Assessment of the accuracy of testicular dysfunction detection in male donkey (Equus asinus) with the aid of colour-spectral Doppler in relation to plasma testosterone and serum nitric oxide levels

This study aimed to determine the usefulness of colour and pulsed Doppler modes for the accurate diagnosis of donkeys suffering from subfertility to determine whether testicular vascularity assessment could be an indicator for sperm functionality. The study sample was composed of 10 male donkeys with normospermia (control group) and 10 donkeys with hypospermia. Animals underwent scrotal circumference measurement, testicular Doppler examination, seminal evaluation, blood sampling and hormonal assay. Semen volume and concentration were significantly (p ≤ .05) lower in the subfertile group (30.25 ± 1.22 ml and 89.44 ± 2.55 × 10⁶/ml) as compared with the control group (82.76 ± 1.65 ml and 452.78 ± 1.25 × 10⁶/ml), and total sperm/ejaculation was significantly (p ≤ .05) higher in the normal donkeys (28.30 ± 2.32 × 10⁹/total ejaculated) as compared with the subfertile group. Intratesticular coloured area showed a marked decline in the hypospermic males. There was no significant difference between the two groups in testosterone level, although the normal group showed an increase in nitric oxide metabolites. Both Doppler indices of the three branches of the testicular artery were elevated significantly (p ≤ .05) in abnormal donkeys, whereas Doppler peak systolic and end-diastolic velocities were increased in the normal group. Male donkeys with subfertility demonstrated lower arterial vascularity parameters in the form of intratesticular coloured area and blood flow rate; therefore, the most optimal parameters for differentiating subfertile hypospermic from normospermic donkeys were found to be the two Doppler indices, velocities parameters, testicular blood flow rate and nitric oxide levels.     

Morphological characteristics of the forebrain in the donkey (Equus asinus): A compared atlas of magnetic resonance imaging and cross-sectional anatomy

The brain is the most essential part of the central nervous system which regulates and coordinates all body activities. Based on its phylogenetic development from the neural tube, the brain is divided into rhombencephalon (hindbrain), mesencephalon (midbrain) and prosencephalon (forebrain). The present study is achieved to describe the morphological characteristics of the normal forebrain in the donkey using the matched magnetic resonance imaging (MRI) and cross-sectional anatomy. Ten cadaveric heads of healthy adult donkeys of both sexes were used. Two heads were examined using a 1.5 Tesla MRI scanner, and the brains of the other heads were gently extracted; six brains were sectioned into transverse, dorsal and sagittal slices, and two brains were grossly inspected. MR images were selected in correlation to their closely corresponding gross sections. Both cross-sectional anatomy and MRI scans showed extensive gyration of the neocortex. The forebrain structures appeared with variable intensities on three sequences, Flair, T1-weighted and T2-weighted MRI, enabling comprehensive evaluation of the relevant neuroanatomical structures. The present study provided a precise neuroanatomical atlas of the forebrain in the donkey which could help in the quick and efficient interpretation of clinical diseases of the forebrain, localization of the forebrain functions and evolutionary neurobiology.     

Evaluation of ovarian blood flow by colour Doppler ultrasound: practical use for reproductive management in the cow

Transrectal real-time ultrasonography (US) has been developed as a research and practical tool in bovine reproduction. Non-invasive US observations have made it possible to provide real-time and serial analyses of ovarian morphological changes and fetal development and have generated new information on reproductive physiology during the bovine oestrous cycle and pregnancy. This has greatly contributed to an understanding of the real-time dynamics of follicular development. US has also allowed for more accurate diagnosis compared with rectal palpation in reproductive management in cattle. Practical applications of US include early diagnosis of pregnancy, identification of twin fetuses, detection of ovarian and uterine pathologies and determination of fetal sex.In recent years, local blood flow has been analysed in individual ovarian follicles and the corpus luteum (CL) in the cow using colour Doppler US. From these observations, it has been found that (1) the blood supply to follicles is closely related to follicular growth, atresia and ovulation, (2) the blood supply to the CL increases in parallel with its growth, and (3) there is an acute increase in blood flow in the mature CL prior to luteal regression. Colour Doppler US may provide an estimate of the physiological status of follicles and corpora lutea. For example, images of blood flow can be used to assess the thickness of the follicular wall and provide a differential diagnosis of follicular and luteal cysts. Assessment of the area of blood flow in the CL using colour Doppler imaging may offer a useful adjunct in estimating CL function, which could be applied to the diagnosis of non-pregnancy and fetal loss. The number of small follicles which have blood flow at the start of gonadotrophin treatment may be a useful index to predict the superovulatory response.With improvements in portability and cost-effectiveness, the evaluation of ovarian blood flow by colour Doppler US is likely to become widely used as a diagnostic tool for monitoring ovarian function in dairy cattle.