The genetic relationship between three Swedish horse breeds was investigated using microsatellite data from 144 loci in 30 horses. The North Swedish Trotter is believed to have been crossed with the Standardbred in the 1950?s to produce a faster trotter. If true, the North Swedish Trotter should be more alike the Standardbred than what the North Swedish Draught Horse is, from which they originate. This was investigated using F-statistics and Nei?s distance in GENEPOP and GENETIX and cluster assignment in STRUCTURE.

Laminitis is a debilitating disease causing much suffering to horses and ponies all over the world. It is manifested in the hooves as a mechanical failure of the suspensory apparatus between the hoof capsule and the distal phalanx. Due to the weight of the horse the disease may result in a dislocation of third phalanx. Six healthy Standardbred trotters were used in this study on whether Standardbreds tolerate forced recumbency as well as Shetland ponies. Recumbency was induced pharmacologically but maintained only by lowering the ceiling height of the box to a height of approximately 125 ? 140 % of the horse´s thoracic height.

The purpose of this thesis was to analyze conception and foaling results of Swedish warmblood and Standardbred trotters using breeding statistics during the years 2000-2006. Key issues in this thesis were: Have the conception and foaling results of stallions changed during the period 2000-2006? What is the effect of the use of various breeding methods? Is testicle size correlated with conception and foaling results? How important are age, breed and level of inbreeding of the stallion for conception and foaling results? Breeding statistics were available for 537 Swedish Warmblood stallions and 305 Standardbred trotter stallions. To be included in the analyses, a stallion must have mated at least ten mares in total over the period 2000-2006. This criterion was met by 313 Swedish Warmblood stallions and 272 Standardbred trotter stallions.

Records of P III fractures from 235 horses, 71 of them were Standardbreds, treated at 3 major Swedish equine hospitals (Strömsholm, SLU and Mälaren hästklinik) between 1994 and 2004 were evaluated for information such as the patients age, sex, breed, type of fracture, affected leg, time and place of the injury, treatment and, if possible, result of treatment. For the Standardbreds, result of treatment was also followed up through written correspondence with owners and by screening AB Trav och Galopp racing-results. Moreover, results of horses with type II and III-fractures treated with rest and therapeutic shooing only were compared to horses in which lag screw fixation were added to achieve interfragmental compression. Compared to the rest of the Swedish horse population, P III fractures were slightly more common among Standardbred horses. The mean age of the affected Standardbred was 5,8 years, compared to 7,9 years in the rest of the horse-population. Most horses injured themselves in the paddock.

The purpose of the study was to investigate whether or not Icelandic horses are less severely affected in clinical symptoms of cough or decreased performance than other breeds of horses. A breed variation in chronic respiratory disease severity was suspected based on clinical experience at the Institution for surgery & medicine, large animal, SLU Uppsala. A retrospective journal study of 17 Icelandic horses and 17 Swedish Standardbred horses with chronic problems with cough and/or decreased performance compared several measurements of disease severity. The clinical signs, physical examination and laboratory testing results compared were respiratory rate, abdominal breathing, lung auscultation, endoscopy results, broncho-alveolar lavage (BAL) results and the blood gases pO2 and pCO2. All parameters were available for all 34 individuals except for the blood gases, which were analysed, in only four Icelandic horses and four Swedish Standardbred horses. The only parameters that appeared different between the two groups were respiratory rate and pO2. The four Icelandic horses, which had blood gases analysed, had more severe hypoxemia.

The aim of the project was to study the effect of oral administration of glucose and leucin on the resynthesis of muscle glycogen after intense exercise in Standardbred trotters. In a crossover design, 11 Standardbred trotters performed a standardized exercise test on two occasions in order to deplete muscle glycogen. The exercise test comprised a warm up period, 7 repeated bouts of exercise on an uphill 500 m slope, and a recovery period. After the exercise test horses received: 1) a solution of glucose and leucine via a nasogastric tube at 0 minutes and at 240 minutes post exercise and a single bout of glucose at 120 minutes post exercise or 2) water (placebo) at 0, 120 and 240 minutes. Blood samples for measurement of glucose and insulin concentrations were collected at rest, when the horses returned to the stables directly after exercise and throughout the 6 hour recovery phase. During the first recovery hour, samples were collected every 15 minutes and then every 30 minutes over the next 5 hours.

Equine metabolic syndrome (EMS) it?s a clinical condition that includes obesity, regional adiposity, insulin resistance (IR) and laminitis. A similar syndrome exists in human medi-cine, the metabolic syndrome (MS), were systemic hypertension also is a prominent fea-ture. The systemic hypertension seen in humans with MS is partly due to a vascular endo-thelial dysfunction with an enhanced endothelin-1 (ET-1) mediated vasoconstriction. There are indications that systemic hypertension might be a feature in EMS as well but if ET-1 is involved in the development of the systemic hypertension in horses is not known.

EVA, Equine Viral Arteritis, was diagnosed for the first time in 1953 in USA. The disease gained international interest in 1984, when there were several outbreaks of abortion at Thoroughbred studs in USA. EAV, Equine Arteritis Virus, is an RNA virus in the Arteriviridae family. There is only one serotype of EAV but several strains and the strains have different virulence. EAV is transmitted in two different ways: by aerosols, or by venereal transmission.

The aim of this study was to evaluate whether gallop training, rather than regular drive training, is worthwhile for trotters race performance. Another aim of the study was to expand the author?s riding- and driving capacity, and get more practical experience on the impact of interval training on trotters. The sample population in the study was two trotters, one Standardbred, and one cold-blood. Given the small sample population, the results of the study is only indicative on the effects of gallop training on trotters, and not conclusive.

The aim of this study was to evaluate whether gallop training, rather than regular drive training, is worthwhile for trotters race performance. Another aim of the study was to expand the author?s riding- and driving capacity, and get more practical experience on the impact of interval training on trotters. The sample population in the study was two trotters, one Standardbred, and one cold-blood. Given the small sample population, the results of the study is only indicative on the effects of gallop training on trotters, and not conclusive.

Abortion during late gestation is often caused by placental dysfunction such as placentitis. To prevent this from happening the placenta can be monitored pre partum so treatment can be started at an early stage. Methods for monitoring the placenta include hormonal monitoring, presence of clinical signs of placental dysfunction and ultrasonographic evaluation of the fetus and the placenta. Transrectal ultrasonography provides a very good image of the caudal portion of the allantochorion where an ascending placentitis normally establishes. An increased combined thickness of the uterus and the placenta, CTUP, has been associated with placental failure. This study included ten Swedish Standardbred trotter mares in late gestation. They were monitored by transrectal ultrasonography of the placenta two times with approximately a month in between. CTUP was measured on each examination.

Samodling är en odlingsmetod som kan användas för att förbättra dagens odlingssystem. Metoden innebär att två eller flera kulturer odlas tillsammans under en större del av växtsäsongen. Samodling kan användas på flera olika sätt för att förbättra odlingsförhållandena för antingen huvudgrödan eller hela odlingen. Den har en bevisad effekt på olika skadegörare och kan minska angreppen i odlingen. Samodling kan även användas för att minska ogrässpridningen, förbättra mikroklimatet, samt öka antalet maskar och naturliga fiender i odlingen.

Suspensory ligament injuries are a common cause of lameness among sport horses. These injuries are expensive due to slow healing, extensive convalescence and high risk of recurrence. The prognosis has been reported to be everything from good to guarded depending on the size of the lesion and the location within the suspensory ligament. The purpose of this study was to determine how different factors such as age, use, and location of the lesion are associated with the final outcome after a suspensory ligament injury. Material: Hospital records of 27 horses treated for suspensory ligament injuries at SLU equine hospital in Skara, Sweden, between January 2002 and July 2003 were examined retrospectively.

Inbreeding has become a problem in some horse breeds. Studies show that it may lead to inbreeding depression which affects e.g. reproduction traits. In the wild there are mechanisms that make horses avoid mating with close relatives. When selection is done by humans this mechanism is removed and intensive breeding for a few traits, for example good racing results, can become a problem.

In the latest edition of NRC (2007) the feeding recommendations for Ca and P to growing horses were increased with 35 and 25 %, respectively, based on results from a Canadian study showing that daily endogenous fecal losses of Ca and P were greater than previously suggested. A Ca absorption efficiency of 50 % is used for all horses. However, the true absorption efficiency might be as high as 70 % in young horses. P absorption efficiency is assumed to be higher for growing horses because their diets are often supplemented with inorganic P. Thus, an efficiency of 45 % is used for growing horses as compared to 35 % for mature horses.