What does a horses pedigree mean?

What does it mean when a horse is inbred?

In Thoroughbreds, who have less occurence of linebreeding than Arabians, horses are said to be “inbred on a coefficient” if the same animal appears several times in the pedigree. “Inbred 2:3” means that the same horse appears once in the second and third generations.

Does inbreeding affect birthing rates in endangered horse breeds?

However, high levels of inbreeding in the endangered Przewalski and Sorraia horse breeds are associated with decreased birthing rates [ 2, 3 ]. It is possible that inbreeding has no measurable effects on reproductive traits until it reaches a very high level.

Where is the sire and dam on a pedigree?

The sire is always positioned at the top of the pedigree and the dam at the bottom. TAIL FEMALE LINE The ‘bottom line’ of a tabulated pedigree – ie the dam, second dam, third dam, fourth dam etc. TAIL MALE LINE The ‘top line’ of a tabulated pedigree – ie the sire, grandsire, great-grandsire etc.

What is the bottom line in a horse pedigree?

The female line of descent always appears at the bottom of a tabulated pedigree and is therefore often known as the bottom line. In addition, the maternal grandfather of a horse has a special term: damsire . ” Linebreeding ” technically is the duplication of fourth generation or more distant ancestors.

Is there inbreeding in Thoroughbreds?

The results indicate that inbreeding in Thoroughbreds has increased over the past 40 years, with r = 0.24, P < 0.001 demonstrating that there is a highly significant, though relatively weak correlation between the year of birth and inbreeding coefficients.

Does inbreeding affect gestation length and foaling rate?

Some studies have similarly shown that inbreeding has no effect on gestation length [ 12, 13 ], or foaling rate [ 11] in domestic horses. However, high levels of inbreeding in the endangered Przewalski and Sorraia horse breeds are associated with decreased birthing rates [ 2, 3 ].

Do artificial breeding practices mitigate the effects of inbreeding in Thoroughbreds?

The artificial breeding practices used in the Thoroughbred population that only allow a small proportion of high-quality males to breed may mitigate any effects of inbreeding on offspring sex ratios, and result only a small measurable heritable effect.

How does inbreeding affect foaling rates in Australian Thoroughbred mares?

Genetic bottlenecks and inbreeding can increase the frequency of deleterious variants, resulting in reduced reproductive levels in a population. In this study we examined the influence of inbreeding levels on foaling rate, gestation length and secondary sex ratio in Australian Thoroughbred mares.

What are the effects of inbreeding on reproductive traits?

The effects of inbreeding on reproductive traits vary between studies. Increased inbreeding levels were associated with reduced fertility in some domestic and wild horse populations [ 2, 3, 10 ].

Are Quarter Horses line bred?

That’s as close as they got, so while that’s obvious line breeding it’s less line breeding than one might expect for the father of one of the most devastating genetic diseases in the Quarter Horse breed. Symptoms include severe lesions and scarring on the back and withers.

What do the numbers on a horse pedigree mean?

On the right side of the pedigree, you’ll notice a column of numbers and letters that looks something like 5-f, 8-f, etc. These are female family numbers and trace the tail female pedigrees back to certain taproot mares.

Does inbreeding affect reproduction in horses?

It is possible that inbreeding has no measurable effects on reproductive traits until it reaches a very high level. Both the Sorraia and the Przewalski’s horse population have extremely high inbreeding levels (0.21 and 0.38, respectively) due to small effective population sizes and recent severe population bottlenecks [ 2, 3, 26, 27 ].

Is foaling rate and gestation length heritable?

While both gestation length and foaling rate were heritable, no measurable effect of inbreeding on either trait was found. However, we did find that the genetic value for both traits had decreased within recent generations. A number of environmental factors also had significant effects on foaling rate and gestation length.

What is the importance of inbreeding in animal experiments?

Laboratory animals. The inbreeding guarantees a consistent and uniform animal model for experimental purposes and enables genetic studies in congenic and knock-out animals. The use of inbred strains is also important for genetic studies in animal models, for example to distinguish genetic from environmental effects.

Why does foaling rate decrease with age?

The decrease in the genetic value of foaling rate is likely to be because horses with unfavourable genetic potential have not yet been selected out of the population. The change in genetic value of gestation length may be due to selective breeding favouring horses with shorter pregnancies.

How many foals can a horse have in one pregnancy?

Horses produce only one foal from an eleven-month gestation period, making the maintenance of high reproductive rates essential. Genetic bottlenecks and inbreeding can increase the frequency of deleterious variants, resulting in reduced reproductive levels in a population.

Do environmental factors affect foal sex ratios in Thoroughbreds?

However, we postulate that the high level of veterinary management and care provided to Thoroughbred horses in commercial stud farms examined in this study has resulted in no environmental or inbreeding factors having a measurable influence on foal sex ratios.

What is the relationship between inbreeding and genetic variation?

Abstract Increased rates of inbreeding are one side effect of breeding programmes designed to give genetic progress for traits of economic importance in livestock. Inbreeding leads to inbreeding depression for traits showing dominance, and will ultimately lead to a decrease in genetic variance within populations.

Do thoroughbreds have a problem with inbreeding?

Whether the breed is currently experiencing detrimental effects of inbreeding or not, there is still ongoing concern that the ever-narrowing gene pool of the Thoroughbred may be restricting genetic progress in both athletic and reproductive performance and contributing to eventually increased frequency of heritable diseases (Cunningham, 2001).

What are the effects of inbreeding in Thoroughbreds?

Effects of Inbreeding in Thoroughbreds. “Characteristics such as flightiness may be common in the Thoroughbred breed because they may be a contributing factor to their superior athletic performance,” Todd said. “On the other hand, there has been almost no selection on Thoroughbred horses for characteristics such as cold tolerance,…

How do you read a horse’s name?

Some horses will have a purple mark in the section for their name, some have other colors, like red, and green. There are other symbols too. If you could give me a rundown on how to read these symbols and colors that’d be awesome! This is a link to the pedigree of a horse in my horse’s pedigree.

What is the difference between a sire and a pedigree?

BY A horse is ‘by’ a certain sire – this term is never used for the dam. CATALOGUE-STYLE PEDIGREE A pedigree set out as in a sales catalogue – usually with a tabulated pedigree at the top, a description of the sire’s achievements at stud, and then detailed information on the dam and her race record, other progeny etc.

How do you identify an ancestor in a pedigree?

If an ancestor shows up more than once in the pedigree table, you can identify where it occurs by locating the matching colored boxes. In the first few generations of the pedigree, after the horse’s name, year of birth, and color, comes a race record and earnings for that horse.

What is the purpose of line breeding in animals?

Line Breeding. Line breeding is a less intensive form of inbreeding than close breeding. The object of line breeding is to keep the offspring related to an outstanding animal, usually male, which had desired characteristics. It aims to avoid some of the dangers attendant with close breeding. Uses of Line Breeding.

Why is inbreeding important?

Laboratory animals. The inbreeding guarantees a consistent and uniform animal model for experimental purposes and enables genetic studies in congenic and knock-out animals. The use of inbred strains is also important for genetic studies in animal models, for example to distinguish genetic from environmental effects.

Is inbreeding bad for your horse?

“A Thoroughbred horse that may be a superior racetrack performer may still carry some hidden genetic load, so inbreeding to them in future generations may have unexpectedly negative effects on some of their descendants,” said Todd.