An equine chromosome 3 inversion is associated with the tobiano spotting pattern in German horse breeds

The tobiano white-spotting pattern is one of several known depigmentation phenotypes in horses and is desired by many horse breeders and owners. The tobiano spotting phenotype is inherited as an autosomal dominant trait. Horses that are heterozygous or homozygous for the tobiano allele (To) are phenotypically indistinguishable. A SNP associated with To had previously been identified in intron 13 of the equine KIT gene and was used for an indirect gene test. The test was useful in several horse breeds. However, genotyping this sequence variant in the Lewitzer horse breed revealed that 14% of horses with the tobiano pattern did not show the polymorphism in intron 13 and consequently the test was not useful to identify putative homozygotes for To within this breed. Speculations were raised that an independent mutation might cause the tobiano spotting pattern in this breed. Recently, the putative causative mutation for To was described as a large chromosomal inversion on equine chromosome 3. One of the inversion breakpoints is approximately 70 kb downstream of the KIT gene and probably disrupts a regulatory element of the KIT gene. We obtained genotypes for the intron 13 SNP and the chromosomal inversion for 204 tobiano spotted horses and 24 control animals of several breeds. The genotyping data confirmed that the chromosomal inversion was perfectly associated with the To allele in all investigated horses. Therefore, the new test is suitable to discriminate heterozygous To/+ and homozygous To/To horses in the investigated breeds.

Retrospective evaluation of all recorded horse race starts in Switzerland during a four-year period focusing on discipline specific risk factors for clinical events

REASONS FOR PERFORMING THE STUDY: Racetrack injuries are of welfare concern and prevention of injuries is an important goal in many racing jurisdictions. Over the years this has led to more detailed recording of clinical events on racecourses. However, risk factor analyses of clinical events at race meetings have never been reported for Switzerland OBJECTIVE: To identify discipline-specific factors that influence the occurrence of clinical events during race meetings with the ultimate aim to improve the monitoring and safety on racetracks in Switzerland and optimise racehorse welfare. STUDY DESIGN: Retrospective study of horse race data collected by the Swiss horse racing association. METHODS: All race starts (n = 17,670, including 6,198 flat, 1,257 obstacle and 10,215 trot race starts) recorded over a period of four years (2009-2012) were analysed in multivariable mixed effect logistic regression models including horse and racecourse related data. The models were designed to identify discipline specific factors influencing the occurrence of clinical events on racecourses in Switzerland. RESULTS: Factors influencing the risk of clinical events during races were different for each discipline. The risk of a clinical event in trot racing was lower for racing on a Porphyre-sand track than on grass tracks. Horses whose driver was also their trainer had an approximately two times higher risk for clinical events. In obstacle races, longer distances (2401-3300 m and 3301-5400 m respectively) had a protective effect compared to racing over shorter distances. In flat racing, five racecourses reported significantly less clinical events. In all three disciplines, finishing 8th place or later was associated with clinical events. CONCLUSIONS: Changes in management that aim to improve the safety and welfare of racehorses, such as racetrack adaptations, need to be individualised for each discipline.

American beef producer.

Mode of access: Internet.

American Hackney stud book. Annual bulletin.

List of members included.

Pig breeders' annual.

Mode of access: Internet.

Ayrshire herd record.

New ser. v. 1-35 also as American and Canadian Ayrshire herd record, old ser. v. 5-39.

A report on the National Seminar of American Indian Women, held August 2-8, 1970 at Colorado State University, Fort Collins, Colorado.

Sponsored by the Country Women's Council, U.S.A. and the Associated Country Women of the World societies in the United States.

Statistics of the American and foreign iron trades /

Vols. for 1879-84 have subtitle: Annual report of the Secretary; for 1885-1911: Annual statistical report of the American Iron and Steel Association; for 1912: Annual statistical report of the Bureau of Statistics of the American Iron and Steel Institute.

Annual statistical report - American Iron and Steel Institute.

Title varies slightly.

Standard of perfection, standard bred rabbits and cavies, 1955 to 1960.

Mode of access: Internet.

Guide book and standard.

Mode of access: Internet.

Proceedings of ... meeting /

Vol. 1 contains proceedings of the 1st (1903) and 2nd (1905) meetings.

Horse publications and visual materials /

"October 1980"--p. 2 of cover.

Bulletin of the American Iron and Steel Institute.

Contains articles on iron and steel statistics, on the improvement of methods of producing iron and steel, and on the promotion of health and safety among employees.

The American Oxonian.

Vol. for 1934- include Addresses and occupations of Rhodes scholars and other Oxonians (called 1934-36, Addresses and occupations of Rhodes scholars).