Background: Mastitis in Dairy cattle is a common ailment worldwide. A cause of mastitis can be bacteria such as Escherichia coli. Mastitis is not a deadly ailment and sometimes the dairy cows show no symptoms but if certain virulence genes are present in the bacteria that cause the mastitis, the bacteria can be transmitted to humans and cause severe diseases. The potential presence of enterohemorrhagic Escherichia coli (EHEC) in particular would be a major concern for human health.Aim: The aim for this study was to analyze the presence of virulence genes known to be present in E.coli strains isolated from dairy cows with mastitis in Sweden.Method: A Qiagen BIO ROBOT EZ1 was used to purify DNA from 90 bacterial cultures. A panel of virulence genes were amplified and biotinylated from the purified DNA by PCR and an E.coli based DNA microarray was used to detect presumed virulence genes in E.coli.Result: There were no samples that had all the genes traditionally used to classify E.coli as EHEC or potential EHEC.

This paper shortly describes the coronavirus family, bovine corona viruses (BCV) properties and two diseases that BCV causes, winter dysentery and calf diarrhoea. The purpose of the study was to compare different diagnostic methods to detect BCV. Different methods are discussed, PCR, ELISA, immunofluorescense and virus isolation. Investigations were made in three different herds with winter dysentery; one dairy cattle farm with about 100 cows of different ages, one testing station for bulls with about 150 bulls and another small Dairy cattle farm with 26 cows and 20 replacement heifers and calves. Faeces and nasal swabs were analysed with PCR and ELISA. The result shows that PCR seems to be a reliable method for detecting BCV but that the ELISA test can not be used as a reliable diagnostic method to analyse samples from animals with winter dysentery..

Milk yield levels in dairy cows are influenced by many factors such as nutrition, breed, health status, management and environment. This study was conducted among small scale farmers in Zambia, where the climate can be dry for up to six months per year and cause a lack of green pasture for livestock and on-farm produced feed. The purpose of this study was to identify management factors that can influence milk yield at small scale dairy farms in Zambia, and present advice that could improve productivity, without the need of expensive investments. The study included semi-structured questionnaires presented to the farmers (n=29) including questions about cattle management and milk production. Testing of somatic cell count (SCC) with DCC (DeLaval Cell Counter) from herd milk samples (n=56) and observation of housing and animal body condition on-farm was also made.

Claw diseases are common diseases in modern dairy production. They are painful for the cow and costly for the producer. Differences in the prevalence of claw disease depending on housing system have previously been observed. This raises the question if there are genotype by environment (GxE) interactions for claw diseases in different housing systems. To investigate this claw trimming records for Swedish Red Dairy cattle (SR) and Swedish Holstein cows (SH) were retrieved from the Swedish Dairy Association.

Claw health has been recorded by claw trimmers at trimming in Sweden since 1996, but data was then captured at each AI association. From 2003 data was captured by central scanning and entered directly to the national cow data base at the Swedish Dairy Association (SDA). This reporting was introduced because SDA wanted to be able to use these records to improve dairy cow claw health by breeding. It is desirable with cows that have healthy claws, because poor claw health can contribute to impaired production and fertility. The claw health report begins with some information about herd, claw trimmer, date et cetera and continues with the part where the claw health is recorded. Here the ID of each cow is filled in and on the same row the conditions for dermatitis, heel horn erosion, sole haemorrhage and sole ulcer are recorded as no lesion (blank), slight lesion (/) or severe lesion (X).

With increased milkproduction in our Dairy cattle, comes a risk for a reduced fertility. Studies performed on animals and humans have shown that it is possible to manipulate the oestrous cycle through exposure to pheromones. This means that pheromones could potentionally be used to make reproduction more efficient. To evaluate the bioactivity of the substances in question, there is need for a bioassay. In insects, pheromones can induce a changed cardiac activity.

To turn the dairy heifers out on pasture is the most natural way for the cattle to get feed. At the same time it is cheap and if it is right treated a feed of high nutritive value. The problem today is to get dairy heifers to grow enough when they are grazing at natural pasture for the entire summer. Therefore, the opinions differ whether pasture is a resource or a problem. The increasing interest of pasture production is due to the fact that you can receive grants for preserving valuable natural assets and cultural landscape elements in the pasture land. A high grazing pressure is necessary to preserve an open landscape and a great variety of species. In the same time the heifers have to supply their nutritive needs in order to grow and be large enough to show heat and be pregnant in right time to calve with a sufficient body size and at an economically right age. This paper includes a literature review on natural pasture, pasture production, and growth of dairy heifers together with own interviews with dairy farmers about their point of view to the pasture husbandry on the farms, how they plan for pasture, look after natural pasture, treatment areas and take care of the calves and heifers. The results indicate that the time it takes and the demanded work are the biggest factors to how and why the farmers do as they do..

Oestrus in Dairy cattle has changed over the last decades; the intensity of oestrus has declined and the duration decreased. Several studies have shown that not all dairy cows stand to be mounted, and that oestrus expression in many cases may be characterized by other behaviours. The aim of this study was to investigate oestrus behaviour in a herd of todays? high producing Dairy cattle. The study was carried out at Jälla naturbruksgymnasium in Uppsala during one week in January 2011.

The ability of dairy cows to survive and the economic importance of this have been in-creasing in Dairy cattle breeding lately. Increased longevity contribute to an increased pro-portion of cows that produce milk in more productive lactations and reduces the replace-ment costs together with a good health and fertility. Unfortunately it is often argued that longevity has been decreasing due to a strong selection for production traits in Dairy cattle.The aims of this study were to find correlations between different longevity evaluations and between different estimates on longevity and other traits in the Nordic Total Merit (NTM) breeding value. The aim was also to compare different traits for cows of two differ-ent longevity groups.The data were Predicted Breeding Values (PBV) from Nordic HOL and SR bulls and records from Holstein (HOL) and Swedish Red (SR) cows estimated by the Swedish Dairy Association.The three Swedish longevity indexes were very highly correlated (>0.89) and the corre-lations between the Swedish official longevity index and the five Nordic Cattle Genetic Evaluation (NAV) longevity indexes varied between 0.73-0.83.In the sire evaluation part, the traits most negatively correlated with longevity for HOL were dairyness, protein and fat index. In SR, milk, protein, and fat index only had slightly positive correlations with longevity.

Heat stress negatively influences the performance of Dairy cattle such as lactation and reproduction. Heat stress can cause production losses as well as welfare problems. Years of research have shown that heat stress is a huge problem for Dairy cattle in both the tropics and temperate zones but no such research have so far been done in northern European countries. It seems like shade is an important tool when improving pasture conditions and therefore deserves more attention. The aim with this study was to investigate whether there is a need of providing shade for grazing dairy cows during the summer in Sweden. Two groups of lactating Swedish Red dairy cows (n=15 per group) were kept on pasture.

Very little is known about the health situation amongs Swedish dairy goats. The population of Swedish dairy goats can only be estimated, and that number is somewhere .

To value the risk and opportunity for our production in Sweden it is necessary to understand the marketing development for beef cattle production in the world. We have chosen to look at the Brazil beef cattle production. They are one of the biggest producers, have good opportunity to develop further and have a big affect at the world market. The method of our work is to gather information from experts of beef cattle production, located in Brazil. We have also gathered information through studies of literature. The factors that will have a big influence at the Brazil beef cattle production during the upcoming years is more efficient land use, lower age of slaughtering and extended use of feedlot-system. Our conclusion is that the Brazil beef cattle will have a sharp increase during the next five years. The amount of pasture will not change during that time.

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.

When cows in Sweden are inseminated the heat strength is reported to the Swedish milk-recording scheme and AI scheme. Cows that show strong signs of estrus are desirable and the trait is included in the Swedish breeding goal. A strong heat makes it easier to inseminate at the right time and to avoid long and expensive days open. Since ten years the heat strength is scored from one to five by the farmer and reported to the milk-recording scheme and AI scheme. Earlier the score was from one to three and the decision was made by the AI technician.

The aim of this literature study was to analyze how milk urea concentration is working as a measure of the nitrogen supply to rumen microbes and indicator of the environmental load. Questions included in this literature study were how to improve the Dairy cattle nitrogen efficiency and what correlations there are between milk urea, nitrogen efficiency and crude protein content in the feed. Effects on the reproduction from high ration protein content are also addressed. Dairy cattle are today fed with large proportions of protein which could lead to high expenditure of feed and environmental pollutions. The nitrogen can be lost to the environment by different pathways; leaching, denitrification or by emission to the air.