In Sweden regulations stipulates that dairy cows are kept on pasture, or given the opportunity to spend time outside during a coherent period of between two to four months, depending on region. The transition out to pasture is a big change from the winter period in the stable, especially for the modern high yielding dairy cows. The let out to pasture includes a change in feed, environment, and new routines. There are indications that the milk somatic cell count (SCC) rises in a peak shortly after the let out. The purpose of this study was to see if peaks in the SCC could be observed after the let out, and to study the contribution of inflammatory cells (neutrophils) and if the Milk composition are affected. The study included 35 cows that were kept in stable during the winter.

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.

Protein is an important component in various milk products and has a crucial role in the final quality. Excluding non-protein nitrogen, bovine milk contains about 3.3% protein whereas about 80% of this fraction consists of casein. There are four major members in the casein family: ?s1-casein, ?s2- casein, ?-casein and ?-casein. Proteolytic enzymes are the cause of degradation of the economically important milk proteins.

Syftet med försöket har varit att utröna hur den naturliga variationen ser ut från dag till dag imjölk från separata juverdelar och hur sammansättningen i mjölken skiljer sig inom kor medolika juverhälsa. I den här studien användes 10 kor från Sveriges Lantbruks Universitet sommjölkades kontinuerligt, 2 gånger per dag i 21 dagar på juverfjärdedelsnivå. Mjölken vägdesvid varje mjölkning och analyserades sedan på antal somatiska celler (SCC), laktos, fett,protein, kasein och vassle protein. Resultaten visar att det är signifikanta skillnader imjölksammansättning mellan juverfjärdedel inom ko. För variation är mjölkmängd denparameter som varierar mest och varierar väldigt mycket mellan juverfjärdedelar.

Worldwide consumption of cheese has increased over the years. The average Swede consumes somewhere around 20 kilograms of cheese per year, which is an increase of a 100 % over the past 50 years. One of the most popular kinds of cheese during the past decades is mozzarella, due to its? use as pizza cheese. Flavor and consistency differ between the traditional kind, made out of buffalo?s milk, and the industrially made kind, made out of cow?s milk.

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.

The coproduct, dried distillers grains + solubles (DDGS) from ethanol production based on wheat contains much rumen degradable protein and fiber with low digestibility. To compliment this quality in an effective way a grass silage low in protein and much digestible fiber is needed. The aim of the study was to investigate the effects of adjusting the crude-protein concentration and fiber quality of the silage when feeding DDGS and of varying the inclusion level of DDGS, when feeding the adjusted grass silage, on intake, milk yield and composition, faecal traits and feed efficiency. Four different total mixed rations were compared. The normal grass-clover silage had a crude protein content of 17,8 % and an NDF content of 46,2 % of dry matter. The adapted grass silage had a crude protein content of 14,6 % and an NDF content of 52,9 % of dry matter. The diets were formulated to have similar nutritional content except for A + 4 which had a higher content of rumen degradable crude protein and a lower concentration of NDF.

Approximately 20% of the milk within the udder of a cow is stored in the cistern and immediately available for milk removal, while activation of the milk ejection reflex is required for removing the remaining milk stored in the alveolar compartment. The aim of this literature review is to describe, evaluate and consider implications of the three different suckling activities that the calf displays during a suckling bout. In terms of milking, these phases are represented by pre-stimulation, stimulation during milking and post-stimulation. Pre-stimulation is commonly performed in order to induce the milk ejection reflex, whereby the hormone oxytocin is released and the alveoli in the secretory tissue are contracted. Time requirements regarding pre-stimulation must be considered in relation to lactation stage and milking interval.

Mastit är en sjukdom som leder till stora problem i svenska mjölkkobesättningar. De flesta mastiter är subkliniska inflammationer som ofta inte upptäcks på grund av avsaknaden av synliga sjukdomssymtom, men där SCC är förhöjt och mjölkkvaliteten försämrad precis som vid klinisk mastit. Detta leder till att mjölk med förändrad sammansättning och kvalitet levereras till mejerierna som därmed har sämre förutsättningar att framställa mejeriprodukter av hög kvalitet. Även lantbrukaren drabbas ekonomiskt, dels på grund av att ett förhöjt celltal inte ger maximalt betalt för mjölken och dels på grund av en minskad mjölkmängd då all mjölk från kor med konstaterad subklinisk mastit ofta kasseras. Vid mjölkning i automatiska mjölkningssystem finns möjlighet att separera mjölken på fjärdedelsnivå redan vid mjölkning, detta sker dock inte idag.

Botanically diverse pastures are commonly used in New Zealand to reduce the ruminant environmental impact by reducing the methane production from the rumen digestion. In order to evaluate the effects diverse pasture species have on the milk fatty acid profile seventy-two lactating Friesian-Jersey crossbred dairy cows were used in a randomised block design with two replicates of six treatments. Six different pasture mixtures were fed at a daily allowance of approximately 15 kg DM/cow/day. The mixtures were categorised as either a simple or a diverse pasture. The simple mixtures all contained white clover with the addition of either a standard diploid perennial ryegrass (RG), a diploid high sugar ryegrass (HS) or tall fescue (TF).

Mastitis, inflammation in the udder tissue, caused by S. aureus is a big problem in dairy cattle production. It causes suffering for the cow and curing or replacing the infected cow is costly for the farmer. It is known that beef cattle also suffer from mastitis caused by S. aureus.

Feed costs constitute a large part of the expenses of dairy farmers. Pasture is a high quality feed with a low cost. However, feeding with concentrates has been shown to enhance milk yield (Leaver, 1985; Bargo et al., 2003; Stockdale, 2004). The purpose with this study was to investigate how milk yield and Milk composition were affected as the concentrate proportion in the diet decreased. Pasture behaviour was examined to see if the different concentrate levels affected the time cows spent grazing and ruminating.

Milk yield levels in dairy cows are influenced by many factors such as nutrition, breed, health status, management and environment. This study was conducted among small scale farmers in Zambia, where the climate can be dry for up to six months per year and cause a lack of green pasture for livestock and on-farm produced feed. The purpose of this study was to identify management factors that can influence milk yield at small scale dairy farms in Zambia, and present advice that could improve productivity, without the need of expensive investments. The study included semi-structured questionnaires presented to the farmers (n=29) including questions about cattle management and milk production. Testing of somatic cell count (SCC) with DCC (DeLaval Cell Counter) from herd milk samples (n=56) and observation of housing and animal body condition on-farm was also made.

In a time when milk producing farm businesses face decline in profitability it is of great importance to examine how the situation can be improved. This thesis is a study off efficiency in milk producing farm businesses represented by Swedish, Dutch and German farms. The aim of this study is to investigate whether any differences exist between companies in these countries. Moreover, the study includes a mapping of a number of factors that determine how efficient milk production can be managed. This mapping is based on a literature review on prior efficiency studies followed by qualitative interviews with milk production advisors as well as a questionnaire sent out to dairy farmers in Sweden.

Heat stress negatively influences the performance of dairy cattle such as lactation and reproduction. Heat stress can cause production losses as well as welfare problems. Years of research have shown that heat stress is a huge problem for dairy cattle in both the tropics and temperate zones but no such research have so far been done in northern European countries. It seems like shade is an important tool when improving pasture conditions and therefore deserves more attention. The aim with this study was to investigate whether there is a need of providing shade for grazing dairy cows during the summer in Sweden. Two groups of lactating Swedish Red dairy cows (n=15 per group) were kept on pasture.