Almost for as long as there has been breeding on bovine species, there has been a wish to have a higher proportion of offspring of either one or the other gender. In dairy cattle, heifers are more valuable, while in beef stock bulls are preferred. Semen is sorted based on the difference in DNA content between the X- and Y-chromosome in the genome of the sperm. X-chromosomes contain on average between 3,70 to 4,22% more genetic material than the Y-chromosome. Commercially it is the method of flow cytometry that is being used, which is always under improvement.

After a workshop in Kuopio held in June 2006, Interbull decided to go forward with the development of a system for beef international genetic evaluation and a three year project called Interbeef was launched in June 2007. The participating countries are so far limited to Europe and the only trait evaluated at present is adjusted weaning weight (weight at 200 days). The results from a first international genetic evaluation have been shared with the countries but are not yet official. The evaluation is based on data from purebred Charolais and Limousin. To achieve good estimates of proofs in an international context it is important that methods for data validation and model selection are implemented.

Neospora caninum is an intracellular parasite that was first recognized in dogs in 1984. The parasite is now one of the most commonly diagnosed infectious causes of abortion in cattle word wide. N. caninum is transmitted to cattle in two ways. They may be infected from eating food contaminated with oocysts from a definitive host or they may be infected in utero from an infected mother. The infection is transmitted efficiently from cow to her offspring and this can occur for generations.

Many pedigree dogs are suffering from inherited diseases or personality disorders caused by selective breeding. The Swedish lapphund is a breed that has been suffering from some loss of genetic variation due to the heavy use of only a few males. Concerns have arisen and crossbreeding has been discussed as a way to manage gene loss. Four breeds has been taken into consideration for this purpose; schipperke, finish lapphund, Norwegian buhund and Norwegian elkhound, black. These breeds has been tested theoretical by a comparison of mentality and health.

In Swedish sheep industry it is desired to have lambs slaughtered evenly distributed over the year. Swedish sheep are generally seasonal breeders with lambs born in the spring and slaughtered in the autumn. Some of the breeds, e.g. Swedish Finewool and Roslag sheep breeds have shown ability to lamb out of season. For increased knowledge on the possibilities to breed for out-of-season lambing in Swedish sheep breeds, the aim of this master thesis is to study the variation in frequency of two alleles in the MTNR1A gene in the three breeds; Gotland, Swedish Finewool, and Roslag sheep.

Most of the beef production in Sweden has been integrated with milk production. Since the 1990:s, the number of dairy cows has decreased. A specialised beef production has developed in purpose to compensate for this decrease. The consumption of beef have increased in the last decade, but the Swedish production has no followed this trend. In 2004, the percentage of beef self-sufficiency in Sweden was 60 %.

The release of green house gases and the environmental impacts humans have on the environment are huge and might cause irreversible changes to our earth. Meat is considered to have large impacts on the environment, especially beef meat and therefore there have lately been considerable discussions on the sustainable level of meat consumption and production. The main goal with this thesis is to study sustainable meat production and meat consumption in the county of Dalarna in Sweden. Indicators for sustainable meat production and meat consumption were developed and applied on three cases. Interviews were carried out with a municipality in the region that represents the consumer and three beef farmers that represents the producers.

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.

Many dairy farms doesn?t keep their bull calves and cross cow calves, they sell them to breeders instead of raising them their self. It should be possible for the dairy farmers to do it them self?s. There is also a possibility to bread one calf from the cross heifers. The purpose of the investigation was to see if there is any economic possibility to breed beef cattle. I have used the same sample farm trough the hole study, because it would be easier to fallow the study.

The release of green house gases and the environmental impacts humans have on the environment are huge and might cause irreversible changes to our earth. Meat is considered to have large impacts on the environment, especially beef meat and therefore there have lately been considerable discussions on the sustainable level of meat consumption and production. The main goal with this thesis is to study sustainable meat production and meat consumption in the county of Dalarna in Sweden. Indicators for sustainable meat production and meat consumption were developed and applied on three cases. Interviews were carried out with a municipality in the region that represents the consumer and three beef farmers that represents the producers.

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.

There are many theories why animals play but none have jet been proven. During observation on Canids, play seems to be important when they learn to control the intensity of the bite and to facilitate the social structure within a group. When dogs play they perform behaviours that otherwise are used during hunting, reproduction and aggression that in another context would be for example hostile. The dog is one of the species that we humans have domesticated and they have been exposed to an intense and concentrated breeding so they can function in different areas, for example herding and hunting. This breeding has resulted in that the pure bred dogs can be very different between the breeds.

In today?s genetic evaluation of Swedish beef cattle, mainly traits that are directly related to productivity are measured. However, other traits, such as temperament and mature cow weight affect the economy of the farmer, as well as the welfare of the animals. This thesis evaluates possible ways of measuring new traits, with focus on temperament and mature weight of suckler cows. The goal is to examine the possible benefits of including these traits in the Swedish breeding scheme.

Inom den svenska mjölkbranschen är användandet av köttrassemin i mjölkkobesättningar ett hett diskussionsämne för tillfället. Mjölkpriset är lågt och det sänker priset på dräktiga kvigor. Besättningar med god hälsa har lägre rekryteringsbehov och behöver inte alla sina kvigor för att upprätthålla koantalet och har nu svårt att sälja sina överskottskvigor. Med en kärv livdjursmarknad, tyngd ekonomi och växande besättningar borde köttrassemin bli ett alltmer attraktivt komplement i avelsplaneringen. Uppsatsen kommer att kretsa kring hur man optimalt kan använda köttrassemin i svenska mjölkbesättningar.

Icelandic horses are becomming increasingly common in Sweden. The owners of Icelandic horses in Sweden usually believe their horses to be different from other breeds. Icelandic horses are predominantly considered to be less reactive, less neophobic and easier to handle than other breeds. Swedish owners of Icelandic horses also usually try to house and handle their horses in a way similar to the traditional extensive Icelandic way. There are no scientific studies of breed differences between Icelandic horses and other breeds, or of the housing of Swedish Icelandic horses.