The Annexin-V/propidium iodide (AV/PI) assay detects early membrane changes in spermatozoa and viability using flow cytometry. It is an objective method that evaluates a much larger number of single spermatozoa compared with the usual estimation of motility, the most commonly used method for routine sperm evaluation. In the present study four ejaculates from four Stallions were used in a split-sample design to investigate whether and how the number of intact spermatozoa is affected over time and after incubation at different temperatures, either those recorded during shipment of Stallion semen for AI (9 or 5°C) or room temperature (20°C). The Annexin-V results did not reflect the motility results that were monitored in parallel. While motility decreased over time, the number of spermatozoa with intact membranes (viable) remained unchanged for at least 21 hours following a short period of initial instability.

This project was initiated by a veterinarian, that at Stallion performance tests for breeding during a number of years, noted breed differences in various types of testicular disorders. Therefore it was of interests to examine the proportion of testicular disorders within certain breeds. The aim with the project was in a first part to study cryptorchidism in common horse breeds in Sweden. Information about castrations of Stallions performed during a 10 year period (2000-2009) was collected from computerized case records at five animal hospitals. The case records showed the numbers of castrations, normal cases and cases preformed on Stallions with cryptorchidism, abdominal respectively inguinal.

The main purpose of this study was to study the heredity of osteochondrosis (OC) in fetlock-, hock- or stifle joints within the Swedish half-bred population, using data from the regional animal hospital in Helsingborg. A large number of horses with clinical symptoms, for example lameness, are radiographed every year at the regional animal hospital in Helsingborg. In addition, many clinically healthy horses are radiographed in order to be sold (inspection radiographed / export radiographed). This study is based on electronically stored data from horses in both of these groups of patients that underwent joint radiography at the regional hospital in Helsingborg during the years 1992-1999. The first file (inspection file) contained 1035 observations from 983 horses that had their fetlock-, hock - or stifle joints radiographed for inspection or export. The other file (clinical file) contained 6121 observations from 3800 horses that were radiographed due to clinical symptoms in the fetlock-, stifle or hock joints.

In this trial we used QualispermTM as an objective method of measuring Stallion semen. Samples of semen were analyzed before and after centrifugation. Motility and concentration were statistically analyzed. During the trial all the objective mesaurments were compared to a subjective method. The advantages of QualispermTM compared to older CASA- systems is it´s ability of measuring a greater amount of spermatozoa while it also grades them into different subpopulations. These subpopulations have different qualities that decides their capacity of fertilization. The results showed that this objective method might be used practically. Although, there are still some disadvantages, such as high costs and the necessarity of accurat training of the handler. If it´s possible to prove further relevant results that also are statistically correct, this could prove the usefulness of QualispermTM as an objective measurment method in the daily work at gestuts and Stallion stations, thus giving the staff a reliable instrument in assisting the work for an improved horse breeding in Sweden, improving both in quality and economically..

This EEF-project is a part of a larger project at SLU, Division of Reproduction, Dept of Clinical Science, with the intention of developing and evaluating new methods for the assessment of Stallion semen quality. Over the last 10 years there has been an increase in the use of artificial insemination with cooled semen in Swedish horse breeding. At the same time, foaling rates have decreased. This has lead to a need for new and better methods of assessing the quality of Stallion semen. This EEF-project was based on an objective method to calculate motility, with QualispermTM, in fresh and cooled Stallion semen, and after selection. Today sperm motility evaluation is mainly done subjectively by visual assessment with a light microscope, and the correlation between these motility results and fertility have varied.

There is considerable variation between Stallions in semen quality and fertility due to the fact that selection of Stallions for breeding is not based on fertility or semen quality but on performance. The increasing use of cooled semen for artificial insemination has resulted in decreasing pregnancy rates. Therefore the equine breeding industry needs new methods for evaluation and development of sperm quality and fertility. This study is a part of such a project and is performed by SLU in cooperation with Flyinge AB. Ten Stallions at the Flyinge National Stud were used in the study and three ejaculates were collected from each Stallion.

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.

Breeding-induced endometritis in horses seems to be down-regulated by certain components in the seminal plasma. These components are most likely some of the proteins in the seminal plasma in the Stallion ejaculate, the so-called spermadhesins. This study aimed to recognize these proteins and determine their quantities in different fractions of the ejaculate. Fractionated ejaculates from four Stallions were used to determine the presence and amount of proteins by way of size-excluding chromatography. All former known proteins, except two, were recognized in this study.

At SLU, Divison of Reproduction, Dept of Clinical Science, there is an ongoing project on the development and evaluation of new methods for the assessment of Stallion semen quality. This EEF-study, which is a part of that larger project, has focused on the effects on motility and fertility of Stallion semen of two different extenders and selection. Both an objective method and a subjective method for analysis have been used and compared in the study. The increase in the use of artificial insemination with cooled semen in Swedish horse breeding over the last decade is thought to play a part in declining foaling rates (Kareskoski et al, 2006, Kuisma et al, 2006). This calls for better evaluation methods of semen quality since cooling and transportation put higher demands on semen quality in order to maintain fertility (Aurich, 2005).

Syftet med denna litteraturgenomgång var att presentera några av de vanligast förekommandelaboratorietesterna som används idag vid utvärdering av spermakvalité hos hingstar. Engranskning har också gjorts för att försöka utröna om det går att förutse hingstars fertilitetutifrån resultaten av dessa tester. De metoder som presenteras analyserar motilitet, morfologioch funktion hos spermierna i ett ejakulat. För att kunna fullfölja en befruktning krävs det attspermien uppfyller vissa kriterier. Detta för att kunna ta sig fram till äggcellen och smältasamman med denna och bilda ett embryo.

In Sweden the breeding organization for the Swedish Warmblood horse uses a traditional scoring system when evaluating horses. The horse is scored subjectively in relation to how good each trait is in relation to the breeding objective. Other countries, for example the Netherlands, instead use a linear scoring system. The linear scoring system evaluates the horse on a scale between two, for the breed, biological extremes which makes the evaluation more objective since the judges personal values does not influence as much. The breeding organization for the Swedish Warmblood is today planning a change towards a linear scoring system.

Most Swedish Warmbloods are bred by artificial insemination (AI). Quality control of the semen consists of the subjective evaluation of motility. There is a need for a more accurate and objective method of rating the semen. In this study we compared fluorometry with flowcytometry as a method for evaluating sperm viability. Semen was collected from three Stallions, stationed at Markebäcks Gård, Askersund, three times during week 15 and week 34, 2008.

Millions of preselected progeny have been born since the development of The Beltsville Sperm Sexing Technology 1986. The method is based on flow cytometry and sorting is done on the basis of DNA difference of the X- and Y-chromosomes. Preselection of progeny provides an opportunity to obtain genetic gain and increased production as well as increased animal welfare and decreased environmental impact. However, the method is associated with low fertility, high costs and uncertainty whether the sorting process contributes to DNA damage and thereby results in genetically impaired progeny. Today, sex sorted sperm is only commercially available in the bovine industry, due to the fact that bull sperm is more suitable for selection than sperm from other species.

Testicular measurements and daily sperm output (DSO) are important factors affecting reproductive capacity of Stallions. In the present study testicular measurements of 10 Swedish half-blood Stallions were determined (height, length, width and volume). Ejaculates were collected from each Stallion once daily for 10 days to evaluate some important seminal characteristics: gel-free ejaculate volume, sperm concentration, percent progressively motile spermatozoa and total number of spermatozoa (TSN). The gel-free ejaculate volume was measured with a graduated cylinder, the sperm concentration was counted in a Bürker chamber, the sperm motility was estimated in a phase-contrast microscope and TSN was determined by multiplying the gel-free seminal volume by the sperm concentration. Testicular measurements were as follows (left and right testis): height 7,5 cm and 7,8 cm, length 10,6 cm and 10,8 cm, width 6,5 cm and 6,6 cm, volume 278,2 cm3 and 293,8 cm3, scrotal width 12,3 cm and total testicular volume 572,0 cm3 .

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.