In some herds it has been observed that extremely short teats have become a problem; with a negative influence on the milking performance. The aim of this study was therefore to investigate to what degree the quality of the teats and the milk in cows with short teats is affected as compared with cows with normal teat length and furthermore if the milking performance could be improved by using a liner adapted to short teats. This study was divided in two parts. In the first part, it was examined if there were any differences between short teats and teats with normal length with reference to the milking performance, udder emptying, teat treatment, milk quality, and udder health. 11 pairs of cows were used and in each pair of cows one cow had teats shorter than 40 mm while the other cow had teats longer than 50 mm.

The objective of this work was to evaluate and compare three field methods for detection of mastitis, California Mastits Test (CMT), DeLaval cell counter DCC (DCC) and FMA2001 Farm Milk Analyzer (FMA2001). Furthermore, to investigate at what cell count level clinical symptoms of mastitis are seen, and finally to check if the clinical findings and cell counts could be related to bacteriological findings. DCC and FMA2001 are new analytic instruments to be used on dairy farms for detection of mastitis. CMT has been a widely used cow-side-test of milk quality in mastitis control efforts, but it cannot be used for estimating cell counts in scientific studies or investigations. Two hundred and eight quarter milk samples from 52 cows were analysed with DCC and CMT, and 168 of these samples with FMA2001. Microbiological examination was done on 38 milk samples with CMT scores of 4 and 5.

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.

The aim of this undergraduate thesis was to formulate advices regarding the use of field beans, cultivated together with spring wheat, as whole-crop silage in feeding to dairy cows. In the thesis, optimal harvest time of the field bean/spring wheat crop, as well as the feeding value and the fermentation quality, was studied. On the research station at Röbäcksdalen in Umeå field bean/spring wheat (70 % respective 30 % of normal seed rate for the pure crop) and pea/oat (70/30) was grown in field experiments both 2002 and 2003. The following year, 2004, the pea/oat crop was excluded and instead field bean and spring wheat was cultivated in three different mixed ratios (field bean/spring wheat; 100:0, 70:30, 30:70). Every year the crops were harvested at four different development stages and the green forages were used in ensiling experiments.

To enjoy the richness of the grazing cows and high yield during the summers, even during the winter, cheese has been the way to store milk for thousands of years. Nowadays yield is high all year around and the cheese production is possible during all seasons. The aim of this paper is to investi-gate how and why the seasons influence taste and texture of pressed and ripened cheese. Milk is composed of proteins, fat, Lactose and water but contains also a lot of vitamins. The quality of milk is very important for the final constitution of cheese.

Milk fat is an important feature in many different milk products and other foodstuffs and it is often crucial for the dairy plants that the milk fat is stable for different manufacturing processes. Lipolysis is the enzymatic degradation of fat and is the one of the causes for an elevated amount of free fatty acids (FFA) in milk. Further, the change in fatty acid (FA) composition in milk can affect the stability of the product and also the manufacturing process. Both internal and external factors, at farm level or at the dairy plants can affect both FA composition and content of FFA. Milking frequency (MF=number of milkings per cow and day) and the composition of feed are two examples of factors generally performed at farm level. The objective of the present study was to evaluate how FA composition of milk and amount of FFA are influenced by two different ingredients supplemented to concentrate.

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.