Pál Rafai

Evaluation of mycotoxin-contaminated cereals for their use in animal feeds in Hungary.

In the period between December 5, 1991 and September 17, 1998, 760 maize, 367 wheat, 119 soybean, 222 barley, 85 bran, 32 triticale, 60 oat, 14 rye and 22 sunflower samples were investigated for the presence and concentration of seven fusariotoxins (T-2 toxin, zearalenone, deoxynivalenol, nivalenol, diacetoxyscirpenol, HT-2 toxin, fusarenone-X) and OTA. The comparison of analytical data with those of the relevant literature revealed that although the incidence rate and/ or concentration of Fusarium mycotoxins and OTA in Hungarian-grown cereals is occasionally considerable, the position of the country is not worse than the average of countries. Our findings indicate that soybean tends to be good substrate for trichothecene-producing fungi and the rate of contamination is regarded as substantial. The commodities were assorted into one of three quality categories. The proportion of objectionable samples was only 3.0, 2.2, 2.3 and 1.7% in maize, wheat, barley and soybean samples, respectively. However, this low rate of objection might still be a source of great economic loss. The proportion of objectionable samples was much higher in the case of bran, oat and triticale (7.1, 6.7, and 6.3%, respectively). The results of the present investigation indicate a need for regular screening for mycotoxins of importance and individual appraisal of each commodity from the point of their use in animal feeds.

Characterisation and effects of a xylanase enzyme preparation extracted from Thermomyces lanuginosus cultures

This paper describes the production of an enzyme preparation from the fungus Thermomyces lanuginosus. Thermal resistance, pH stability and lignocellulolytic activity of the enzyme preparation high in xylanase were studied on a variety of grains and forages. The enzyme preparation preserved more than 70% of its original xylanase activity for 4 and 1 h at 60 and 70 degrees C, respectively. The xylanase activity remained over 80% when the preparation was incubated for 30 min at pH 4.5. In vitro digestibility studies indicated that the enzyme digested 7.5, 8.5 and 8.0% of the dry matter (DM) of barley meal, wheat bran and oat meal samples, respectively. When applying 60-min incubation, 7.5, 7.3 and 8.4% of DM of the oat straw, alfalfa hay and triticale straw was digested, respectively. When the time of digestion was increased to 360 min, the sunflower hull showed 15.8% DM digestibility.

Biotransformation of trichothecenes alleviates the negative effects of T-2 toxin in pigs

Between 49 and 70 days of age, three groups of growing pigs (n = 10 each) were fed diets containing 0, 0.3 and 0.5 mg/kg T-2 toxin, respectively, for 21 days. The feed of another two groups of pigs (n = 10 each) contained 0.3 or 0.5 mg/kg T-2 toxin, respectively, plus a feed additive developed for splitting up the molecular structure of Fusarium toxins, in particular trichothecenes, by deepoxidation of the molecule, at 2 kg/tonne concentration. One group (n = 10) served as positive control; their feed was free from T-2 toxin but contained the feed additive at the above concentration. Toxin concentrations at these low dietary levels impaired the feed intake and growth rate of pigs. The feed additive alleviated the negative effects and justified its potential for prevention. Data of the present study indicated a 0.2 mg/kg feed no observed effect level (NOEL) of T-2 toxin in growing pig feeds.

Effect of current intensity and duration on the effectiveness of head-only electrical stunning in pigs under commercial conditions

After head-only electrical stunning of pigs sequential animal-based measurements were carried out right after stunning as well as before and after bleeding in order to analyse how unconsciousness is achieved and maintained in relation to recorded and calculated technical parameters such as electric current intensity, electric work, duration of stunning, and stun-to-bloodletting period. The measurements were performed at three different slaughterhouses on 9 different days under routine slaughtering conditions. The data of 405 pigs were analysed. The effectiveness of stunning was measured by the number of parameters at two (adequate and acceptable) levels. Current intensity had a predominant effect on the effectiveness of stunning and on the maintenance of unconsciousness. The duration of stunning played a role only as part of the electric work, which manifested itself in the maintenance of unconsciousness. Stunning proved acceptable in 99% of the cases, provided that the minimum current intensity of 1.02 Amp was secured. In 99% of the cases unconsciousness could be maintained at an acceptable level beyond bloodletting when the electric work was at least 8,089.38 Joules. Recovery of consciousness depends on the stun-to-stick period: the best time of bloodletting is less than 32 seconds from the end of stunning.