1997 * VIII * 3

H. Kasesalu.  
  75 years of Forestry Training and Experimental Centre of Järvselja 207
J. Kuum.  
  70 years agricultural transmissions in the Estonian Radio 214
A. Bender.  
  About the level of timothy, meadow fescue and perennial ryegrass breeding in Jõgeva 217
About the level of timothy, meadow fescue and perennial ryegrass breeding at Jõgeva. On the base of average data of three-year experimental cycle we can state that the yield capacity of Swedish and Estonian timothy cultivars did not differ significantly in Estonian climatic conditions. Among the perspective Swedish breeds TT8502 yet outyielded significantly standard cultivar ‘Jõgeva 54’ but not the dry matter yield of new variety ‘Tia’.

Swedish meadow fescue cultivar ‘Kasper’ performed well in Estonian conditions – exceeded significantly both standard cultivar ‘Jõgeva 47’ and new cultivar ‘Arni’, bred at Jõgeva, by the yield of green mass and crude protein, surpassing of dry matter yield of ‘Arni’ was statistically nonsignificant.

Swedish perspective meadow fescue breeds revealed approximately equal yield data with standard cultivar.

Swedish and Estonian cultivars and breeding numbers of perennial ryegrass possessed roughly equal yield capacity. Neither Swedish nor Estonian plant breeders have not been able to solve definitively the concern about winterhardiness of this species, that is why risk accompanies in the forage production with it’s cultivars.

On the base of results obtained from the trials conducted during 1992…1995 we can conclude that the newest cultivars of forage grasses bred at Jõgeva Plant Breeding Institute do not succumb in local climatic conditions by yield potential to newer cultivars and perspective breeds developed in Sweden.

On the discussion concerning the final reports about the trials the partners could state with satisfaction that the positive appreciation given to the breeding of forage crops at Jõgeva 5 years ago has found an affirmation later through the concrete experimental results.

A. Kaasik, H. Kask.  
  Degradability of grain and rapeseed meal fractions of different size in the rumen of cattle 225
Degradability of grain and rapeseed meal fractions of different size in the rumen of cattle. A trial was carried out with three rumen fistulated dry cows. The cows were fed a ration consisting of 4 kg gramineous hay, 1.5 kg barley meal and 0.5 kg soybean oil meal.

The data on dry matter and protein degradability of three fractions of oat, wheat and rapeseed meal in the rumen were studied. Size of the meal fractions were >2 mm (F1), 1…2 mm (F2) and 0.315…1 mm (F3). F1 fraction of rapeseed meal, which was not practi-cally formed, was not studied. The samples were incubated in the rumen of cows for 2, 4, 8, 16, 24 and 48 hours. The dry matter and protein content in feed samples was determined before and after incubation in the rumen. On the basis of the results the amounts of degradated dry matter and protein were determined.

The analysis of the trial results showed that the difference in dry matter and protein degradability of the fractions of oat, wheat as well as rapeseed meal of different size is statistically significant (P<0.001), except the difference in the protein degradability of oat fractions F1 and F2.

The effective dry matter degradability of wheat meal fractions was as follows: F1 – 58.2 %; F2 – 73.2 % and F3 – 75.7 %, that of oat meal fractions was F1 – 59.7 %; F2 – 72.4 % and F3 – 77.8 % and rapeseed meal fractions: F2 – 43.2 % and F3 – 50.7 %, respectively. The effective protein degradability of wheat meal fractions was as follows: F1 – 46.2 %; F2 – 57.0 % and F3 – 64.4 %, that of oat meal fractions: F1 – 82.0 %; F2 – 82.8 % and F3 – 75.2 % and that of rapeseed meal fractions: F2 – 43.4 % and F3 – 54.8 %, respectively.

The statistically significant correlation was observed between ruminal dry matter and protein degradability of wheat meal fraction F1 (r=0.9656**), F3 (r=0.9611**), oat meal fraction F3 (r=0.9299) and rapeseed meal fraction F3 (r=0.9765**).

R. Kalmet.  
  The symptoms of mineral nutritional disorder of plants 236
The symptoms of mineral nutritional disorder of plants. Visual patho-logical symptoms, caused by either abundance, absence or incorrect proportion of plant mineral elements in substratum, can be found in case of intensified effect of these factors. In case of insufficient effect of the above mentioned factors on the optimal proportion of the nutrient the deficiency in latent – undected. Pathological symptoms can reflect the absence of a particular nutritional element, but in most cases the symptoms are atypical in character, predominantly in the form of either chlorosis or a necrosis reflecting the absence of combined nutrients. Plants exposed to the soil saturated with nutritional elements can suffer severely as a result of problems of assimilation. The process of assimilation can be condi-tioned by a variety of factors such as the pH and humus contents of the soil, inter-relation of the elements, weather conditions, etc. Chemical analysis of a plant in earlier stage of growth can either reveal the potential nutrient supply of the plant, or the latent deficiency of it. Furthermore, analysis of the soil can provide essential information of the mineral contents of the planned place of growth.
R. Kask, H. Niine.  
  Phosphorus and potassium in the pedogenesis of Estonian soils 246
Phosphorus and potassium in the pedogenesis of Estonian soils. The special characteristics of the phosphorus and potassium content and its vertical differen-tiation in soil is generally connected with the typological units of the soils.

With the accumulation of humus in the soil, the content of the total and lactate soluble forms of phosphorus and potassium in the humus horizons increases. With the accumulation of the organic matter in the form of peat the total content of phosphorus increases and that of potassium decreases in the mass of soil. The content of the lactate soluble forms and their part in the total content increase with the peaty formation in case of both elements.

In the first stage of the degradation of the mineral part of soil, that is, in the stage of carbonate leaching, the content of leaching horizon phosphorus and potassium increases. As the result of the decomposing of aluminium-silicate minerals and the vertical transfer in the process of lessivation, podzolization and gleying the content of phosphorus and potassium in the eluvial horizons decreases, in the illuvial horizons increases. The illuviation of lactate soluble phosphorus is the greatest in the depth where the acid reaction transfers to neutral (pH 6…7) and is more extensive, the greatest depths of the mineral-profile is enfolded into degradation. The vertical differentiation of lactate soluble potassium is connected with the amount of the clay ingredients in the soil mass.

With the increasing degradation of the mineral ingredients in the soils and with the peaty formation of the soils becoming marshly in the native process of evolution the total content of phosphorus and potassium and their supply in the soil decreases. In order to keep the content of phosphorus and potassium optimal in the soil of cultivable land we must fertilizer among the others the loss of phosphorus and potassium in connection with the degradation of mineral ingredients of the soil.

Ü. Oll, S. Tölp, J. Tölp, H. Pärn.  
  Meeting the protein requirement of dairy cows in a long-term feeding experiment 259
Meeting the protein requirement of dairy cows in a long-term feeding experiment. The aim of this work was to compare three possibilities of meeting the protein requirement of dairy cows. Altogether 72 Estonian Red cows with 200 periods of lactation were used in the experiment. The treatments differed in the composition of concentrate feeds as follows: (a) complete concentrate feed (produced in a feed manufacturing plant), (b) barley meal + oil meal, (c) barley meal + urea. Urea was supplied to barley meal at the rate of 2.5 or 3.5 per cent. The ration of each cow was formulated once a month taking into account 6 g/MJ digestible crude protein (DCP) for maintenance and 60 g DCP per 1 kg ECM. One gram of urea was equivalent to 2 g DCP. The milk yield and feed intake of each cow were determined at every milking and feeding, the milk fat content every 10 days, and the milk protein content once a month.

The results are given per cow and lactation. The milk yield (kg), milk fat and protein content (%), and the milk fat and protein yield (kg) were as follows: (a) 4478, 4.17, 3.555, 186.9 and 159.0, (b) 4556, 4.08, 3.48, 185.7 and 158.6, (c) 4492, 4.11, 3.555, 184.8 and 159.4. The ECM-yield made up: (a) 4594, (b) 4608 and (c) 4569 kg.

On average per cow and lactation the cows consumed the following amounts of metabolizable energy (MJ) and DCP (kg): (a) 39,327 and 354.3, (b) 43,383 and 412.5, (c) 42,424 and 289.4 (without urea) or 381.1 (with urea). The CP content of the rations DM was: (a) 13.8, (b) 15.1, (c) 12.1 (without urea) or 15.6 (with urea) per cent.
It can be concluded that the milk yield was practically on the same level in all the groups. Urea can meet the protein requirement, if it is carefully used. No urea poisoning was noticed.

Key words: Protein requirement of dairy cows, urea supplement, protein nutrition of dairy cows.