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• Optimizing fish structure in angling ponds focusing on white fish

  33-36

  József Molnár

  Balázs Csorbai

  Gergely Bernáth

  Levente Várkonyi

  Béla Urbányi

  Zoltán Bokor

  Views:

  256

  According to new amendments of laws, commercial fishing licenses of natural waters shall not be issued from the calendar year 2016 in Hungary. However, the most settlement of white fish to angler ponds originated from natural waters. Currently, there is no sufficient quantity of fish species belonging to this group available to fulfil the settlement commitments of fish farmers. The aim of this recent study is to develop a breeding and production technology that is suitable for settlement of large quantities of this fish species of appropriate length of (4–5 cm). The following methods are investigated: aquaculture cage system (pond-in-pond system), monoculture and mixed population with different ratio of white fish in fish structure. Due to the different environmental needs of different fish species, many parameters need to be investigated, for example: stocking density, feeding, oxygen level, monoculture or mixed populations, growth potential and mortality. A preliminary experiment was carried out following the artificial propagation of ide (Leuciscus idus) following a 21-day larval rearing experiment in which the effect of different stoking density was investigated for mortality and growth. On the basis of the expected results, the optimal conditions for the aquaculture cage system will be described, regarding to the white fish stock.

• The effect of genotype and the location of sampling on the mineral content of wool

  157-160

  Erika Szigeti

  János Kátai

  István Komlósi

  János Oláh

  Csaba Szabó

  Views:

  536

  Mineral supplementation is very important in high producing farm animals. The estimation of exact mineral intake is very difficult in forage eating animals, like sheep. Accessing of long term mineral status seems to be possible using wool mineral analysis. However several factors can affect the results. Therefore, the aim of this study was to test the effect of breed and sampling location on the mineral content of sheep wool. 20 Dorper and 20 Tsigai sheep were chosen from the same farm. Samples were obtained from 3 locations (withers, side and quarter) and tested for 8 elements: Ca, Mg, Na, Co, Cu, P, S, Se , Zn. The samples were cleaned with ethyl alcohol from organic contamination, then after adding nitric acid were mineral analized using ultrasonic cleaning unit. The samples were analysed with ICP-OES (Perkin-Elmer, Optima 3300 DV). Statistical analyses were carried out by GLM procedure of SAS statistical analyses software. Differences between means were checked with Tukey-test. Significant breed differences were detected in the case of Mg, Na, S, Se in spite of the same feeding regime. The wool mineral content were within the reference range. The sampling location had no effect on the mineral content of wool.