Brun., 2011, LIX, No. 6, pp. 271-280 On two farms (A and B), samples of bulk milk produced by dairy cows of the Holstein (H) and Czech Fleckvieh (CF) breeds were collected every week on the same day within the time interval of 36 weeks. The aim of this sampling was to determine the eff ect of barn airspace temperature on milk compositon and its technological parameters. The following average values of all bulk milk samples (n = 72) were recorded: barn airspace temperature (BAT) 12.08 °C; rennet coagulation time (RCT) 211 sec.; curd quality class (CQC) 1.53; titratable acidity (TA) 7.16 °SH; protein content (P) 3.46 %; fat content (F) 4.09 %; lactose content (L) 4.79 %; and solids non fat (SNF) 8.86 %. As compared with H, dairy cows of CF breed produced milk with statistically signifi cantly higher (P < 0.01) contents of P (+0.27 %) and SNF (+0.26 %). The remaining diff erences were statistically insignifi cant (P > 0.05): BAT (−2 °C); RCT (−4 sec.); CQC (0 class); TA (+0.11 °SH); F (+0.05 %) and L (−0.03 %). As far as the eff ect of temperature was concerned, calculated correlation coeffi cients and plotted graphs indicated a marked eff ect of BAT on RCT; F and P. This eff ect was in all cases markedly negative: at lower BAT, F and P values were higher and RCT longer while at higher temperatures they were lower and shorter. These trends were similar in both breeds regardless to diff erences in average values of aforementioned parameters.

Low plant species richness and abundance, as well as contamination, can lead to a lack of nutrients in the diets of pollinators. This can cause increased oxidative stress, low resistance to disease and reduced detoxification ability. We proposed three forage mixtures with different botanical compositions, all of which should provide continuous forage for a wide range of pollinators. The monitored mixtures were treated by foliar application with selenium and zinc. Both elements should increase the quality of pollen and nectar. The effect of meadow mixtures and microelements on pollinator abundance, richness, and preference was evaluated using data obtained via the line transect method. Furthermore, the amount of selenium and zinc in the flowers was determined. It was found that the microelement treatment did not have any effect on the abundance and richness of the main pollinator taxa, which were affected only by a botanical composition of meadow mixtures. However, a preference for zinc-treated forage was observed in Apis mellifera, and a preference for selenium-treated forage was observed in Bombus spp. These two eusocial taxa appear to respond to an increased amount of microelements in the treated meadow mixtures. On the contrary, Lepidoptera was tied to untreated forage, where they were probably pushed by social bee species due to the competition.

The presence of mycotoxins in animal feed cause health disorders and can also contribute to other factors such as stress, lack of nutrition, infectious agents etc. The aim of this article was to study effect of feed ration contaminated with mycotoxins on liver histology and live weight of laboratory rats. 15 pieces of laboratory rats were divided into 3 groups (A, B, C). The rats in first group (A) fed with part of 30 % mycotoxin-contaminated barley, in second group (B were fed with 60 % and in control group (C) were fed without mycotoxin-contaminated barley. Content of deoxynivalenol (DON) was 9634 µg / kg and content of zearalenone (ZEN) was 2192 µg / kg. Barley monodietus were given rats in all groups to induce a nutritional imbalance. The aim of this study was to monitor the effect of mycotoxins and nutritional imbalances on weight gains and liver histology. The question is, "will the presence of mycotoxins in feed dose increase negative effect of a monodiets on health status?" No significant differences were found between the observed parameters. The presence of mycotoxins did not aggravate the negative effect of the monodiets on liver histology of the experimental rats.

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