The heterosis effect and breed group effect of crossbreds between Swedish Holstein (SH) and Swedish Red (SRB) was estimated in this study. Observations on cows born between 1990 and 2012 were used to estimate the heterosis effect and breed group effect for several traits included in the Nordic breeding goals: production, fertility, udder health, calving performance, survival and other diseases. Breeding within the Holstein dairy breed has earlier been focused on increased milk production and conformation. This, combined with an intensive use of individual animals, has resulted in a radical increase of milk yield in the Holstein dairy cow population all over the world. However, this breeding strategy has resulted in increased inbreeding and several functional traits have impaired.

Barren rearing environment and early weaning of piglets can lead to a high level of distress, behavioural disturbances and reduction in weight gain. The main aim of this thesis was to study the effects of potential enrichment objects on piglet?s behaviour and weight gain during the pre- and post-weaning period. The second aim was to examine what type of object stimulated the highest frequency of interaction. The study was carried out at the Swedish Livestock Research Centre in Lövsta where a batch of litters from 10 first-parity Yorkshire sows were used.

Eight healthy 3-day-old foals were given repeated injections of trimethoprim-sulfadiazine intravenously for 3 days, at a dosage of 15 mg/kg bodyweight (2,5 mg trimethoprim and 12,5 mg sulfadiazine). Blood samples were collected prior to each administration and for the following 24 hours after last administration. Serum concentrations of trimethoprim and sulfadiazine were measured and the pharmacokinetics for the substances were studied. The elimination half time (t½) and clearance (ClB) for trimethoprim and sulfadiazine for the foals did not diverge from adult horses. According to these data it is possible to assume that the same dose interval and dose can be used for foals as for adult horses.

Eight healthy 3-day-old foals were given repeated injections of trimethoprim-sulfadiazine intravenously for 3 days, at a dosage of 15 mg/kg bodyweight (2,5 mg trimethoprim and 12,5 mg sulfadiazine). Blood samples were collected prior to each administration and for the following 24 hours after last administration. Serum concentrations of trimethoprim and sulfadiazine were measured and the pharmacokinetics for the substances were studied. The elimination half time (t½) and clearance (ClB) for trimethoprim and sulfadiazine for the foals did not diverge from adult horses. According to these data it is possible to assume that the same dose interval and dose can be used for foals as for adult horses.

Eight healthy 3-day-old foals were given repeated injections of trimethoprim-sulfadiazine intravenously for 3 days, at a dosage of 15 mg/kg bodyweight (2,5 mg trimethoprim and 12,5 mg sulfadiazine). Blood samples were collected prior to each administration and for the following 24 hours after last administration. Serum concentrations of trimethoprim and sulfadiazine were measured and the pharmacokinetics for the substances were studied. The elimination half time (t½) and clearance (ClB) for trimethoprim and sulfadiazine for the foals did not diverge from adult horses. According to these data it is possible to assume that the same dose interval and dose can be used for foals as for adult horses.

The aim of this report is to create an easily accessible guide to basic hygiene, cleaning and disinfection within the small animal practice. It is based on a literature study, using mainly research from the public health sector, due to the lack of relevant scientific reports within the veterinary field. To prevent the spread of infectious diseases it is important that the staff understands the importance of basic hygiene. Hand hygiene and disinfection and cleaning with water and detergent combined are the most important routines to prevent spreading of disease. In conclusion the differences between the veterinary and the public health sector are small, but some basic differences exist due to the nature of the patient?s needs.

Every year about 210 000 tones dry weight of sewage sludge is produced in Sweden. Most of the sludge is applied to agricultural land, plantsoil and landfill cover. Sewage sludge contains essential nutrients such as nitrogen and phosphorus. Nitrogen is limiting growth on solid ground in Sweden and can therefore be used as fertilizer to increase productivity. In order that the sludge can be spread to forest land it requires first a conversion of sludge to pellets, to make it more manageable.

Fusarium graminearum is one of the most important pathogens on cereals and causes major crop losses around the world. The most cultivated cereal in Sweden is winter wheat. F. graminearum produces both sexual and asexual spores for dispersal. Multiple factors affect the production of these spores.

Approximately 20% of the milk within the udder of a cow is stored in the cistern and immediately available for milk removal, while activation of the milk ejection reflex is required for removing the remaining milk stored in the alveolar compartment. The aim of this literature review is to describe, evaluate and consider implications of the three different suckling activities that the calf displays during a suckling bout. In terms of milking, these phases are represented by pre-stimulation, stimulation during milking and post-stimulation. Pre-stimulation is commonly performed in order to induce the milk ejection reflex, whereby the hormone oxytocin is released and the alveoli in the secretory tissue are contracted. Time requirements regarding pre-stimulation must be considered in relation to lactation stage and milking interval.

The purpose of this study was to investigate the occurrence of Verotoxin-encoding bacteriophages in mussels, cultured downstream the sewage treatment plant in Lysekil.Mussels were collected in three growing areas from April 2008 to March 2009. Real-time PCR was performed for detection of vtx1 and vtx2 genes and enrichment of bacteriophages on non Verotoxin-producing Escherichia coli O157: H7 was carried out. All samples in real-time PCR analysis were negative; no presence of Verotoxin-encoding phages was shown. No plaque was formed on blood agar base plates, indicating that no bacteriophages had been taken up by E. coli bacteriaThe levels of Verotoxin-encoding phages and E.coli outside the sewage treatment plant in Lysekil were not high enough to be able to form VTEC in mussels, indicating that the faecal contamination was low.

Two species of bees in the genus Apis, real honey bees, has long been of interest for man. These two are the European honey bee, Apis mellifera, and the Asian honey bee, Apis cerana. In Vietnam, beekeeping is of great importance, both with A.cerana and A.mellifera. The aim of this project was to investigate if the introduction of the European honey bee in Asia has affected the Asian honey bee, and whether different pathogens from A.mellifera have been transferred to A.cerana. Totally 40 samples, 20 from every species, were analysed for 8 different viruses.

Drinking water is produced from raw water and is either from groundwater or surface water. This thesis aims to find out if the cleaning process of raw water is sufficiently effective. This is important because consumers are otherwise at risk of waterborne infection caused by pathogens. There are three groups of pathogens; bacteria, virus and parasite. These have different characteristics which mean that they require different water treatment to be separated.

Drinking water is produced from raw water and is either from groundwater or surface water. This thesis aims to find out if the cleaning process of raw water is sufficiently effective. This is important because consumers are otherwise at risk of waterborne infection caused by pathogens. There are three groups of pathogens; bacteria, virus and parasite. These have different characteristics which mean that they require different water treatment to be separated.

Background: As a part of a national health control program, Statens VeterinärmedicinskaAnstalt performs diagnostics to screen flocks for certain pathogens causing high mortality,morbidity and/or serious economical losses. There are several viruses in the programincluding IBDV (infectious bursal disease virus), IBV (infectious bronchitis virus) and NDV(Newcastle disease virus). Method: 96 serum samples were collected from different poultryflocks in Sweden and analyzed by ELISA, which are currently used in the health controlprogram as well as by a commercial prototype of a multiplex immunoassay manufactured byLuminex Corp., which is currently under evaluation at the United States Department ofAgriculture USDA. This 4-plex assay detects antibodies for the three above-mentionedviruses as well as antibodies of avian reovirus. In the context of this study the ELISAs run inroutine diagnostics as well as a REO ELISA were used as the standard for comparison.Result: The antibody concentration in serum from vaccinated chickens was high while theantibody concentration level in serum from not vaccinated chickens was low.

Drinking water is produced from raw water and is either from groundwater or surface water. This thesis aims to find out if the cleaning process of raw water is sufficiently effective. This is important because consumers are otherwise at risk of waterborne infection caused by pathogens. There are three groups of pathogens; bacteria, virus and parasite. These have different characteristics which mean that they require different water treatment to be separated.