Measurement of Faecal Progesterone Metabolites and its Application for Early Screening of Open Cows Post‐insemination

Abstract

The present study investigated the changes of serum progesterone (P4) and its faecal metabolites in pregnant and non-pregnant cows (Expt 1) and the feasibilty of using faecal P4 metabolites for early screening of open cows post-insemination (Expt 2). In Expt 1, seven crossbred Holstein-Friesian (HF) cows were studied. Serum and faecal samples were collected once daily from the day of artificial insemination (AI) until 25 days after AI. In Expt 2, 27 crossbred HF inseminated cows were employed. Serum and faecal samples were obtained on the day of AI (day 0) and on days 19-22 post-insemination. Enzyme immunoassay measurements of serum P4 and faecal P4 metabolites were established. The low detection limit of the assay was 0.01 ng/ml and the amount of P4, resulting in a 50% reduction in the initial binding value, was 1.07 ng/ml. The intra- and inter-assay coefficients of variation were <8% and <14%, respectively. A positive correlation between the levels of serum P4 and faecal P4 metabolites was found in every single cow (r = 0.73-0.88, p < 0.001) and pooled data (r = 0.78, p < 0.001). The estimated value of faecal P4 metabolites at 100 ng/g of faeces was equal to the serum P4 levels of 1 ng/ml. The accuracies of pregnancy and non-pregnancy diagnosis based on the analyses of faecal P4 metabolites between day 0 and days 19-22 post-insemination, were 67% and 100%, respectively. In conclusion, the measurement of faecal P4 metabolites can be a potentially alternative method for early screening of open cows post-insemination with the same accuracy and precision, as measured by serum P4 assay.

Effects of storage temperature and time on fecal progesterone concentration<br>in camel (Camelus dromedarius)

“…It was lower than that found by Kornmatitsuk et al (2007) in cows (89.7%). The parallelism between the theoretical and observed concentrations of metabolites of progesterone in the feces was estimated by the linear regression analysis which gave the following equation with a correlation coefficient of 0.991: y = 0.743 x + 0.046, where x = the theorical concentration and y = the observed concentration.…”

“…This technique is stressful for animal and requiring a strict conservation of samples. As an alternative, the measure of steroid metabolites in feces is widely suggested to monitor reproductive hormones in wildlife species (Graham, 2004;Freeman et al, 2010) as well as in domestic animals (Cebulj-Kadunc et al, 2000;Kornmatitsuk et al, 2007). It is a non-invasive method, since it avoids the stress effects related to blood sampling and fecal samples are easily collected and stored.…”

Characteristics of oestrous cycles in Holstein cross-bred dairy heifers: An evidence of delayed post-ovulatory progesterone rise

“…Samples were centrifuged at 3,000 rpm for 10 min and plasma was stored at -20°C until analyses. Progesterone was determined by means of EIA (Enzymelinked immunoassay) as described by Kornmatitsuk et al (2007). The main metabolite of PGF2 α (15-ketodihydro-PGF2 α [PG-metabolite]) was analysed by RIA, according to Granström and Kindahl (1982).…”

Pregnancy detection and monitoring in cattle via combined foetus electrocardiogram and phonocardiogram signal processing

“…These tests use either blood or milk to detect a marker of pregnancy. Some of the markers that have been examined as indicators of pregnancy in cattle include oestrone sulfate [12,13], progesterone [14-16] and pregnancy associated glycoproteins (PAG) [17,18]. Oestrone sulfate is produced by the foetus and as such offer high specificity.…”