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 incidence of many of the most common diseases in dairy cattle has been proven to be highest during the time closest to calving. It is possible that the current breeding strategy with 12 month calving intervals increases the risk for disease in dairy cattle, which is problematic concerning both animal welfare and for economic reasons. The economic incentives behind a calving interval of 12 to 13 months have mainly been based on milk- and feed- costs and no costs due to diseases or fertility disturbances have been included.The aim of this study was to see if a lengthening of the calving interval would result in lower disease frequency. The hypothesis is that cows with a planned calving interval of 15 months have a lower disease incidence than cows with a calving interval of 12 months due to less number of calvings. Therefore the difference in disease frequency should be larger when compared over a long period of time, such as over lifetime, since cows with a longer calving interval experience fewer calvings.The study was performed between August 17th, 1994, and January 24th, 2007.

Sweden is considered to have one of the world's highest animal welfare standards in agriculture. Despite this, there are shortcomings in animal husbandry. One example is overcrowding, which is a way to increase stock size without making costly investments in the buildings. It can be carried out systematically to increase profitability or due to, for example uneven calving during the year. The European Commission criticizes the fact that stocking density is not controlled under Swedish welfare inspections.

Magnesium is an essential mineral that is important for several physiologic and biochemical processes in the body. Deficiency of magnesium is mainly associated with grass tetany, but can also appear in cows during the indoor period. Since long it is known that potassium has a negative effect on the absorption of magnesium. Due to the fact that potassium fertilisation leads to a higher potassium content in forage, it is of interest to study interactions of potassium on the magnesium balance in dairy cows. There are few studies about magnesium feeding to dairy cows in Sweden and the purpose of this study was to investigate how much magnesium and from which feed-sources dairy cows in Sweden get their magnesium. Data was collected from seven farms in the northern part of Uppland and from seven farms in Skaraborg in Sweden.

Sweden is considered to have one of the world's highest animal welfare standards in agriculture. Despite this, there are shortcomings in animal husbandry. One example is overcrowding, which is a way to increase stock size without making costly investments in the buildings. It can be carried out systematically to increase profitability or due to, for example uneven calving during the year. The European Commission criticizes the fact that stocking density is not controlled under Swedish welfare inspections.

Distillers? grain is a by-product of ethanol production. Corn, wheat and barley are the grains that are generally used in the distillery process. Distillers? grain is rich in protein and phosphorus.

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.

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.

Investment costs for eight different type housing systems for dairy cows has been calculated in order to compare the building costs as a function of herd size, shelter type and automatization. A commercial calculation programme for building was used and complemented with prices of equipments specific for dairy cow building. Herd sizes were 120, 250 and 400 cows. The milking equipments were automatic milking system (AMS), parallel parlour with 32 stalls (2x16) and rotary parlour with 24 stalls. Shelter was either insulated equipped with automatic cable driven scrapers on solid alleys, automatic feed wagon on rails, or uninsulated with manual manure handling and a tractor driven mobile mixer wagon on a drive-through feeding table. Building cost per cow or per kg milk was calculated using an average life time and 6 % interest rate and annual milk yield is 9 500 kg/cow and year. Structure effect 3-4 % higher for an insulated structure than in an uninsulated for 400 and 120 herd respectively. This is much lower compared to what is normally argued.

The purpose of this literature review was from dairy cows? behaviour and welfare point ofview describe how feed bunk and cubicles in a loose house system should be designed. Todaydairy cows in Sweden and in the world have high demands because of a high milk production,stress and higher risk of being afflicted with diseases. Through selection in breeding the bestquality can be performed, but high demands of the environment for the dairy cow is above allalso important for a good welfare and for a good milk production. Feed bunks and cubiclesare just some parts to be designed in the best way for a good animal welfare.

The Swedish government has proposed that 20 % of the cultivated land in Sweden should be organic by the year 2010 (The Swedish Board of Agriculture, 2008). In addition to this the production of organic food like milk, meat and egg should increase considerably. To reach the government?s goal it is necessary that the Swedish farmers get motivated to convert their production from conventional to organic. Milko is a dairy association that has chosen to focus on organic products, they want to be the leading organic dairy association, and therefore they have a large need for organic milk (Milko, 2008).

The resting area is the most important place in the barn for the dairy cow, sometimes called the heart of the free stall system. Inadequate design of the lying area, and lack of or poor quality of bedding materials may reduce the hygiene of the stall. Poor management regarding the cleanliness of the resting area may lead to poor animal hygiene and increased bacterial growth. This in turn will lead to increased risk for environmental mastitis as well as impairing milk quality through contamination with spores. In this literature study the most commonly used bedding materials; straw, sawdust, wood shavings, clean sand, recycled sand, peat and recycled manure solids, are compared to one another with regards to their ability to resist bacterial growth. Effects of adding hydrated lime to bedding materials have also been studied. Most bacteria need humidity and prefer a quite high water activity to be able to grow.

This thesis consists of four case studies. The objective is to find out how to get a well functioning cow traffic in an automatic milking system. Different technical and building solutions are analysed and some adjustments are proposed for the DeLaval herd management software. Case study 1: Lactation chart comparison from traditional cow traffic and Feed First? cow traffic Case study 2: Farm A - a study of the precedence passage and the cow traffic Case study 3: Farm B ? an overview of the farm and their way of working Case study 4: Key factors ? how can we judge how well a VMS farm is working? Case study 1: Lactation chart comparison from traditional cow traffic and Feed First? cow traffic In this survey data is analysed from before and after rebuilding to Feed First? cow traffic. Lactation graphs are compared between traditional cow traffic and Feed First? cow traffic.

During the last decade a new technique in animal breeding has developed called genomic selection. It is based on estimations of the effect from genetic markers on traits that are calculated in a reference population. By genotyping individuals, genomic breeding values can then be estimated without phenotypic observations. The aim of this essay is to investigate the response of genomic selection on breeding schemes for dairy cattle. The accuracy of the genomic breeding values is affected by the proportion of observations included in the validation set and how often the equation for estimating breeding values is reevaluated.

The relatively poor economy in European dairy farming might be improved from efficient feeding systems and dietary management. Increasing herd sizes and transition to loose housing systems in Sweden, increases the possibilities for other feeding systems than separate feeding that is the traditional feeding system in Sweden. Other possible feeding systems are partial mixed ration (PMR) and total mixed ration (TMR), where the TMR system sometimes is associated with overfeeding and thereby increased environmental impact and high feed cost. Diets providing nutrients above or below animal requirements are considered as unbalanced, which in turn are associated with reductions in health, fertility and milk production. On the other hand, a balanced feed ration improves feed efficiency, nitrogen utilization and profitability.