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In the topic of the reproductive cycle assessment and pregnancy diagnostics, there is an emerging need to develop immunoassays which are suitable for measuring faecal progesterone metabolite level. Faeces samples can be collected very easily and are alternatives for blood sampling in zoo and wild animals. However, the extraction of hormonal content is a labour-intensive process, which requires relatively long time. This step can be shortened and centrifugation can be avoided, however, the agreement of the results from different extraction protocol is a key for the proper analysis. The aim of this study was to analyse the agreement of data from different extraction protocols (a laboratory based and an on-field alternative) using faeces samples of different species.

Faecal samples were collected from different species; cattle, giant anteater and sloth. Ethanol-based ethanol method were used in all the samples. Before the extraction, each sample was divided into two treatments, that is, centrifugation and manual shaking. Furthermore, after extraction, all samples were refrozen and rethawed to analyse the possible degradation of hormonal content. Progesterone metabolite analysis was carried out with ELISA. Intraclass coefficient of centrifuged and shaked samples were calculated to assess the agreement of data. Interassay coefficients of repeatedly frozen-thawed samples are calculated to assess the reproducibility of measurement.

Mean interassay cv% of hand-shaked samples of cattle, anteater and sloth were 7.76 ±5.02, 20.8±12 and 12.1±11, respectively. These results did not differ from the interassay cv% of centrifuged samples. Intraclass coefficients of the results of the two treatments were 0.966, 0.856 and under 0.5 in cattle, anteater and sloth, respectively.

Our results show that the extraction of progesterone metabolites from faeces samples can be carried out on the field. However, there are species-specific differences in the agreement of data, which have to be taken into account, when this extraction method is applied on the practice. The repeated freeze-thaw cycle did not effect the intraclass coefficient and reproducibility, which suggest that the collected samples can be stored and later processed on diverse occasions.