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Acta Veterinaria Hungarica
Authors: Zoltán Szelényi, Dorottya Győri, Szabolcs Boldizsár, Levente Kovács, Attila Répási, László Molnár, and Ottó Szenci

The aim of this study was to examine the effect of twin pregnancy, fetal laterality, the number of corpora lutea (CL) and cavitary CL on pregnancy losses in Holstein-Friesian cows with a positive pregnancy diagnosis based on ultrasonography between days 29–42 after AI. Pregnancy was confirmed by transrectal palpation between days 57–70 after AI and at the time of drying-off as well. Twin pregnancy rate was 8.4% at the time of the early pregnancy examination. Pregnancy loss did not differ between singleton- and twin-carrying animals either between days 57–70 of gestation or at drying-off. More losses occurred in singletons between days 29–42 and 57–70 in cows with cavitary than in cows with noncavitary CL (12.1% vs. 3.6%; P < 0.05) and in cows with double CL than in cows with single CL (7.3% vs. 3.6% %; P < 0.05). Between days 57–70 of gestation and drying-off this difference was still significant (20.7% vs. 3.7%; P < 0.001), while it was non-significant between cows with one CL (5.7%) vs. double CL (3.7%). Cavity occurrence was not affected by hormone therapy prior to AI (either PGF2α or OvSynch; 4.4% vs. 5.4%, respectively); however, the number of CL was reduced by the treatments (11.6 vs. 19.6%; P < 0.0005). In twin pregnancies there was no difference in the pregnancy losses between bilateral and unilateral pregnancies at any time point. The length of gestation was 278.2 ± 10.5 (singleton) and 267.4 ± 31.2 (twin) days, respectively (P < 0.01). The stillbirth ratio was higher in twin carriers than in singleton carriers (19.5% vs. 5.3%; P < 0.001).

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Őszi káposztarepce N-, C- és S-tartalmának alakulása N-trágyázás hatására mészlepedékes csernozjom talajon

Changes in the N, C and S contents of canola in response to N fertilization on calcareous chernozem soil

Agrokémia és Talajtan
Authors: Máthéné Gáspár Gabriella, Radimszky László, Győri Zoltán, Hüvely Attila, and Németh Tamás

Az őszi káposztarepce (Brassica napus L. subsp. napus) nagy N- és S-igénye számos hazai és külföldi tanulmányból ismert. Ezért a repce okszerű tápanyagellátását célzó N-trágyázási tartamkísérlet vizsgálatait kiterjesztettük a S-tartalom, a N/S arány, s előzőeken túl a N-trágyázás növényi C-tartalomra gyakorolt hatásának, a C/N arány változásának jellemzésére.

A kísérletet Nagyhörcsökön mészlepedékes csernozjom talajon végeztük 2003– 2004-ben, egy N-trágyázási tartamkísérlet részeként. Az őszi N-adagok a kísérlet főparcelláin (jelölésük 1–4.): 0, 75, 150 és 225 kg N/ha, a tavasziak pedig a főparcellán kialakított alparcellákon (jelölésük 1–5.): 0, 50, 100, 150 és 200 kg N/ha voltak. Az egyes főparcellák NO3-N-tartalma a kísérlet kezdetekor a tartamkísérlet hatásaként már jelentősen különbözött. A főparcella hatásában így a talaj kezdeti NO3-N-tartalma és az őszi N-adag együttesen érvényesült, s határozta meg a tavaszi fejtrágya hatásosságát.

A maximális (2 t/ha) termést a talaj növekvő NO3-tartalmának megfelelően, egyre kisebb újabb műtrágyaadag kijuttatásával értük el. A N-adagok megbízhatóan csak az 1. és 2. főparcellán változtatták meg a termés mennyiségét, továbbá annak N-, S- és C-tartalmát.

Kísérletünk valamennyi mutatóra, a virágzáskori levél és a mag N- és Startalmára, a levél N/S arányára vonatkozóan kedvező S-ellátást jelzett. A levél átlagosan 0,97%-os és a mag 0,43%-os S-tartalma magasabb, a levél átlagosan 4,5-es N/S aránya pedig az ismert határértéknél jóval alacsonyabb volt.

Az eredmények alapján megállapítható volt, hogy a repce jó S-ellátását a mészlepedékes csernozjom talaj biztosította. Eredményeink megerősítették a N-trágyázás termés mennyiséget meghatározó szerepét, s jelezték adott ökológiai feltételek között a repcetermés további növekedésében a vízellátás fontosságát.

The high N and S requirements of canola (Brassica napus L. subsp. napus) have been widely reported. Long-term experiments on the N fertilization of canola were thus expanded to include the determination of S contents and N/S ratios, and to analyse the effect of N fertilization on plant C contents and changes in the C/N ratio.

The experiments were carried out on calcareous chernozem soil in Nagyhörcsök in 2003 and 2004, as part of a long-term N fertilization experiment. The N rates applied to main plots 1–4 in autumn were 0, 75, 150 and 225 kg N/ha, while those given to sub-plots 1–5 in spring were 0, 50, 100, 150 and 200 kg N/ha. At the start of the experiment the NO3-N contents of the main plots already differed substantially due to the effect of the long-term treatments. The effect of the main plots, which influenced the effectiveness of topdressing in spring, was thus a combination of the initial soil NO3-N content and the N rate applied in autumn. As the NO3 content of the soil increased, the additional fertilizer rate required to obtain maximum yield (2 t/ha) declined. The N rates only had a significant effect on the yield, and on the N, S and C contents of the yield in main plots 1 and 2.

Favourable S supplies were indicated by all the parameters studied in the experiment, including the N and S contents of the seeds and the N/S ratio of the leaves. The average 0.97% S content in the leaves and 0.43% in the seeds was higher than the accepted limit values, while the average 4.5 N/S ratio in the leaves was considerably lower.

It could be concluded from the results that the calcareous chernozem soil provides good S supplies for canola. The results confirmed the decisive role of N fertilization in the yield level and indicated the importance of the water supplies in achieving further increases in yield under the given ecological conditions.

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The estimation of environmental risk caused by pollution with potentially toxic elements (PTE) is usually carried out using the (3+1) step sequential extraction procedure suggested in 1993 by the Community Bureau of Reference (BCR). In the 1st step the water-soluble, exchangeable and carbonate-bound element content is extracted with acetic acid. In 2002 a fractionation procedure based on the application of supercritical CO2, subcritical H2O and of a mixture of subcritical H2O/CO2 was proposed, which allowed the water-soluble and carbonatebound element contents to be extracted separately from sediment or soil samples weighed into the preparative column of a supercritical fluid extractor and diluted with quartz sand in a mass ratio of 1:20. The aim of the present study was to develop a new reduced-size column construction with which this dilution rate could be decreased to 1:2. A kinetic study was performed to determine the extraction time necessary for samples with different carbonate contents and the extracted element contents were compared to the results of the BCR sequential procedure on the same samples. It was established that fractionation using the reduced-size column may be a rapid way to obtain more reliable information on the easily mobilizable (watersoluble and carbonate-bound) PTE content of soils and sediments than was previously available to supplement BCR fractionation.

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