare in populations, it

6035-580: The program. Chief Rider Ignaz Lauscha 's first trip to teach in South Africa was in January 1976, later on Rider Ernst Bachinger , Chief Rider Hubert Eichinger and Chief Rider Andreas Hausberger helped to train the stallions and riders. 25°58′13.4″S 28°3′17.3″E  /  25.970389°S 28.054806°E  / -25.970389; 28.054806  ( South African Lipizzaners ) Riding academy Horses are often kept inside buildings known as barns or stables, which provide shelter for

6120-664: The property of Lord Digby . Then, in December, 1948, Jankovics-Bésán brought the horses to South Africa where he settled in Mooi River in KwaZulu-Natal . Major George Iwanowski (born 13. March 1907, died 28. May 2008), a former Polish cavalry officer, set up the tradition of classical horsemanship in South Africa on his own. Iwanowski was born on the property of his family in Lebiodka , Poland (today Belarus ). He earned

6205-468: The purpose of providing lessons for people learning to ride or even as a livery stable (US) or hireling yard (UK), where horses are loaned out for activities in exchange for money. When operated as a business where owners bring their horses to be boarded, they are known as " livery yards " (BrE) or "boarding stables" (AmE and Australian English). There are a number of arrangements that horse owners can make with operators of these stables. The least expensive

6290-440: The rate of casual inbreeding. Many of the traits that affect profitability in crosses of modern dairy breeds have not been studied in designed experiments. Indeed, all crossbreeding research involving North American breeds and strains is very dated (McAllister, 2001) if it exists at all. The BBC produced two documentaries on dog inbreeding titled Pedigree Dogs Exposed and Pedigree Dogs Exposed: Three Years On that document

6375-401: The riding school being able to offer the horse to paying customers other than the owner. Horses are often exercised under human control, ridden or competed within designated fenced or enclosed places, usually called schools, pens or arenas. These can be of almost any size, provided they are sufficiently large for a horse to move freely, and can be located indoors or outdoors. The smallest are

6460-511: The same allele in an ancestor. These two identical alleles that are both derived from a common ancestor are said to be identical by descent . This probability F(A) is called the " coefficient of inbreeding ". Another useful measure that describes the extent to which two individuals are related (say individuals A and B) is their coancestry coefficient f(A,B), which gives the probability that one randomly selected allele from A and another randomly selected allele from B are identical by descent. This

6545-402: The singular form "stable" is also used to describe a building. In British English (BrE), the singular term "stable" refers only to a box for a single horse, while in the USA the term "box stall" or "stall" describes such an individual enclosure. In most stables, each horse is kept in a box or stall of its own. These are of two principal types: The choice of type of box is likely to relate to

6630-455: The takeover, allows the new selected gene complement of the incoming alpha male to prevail over the previous male. There are genetic assays being scheduled for lions to determine their genetic diversity. The preliminary studies show results inconsistent with the outcrossing paradigm based on individual environments of the studied groups. In Central California, sea otters were thought to have been driven to extinction due to over hunting, until

6715-542: The top end, the facility operator manages the entire care of the horse, including riding and training. In the UK, this is called "full livery". In the US, such settings may be called a "training stable". There are intermediate stages of care with parts of the care of the horse undertaken by each party, using terms such as "part livery" or "part board", with the terms not universal, even within individual countries, and usually agreed between owner and operator. Some stables also offer

6800-408: The trait carries throughout a population, all individuals can have this trait. This is called the founder effect . In the well established breeds, that are commonly bred, a large gene pool is present. For example, in 2004, over 18,000 Persian cats were registered. A possibility exists for a complete outcross, if no barriers exist between the individuals to breed. However, it is not always the case, and

6885-425: The transfer of deleterious alleles may be achieved by reproductive isolation, sterilization , or, in the extreme case, culling . Culling is not strictly necessary if genetics are the only issue in hand. Small animals such as cats and dogs may be sterilized, but in the case of large agricultural animals, such as cattle, culling is usually the only economic option. The issue of casual breeders who inbreed irresponsibly

6970-558: The type of gene action affecting a trait. Inbreeding is also used to reveal deleterious recessive alleles, which can then be eliminated through assortative breeding or through culling. In plant breeding , inbred lines are used as stocks for the creation of hybrid lines to make use of the effects of heterosis . Inbreeding in plants also occurs naturally in the form of self-pollination . Inbreeding can significantly influence gene expression which can prevent inbreeding depression. Offspring of biologically related persons are subject to

7055-439: The young of both sexes, thought to be a mechanism by which the species instinctively avoids some of the genetic consequences of inbreeding. In general, many mammal species, including humanity's closest primate relatives, avoid close inbreeding possibly due to the deleterious effects. Although there are several examples of inbred populations of wild animals, the negative consequences of this inbreeding are poorly documented. In

7140-495: Was in 1957. There were 4 riders. Other than Iwanowski, all riders at the academy were women. Some riders of the first graduating class were Mietie of Hartesveldt, Margie Widman, Ann Sutton, Lynn Jarmen, Gill Meyer, Anne Webb, Ania Glintenkamp, Eva Sydow, Carol Kretszchmar, Maureen Quinn, Helen Dalgliesh and Valerie Welsh. Other staff of the Spanish Riding School continued to travel to South Africa to further develop

7225-423: Was often practiced among European royal families, usually for interests of state. Over time, due to the relatively limited number of potential consorts, the gene pool of many ruling families grew progressively smaller, until all European royalty was related. This also resulted in many being descended from a certain person through many lines of descent, such as the numerous European royalty and nobility descended from

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