Cryptosporidium parvum is recognized as one of the most important pathogens causing enteritis and severe diarrhoea in calves up to 1 month of age. Although the infection may be responsible for some mortality, its impact is mainly associated with the impairment of intestinal functions and lower performance of animals. The aim of this study was to determine the effect of cryptosporidiosis on the intestinal functions in neonatal experimentally infected Holstein calves. Absorption tests with d-xylose and retinyl-palmitate, and the lactulose/mannitol test of intestinal permeability were simultaneously performed in 1-week intervals from challenge to full recovery. In infected animals, reduced intestinal absorptive capacity for both D-xylose and retinyl-palmitate was observed on day 7 post-infection (p.i.). At the same time, a more than 100% elevation of intestinal permeability was observed in the infected calves. All intestinal functions, except absorption of retinyl-palmitate, were significantly affected and changes were detected up to day 14 p.i. In contrast, results of all tests obtained on day 21 p.i. suggest full recovery of the infected intestine. Significantly, growth of the calves which had recovered from cryptosporidiosis was still affected between days 14 and 21 p.i.

The aim of this study was to utilize the lactulose/mannitol test for assessment of intestinal permeability (IP) in preruminant calves. IP was increased experimentally by administration of Indomethacin. Both sugar markers were determined simultaneously as silyl-derivates in 5 h urinary production using the gas liquid chromatography technique. The index of IP was determined as the ratio between urinary recovery (%) of 10 g lactulose to 5 g D-mannitol. The IP index in control calves was 0.242±0.048. Doses of 20 and 60 mg Indomethacin did not significantly affect IP, but the IP index was significantly enhanced in calves receiving 120 mg of drug (0.541±0.091; P<0.01). Results of this study show that ratio of lactulose to D-mannitol in urine reflected the treatment by the highest dose of Indomethacin and that the test may be used for determination of IP in preruminant calves.

No abstract

MORAVCOVÁ J., KLEINOVÁ T. (2001):The determination of isoflavones and coumestrol by capillary electrophoresis. Czech J. Food Sci., 19: 132138.The separation of six isoflavones (biochanin A, isoformononetin, formononetin, prunetin, daidzein and genistein) and coumestrol on an uncoated fused-silica capillary electrophoresis column was optimised using alkaline borate buffer as electrolyte and DAD detection. A baseline separation of all analytes except a pair, formononetin-biochanin A was achieved at pH 10.5 in 25 min. Detection limits were low (0.1 µg/ml) and the linearity of the detector response was established in the concentration range 0.4-60 µg/ml (180 µg/ml for coumestrol). Coumestrol was synthesized and the carbon signals in 13 C-NMR spectrum of both coumestrol and di-O-acetylcoumestrol were assigned for the first time using two-dimensional HMQC technique.

High performance capillary electrophoresis (HPCE) on an uncoated fused-silica capillary column using a borate buffer at pH 9.2 as electrolyte and diode-array detection was developed for the determination of coumestrol in alfalfa. The linear detector response was established in the concentration range 0.76140 mg.dm 3 , the minimum detectable limit was 0.39 mg.dm 3 , and migration time of coumestrol was 5 min. 3-Isobutyl-1-methylxanthin was used as an internal standard. Coumestrol was isolated by acid extraction employing a mixture hydrochloric acid-acetonitrile at 95°C for 30 min followed by solid phase extraction. Relative standard deviations of reproducibility and repeatability were 1.77% and 5.49%, respectively. Spiking recovery value of 92% was achieved. Alfalfa, variety Morava, contains 148248 mg.kg 1 coumestrol in dry matter. The proposed method is useful for routine analyses.