Lateral flow immunoassay for whole blood progesterone detection as a tool for assessment of reproductive status in cattle.

Abstract

Reproductive inefficiency is one of major challenges affecting dairy farming in Kenya. This is partly caused by poor estrus detection, delayed determination of unsuccessful artificial insemination (AI) and sub-optimal calving to conception interval. Blood levels of progesterone hormone (P4) are a valid indicator of the reproductive status of an animal. Progesterone levels can be used to determine the estrous phase of an animal and also pregnancy status. This study evaluated P4 levels across the reproductive cycle in dairy cattle in Kenya using the whole blood semi quantitative lateral flow immunoassay (LFIA) manufactured by Diagnostics for All Company and compared the findings with those by plasma quantitative enzyme linked immunosorbent assay (ELISA). Blood was collected from 46 animals to establish the P4 profiles at the various stages of the reproductive cycle using ELISA. Subsequently, P4 levels were analyzed by LFIA and ELISA in blood from 100 dairy cattle and the tests compared. The P4 profiles of dairy cattle in the study ranged from 0-10ng/ml. The LFIA test results were scored from 1-3. Progesterone levels with scores of 1 to 2 were recorded in pre-pubertal and follicular phase animals, corresponding to P4 levels ranging from 0.01 to 2.4 ng/ml by ELISA. Non pregnant luteal phase and pregnant animals had higher (P>0.05) LFIA scores of 3 representative of P4 levels ranging from 6 to 10 ng/ml. The semi-quantitative P4 levels as determined by the LFIA were highly correlated (r = 0.95; Kappa 0.93) with the quantitative ELISA P4 levels for low and high P4 concentration. The findings of the current study show that LFIA is a reliable method for determination of P4 levels in whole blood that can be used as a point of care decision support tool for reproductive management of dairy cows.