The purpose of this literature review was to investigate how the rearing systems influence the behaviour of dairy calves. Calves are social animals that form groups within the herd where play and social licking between calves are important social activities. Suckling is a complex behaviour and essential for the calf's survival. In the modern rearing systems the calf is usually separated from its mother soon after birth. Calves are then kept in individual pens, group pens or, more rarely, with a foster cow.

The dry period is usually 6-8 weeks and in this period the basis of the performance in the following lactation is settled. In an average herd about 15% of the cows are dry (Marcussen & Krog Laursen, 2008). In many herd the dry cows are set aside, that means setting aside 15% of your herd, at the time when they are preparing for their next lactation. The recommendation for number of groups differs depending on country traditions or reasons for grouping. If you look at recommendation for feeding, some companies selling feeding equipment advocates one group throughout the dry period, but the number differs from one to three.

The dry period is usually 6-8 weeks and in this period the basis of the performance in the following lactation is settled. In an average herd about 15% of the cows are dry (Marcussen & Krog Laursen, 2008). In many herd the dry cows are set aside, that means setting aside 15% of your herd, at the time when they are preparing for their next lactation. The recommendation for number of groups differs depending on country traditions or reasons for grouping. If you look at recommendation for feeding, some companies selling feeding equipment advocates one group throughout the dry period, but the number differs from one to three.

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).

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.

Today automatic milking systems (AMS) are growing in popularity. In these systems the cows are loose and have to get to the robot and the feed on their own. The cows ranking in this system affect their welfare. In this study data from seven years in an AMS was used and analysed. The aim was to investigate how ranking could affect the behaviour of the cows at milking and at feeding.

The aim of this study was to investigate the effects of an infusion of hypertonic saline solution (HSS) in combination with an oral waterload on cows suffering from rightsided displacement of the abomasum (RDA). Six dairy cows were treated with 7,2% HSS in a dosis of 5 ml per kg bodyweight. They also received an oral waterload of approximately 15 liters. To monitor changes in fluid-, acid-base- and electrolyte-balance, bloodsamples were collected during the next 24 hours. During this period, the cows also underwent surgery to empty and correct the position of the abomasum.

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.

Nötcenter Viken is a Swedish nucleus herd for dairy cattle. The goal for the farm is to select suitable mothers for the next top generation of bulls. Today the selection for udder health is based on a pedigree index and phenotype data. The pedigree index is based on the cow?s father and grandfathers breeding values.

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.

Higher demands of competitiveness and efficiency have led to increasing sizes of farms, with more land, more capital and more comprehensive logistics. The aim is to gain benefits of scale economies that reduce the production cost per unit. However, a greater extent of the business exposes the farm of increased risk where small deviations rapidly can erase the benefits. A modern dairy farm thus put high demands on the farmer?s ability to coordinate, plan and manage the forage production through the whole process until storage to obtain silage of the desired quality and quantity at the right price. The objective of this study was to design a simple model, i.e.

Mastitis is an important disease in dairy cattle. It is very costly for the farmers and affects a large number of animals. Few studies have been made investigating the outcome of treatment for acute clinical mastitis under Swedish conditions, and it can be problematic to use the results in foreign studies since both the microbial flora as well as treatments may be different from the situation in Sweden. In this project we have investigated data on clinical mastitis and antibiotic treatment in the dairy herd at Jällaskolan, Uppsala based on recordings during the last ten years. The material includes both Swedish Red (SRB) and Swedish Holstein (SLB) breeds, which have been kept at the farm under similar conditions.

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.

Concentration of protein in bovine milk is one of the most significant milk quality parameters, to a large extent determining the price for milk to the producer. Mastitis is a common disease among dairy cows, negatively affecting not only milk yield but also milk protein composition. Milk from mastitic cows tends to have lower cheese yield, negatively affected processability properties and sensory quality, due to changed protein quality and composition. Poorer milk protein quality would have an economically negative impact on dairy industry. Only few studies have investigated the short term effects of mastitis on milk protein composition.

Earlier studies of musculoskeletal problems with milkers working in milking parlour operators have shown that it is a physically demanding occupation. The extremities that are most exposed are neck, shoulders, hands and wrists. Those systems that have been studied in present cases are fishbone and some tandem barns. There have been changes in the working environment during the past ten years. The mechanisation has been developed for the better with automatically removers of the milking units and vertically adjustable floors in almost every daily milking barn. In other hand the milk production are more industrialised and more related to stress today.