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.

To investigate effects of nitrogen on in-lake CO2 and CH4 production during winter, three pair of lakes was subject for a fertilizing experiment in which one lake in each pair was fertilized with nitric acid (HNO3) directly into the water column in the summer of 2012. The lakes in each pair are assumed to be morphologically, hydrologically and biologically similar, that is, the non-fertilized lakes are considered references. The pairs do differ in one major way by being progressively less humic, going from around 25 mg/l to 10 mg/l DOC. Sampling and analysis was carried out at the end of the frozen period in 2013. Results show a significantly higher concentration of both CO2 (p<0,001) and CH4 (?=0,1, p=0,053) between impact and reference sites in the two less humic pairs.

In Sweden, there has been a continuous increase in the volume of housing construction for dairy cattle. Since 2004, the number of new, rebuilt and extended dairy cow houses undergoing preliminary inspection by the authorities has grown. The livestock farms have mostly focused on cow units instead of calf and heifer sheds; which has led to a need for information in this area. The purpose of the study was to improve advisors? knowledge about bovine building construction and function; to enable them to provide more qualified advice to conventional and organic milk producers who sustain larger herds.

Several bulls in Sweden are culled because of lameness. Studies of beef bulls have shown that osteochondrosis is an important underlying cause of hind limb problems (Persson, 2003; Dutra, 1998). Osteochondrosis in horses, dogs, swine, poultry and man are well documentated in the literature, but there are few studies in cattle. The prevalence of osteochondrosis in dairy bulls in Sweden is unknown. The aim of this study was to investigate the presence and localisation of osteochondrosis in the hindlimbs of dairy bulls. This study consists of 48 one-year-old bulls divided into four groups related to which farm they came from.

Escherichia (E) coli is one of the most common udder pathogens associated with acute clinical mastitis in Swedish dairy cows. The aim of this study is to review some of the existing literature on E coli mastitis from a Swedish perspective. The bacteria, its most important characteristics, and diagnostics under field conditions is covered, as well as what happens during infection, how E coli affects the cow and which consequences this have. Clinical symptoms associated with E coli mastitis are described and information on when these cases of mastitis usually occurs is given. Risk factors in the cow?s enviroment are described as well as the importance of the cow?s immune defence.

Käppala wastewater treatment plant situated on the island of Lidingö northeast of Stockholm is running a project during 2004 and 2005 with the purpose to map out the capacity of anaerobic digestion in the digesters that treat primary and excess sludge. The purpose of this thesis work, which is part of that project, was to characterize the present anaerobic digestion process and to investigate its capacity to treat other organic wastes such as restaurant waste and waste from water works. To decide the potential of both methane and biogas production from different substrates batch laboratory tests were carried out. To imitate the anaerobic digestion process at Käppala continuous tests with small scale reactors were carried out. These reactors were later fed with restaurant waste.The batch laboratory tests showed that primary sludge had a potential biogas and methane production of 0,62 and 0,35 Ndm3/g VS respectively after 40 days of digestion.

The biogas plant Kungsängens gård, owned by Uppsala Vatten och Avfall AB, produces biogas and biomanure from organic household waste, food processing waste and slaughterhouse waste. In year 2012, 4.4 million Nm3 of biogas were produced from 25 200 tons of waste. Before digestion all substrate is sanitized by one hour?s pasteurization at 70°C in order to kill pathogens. Another method, integrated thermophilic sanitation (ITS), is of interest in order to decrease the energy demand.

The producers of grain in Sweden are facing a rough future. The competition is getting harder all the time, in Sweden, in EU and also from the ?world market?. The producers have to be more efficient and have to have bigger units. Many producers might have to look for new alternative production opportunities.

This study was made on former agricultural areas that had been planted with spruce or pine, in the county of Västerbotten. The goal of the project was to investigate suspected deficiency of boron in these areas. Several objects have been reported for possible deficiency and some of these have the characteristic symptoms of boron-deficiency. The hypotheses are that 1) Boron deficiency is present at several of the investigated objects. 2) Planting of forest on cultivated postglacial sediments leads to a successive podzolisation with a decreasing content of organic matter in the mineral soil, due to decomposition, and a decreasing pH in the soil, even on locations that have been added lime. To be able to confirm or reject the hypotheses a number of tests were performed.

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.

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.

This study forms part of the R&D project "Improved survival of bird chicks in organic fields" managed by the Rural Economy & Agricultural society in Uppsala. The skylark (Alauda arvensis) is a species that has decreased drastically in Sweden as a consequence of more intensive cropping. Studies in England have shown that skylark reproduction can be greatly improved within conventional fields, at a low cost, by establishing patches of bare ground (skylark plots). Within conventional farming, herbicides can be used in case a weed problem arises due to implementation of these skylark plots, whereas this is not allowed in organic farming. This study examined the effects of skylark plots on the weed culture in organic autumn-sown (winter) cereals and whether weeds might cause long-term problems to farmers. The study was conducted in two parts; a field study and a review of the literature regarding the weeds observed. The field study was carried out in 2007 during three weeks in June and three weeks in July, on eleven organic fields with winter cereal in the vicinity of Uppsala.

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.

One of Sweden?s sixteen national environmental objectives strives to decrease the impact on the climate. By 2020, green house gas emissions should be 40 % less compared to the levels of 1990 and a minimum of 50 % of the energy consumption should come from renewable energy sources. Because of this there is a great need of increasing the production of renewable energy. This is where biogas comes in as a competitive alternative.

The discussion about organic and fair trade products has been a big issue during the last few years. Despite an extensive knowledge about the environmental problems and a willingness to do something about it, the consumers are not always acting that way. Children do imitate their parents and other adults at an early age, so if the role models do not begin to act, think and dress ethically correct, neither will the children. Three problems have been identified out of the discussion. They relate to the questions of how older school children and parents of younger school children are taking sides regarding the organic/fair trade clothes and how existing trends in the society as well as those in fashion contexts influence their attitudes and consumer behaviour.