The aim of the present research was to determine the level of cholesterol in the milk of the Latvian cow herds and to find out the effect of the milk fat content on the cholesterol level. Milk samples were obtained from the cows of Latvian Brown and Black and White breeds during the morning and afternoon milking. The milk fat and protein were analysed by Milkscan 133, cholesterol content was determined by spectrophotometer CF 26 LOMO. The average milk fat content was 4,45% and average cholesterol content - 20,94 mg 100 ml*[-1). It was found that the cholesterol content in milk was consistently higher to cows the milk of which had a higher fat content and the cholesterol content was different in the morning and afternoon milking.

The aim of research was to analyse the spread of goats eimeriosis in Latvia, determine the structure of eimeria species as well as the efficiency of treatment of goats eimeriosis. Coprological examination of goats, carried out with Fileborn method, showed that the average level of eimeriosis influence on goats was about 25.2% and 3 dominant species of emeria such as E.arloingi, E.ninakohlyakimovae and E.alijevi. The highest level of influence was discovered to animals under 1 year of age, as with E.ninakohlyakimovae (62.5%) as the dominant specie, to animal above 1 year of age - E.arloingi (57.3%-66.7%), respectively. As the result, such preparations as sulfadimetoxine in dosage 75 mg kg*[-1) amprolsol 50 mg kg*[-1) showed high level (about 91%) of efficiency of emeriosis treatment.

The epidemiology of barley yellow dwarf disease is highly complex, involving numerous interactions between the abiotic environment and the crop, virus and vector - components of the disease. Barley yellow dwarf is the most economically damaging virus disease of grass and cereal crops worldwide. The disease identified as BYD has been reported in all countries in Europe causing losses on barley and oats, wheat and maize; losses on grasses are recognized but more difficult to quantify. There are five different strains of viruses causing BYD disease and all of them induce similar symptoms of chlorosis and stunting in graminaceous hosts. This report represents an overview of system components and their interactions in the epidemiology of barley yellow dwarf disease. As the main components considered here are aphids - (the only vectors of these viruses), host plants and viruses causing BYD disease. Some aspects of interactions between these components are also discussed.

The effect of different fertilizer backgrounds on the potato yield and its chemical composition of different varieties, destined for processing into chips, was investigated at the Elmininkai Research Station of the Lithuanian Institute of Agriculture in 2000. The investigation showed, that potato tuber yield depended on fertilization and genetic characteristics of the potato variety. The most productive potatoes of the following varieties were: early Voke (20,6-36,0) t ha*[-1) and medium late Saturna (27,0-35,4 t ha*[-1)).

One of the main preconditions for an economical milk production is a balanced cow feeding that contains high quality grass forage. Chemical composition of cocksfoot forage during vegetation was investigated at the Research Centre "Sigra" in the Biochemical laboratory of the Latvia University of Agriculture. Changes in the content of crude protein, NEL MJ kg*[-1) of DM, NDF, ADF and DM digestibility were determined. The chemical composition of grass forage depends on many factors, the most significant of which is the harwesting time. The feeding value of the cocksfoot grass decreases during its growing stages as the content of fibre increases and becomes lignified.

Vocational education in all countries provides a specific learning system to their students and students are more motivated to take practical training for their further development. Agriculture-based vocational educational institutions have been facing problems of losing its students since 1998. To promote survival of these schools, a non-agriculture based curriculum was provided. Nowadays, in order to support agriculture-based vocational education, there is a need to do research on the prospects and needs of this type of schooling in Latvia. There is a need for new methods and models of curricula, based on practical needs of students, in order to promote management and marketing skills for future farmers.

The content of reducing sugars can be 30% higher if modified amylase is added to scald. Investigations were carried out with the rye-flour and fine flour scald. Photometrical method was used as a standard method for the determination of reducing sugars. Enzymes were inactvated using the advanced method. Results show, that the amount of reducing sugars is 1.8% lower in rye-flour and 2.1% lower in fine flour compare to the results obtained using the standard method.

Milk quality analyses were carried out at the Department of Veterinary Medicine of the LUA Research Centre "Sigra". The total amount of investigated samples was 140, of which 81.4% proved to be appropriate for extra and first class milk, but 18.6% were unqualitative. The total number of microorganisms ranged from 8000 to 20,000,000, but the number of somatic cells from 1000 to 4,068,000 in 1 ml of milk. Coagulase - positive Staphylococcus aureus were isolated in 8 cases or 5.7%. Coagulase - negative Staphylococcus were isolated in 31 cases or 22.1%. Using the BBL Crystal Indentification System for Gram-Positive microorganisms, four species of microorganisms Staphylococcus aureus, Staphylococcus intermedius, Micrococcus sedentarius and Micrococcus luteus were identified which are building various colonies on Baird-Parker Agar.

Spring barley grain of the new registered Lithuanian variety 'Alsa' and German malty variety 'Otis' cultivation, the influence of different rates of nitrogen fertilisers and fungicide Tango on their yield and quality was investigated in the Rumokai Research Station of the Lithuanian Institute of Agriculture in 1998-2000. It was established that nitrogenous fertilisers have been increasing grain yield in the spring barley 'Alsa' every year. The influence of nitrogen fertiliser was negative on the spring barley 'Otis' only for the 1998 yield due to meteorological conditions, that were favourable for spreading leaf diseases. Fungicide Tango gave a reliable yield increase - from 0,21 to 1,14 t ha*[-1) - through the whole investigation period. The amount of proteins in grains was reliably increasing due to nitrogenous fertilisers within all the years of investigation, excluding the year 1999. Meteorological conditions made a great influence on protein amount in 1999. No reliable interaction was established between nitrogenous fertilisers, grain size and starch. Medium or strong negative correlation was observed between the grain size and proteins (correlation coefficient was deviating from 0,40 to 0,81). A reliable positive correlative relation was established between starch and grain size in 1998 only.