Profiles of progesterone and bovine interferon-τ in repeat breeding and non-repeat breeding Aceh cows

This study aimed at determining the profiles of progesterone and bovine interferon-τ (bIFN-τ) and the correlation between the two in repeat breeding (RB) Aceh cattle and non-RB Aceh cattle. The study was performed on five RB and five non-RB Aceh cows. These cows were subjected to estrous synchronization using the prostaglandin F2 alpha hormone, which was followed by artificial insemination (AI). Serum samples were collected on days 5, 6, 7, 15, 16, and 17 after AI to measure the concentration of progesterone at the beginning and end of the luteal phase and from days 14 to 18 after AI to measure the concentration of bIFN-τ. The concentrations of progesterone and bIFN-τ were determined using enzyme-linked immunosorbent assay. Pregnancy examinations were performed by ultrasonography on days 25, 35, 45, and 55 after AI. Data for progesterone and bIFN-τ concentrations were analyzed using the Mann-Whitney and t-tests, and the correlation between progesterone and bIFN-τ was analyzed using the Spearman correlation test. The average concentration of progesterone in RB Aceh cows tended to be lower than non-RB Aceh cows, but it was not significantly different (p>0.05). Similar results also found in the concentration of bIFN-τ which RB Aceh cows tended to have lower bIFN-τ concentrations compared to non-RB Aceh cows, but it was also not significantly different (p>0.05). Moreover, the concentrations of progesterone and bIFN-τ in RB and non-RB Aceh cows did not show a significant correlation (p>0.05). These results of the ultrasonography showed that non-RB Aceh cows were pregnant from day 25 to day 55 after AI, whereas RB Aceh cows were not pregnant and had early embryonic death. The concentrations of progesterone and bIFN-τ in non-RB Aceh cows tended to be higher than those in RB Aceh cows, although, it was not significantly different. Non-RB Aceh cows were able to maintain pregnancy until day 55, whereas RB Aceh cows were diagnosed with early embryonic death before day 25 after AI.