43-651: A white horse is a horse born white that stays white throughout its life. White Horse , or variants, may also refer to: White horse A white horse is born predominantly white and stays white throughout its life. A white horse has mostly pink skin under its hair coat, and may have brown, blue, or hazel eyes. "True white" horses, especially those that carry one of the dominant white ( W ) genes, are rare. Most horses that are commonly referred to as "white" are actually "gray" horses whose hair coats are completely white. Gray horses may be born of any color and their hairs gradually turn white as time goes by and take on
86-513: A Thoroughbred foaled in England in 1780 named Messenger . He was a gray stallion imported to the United States in 1788. He sired a number of flat racing horses, but was best known for his great-grandson, Hambletonian 10 , also known as Rysdyk's Hambletonian, foaled in 1849 and considered the foundation sire of the breed and from whom all Standardbreds descend. Hambletonian 10 was out of
129-498: A dam with Norfolk Trotter breeding, and the mare and foal were purchased by William Rysdyk, a farm hand from New York state, who successfully raced the colt as a three-year-old against other horses. The horse went on to sire 1,331 offspring, 40 of whom trotted a mile in under 2 minutes 30 seconds. Another influential sire was the Thoroughbred Diomed , born in 1777. Diomed's Thoroughbred grandson American Star, foaled in 1822,
172-467: A high frequency in Standardbreds. OC/OCD is a moderate to highly heritable condition in Standardbreds and similar breeds, and genetic risk factors have been identified. These findings suggest that a change in breeding practices could lower the prevalence within the breed; however, lesions may resolve on their own or can be surgically corrected. In the 17th century, the first trotting races were held in
215-558: A leopard complex coat: whether one copy (heterozygous LP/lp ) or two copies (homozygous LP/LP ) Leopard alleles are present, and the degree of dense white patterning present at birth. If a foal is homozygous for the LP allele and has extensive dense white patterning, they will appear nearly white at birth, and may continue to lighten with age. In other parts of the world, these horses are called "white born." "White born" foals are less common among Appaloosa horses than Knabstruppers or Norikers, as
258-484: A minimal amount of pigment. White markings are usually visible upon closer inspection. Although white horses are sometimes called "albino" there are few cases of a true " albino " horse. There are also references in literature calling white horses "albino". Dominant white in horses is caused by the absence of pigment cells ( melanocytes ), whereas albino animals have a normal distribution of melanocytes. In other animals, patches of unpigmented skin, hair, or eyes due to
301-450: A result, birds and reptiles without the ability to manufacture tyrosinase are more accurately described as " amelanistic ." Horses do not have non-melanin pigments and so if they were albino, would have no pigmentation. The retained pigment of dilute horses, like cremellos, is not comparable to the retained pigment of amelanistic "albino" birds and reptiles. The cream gene, which is responsible for palomino, buckskin, and cremello coat colors,
344-688: A white appearance. Nearly all gray horses have dark skin, except under any white markings present at birth. Skin color is the most common method for an observer to distinguish between mature white and gray horses. White horses have unpigmented skin and a white hair coat. Many white horses have dark eyes, though some have blue eyes. In contrast to gray horses which are born with pigmented skin they keep for life and pigmented hair that lightens to white with age, truly white horses are born with white hair and mostly pink, unpigmented skin. Some white horses are born with partial pigmentation in their skin and hair, which may or may not be retained as they mature, but when
387-453: A white horse lightens, both skin and hair lose pigmentation. In contrast, grays retain skin pigment and only the hair becomes white. White colorings, whether white markings , white patterns or dominant white are collectively known as depigmentation phenotypes , and are all caused by areas of skin that lack pigment cells ( melanocytes ). Depigmentation phenotypes have various genetic causes, and those that have been studied usually map to
430-405: A wide range of pigmentation levels as a species. However, the diagnosis of albinism in humans is based on visual impairment , which has not been described in white horses. Vision problems are not associated with gray, dilute, or white coat colors in horses, and blue eyes in horses do not indicate poor vision. Eyes are pigmented at the front of the iris called the stroma , and in a thin layer at
473-445: A willing submissive nature. Standardbreds race either at a trot or pace . In the trot, the horse's legs move in diagonal pairs; when the right foreleg moves forward, so does the left hind leg, and vice versa. In the pace each foreleg moves in unison with the hind leg on the same side. However, the breed is able to perform other horse gaits, including the canter , though this gait is penalized in harness racing. Pacers still retain
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#1732845625168516-485: Is OCA1A , which impairs tyrosinase production. In other mammals , the diagnosis of albinism is based on the impairment of tyrosinase production through defects in the Color ( C ) gene . Mice and other mammals without tyrosinase have unpigmented pink skin, unpigmented white hair, unpigmented reddish eyes, and some form of vision impairment. No mutations of the tyrosinase or C gene are known in horses. Humans exhibit
559-619: Is a genetic disorder linked to the Frame overo (O) gene and most closely studied in the American Paint Horse . Affected foals are carried to term and at birth appear normal, though they have pink-skinned all-white or nearly-white coats and blue eyes. However, the colon of these foals cannot function due to the absence of nerve cells , and the condition cannot be treated. Foals with Lethal White Syndrome invariably die of colic within 72 hours, and are usually humanely euthanized . Carriers of
602-528: Is possible for trotters to produce a pacer, these gait-specific breeding practices are causing Standardbreds to differentiate into two subpopulations based on gait, more distinct than some breeds. The ability to pace is linked to a single-point mutation in gene DMRT3 , which is expressed in the I6 subdivision of spinal cord neurons; this area is responsible for coordinating the locomotor network controlling limb movements. The point mutation causes early termination of
645-412: Is responsible for a form of albinism. Many famous horses, past and present, were alleged to be "white" by observers, but were actually grays with hair coats turned fully white. Likewise, most white horses used in movies are actually grays , in part because they are easier to find. However, there are a few truly white horses who were used in film. One of the best-known examples was "Silver," ridden by
688-586: The EDNRB and KIT genes. However, much about the genetics behind various all-white depigmentation phenotypes are still unknown. Dominant white (W) is a large group of alleles best known for producing pink-skinned all-white horses with brown eyes, though some dominant white horses have residual pigment along the topline. Some W alleles produce white spotting on horses with a predominately dark coat. Dominant white has been studied in Thoroughbreds , Arabian horses ,
731-581: The Achaemenid court of Xerxes the Great (ruled 486–465 BC), In more than one tradition, a white horse carries patron saints or the world saviour in the end times, including Hinduism , Christianity , and Islam . Standardbred horse The Standardbred is an American horse breed best known for its ability in harness racing where they compete at either a trot or pace . Developed in North America,
774-943: The American White horse , the Camarillo White Horse , and several other breeds. There are 32 identified variants of dominant white as of 2021, plus sabino 1 , each corresponding to a spontaneously-white foundation animal and a mutation on the KIT gene. Researchers have suggested that at least some forms of dominant white result in nonviable embryos in the homozygous state, though others are known to be viable as homozygotes. While homologous mutations in mice are often linked to anemia and sterility , no such effects have been observed in dominant white horses. Dominant white horses typically have white noses that can be subject to sunburn . Sabino-white horses are pink-skinned with all-white or nearly-white coats and dark eyes. They are homozygous for
817-515: The Arabian horse , Clydesdale , Thoroughbred , Standardbred horse , or Shire horse . The Sabino 1 allele is not linked to any health defects, though sabino-whites may need some protection from sunburn . Horses with only one copy of the Sabino1 gene usually have dramatic spotting, including two or more white legs, often with white running up the front of the leg, extensive white on the face, spotting on
860-634: The Lone Ranger , a role actually played by two different white horses. At least one horse who played "Topper," ridden by Hopalong Cassidy , was also white. Another famous white horse is Sodashi , a Japanese Thoroughbred racehorse who won Grade 1 races including Hanshin Juvenile Fillies , Oka Sho (Japanese 1,000 Guineas) , and Victoria Mile . Throughout history, white horses have been mythologized in many cultures. For example, Herodotus reported that white horses were held as sacred animals in
903-622: The Paso Fino Horse Association registers cremellos and other cream colors as "albino." Until 1999, the American Quarter Horse Association (AQHA) described perlino or cremello horses as "albino" in rule 227(j). The AQHA later replaced the word "albino" with "cremello or perlino," and in 2002 the rule was removed entirely. Among Connemara pony breeders, homozygous creams are called "blue-eyed creams" or sometimes "pseudo-albino". The best-known type of albinism
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#1732845625168946-504: The "standard" required of breeding stock, to be able to trot or pace a mile within a certain time limit. Every Standardbred had to be able to trot a mile in less than two minutes and 30 seconds. Today, many Standardbreds are faster than this original standard, with several pacing the mile within 1 min, 50 sec, and trotters only a few seconds slower than pacers. Slightly different bloodlines are found in trotters than in pacers, though both can trace their heritage back to Hambletonian 10. At
989-577: The Americas, usually in fields on horses under saddle. However, by the mid-18th century, trotting races were held on official courses, with the horses in harness . Breeds that have contributed foundation stock to the Standardbred breed included the Narragansett Pacer , Canadian Pacer , Thoroughbred , Norfolk Trotter , Hackney , and Morgan . The foundation bloodlines of the Standardbred trace to
1032-724: The Standardbred is recognized worldwide, and the breed can trace its bloodlines to 18th-century England. They are solid, well-built horses with good dispositions. Standardbreds are generally well-muscled and similar to, but a bit heavier than, a Thoroughbred , with a large head often with a Roman nose profile , straight neck, sloping shoulder, defined withers, a deep girth, strong bone (legs) and hard feet. Standardbreds average 15 to 16 hands (60 to 64 inches, 152 to 163 cm) and typically weigh between 800 and 1,000 pounds (360 and 450 kg). They are most often bay , and less frequently brown , black , chestnut , gray or roan . Standardbreds are considered easy-to-train horses with
1075-429: The ability to trot and do so regularly; however, they are labeled by the gait they race at. Additionally, some trotters are able to pace, but prefer to race at the trot. Today's Standardbreds race in the same gait for their whole career, with rare exception. And although the gaits are similar, the pace is faster than the trot. Today's Standardbreds are commonly bred trotters to trotters, and pacers to pacers. Although it
1118-426: The back of the iris in tissue called the iris pigment epithelium . The iris pigment epithelium prevents damaging light scattering within the eye. Blue-eyed humans and mammals have little or no pigment in the stroma, but retain pigment in the iris pigment epithelium. If pigment is missing from both the stroma and the iris pigment epithelium, the only pigment in the eye is the hemoglobin in blood vessels. This accounts for
1161-511: The colored hairs of their coat become progressively silvered as they age, eventually giving mature gray horses a white or nearly-white hair coat. Gray is controlled by a single dominant allele of a gene that regulates specific kinds of stem cells . Gray horses are at an increased risk for melanoma; 70-80% of gray horses over the age of 15 have a melanoma tumor. True white hair is rooted in unpigmented skin that lacks melanocytes. In contrast, diluted coat colors have melanocytes, but vary due to
1204-411: The concentration or chemical structure of the pigments made by these pigment-producing cells, not the absence of the cells themselves. There are at least five known types of pigment dilution in horses, three which, as described below, can act to produce off-white phenotypes. Horses with strongly diluted coat colors usually have pale eyes (usually blue), cream-colored coats, and rosy-pink skin that contains
1247-597: The dominant SB1 allele at the Sabino 1 locus , which has been mapped to KIT . Sabino-white was one of the earliest dominant white alleles discovered, but was not originally recognized as such, hence the different name. The Sabino1 allele, and the associated spotting pattern, is found in Miniature horses , American Quarter Horses , American Paint Horses , Tennessee Walkers , Missouri Fox Trotters , Mustangs , Shetland Ponies , and Aztecas . Sabino 1 has not been found in
1290-482: The extensive dense white patterning is favored for producing dramatic full leopards. Homozygous leopards have the LP/LP genotype, and may be varnish roan , fewspot leopard, or snowcap patterned. Homozygous leopards are substantially more prone to congenital stationary night blindness . Congenital stationary night blindness is present at birth and is characterized by impaired vision in dark conditions. Lethal white syndrome
1333-528: The first Standardbred horse ever to win US$ 1 million, and the ninth horse to do so worldwide—the first eight were Thoroughbreds. The Amish have been purchasing off-the-track Standardbreds for a long time, and almost all Amish horses were first trained in the racing industry. A horse may have become too slow for racing, but it is not too slow for pulling a buggy . Standardbreds have an easy-going nature and readily take to such an environment. By purchasing ex-racehorses,
White horse (disambiguation) - Misplaced Pages Continue
1376-732: The foundation of the United States Trotting Association in 1939, a closed stud book was proposed. The studbook was not officially closed until 1973, however, it is likely that it was effectively closed prior. In 2009, in an effort to reduce the loss of genetic diversity within the breed, the United States Trotting Association capped the studbook for all new sires to 140 mares per year. This went into effect immediately for trotting stallions, and gradually for pacing stallions. Standardbreds are primarily used for driving and most start their lives headed to
1419-629: The gene by coding for a stop codon , thus altering the function of this transcription factor . Uniquely, both pacing and trotting American Standardbreds are fixed for the DMRT3 variant. This suggest that there is at least one additional genetic variant that controls trotting and pacing in Standardbreds. However, European Standardbreds are not yet fixed for this DMRT3 variant, although homozygous individuals have better performance records. Osteochondrosis (OC) , osteochondrosis dissecans (OCD) , and other related developmental orthopedic diseases (DOD) appear at
1462-507: The gene, who are healthy and normal, can be identified by a DNA test . While carriers often exhibit the "frame overo" pattern, this is not a dispositive trait and testing is necessary, as the pattern can appear in a minimal form as normal white markings or be masked by other white spotting genes. Genetically white horses have unpigmented pink skin (except where a horse with a W allele may have some darker pigmented areas) and unpigmented white hair, though eye color varies. The lack of pigment in
1505-574: The lack of pigment cells ( melanocytes ) are called piebaldism , not albinism nor partial albinism. All so-called "albino" horses have pigmented eyes, generally brown or blue. While true albino horses will have a pale blue or white eye. In contrast, many albino mammals, such as mice or rabbits, typically have a white hair coat, unpigmented skin and reddish eyes. The definition of " albinism " varies depending on whether humans, other mammals, or other vertebrates are being discussed. Despite this, some registries still refer to "albino" horses. For example,
1548-501: The midsection, and jagged or roaned margins to the pattern. The leopard complex, related to the Leopard ( LP ) gene, characterizes the Appaloosa and Knabstrupper breeds with their spotted coats. Leopard is genetically quite distinct from all other white and white-spotting patterns. The fewspot leopard pattern, however, can resemble white. Two factors influence the eventual appearance of
1591-557: The most noticeable difference between a gray horse whose hair coat is completely white and a white horse is skin color: most gray horses have black skin and dark eyes, white horses have light, unpigmented skin. The gray gene does not affect skin or eye color, so grays typically have dark skin and eyes, as opposed to the unpigmented pink skin of true white horses. The skin and eyes may be other colors if influenced by other factors such as white markings , certain white spotting patterns or dilution genes . Gray foals may be born any color, but
1634-643: The race track. Standardbreds are known for their skill in harness racing, being the fastest trotting horses in the world. Because of their speed, Standardbreds are often used to upgrade other breeds of harness racers around the world, such as the Orlov Trotter and French Trotter . In Australia, Canada, New Zealand, the United Kingdom, and the United States, races are held for both trotters and pacers. In continental Europe, all harness races are conducted between trotters. In 1968, New Zealand-bred Cardigan Bay became
1677-400: The reddish appearance of eyes in some types of albinism. In research mammals, such as mice, albinism is more strictly defined. Albino mice occur due to a recessive mutation of the C gene. No such mutation exists in horses. Albino mice lack pigment, but "...the inability of albino animals to produce pigment stems not from an absence of melanocytes...but from a deficiency and/or alteration of
1720-412: The skin and hair is caused by the absence of pigment-producing cells called melanocytes . Some coat colors are characterized by light or white-like coats and even pinkish skin, however these white-like coats are not lacking melanocytes. Instead, white-like coat colors result from various changes in the ways melanocytes produce pigment . Gray horses have the most common "white-like" coat color. However,
1763-481: The structure of tyrosinase in melanocytes which are otherwise normal." This definition of albinism in mice – the inability to make tyrosinase – is extended to other mammals. While mammals derive their pigments only from melanins, fish, reptiles and birds rely on a number of pigments apart from melanins: carotenoids, porphyrins, psittacofulvins, pterins, etc. Most commonly, reptiles with a condition homologous to human OCA1A retain their reddish and orangish hues. As
White horse (disambiguation) - Misplaced Pages Continue
1806-479: Was influential in the development of the breed through the mares of his progeny by American Star 14 being bred to Hambletonian 10. When the sport started to gain popularity, more selective breeding was done to produce the faster harness trotter. The first national Standardbred breed registry was formed in United States in 1879 by the National Association of Trotting Horse Breeders. The name arose due to
1849-553: Was mapped to the MATP gene in 2003 (now known as SLC45A2 ). This gene is sometimes called the OCA4 gene, because one mutation on SLC45A2 is associated with Oculocutaneous albinism type 4. However, other mutations in SLC45A2 are responsible for normal variations in skin, hair, and eye color in humans and . Although SLC45A2 is not the "albino gene"; one of many mutations of the human SLC45A2
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