1998 * IX * 3

M. Karelson.  
  Eesti Aleksandrikool – 100. Põllumajandushariduse kujunemise algusajast 165
J. Kuum.  
  Vanemate külade nimedest 169
Ü. Jaakma, P. Bredbacka, J. Peippo, I. Müürsepp.  
  Veiste embrüote sugupoolte määramine farmitingimustes enne siirdamist 172
Sex determination of embryos before the transfer. Sex determination of embryos before the transfer offers certain economic benefit to the dairy industry: higher proportion of female progeny provides better selection for herd replacement and higher rate of genetic improvement. Recently, a simple and accurate method of bovine embryo sexing based on amplification and detection of Y-chromosomal DNA (PCR), was developed in the Agricultural Research Centre of Finland. The purpose of the study was to evaluate the accuracy of the developed sexing method under field conditions in Estonia and determine the viability of fresh and frozen-thawed biopsied embryos.

Day 7 embryos were obtained from donor cows superovulated with FSH. Compacted morulae and early blastocysts of excellent or good quality were biopsied manually with a microblade in a 100–200 μl drop of PBS supplemented with polyvinylpyrrolidone (PVP). Biopsy size was 10–25% of the total embryo cell mass. The biopsy was transferred to the reaction tube where the cells were lysed and DNA amplification performed according to Bredbacka et. al., 1995. Finally, the tubes were observed under UV light. Pink fluorescence indicated the presence of a male sample in a tube.

The biopsied embryos were stored in PBS supplemented with 10% fetal calf serum (FCS) at room t° until transfer or freezing. The embryos were frozen in 1.5M ethylene glycol in PBS using a standard controlled freezing technique. Synchronized virgin heifers were used as embryo transfer recipients.

Of 72 embryos biopsied for sexing, 39 (54.2%) were diagnosed as females and 33 (45.8%) as males. Transfer of 24 fresh embryos resulted in 66.7% pregnancy rate on Day 60 and birth of 14 calves (58.3%). Thirteen of them were correctly sexed (93.3%). One error was probably caused by biopsy loss during the transfer into the reaction tube.
Six of 14 frozen female embryos were classified as transferable after thawing (42.9%). Following the transfer of them into 6 recipients, 1 female calf was born (16.7%).

These results demonstrate high accuracy of the present sex determination method under farm conditions. The manual biopsy and the identification of sex by detection of tube fluores-cence allowed to decrease the time needed for diagnosis. The viability of fresh biopsied embryos was good as indicated by high pregnancy and calving rates. Nevertheless, survival and pregnancy rates of frozen/thawed biopsied embryos was poor. Further studies are neces-sary to clarify the conditions for the successful storage of biopsied embryos.

Key words: bovine, embryo, sexing, PCR, freezing, calving rate.

M. Järvan.  
  Raskmetallisisaldus köögiviljades sõltuvalt lubiväetiste liigist 176
Content of heavy metals in vegetables depending on different lime fertilizers. The association: lime fertilizer – soil (growth medium) – plant – yield was investigated for content of heavy metals. The effect of liming fertilizers produced in Estonia (oil-shale ash, limestone meal, dolomite meal and mixtures of limestone meal and dolomite meal with differ-ent Ca:Mg ratio) was monitored. The experiments were carried out with vegetables both in greenhouse and open ground conditions.

The greenhouse vegetables (lettuce, cucumber, tomato, sweet pepper) were cultivated on the peat growth medium neutralized with different lime fertilizers. The application rate of lime fertilizer was 8 Kg per 1 m3 of peat. The content of heavy metals in open ground vegeta-bles (carrot, red beet, cabbage) was investigated in field trials carried out on acid soils of South Estonia (pHKCl 4.17). The rate of liming fertilizer was 5 T of CaCO3 per hectare.

The content of heavy metals (Pb, Cd, Zn, Ni, Cr) in oil-shale ash was higher than in limestone and dolomite meals. The content of heavy metals in plants cultivated on peat growth medium in general didn’t correlate with content of heavy metals in liming fertilizers used for neutralization of peat. The content of heavy metals in lettuce depended on acidity of growth medium. There was more Cd, Zn and less Cr in lettuce grown on medium neutralized with dolomite meal (pHKCl 5.6) than on media neutralized with other lime fertilizers (pHKCl 5.9–6.5). In lettuce the content of heavy metals was 2 to 4 times higher than in fruits of tomato, cucumber and sweet pepper grown in the same conditions.

The concentration of Cd, Zn of tomato and cucumber plants was higher in older leaves than in younger ones. The content of heavy metals in dry matter of tomato and cucumber fruits was several times lower than in leaves and didn’t depend on content of heavy metals in lime fertilizer used for neutralization of peat and pH of the growth medium.

The vegetables (carrot, red beet, cabbage) grown on very acid soils contained usually more heavy metals (Pb, Cd, Zn, Ni) than vegetables grown on soils fertilized with lime fertil-izers (5 T of CaCO3 per hectare). Mixture of limestone and dolomite meals (1:1) yielded mostly in lower heavy metal content in plants than oil-shale ash. Carrot and cabbage accu-mulated 1.,6–2.0 times more Cd and 1.5–2.5 times more Zn than cabbage.

A. Kaasik, H. Kask.  
  Odra, kaera ja nisu lõhustuvusest veise vatsas 188
On the degradability of barley, oats and wheat in the rumen of dairy cattle. Three trials with rumen fistulated cows were carried out. In the first and second trial three dry cows and in the third trial three lactating cows possessing 0-energy balance period were used. In the first trial the effect of the fractional composition of wheat, oat and rapeseed meal on the dry matter and protein degradability in the rumen was studied. The second trial was carried out to investigate the influence of processing (grinding or crushing) on the dry matter and protein degradability of wheat, oats and barley in the rumen. In the third trial the effect of a preserver (siloben, AIV-2) on the rumen dry matter and protein degradability of crushed barley and oats was studied. The trials were carried out according to the in sacco methods worked out in Sweden.

On the basis of the results of the trials the following conclusions can be drawn:

  1. The dry matter and protein degradability of finer fractions of grain meal in the rumen is faster and more extensive, compared with that of coarser fractions. A sta-tistically significant difference was observed in dry matter and protein degradabil-ity of all the meal fractions studied, except between the protein degradability of F1 and F2 fractions of oats.
  2. The density of grain is an important parameter in choosing the grain processing method. The dry matter and protein degradability of higher density cereals, e.g. wheat, is better in case of finely ground meal, as the crushed products contain a relatively high proportion of over 2 mm fractions. The finer (< 2 mm) and the rela-tively higher density fractions are more effectively degraded by the rumen microbes.
  3. No statistically significant effect of studied preservers on the effective dry matter and protein degradability of barley was observed. Therefore the preserver (siloben, AIV-2) used for barley ensiling is not significant from the point of view of rumen degradability.
  4. Preserver AIV-2 reduced the effective dry matter and protein degradability of oats. Siloben did not have similar effect. On the basis of the results of the trials it can be stated that the preservers of high formic acid content have presumably a protective effect on oat proteins, i.e. they reduce the protein degradability in the rumen.
  5. The results of the trials indicated that the variation in species composition of rumen microflora and microfauna as well as pH fluctuation in the rumen may have a higher effect on dry matter and protein degradability of barley rather than on that of oats, respectively. This is most likely due to the different starch granule compo-sition of barley and oats (barley – simple granules, oats – compound granules, respectively) as well as different amino acid composition.
R. Kask.  
  Eesti muldade mineraalosa muundumisest ja degradeerumisest evolutsiooniprotsessis 201
About the transformation and degradation mineral component Estonian soil in pedogenesis. The general direction of the development of soils is determined mainly by the natural factors and their mutation. The precipitation level in Estonia (752 mm) surpasses the level of evaporation (462 mm), the average temperature is 5.0 °C.

The peculiarity of the Estonian soil’s parent rock is that the amount of carbonate stone and their decomposition product in them differs greatly (0…100%). The same goes for the parts of clay.

The age of the soils is very different. In South-East Estonian Uplands 10…13 thousand years, in Coastal regions less than 1 thousand years.

In the transformation of the mineral parts of the soil the leading part is played by car-bonate leaching, lessivage, podzolization and gleying. The changes caused by them can be seen in the morphological profile of the soil, in the vertical differentiation of the soil’s granulometrical and chemical composition (Table 6).

In the stage of carbonate leaching, the amount of calcium and magnesium decreases in the soil. But the amount of clay and the elements which are not yet the subjects to the irriga-tion (Si, Fe, Al) increases. Argillization is connected mostly with the decomposition of the carbonate particulars of sand and silt and with the riddance of aluminosilicate clay parts which are contained in carbonate rock (connected with the leaching of carbonates) and with the accumulation in the soil.
In noncarbonate soils the decomposition of aluminosilicate minerals and the improver-ishment from clay parts and ash elements take place.

Estonian automorphic and half hydromorphic soils are all denudational. Such conclusion comes from the soil’s characteristics and from the amount of the dissolved ingredients in the water of the rivers flowing into the sea (Tables 7, 8, 9).

Chemical denudation is a continuos process with growing intensiveness, nowadays in South-Estonia 20…30 mm during one thousand years. In North-Estonia more than 30 mm (Migratsii…, 1974). The mineral part of the soil degrades, which is expressed by the increase of the eluviahorizon’s forming level and by the increase of the horizon’s thickness in compen-sation for (at the cost of) the illuvial horizon.

In order to maintain and increase the potential fertility of soils it is needful to compen-sate among other things also the loss which is connected with the chemical denudation, i.e. the degradation of the mineral part of the soil in its natural evolution process.

K. Kaul, M. Heinloo.  
  Ülevaade vurräkke vabaaktiivsele ringlülile pöördemomendi tekitamise võimalustest patendiuuringu põhjal 224
Review of rotation moment generating possibilities on the circular link of the free-active spinharrow. This paper, based on the patents and author certificates of Soviet Union, presents the study of the possibilities of creating the moment of rotation on the free-active circular link of a spinharrow. The scheme of 66 patents and author certificates for free-active circular links of a spinharrow is compiled. On the base of 23 patents and author certificates have been found, that the moment of rotation on free-active circular link of a spinharrow can be created by 1) spikes, bended a) radially outward from centre of a circular link, b) nonradially outward from centre of a circular link, c) on the revolution direction of a circular link; 2) inclination of the circular link relative to the ground surface, which can be done by a) clamping the circular link to the frame under small inclination angle, b) locating an additional load to one side of a circular link; 3) spikes, which have different shape coeffi-cient in various directions; 4) regular changing the working depth of several spikes of a circular link.
J. Kurõkin.  
  Folliikulite punkteerimine ja munarakkude aspireerimine ultraheli kontrolli all veistel 231
Ultrasound guided puncture of follicles and aspiration of oocytes in heifers. The aims of the present study were to evaluate the function and the practicality of a technically modified device for ultrasound guided puncture of follicles and aspirations of oocytes, to determine the influence of ultrasound guided aspiration of oocytes once a week on cyclicity and possible traumatic effects of repeated puncture of follicles on the genital trakt in heifers.

For puncture of follicles and oocyte aspiration a special stainless steel endovaginal holder equipped inside with multiple angle sector transducer (Pie Medical, 5.0–7.5 MHz) and on ventral position with single lumen needle guide was used. The major difference of the pre-sent device compared to other instruments which have been presented (Pieterse et al., 1988; Gibbons et al., 1994; Looney et al., 1994; Bols et al., 1995) is the possibility for the operator to control the movement of the aspiration needle. In most other instruments presented, the puncture of the follicles is performed by an assistant who manually pushes the needle into the follicles (Pieterse et al., 1988; Gibbons et al., 1994; Scott et al., 1994; Bungartz et al., 1995). It is advantageous if the same person controls both the direction of the probe and the punc-ture of the follicles. A second advantage with the present unit is that disposable needles are used which are simply changed after each puncture session.

Two heifers of the Swedish Red and White breed (13 and 14 months of age) were used in the experiment. All follicles ≥3 mm were punctured and the follicular fluid was aspirated. The cyclicity of heifers was determined on the basis of estrous signs and progesterone (P4) con-centrations in blood plasma. During the first 6 weeks the recovery rate of oocytes (percentage of oocytes recovered out of follicles punctured) was 36.4% (4/11). Following next 6 weeks a recovery rate of 41.4% (8/18) was achieved and after the last 4 weeks the recovery rate reached 73.7% (14/19). Our results show an increasing recovery rate by around 100% during 16 weeks ending up with final recovery rate of 73.7%. In the experiment, follicles larger 3 mm in diameter were punctured only in two heifers. This resulted in a limited total number of follicles punctured and oocytes aspirated. Also the person performing the puncture of follicles had no experience of the technique before the start of the experiment.

The once a week repeated oocyte aspirations appeared to have no influence on the cyclicity as judged by the P4 profiles. However, no external estrous signs (e.g. vaginal discharge, vulvar reddening) were observed in 6 of the 7 estrous cycles. The lengths of the estrous cycles varied from 19 to 21 days, with a mean length of 19.71±0.28 days. The mean length of estrous cycles in which two or three puncture sessions were performed was not significantly different, 19.33±0.33 and 20.0±0.40 days, respectively (P>0.05). On an average, the P4 levels reached maximum concentrations (21.73±3.78 and 25.0±0.25 nmol/l) at days 10.30±1.66 and 10.25±0.05 (P>0.05) of the estrous cycle, independent on number of puncture sessions per cycle. There was a slight, but non-significant difference in the mean length of the luteal phases with two (13.33±1.20 days) and three (16.25±0.47 days) aspiration sessions per cycle (P>0.05). The length of luteal regression did not differ (P>0.05) between cycles with two or three aspiration sessions, 5.66±1.66 and 7.50±0.64 days, respectively. We can con-clude that weekly punctures of follicles during a period of several estrous cycles have no influence on cyclicity in heifers.

Gross examination of the genital tracts following slaughter one week after last aspiration revealed a haematoma on the cranial side of vagina in one heifer and, in the other one, minor fibrous adhesions at the site of puncture of the vaginal wall. Histological examination of ovaries revealed an increased amount of connective tissue in one of the four ovaries.

M. Karelson  
  Kodumajandus Eestis 240