Summary
On the basis of original observations and data from the literature, it can be shown that fluctuations in faecal egg-counts cannot be attributed to any significant extent to changes in the dry matter content of the faeces. The coefficient of variation of egg-counts was found to be 43.46% (s=10.33), while that for dry matter content was 4.48% (s=0.65). The total range in the dry matter content of cattle faeces is not greater than 10%, while in practice a range of only a few percent may be expected.
It is therefore unnecessary to apply correction factors based on faecal consistency or dry matter content faecal egg-counts, since the variations in the latter are not eliminated in this fashion. It would appear that variations in faecal egg-counts are due to other causes, probably to intrinsic factors in the parasites themselves.
Zusammenfassung
Auf der Grundlage von Originalbeobachtungen und Literaturangaben läßt sich zeigen, daß Schwankungen bei Eizählungen aus Stuhlproben nicht in dem entscheidenden Umfang mit Veränderungen im Anteil an Trockensubstanz des Stuhls in Beziehung gebracht werden dürfen. Der Variationskoeffizient bei Eizählungen lag bei 43,46% (s=10.33), während dieser bei der Trockensubstanz 4,48 (s=0,65) betrug. Der gesamte Anteil der Trockensubstanz bei Rinderkot ist nicht höher als 10%, während praktisch nur ein Anteil von wenigen Prozent erwartet werden kann.
Deshalb ist es unnötig, einen Korrektionsfaktor heranzuziehen, der bei der Stuhluntersuchung die Konsistenz des Kotes oder den Gehalt an Trockensubstanz berücksichtigt, da die Variationen bei der letzteren in dieser Weise nicht eliminiert werden können. Es scheint deshalb sicher, daß die Variationen bei den Eizählungen im Kot auf andere Faktoren, wahrscheinlich auf Faktoren, die im Parasiten selbst liegen, zurückgeführt werden müssen.
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Department of Zoology Communication No. 27
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Honer, M.R. The interpretation of faecal egg-counts. Z. F. Parasitenkunde 28, 211–218 (1967). https://doi.org/10.1007/BF00260261
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DOI: https://doi.org/10.1007/BF00260261