A new perspective on the association between radio-immuno and ELISA progesterone assays in Indonesian goats

The Indonesian Kacang goat (Capra hircus) is fecund and is perfect for tropical countries but its production and population have not been optimised. Livestock reproductive improvement requires hormone monitoring. The enzyme-linked immunosorbent assay (ELISA) and radio-immuno assay (RIA) are required for precise progesterone quantification. To our knowledge, this is the first study to compare progesterone estimation methods in Indonesian Kacang goats and correlate them with corpus luteum size throughout an oestrus cycle standardized using oestrus synchronisation. All periods showed a high ELISA–RIA correlation. The data also showed that CL and progesterone concentrations were highly correlated until day 8 but uncorrelated thereafter. Our study found that the two methods were qualitatively similar but required different quantitative range standards. This research emphasizes that the comparison of progesterone hormone test results will differ when different assays are used and data on the range of deviation using these two methods is required.