[Thiamine and its derivates in cattle blood measured by HPLC in healthy animals, in patients suffering from CCN and in their cohorts]. / Analyse von Vitamin B1 und dessen Derivaten im Rinderblut mittels HPLC-Technik bei gesunden, an CCN erkrankten Tieren und deren Kohorten.

The aim of this project was to develop a routine method to measure thiamine and its derivates in blood, to detect the need of vitamin B1-supply in cattle faster and more precise than until now using the transketolase test. For that, thiamine and its derivates (thiaminediphosphate = TDP,-monophosphate = TMP) were analysed in cattle blood by HPLC technique with post-column derivatization. Moreover, the levels in healthy cattle were compared with those in herds with single CCN cases. EDTA-blood-stored up to 10 days by 6 or 20 degrees C- was the most appropriate substrate. Sensitivitiy and specifity were significantly better than (TT, sum of all fractions): 1.95% and 2.10%; thiamine and TMP: 7.02% and 9.17%. The lowest concentration, which could be measured, was 0.5 ng/ml. 72 samples could be analysed daily. In the blood of 280 healthy calves and cows (group A), 201 clinically unsuspicious animals out of stocks with single cases of CCN (group B) and 12 patients with clinical obvious CCN (group C), thiamine and its phosphates were measured and the means calculated (ng/ml). After this, the thiamine status is characterized by (ng/ml): (A) thiamine 13.5 (4.61-28.8),TDP 51.0 (33.1-82.2), TMP 8.79 (2.23-18.1),TT 73.3 (44.6-114); (B) thiamine 8.73 (0.00-20.0), TDP 43.5 (15.5-75.7),TMP 6.15 (0.00-16.6), TT 59.4 (18.7-96.5); (C) thiamine 3.85 (0.00-1 1.5), TDP 14.5 (0.00-28.3), TMP 1.27 (0.00-4.87), TTP 19.6 (4.92-35.9). So, HPLC with post-column derivatization offers a precise, automatically working method for a fast diagnose of thiamine deficiency. The lowest critical value of TT is 40 ng/ml for healthy animals in the blood. The sample (EDTA-blood) can be posted simply at temperatures up to 20 degrees C. In comparison to other measuring methods, this HPLC-technique enables an early recognition of the risk to come down with CCN in endangered cattle herds.

[Influences on fermentation and thiamine metabolism in bovine rumen fluid (in vitro)--part 3: Effects of artificially contaminated hay with Cladosporium herbarum and Fusarium graminearum, respectively]. / Einflüsse auf die ruminale Fermentation und den Thiaminstoffwechsel beim Rind (in vitro)--3. Mitteilung: Wirkung eines experimentell mit Cladosporium herbarum bzw. Fusarium graminearum künstlich verpilzten Heus.

The influence of contaminated hay [Cladosporium herbarum (CL) and Fusarium graminearum (FU), respectively] on fermentation and thiamine metabolism of bovine rumen content was investigated using the longterm rumen simulation technique (RUSITEC). Six investigation periods 25 days long each were carried out. A nine days feeding period with normal hay was followed by the testphase I (five days) with a mixture of normal and mouldy hay and testphase II (five days) with additive an 0.3 mg thiamine per reaction vessel. The last four days served as regeneration time with normal hay. The following marginal effects of mouldy hay on rumen fermentation patterns could be noted. A) During testphase I: cellulase activity: +10.0% (FU); alternation of the thiamine derivate pattern, but no effect on total thiamine content (CL, FU). B) During testphase II the results were more obvious: bacterial protein synthesis: -22.6% (CL), -24.4% (FU). Alternation of the fatty acid pattern: propionate (-7.30% FU), n-butyrate (-3.90% CL, +3.49% FU), n-valerate (-8.5% CH, FU). Cellulase activity: -17.0% (CL, FU). But no effect on total thiamine (CL, FU); alternation of the thiamine derivate pattern: more non phosphorylate thiamine. The noted effects on rumen fermentation and thiamine metabolism were not severe enough to be responsible for the development of a CCN.

[Not Available]. / Einfluß von Epicoccum nigrum, Alternaria alternata, Mucor racemosus und Ulocladium chartarum auf die Protozoenpopulation im Pansen des Rindes (in vitro).

The influence of moulded hay (Alternaria alternata, Epicoccum nigrum, Mucor racemosus, Ulocladium chartarum) and the efficiency of Vitamin B1 substitution to cope these effects on rumen protozoa was investigated using the longterm rumen simulation technique (RUSITEC) for about 25 days. Moulded hay affected medium-sized protozoa to a different extent (Alternaria alternata: -16 %, Epicoccum nigrum: -27 %, Mucor racemosus: -9 %, Ulocladium chartarum: +2 %). The vitamin B1 substitution had positive effects during the feeding of Mucor racemosus and Ulocladium chartarum.

[Not Available]. / Einfluss vonMucor racemosus undUlocladium chartarum auf ruminale Fermentationsvorgänge beim Rind (in vitro).

Using the long term rumen simulation technique RUSITEC a possible relationship between Mucor racemosus and Ulocladium chartarum and cerebrocortical necrosis (CCN) in cattle was investigated. In phase one only M. racemosus or U. chartarum and in phase two M. racemosus or U. chartarum in combination with thiamine were tested. The following differences between test groups and controlls could be noted: sVFA -7,5%, cellulase activity +62,1%, protein concentration -16,4%, thiamine -11% (only phase two). Thus, although a clear influence of M. racemosus and U. chartarum on rumen fermentation could be shown, a relation to CCN was not detected.