Bovine viral diarrhoea virus (BVDV) is the causative agent of a complex of disease syndromes in Cattle with high economical and welfare impacts. BVDV occurs as two biotypes; cytopathic (BVDVcp) and noncytopathic (BVDVncp) determined by differential effects on cultured cells and can also be divided into two genotypes (BVDV1 and BVDV2) on the basis of genomic diversity. The interaction between BVDV and the host?s immune system is regarded a key aspect in the sequel of BVDV infection. Infection with BVDV normally causes an acute transient infection, with mild to subclinical signs, but occasionally results in severe and even fatal disease.

Magnesium is one of the most important minerals in the body and it participates in many essential processes, such as energy metabolism and protein synthezis. Magnesium deficiency in Cattle may occur when they are let out for pasture in the spring, and is associated with tetany, known as grass staggers. A high yielding dairy cow often loses more magnesium daily in the milk than she has available in the body, and magnesium thereby needs to be provided in the feed to prevent the cow from being affected by deficiency symptoms. The uptake of magnesium is mainly located to the rumen and is not regulated by hormones. The surplus is excreted in the urine by the kidneys.

Oestrus in dairy Cattle has changed over the last decades, the duration has decreased and the intensity of oestrus has declined. A possible explanation can be their high and increasing milk production. Heifers ability to show oestrus is probably not affected to the same extent. The aim of this study was to estimate and compare oestrus duration and strength in heifers of the Swedish Red and Holstein breeds. Standing oestrus has been the primary oestrus sign during many years.

Green manuring is a way of creating an organic fertilizer by growing a crop that is mowed down. Besides the fertilizing effect this method has been shown to have a positive influ-ence on soil organic matter as well as weed flora, and green manure is an important me-thod of weed control in organic farming in parts of Sweden. However, the release of nu-trients from the green manure varies and can therefore be difficult to control. Risks for losses of nutrients are also present. Although the area of organic farmland is increasing in Sweden, the use of green manure is decreasing.This report contains a literature study which compiles research on the functions of green manure in a cropping system and also how the crop can be used if harvested, for example to produce biogas.

There are a great possibility to shorten the time between mowing and preservation by spreading of ley crops in connection to the conditioning. In this case the cellular respiration (the plants breeding that consume sugar until the crop is ensiled) should not continue as long and the forage will perhaps get a higher nutritional value. The capacity of the next machine could also be higher because the rake gives swaths with a lot of material. There is also a possibility that spreading of ley crops gives the material a more homogeneous content of dry matter and that gives a reduced growth of clostridium. This is particularly important when the method of harvest doesn?t include any mixing of the material like it does with a round baler or silagewagon.

Fieldstudys on 22 farms (23 silos) to study relationships between the actual particle size of the maize silage and the theoretical length of cut. The measure of theoretical length of cut were stated by the farmers and not measured by us. Particle size of maize silage was determined using the New Penn State Forage Particle Separator. SLU Skara made a special sieve for us, that had larger holes than de original sieves. The samples were shaken after instructions and then the material was weighted. We have also been taking out samples for microbiological analyses from the silos on 13 of the farms.

The world?s growing need for energy together with a desire to ward off the worst consequences of global climate change has resulted in a never seen desire to invest resources in renewable energy sources. Biogas production through anaerobic digestion is one of those growing energy sources. In Sweden there are over two hundred plants that uses this biological process to break down organic substances while producing carbon dioxide and the energy-rich gas methane.This master?s thesis has focused on development of the mixture of different organic substances that is treated at a specific plant, namely Mosserud biogas plant.

Green manuring is a way of creating an organic fertilizer by growing a crop that is mowed down. Besides the fertilizing effect this method has been shown to have a positive influ-ence on soil organic matter as well as weed flora, and green manure is an important me-thod of weed control in organic farming in parts of Sweden. However, the release of nu-trients from the green manure varies and can therefore be difficult to control. Risks for losses of nutrients are also present. Although the area of organic farmland is increasing in Sweden, the use of green manure is decreasing.This report contains a literature study which compiles research on the functions of green manure in a cropping system and also how the crop can be used if harvested, for example to produce biogas.

Parasitangrepp är en av de vanligaste och allvarligaste orsakerna till produktionsbortfall hos får och nöt. Akut sjukdom till följd av parasitangrepp uppstår ofta plötsligt och med hög mortalitet. Kroniska parasitangrepp kan vara svåra att upptäcka, då djuren inte alltid uppvisar symptom, men dessa angrepp kan ge följder över en längre tidsperiod med bl.a. nedsatt produktion av mjölk och ull samt sämre tillväxt av lamm och kalvar. Inom modern djurproduktion idag är den primära nematodkontrollen att begränsa antalet infektiösa larver på betet genom strategisk användning av anthelmintikum kombinerat med beteshygien.

The community Vessigebro, in Falkenberg and its surrounding areas housing one percent of all dairy Cattle and two percent of all pigs in Sweden. This means that there is a large amount of manure as a basis for producing biogas in the area. A number of farmers have therefore formed a cooperative named Vessigebro biogas and started the project Green Vessigebro, with the goal of creating the conditions for a more profitable and more sustainable agriculture production.The study deals with the conditions and sale opportunities of the feasibility study Green Vessigebro. The study has looked at the work that was previously carried out for the biogas that could be produced on the farms in Vessigebro, The main pipeline for natural gas on the Swedish west coast and its operators, the Swedish Competition Act , Electricity Act , Natural Gas Act, the District Heating Act , Sustainability Act , previously proposed measures, municipality interest in biogas from Vessigebro , possible collaborations, possible sale opportunities and perform calculations with data from the municipality Ljungby for a suggested transportation of biogas between Vessigebro and Ljungby.The study shows that there are several interesting sale opportunities for biogas from Vessigebro. The production and use of biogas in Sweden is increasing and the trend seems set to continue.

Djurvälfärd vid tidpunkten för slakt är en fråga som engagerar allmänheten. De flesta nötkreatur i Sverige bedövas med bultpistol inför slakt, med syftet att befrias från onödigt lidande. Undersökningar visar dock att bedövningskvaliteten i många fall inte är tillräckligt hög efter skottet. Den här litteraturstudien syftar till att undersöka hur en god bedövningskvalitet säkrast kan uppnås vid bultbedövning, det vill säga vilka vapen, vilken träffpunkt och vilken skjutkraft som har visat sig ge bäst resultat, samt hur situationen ser ut i dagsläget. Tidigare studier har visat att mellan 8,7 och 31,8 procent av djuren inte uppnår en god bedövningskvalitet efter skottet och statistiken ser ännu sämre ut för tjurar och äldre djur. Vilka indikatorer som används för att bedöma bedövningskvaliteten varierar lite mellan olika slakterier men den vanligaste och förmodat säkraste indikatorn är att titta på djurets eventuella kornealreflexer. Skottets träffpunkt finns reglerad i lagstiftningen men studier har visat att även avvikelser från denna punkt kan ge en god bedövningskvalitet om vapnet som används har tillräckligt hög kapacitet.

Hunger is a problem in some parts of the world (www, FAO 1, 2012). The lack of food is often a result of insufficient knowledge in soil fertility management (Röing de Nowina, 2012). Ongoing hunger and malnourishment are quite prevalent in Sub-Saharan Africa and are often combined with poverty (www, FAO 1, 2012). Farming is the most common occupation in this area and the farms are often small-scale farms with subsistence crops and a few Cattle. The farmers who operate these small-scale farms are economically a weak group.

People who invest capital in promising projects as a profession are called venture capitalists. They are constantly looking for new investment opportunities. Recently, media have observed a growing interest in forest land as capital investment. This is because several fund and investment company market the possibility of safe return through investment in woodland, both in Sweden and abroad. When an investment in forests is seen as an acceptable investment option, focus turns to nearby areas, namely agricultural land.

Sweden signed, in 1992, the Convention on Biological Diversity (CBD) and has thus assumed responsibility for the indigenous biodiversity. That also means that Sweden has a conservation responsibility for the Swedish Friesian (SLB) (SJV, 2007a). In a survey conducted by the Board of Agriculture (SJV) in 1996, it appeared that there were around 780 cows and heifers of the SLB breed (SJV, 1997). SJV did in 2006 a plan for the development of livestock genet-ic resources and the number of cows of SLB was estimated at approximately 200. This meant that the SLB was in need of being conserved and SJV assumed it would be categorized as threatened.The primary objective of conservation of a breed is to reduce the loss of the original genetic variation (Lacy et al., 1995).

The virus-mediated disease Rift Valley fever (RVF) was discovered during an outbreak in Kenya in the 1930s. Since then it has spread to most parts of Sub-Saharan Africa, and in the last decades several outbreaks have caused economic and health issues in Africa, Yemen and Saudi-Arabia. The disease mainly affects domestic livestock, causing abortions, but is also a zoonosis. To be able to control the spread of the disease it is important with surveillance for better knowledge about the distribution and virus circulation even in inter-epidemic/epizootic periods. The human population is growing, and people and their livestock constantly move closer to areas with wild animals which act as reservoirs for different viruses. Also, humans and their animals often get within reach for arthropod vectors, hosting or carrying viruses.