SAMMANFATTNINGMastit är den vanligaste och mest kostsamma sjukdomen hos mjölkkor. Enligt statistik från Svensk Mjölk har cirka 65 % av alla kor i Sverige mastit någon gång under en laktation. Subklinisk (utan märkbara symtom) mastit utgör det största problemet. De är svåra att upptäcka då även mjölken ser normal ut, vilket resulterar i att den hamnar i tanken och levereras till mejeriet. Mjölk från kor med mastit har ett ökat celltal samt försämrad kvalitet och sammansättning vilket i slutändan medför sämre betalt för lantbrukaren.

In modern dairy production the milking frequency is increased in some herds due to introducing of automatic milking systems or the farmers decision to milk high producing Dairy cows more than two times a day. With more frequent milkings the milk yield increases while the content of fat and protein decreases. However, how the composition of protein is influenced is not fully evaluated. The purpose of this study was therefore to see if a higher milking frequency had any impact on the milk production and especially on the protein composition. This study was conducted as a half udder experiment.

There are various arguments for using total mixed rations (TMR) or not. Cows can easily become fat and thus poorly utilize the feed while it can be stated that TMR also has a positive effect on cows? health and wellbeing as the rumen environment is more constant than when separate feeding is applied. Studies do show that that especially low yielding cows kept in groups get fatter when fed TMR. The overfeeding implicates higher feeding costs. This study included 10 herds where 5 had TMR and 5 hade separate feeding of forage and concentrates.

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.

After parturition the energy demand for milk production is greater then the energy provided from the diet. The cow mobilises therefore body tissues to compensate for the energy loss. Live weight and body condition scores decreases as a consequence of the mobilisation. The aim of this study was to analyse the relationship between body condition score, live weight and subcutaneous fat depth measured by ultrasound and the changes during the lactation. Possible differences between Swedish Holstein (SLB) and Swedish Red and White Cattle (SRB) were also investigated.

The decrease in the number of dairy farms in Sweden has been ongoing for a longer period of time. But the fact is that this has previously not had any big effects on total amount of milk produced in Sweden. The main reason is that the remaining dairy farms get larger. However, during the past year, there has been a decrease in the total amount of produced milk, because the decrease is faster than the increase within the farms that are left. During the same period of time the supply of milk on the global market also has decreased. In spite of the fact that the global supply have decreased and the fact that the milk price increases, there are dairy farmers in Sweden who chose to exit the market.

Maize for silage has been used as fodder in different parts of the world for a long time and has recently become more common also in Sweden. Our cold climate has been a problem as maize is very sensitive to low temperatures and frost. With new varieties and better techniques for cultivation it is now possible to grow maize in the southern and middle parts of Sweden. As for the north of Sweden the length of the cultivation season is a limiting factor as there are too few days with temperatures of over +10 ºC. Maize is well suited for silage making but oxygen-free conditions are required.

Difficult calvings and stillbirths are problems in Swedish dairy production that result in large expenses for the farmers and welfare issues concerning the animals. A common opinion is that the live weight of SRB and SLB is increasing, and whether increased weights have caused the increase in calving problems has been discussed. The aim of this study was to investigate the relationship between the relative birth weight (calf/cow) and calving difficulty and stillbirth, respectively. The importance of breed and parity for the relative weight has been investigated, and comparisons with previous studies have been made to evaluate whether the relative weight has changed over the last decades or not. The study was based on 807 calvings, registered during the period 1993-2003 in the experimental dairy herd of the Swedish University of Agricultural Sciences (Jälla).

Developments in milk production are heading towards fewer but larger herds where the milking process is often fully automated. Automatic milking systems were launched in the 1990?s and in the year 2010 the Automatic Milking Rotary (AMR) was introduced. As a rule there are no supervision personnel present during the milking event in systems with automatic milking. This means that there is a risk that cows can be incompletely milked in one or more udder quarters, for example if the robots fail in attaching the milking cups or if the cow kicks off the milking unit.

The purpose of this review was to study the cow eye physiology, focusing on how it registers light, and to see how light affects the cow?s milk yield. It has been showed in studies that more hours of light per day (16 hours of light a day) as opposed to about 9-12 hours of light a day, increases milk yield for Dairy cows. This review contains suggestions on how this is connected with the physiology of the eye. Vision is an important sense for many mammals, and is used to check out the animals surroundings. Sensor cells in the eyeball help in turning photons from the light into signals to the brain.

Ultrasound is still a relatively new method for the diagnosis of abdominal conditions in cattle. The objective of this study is to evaluate ultrasound as a diagnostic tool for the common diseases affecting high-producing dairy cattle, for example traumatic reticuloperitonitis, right- and left displacement of the abomasum, fatty liver, wound infections and abscesses. This paper is a combined litterature study and a report of the results from ultrasound examinations of bovine patients at the ruminant clinic at the Swedish University of Agricultural Sciences. The study includes two healthy cows from the ruminant clinic, and seven patients with abdominal related diseases. The examinations were made with a 2-6 MHz curvilinear transducer and both the right and left sides of the abdomen were scanned.

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.

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.

Milk and milk consumption has been subject of discussion for a long time, and is still a hot topic. Recently, as study was published that observed a correlation between milk intake and increased risk of fractures and mortality. The authors proposed the milk?s content of D-galactose as the possible mechanism, since D-galactose is used indicated ageing in animal models. Therefore, this study aims to develop a method to determine the amount of galactose, glucose and lactose in milk and fermented milk and apply it on to dairy products on the Swedish market.

The European Union provide 27 % of total volume raw milk produced in the world. This number is steadily decreasing due to that the world milk production increase is more rapid than EU production growth. The growing middle-class change the demand for food, a higher standard of living increase the demand of milk products as well as other various animal products. Since 1984 the EU milk quota has limited the supply from EU, but the quota will expire April 1st 2015. The European Milk Board expect that the removal of quotas will make the farm gate price decline.