Oral and Poster Abstracts

amount of saponins was observed in March, in the rain season, and the
lowest amount in July. These results shoed the great variation in levels of
saponins during the experiment, suggesting a relation between the
pluviometric precipitation and/or cycle of life in these species of
Brachiaria evaluated. Acknowledgements to Coordenaçao de
Aperfeiçoamento de Pessoal de Nível Superior (CAPES) and to
Conselho Nacional de Desenvolvimento Científico e Tecnológico
(CNPq) by financial support.
Key words: brachiaria, spectrophotometry, sporidesmin,
photosensitization, protodioscin
521 The Effect of Dry Period versus Continuous Lactation on ßcarotene,
Vitamin A and Vitamin E in the Mammary
Secretion
F. Schweigert 1 , A. Wesser 2 , I. Buchholz 2 , J. Raila 1
1
University of Potsdam, Department of Physiology and
Pathophysiology, Potsdam-Rehbruke, Germany
2
University of Leipzig, Department of Veterinary Physiology, Leipzig,
Germany
ß-carotene and fat-soluble vitamins A and E are accumulated during the
dry period in the mammary gland and secreted with colostrums together
with the accumulated immunoglobulins. Both are of great importance for
the health of the new borne calf. In this study changes in fat-soluble
vitamins A, E and ß-carotene (rpHPLC) and IgG1 (immunodiffusion) in
the secretion of the mammary gland during late gestation in dry dairy
cows (n=12) and those which were milked until parturition (n=5) were
compared over a total period of 11 weeks starting 8 before parturition.
Results showed a biphasic increase in all components during the dry
period. The first approx. 30 d ap and the second closely toward parturition.
In animals with continuous lactation an increase towards parturition was
observed as well but maximum levels were reached earlier approx. 20 ap.
Absolute levels were comparable in both groups. In both groups low
levels characteristic for mature milk were reached within a few days after
parturition (P