Danicke S., D. Gädeken, K.-H. Ueberschar, U. Meyer and H. Scholz

An experiment was carried out to examine the effects of a Fusarium-contaminated wheat (10 mg deoxynivalenol and 0.76 mg zearalenone, ZON, per kg dry matter) on fattening performance and slaughter yields of growing bulls, and on carry over of ZON into tissues and body fluids. In a second study, rumen physiological parameters were investigated in wethers equipped with a rumen fistulae. Moreover, the influences of a detoxifying agent (Mycofix®Plus, MP, Biomin GmbH, Herzogenburg, Austria) were considered as an additional experimental factor beside the contamination of the wheat (uncontaminated control wheat, Fusarium-toxin contaminated wheat). The experiments were designed according to a complete two by two factorial model of ANOVA which required

the testing of both the control diet and of the contaminated diet either in the absence or presence of MP.
The fattening experiment with bulls (n=14 per treatment) covered the live weight range between 244 kg and 460 kg. The respective wheat batches were included in the concentrate portion at 64 %. Concentrates were fed restrictively whereas maize silage was offered for ad libitum consumption. Daily dry matter intake and live weight gain (kg per animal and day) were 7.40, 7.52, 7.51 and 7.49 and 1.367, 1.296, 1.380 and 1.307 for bulls fed the unsupplemented control wheat, the supplemented control wheat, the unsupplemented and Fusarium toxin contaminated wheat and the supplemented Fusarium toxin contaminated wheat, respectively. Feeding of the Fusarium toxin contaminated wheat resulted in a reduced dressing percentage, an increased weight of the emptied gastro-intestinal tract and a reduced weight of the testicles. No MP-effects were seen for these parameters. ZON or its metabolites were not detected in edible tissues.
The rations for wethers were composed of hay and of the respective wheat batch at a ratio of 1 to 1 on a dry matter basis. The results of the rumen physiological parameters revealed that the molar ratios of short chained volatile fatty acids and ammonia concentration in rumen fluid remained unchanged in response to dietary treatments whereas the addition of MP to the diets buffered the postprandial decrease in rumen pH. This effect was independent of the mycotoxin contamination of the wheat. The pH-differences in rumen fluids collected from wethers fed the MP-supplemented and unsupplemented rations amounted 0.2 to 0.3 on average in the time period between 1.5 h and 5 h after feeding. The kinetic profile of the in sacco dry matter degradation indicated a reduced degradation velocity for wheat straw incubated in wethers fed the mycotoxin contaminated rations whereas no changes were obvious when alfalfa hay was incubated. MP had no effect on the kinetics of dry matter degradation.


کد مقاله : MPR-001





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