2006 * XVII * 1

M. Ivask, A. Kuu, M. Truu, J. Truu.    
  The effect of soil type and soil moisture on earthworm communities 7
Twenty four study areas of three most widespread soil types (pebble rendzinas, typical brown soils and pseudopodzolic soils) all over Estonia were selected. In each group of soil type, eight fields were selected for studies in 2003–2004. The mean abundance of earthworm communities was the highest in pseudopodzolic soils (107.11±22.4 individuals per m2) and lower in pebble rendzinas (47.94±11.25 individuals per m2) and typical brown soils (72.97±15.13 individuals per m2). The number of earthworm species in a community was 1–6. In all fields 7 species of earthworms were found, also a few individuals of 3 species. Soil moisture influences the abundance of earthworm communities more than soil type whereas ecological and specific structures are less influenced by soil moisture. Pebble rendzinas are suitable habitats for earthworms but periodical drying out decreases the abundance of earthworms. In pseudopodzolic soils the abundance is higher if there are optimal moisture conditions, due to increasing abundance of ecologically tolerant endogeic species. In typical brown soils the diversity and number of juvenile individuals is high which indicates suitable conditions for habitat in this type of soil.

Keywords: earthworms, abundance, biological diversity, soil microbial community, soil type, soil moisture.

M. Järvan.  
  Rare earth elements affecting the biological processes and yielding abilities of cultivated crops 17
Rare earth elements affecting the biological processes and yielding abilities of cultivated crops. The research work was conducted at the Estonian Research Institute of Agriculture in 1997–2002. For the trials a highconcentration original solution of rare earth elements (REE), resulting from the production process of AS Silmet, was used. REE solutions of different concentrations were used to treat the plants in several ways: soaking of seeds, application into soil with nitrogen fertilizer, added to tank-mixes in weed control in cereals, as diluted water solution for mixing into peat substratum, plants were sprayed with low-concentration solutions also during the growth period. Trials were conducted with the following crops: spring wheat, field and garden peas, lettuce, tomato and cucumber. In vessel trials the treatment of wheat prior to sowing with REE solutions of low till moderate concentration increased the mass of young plants depending on the concentration, duration of treatment and length of day by 5.9–26.2%. In field trials the yield of wheat increased by 14.0% under the influence of micro-amount of REE added to herbicide solution in weed control. Soaking of pea prior to sowing with REE solutions increased the mass of young plants and yield of row pods. Also the content of phosphorus and potassium in pea roots increased considerably. Thus, it can be concluded that REE affect even the uptake of plant nutrients. The best ways of use and optimum concentration of REE for field and greenhouse crops depend on the species, growth conditions and probably many other factors that would need further investigation.

Keywords: rare earth metals, soaking, spraying, cereals, vegetables.

A. Lember, H. Tikk, V. Tikk, K. Tamm, A. Karus, S. Kuusik, M. Rei.    
  The use of linseed oil in enriching the lipids of hen broiler, quail and rabbit meat with ω-3 fatty acids 45
In the trials with hen broilers were investigated the effect of 2.5% and 3.5% of linseed oil added to mixed concentrated feed on the ω-3 fatty acid content of the total lipids of broiler meat and fat after 10 days of feeding (29.–39. day of life) and the effect of aforementioned amounts of linseed oil on the dressing percentage of broilers and the proportion of haunch and breast muscle in carcass, also the taste characteristics of meat.

It was concluded that for enriching broilermeat with ω-3 fatty acids, it would be suitable, based on the data of the current trial, to feed the chicken broilers 2.5% linseed oil with mixed concentrated feed during 10 days prior to slaughtering. Feeding 3.5% linseed oil would be more expensive, furthermore, the amount of ω-3 fatty acids in tissues will be sufficient also in case of 2.5% linseed oil and most probably the tasting figures of meat will improve as well.

For the enhancement of ω-3 fatty acids content in quail meat and quail fat with the help of local feeds rich in ω-3 fatty acids, two trials were carried out on Matjama quail farm of Järveotsa farmstead in September- October 2004.

In the first experiment the trial group quail broilers (from 21. to 42. day of life) were fed 8% linseeds or 10% linseed cake in the basal ration. The best results appeared in using the ration which contained 8% linseeds.

Based on the results of the first trial, the amounts of diets rich in ω-3 fatty acids were adjusted in the second trial: now 6% linseeds and 12% linseed cake were included in the rations of different trial groups. These rations were used during the last two feeding weeks of the quail.

In the second trial, feeding the quail rations which had been adjusted according to the digestibility of nutrients, a wholly satisfactory ω-3 fatty acids content (8.1%–13.8%) in total lipids of different tissues of quail carcasses was achieved. Rations containing either 6% linseeds or 12% linseed cake during the two weeks prior to killing can be recommended for the production of the so-called health quail meat enriched with ω-3 fatty acids.

From linseed oil fed to young rabbits in order to enrich their meat and internal fat with ω-3 fatty acids in two trials, the trial animals assimilated ω-3 fatty acids very successfully, by 70%. Young bucks and does converted ω-3 fatty acids from linseed oil to almost the same degree.

As far as saturated fatty acids are concerned, feeding linseed oil decreased their content in meat lipids and internal fat proportionally with the duration of feeding linseed oil.

In enriching rabbit meat and internal fat, better results were obtained by feeding 2 g linseed oil per day to young rabbits in the course of one month. 100 g of the meat of a rabbit who had been fed in this manner contained 0.4 g and 100 g of internal fat contained 16.4 g ω-3 fatty acids which make up 0.5% and 20.5%, respectively of the daily need of a grown-up human for ω-3 fatty acids.

Keywords: ω-3 fatty acids, monounsaturated fatty acids, polyunsaturated fatty acids, linseed oil, fatty acid composition of meat lipids.

O. Sada, B. Reppo.  
  Working time expenses and degree of difficulty of pig tending 73
The selection of farm technologies and fixtures is usually made on the basis of the assessment of the technical-economical indicators (reliability, working time and operating expenses) thereof. Upon the comparative assessment, it is also important to accord consideration to the energetic workload of the human being by the working environment. The article presents the data received in the pig farms in relation to feeding the pigs, cleaning the pens, removing the manure and the working time expense of feeding the animals and the degree of difficulty of the pigtender’s work. The pig farms under observation were those where in the pig groups of different sizes young, fattening pigs, pregnant sows and sows with piglets were kept. The animals were fed using the dry or liquid feed that was delivered either mechanically or manually.

Keywords: pigtender, keeping technology, litter spreading, feeding, wheelbarrow, automatic feeding line, watering, manure removel, chain scraper conveyor, scraper device, chronometric research, working time expense, pulse tester, degree of difficulty of work.