Methodik und Anwendung der Defaunierung beim wachsenden Wiederkäuer

Abstract

Methods and application of defaunation in the growing ruminantDefaunation (selective destruction of protozoa in the rumen) is suitable for the evaluation of the effects resulting from the activity of the rumen ciliate protozoa and also for possible growth promotion in ruminant fattening. In scientific experiments defaunation should be practised with detergents, whereas nutritive methods seem to be of advantage for the practical application of defaunation. Ruminants reared without ciliates from birth by isolation show, in contrast, no advantage over faunated animals.The evaluation of experiments with defaunated animals showed clear effects on the digestive physiology. Bacterial counts increase up to a 2-3 fold value and the formation of ammonia and methane is reduced by about a third on average. The proportion of butyrate is lower, while the proportion of propionate increases. With regard to the higher total content of volatile fatty acids in artificially defaunated animals there is an increase in propionate content of rumen fluid. This is not valid for animals kept ciliate-free by isolation from birth. The apparent digestibilities of almost all nutrients decrease after defaunation by 1-2 percentage units because of the reduced fermentation activity in the rumen. Daily live-weight gain, N retention and food conversion efficiency are clearly improved in artifically defaunated animals, while isolation from birth leads to exactly contrary effects.An evaluation of the defaunation experiments in relation to the applied food composition showed that defaunation seems to be of advantage if rations contain protein of a high rumen degradability, especially if the ration crude protein content is low. O n the other hand, the ciliates seem to be of some importance if rations rich in starch are fed, but in this case the effects are not so clear as with protein. EinleitungEs ist seit langem bekannt, dai3 die Protozoen, speziell die Ciliaten, eine wichtige Rolle beim Nahrungsabbau im Pansen von Wiederkauern spielen, aber auch, dai3 sie nicht essentiell fur das Wirtstier sind (BECKER u. Mitarb., 1929). Daher wurde eine groi3e Zahl von Versuchen zur Bedeutung und Aktivitat einzelner Protozoenarten und zum Teil auch US. Copyright Clearance Center Code Statement: 0721-0981/86/331&0721$02.50/0 722 KREUZER der Gesamtpopulation durchgefiihrt. Die Ergebnisse hieraus sind wiederum in einigen Ubersichtsarbeiten zusammengefah (z. In diesen Literaturubersichten wird auch auf die Defaunierung (vollstandige Entfernung der tierischen Mikroben aus dem Pansen des Wiederkauers) als eine Methode zur Untersuchung der Protozoentatigkeit hingewiesen. Es sollte moglich sein, im Differenzverfahren durch den Vergleich von defaunierten Tieren und Tieren rnit normaler Fauna Effekte der Ciliaten auf verschiedene Parameter zu messen. Die Aussagekraft dieses Verfahrens wird jedoch durch das Kompensationsverhalten der weiterhin vorhandenen Bakterien etwas eingeschrankt. Da sich aber aus zahlreichen Versuchen mit protozoenfreien Tieren ein ansehnlichks Datenmat...

Effect of maize starch concentration in the diet on starch and cell wall digestion in the dairy cow

“…With HMS, also more butyric acid may have been produced from fermented starch than with LMS, because of the slight increase of rumen pH (Bannink et al, 2008). Alternatively, the increased proportion of butyric acid may reflect an increase in the number of protozoa at the highest level of maize starch as reported by Kreuzer (1986). Results of the fractional passage rates of Yblabelled forage agreed with those of Lund et al (2006).…”

The effects of protozoa and of supplementation with nitrogen and sulfur on digestion and microbial metabolism in the rumen of sheep

“…While rumen H2 S levels in Experiment 1 were adequate to maintain active fermentation, previous studies have shown that protozoa may also enable digestion to continue in sheep with less than 1 p H2S S/mL in the rumen (Hegarty et al 1991). This role of protozoa in maintaining rumen N and S supply has not previously been appreciated because most comparisons of faunated and fauna-free sheep have been made on S-and N-adequate diets which sustained rumen NH3 concentrations greater than 50 mgN/L (see Kreuzer 1986).…”

“…without rumen protozoa). While differences in rumen N and S metabolism have been noted between faunated and fauna-free ruminants, these comparisons have usually been made when the diet provided sufficient N and S to meet the requirements of rumen microbes (Kreuzer 1986). Because the seasonal deficiencies of nitrogen (N) and/or sulfur (S) that occur in many Australian pastures may restrict rumen function (Kennedy and Siebert 1972; Rees et al 1982)) it was our concern that the productivity of fauna-free ruminants under these conditions could not be predicted from available information.…”

Sulphur availability and microbial fermentation in the fauna-free rumen

“…This improved productivity is associated with an increased protein flow from the rumen (VEIRA et aI., 1984;USHIDA et a\., 1986) and a greater protein to energy ratio in the nutrients available for absorption (BIRD, 1989). Protozoa release NH 3 as an end-product of protein digestion (MAlI and HUNGATE, 1965) so animals without protozoa usually have a reduced rumen NH 3 concentration (KREUZER, 1986). It has recently been suggested that sulphide production in the rumen may be similarly reduced when there are no protozoa in the rumen (IVAN et a\., 1986).…”