Evaluation of the effect of sustained-release progesterone injection on the expression of interferon-related genes in repeat-breeder dairy cows.

BACKGROUND: Repeat-breeder cows repeatedly fail to conceive after at least three attempts and return to oestrus at apparently normal intervals. Repeat-breeder cows cause economic losses in dairy farms in different ways. OBJECTIVE: In the present study, we investigated the effect of sustained-release progesterone injection in two different doses on the expression of interferon-related genes in repeat-breeder dairy cows. METHODS: A total of 96 repeat-breeder primiparous and multiparous cows were assigned among three groups: control group, inseminated and do not receive progesterone treatment; P400 and P600 groups, inseminated and received a single-intramuscular injection of 400 and 600 mg slow-release progesterone 5 days after insemination, respectively. Blood sampling was carried out on Day 20 after AI for progesterone measurement and evaluation of gene expression for ISG15, MX1 and MX2 genes. RESULTS: One injection of sustained-release progesterone increased the expression of ISG15, MX1 and MX2 genes with differences between two different progesterone concentrations. For all three genes, the level of gene expression was higher in progesterone-supplemented group than in control group, when P400 and P600 groups considered together. The level of MX2 gene expression was significantly higher in pregnant cows than non-pregnant cows. There was a significant positive correlation between expression level of all three genes and blood progesterone concentration. The expression level of ISG15 gene showed a significant positive correlation with MX1 and MX2 gene expression. CONCLUSION: The use of this sustained-release progesterone is simple and can be used in repeat-breeder cows to improve fertility.

Evaluation of the efficiency of TaqMan duplex real-time PCR assay for non-invasive pre-natal assessment of foetal sex in equine.

Accurate diagnosis of foetal sex in pregnant mare is helpful for many breeders, both for private or commercial purposes. In this study, in order to pre-natal foetal sexing in equine, we used TaqMan duplex real-time PCR to detect the specific regions of SRY and TSPY genes on extracted cell-free foetal DNA from maternal blood. Peripheral blood samples from 50 pregnant Arabian mares with singleton foetuses were collected. Cell-free foetal DNA was extracted from maternal plasma, and duplex real-time PCR assays were performed with TaqMan probes and primers. Amplification of glyceraldehyde-3-phosphate dehydrogenase (GAPDH) gene was used as control of DNA extraction procedure. From the 50 sampled mares, 28 cases had female and 22 mares had male foetuses. The final results for 46 samples were conclusive, and from them, 43 cases were predicted correctly. Sensitivity, specificity and accuracy of the test were 90.48%, 96% and 93.48%, respectively. In conclusion, a TaqMan duplex real-time PCR was set up to pre-natal detection of foetal sex in equine. The method was fast and decreased the false-positive and false-negative results. The technique can be used as a routine procedure in farms by collecting only a blood sample.