Use of early conception factor test for determining pregnancy and embryonic mortality status of dairy cows

The aim of this study was to evaluate the accuracy of the ECF test for detecting the pregnancy status and embryonic mortality and to compare the reliability of ECF test from among ultrasonography and serum progesterone level. In this study, two groups were designed: the study group (n = 15) and control group (n = 9). All cows were observed for estrus activity four times daily. Cows in the study group were inseminated. After insemination, at the 7, 20, 30 and 45th days ECF test and ultrasonographic examination were applied to check the pregnancy status. Cows in the control group were not inseminated and examination procedure was performed like in the study group. Twenty days after insemination, pregnant positive cows that had been determined by ultrasonography were designated the study group. Twenty days after insemination, ECF test were applied and progesterone levels were determined in the serum samples obtained from pregnant positive cows. Fifteen cows in the study group were checked 20 days after insemination and determined pregnant. Their pregnancy status was confirmed 20 days after insemination by using ultrasonography. In the 30 th and 45th days ultrasonography was repeated, after which 13 cows were determined pregnant. In the serum of these two cows progesterone levels fell under 2 ng/ml. However, in the 20th day these cows' progesterone levels was higher than 2 ng/ml, in two cows embryonic death occurred. In cows which were determined as pregnant by ultrasonography at the 20th day, the ECF test was applied at the 7th day and 10 cows from this group had a positive reaction (66.7%). Test specificity, PPV and NPV results were 44.4%, 66.7% and 44.4% respectively; at the 20th day the ECF test was positive for 9 cows (60%), specificity, PPV and NPV results were 33.3%, 60.0% and 33.3%; at the 30th day, the ECF test was positive for 12 cows (92.3%), test specificity, PPV and NPV results were 45.5%, 66.7% and 83.3%; at the 45th day, 10 cows (76.9%), test specificity, PPV and NPV results were 54.5%, 66.7% and 66.7% respectively. Between the study groups, the ECF test accuracy at the 7th and 20th days were found lower than at the other days. The test's accuracy was determined the highest at the 30th day (70.8%), and the lowest at the 20th day (50%). The results show that ECF test is an unreliable method for pregnancy diagnosis and for determining embryonic death in dairy cows and these data indicate that the current ECF test cannot accurately identify the nonpregnant cows

Surface characterization of poly(L-lactic acid)-methoxy poly(ethylene glycol) diblock copolymers by static and dynamic contact angle measurements, FTIR, and ATR-FTIR

The surface composition and surface free energy properties of two types of amphiphilic and semicrystalline diblock copolymers consisting of poly(L-lactic acid) coupled to (methoxy poly(ethylene glycol) (PLLA-MePEG) having differing block lengths of PEG were investigated by using static and dynamic contact angle measurements, transmission Fourier infrared spectroscopy (FTIR), and attenuated total reflection spectroscopy (ATR-FTIR) and compared with results obtained from PLLA and MePEG homopolymers. The contact angle results were evaluated by using the van Oss-Good method (acid-base method), and it was determined that the Lewis base surface tension coefficient (gamma(-)) of the copolymers increased with an increase of the PEG molar content at the copolymer surface. This result is in good agreement with the transmission FTIR and ATR-FTIR results but not proportional to them, indicating that the surfaces of the copolymers are highly mobile and that the molecular rearrangement takes place upon contact with a polar liquid drop. The dynamic contact angle measurements showed that the strong acid-base interaction between the oxygen atoms in the copolymer backbone of the relatively more hydrophilic PEG segments with the Lewis acidic groups of the polar and hydrogen-bonding water molecules enabled the surface molecules to restructure (conformational change) at the contact area, so that the PEG segments moved upward, whereas the apolar methyl pendant groups of PLLA segments buried downward