Veterinary Obestrics and Gynaecology

Permanent URI for this collection

http://etd.aau.edu.et/handle/123456789/211

Browse

Browsing Veterinary Obestrics and Gynaecology by Author "Dr. Tilaye Demissie"

Now showing 1 - 2 of 2
  • No Thumbnail Available
    Item
    Ovarian follicular dynamics and conception rate in Boran cows previously subjected to repeated ovum pick up
    (Addis Ababa University, 2021) Gezahegn Berhan; Dr. Tefera Yilma; Dr. Tilaye Demissie
    The study was conducted to investigate the effect of repeated ovum pick-up on ovarian follicular dynamics, serum estrogen and progesterone pattern, and the conception rate of Boran cows. Eight Boran cows were estrous synchronized by 500μg PGF2α at 11 days intervals. After the second PGF2α injection ovaries were scanned by transrectal ultrasonography every 12 hrs for the first two days and then every 6 hrs until ovulation. From the day of ovulation onwards, the ovaries were examined twice daily (at 12 hrs interval) to characterize the growth and regression pattern of ovarian follicles during two consecutive estrous cycles. A blood sample was collected every other day to evaluate estrogen and progesterone concentrations. The mean (±SEM) IOI was 21.1±1.19 days for cows with two waves and 22.66±0.57 days for cows with three waves. The length of the IOI was not significant (P>0.05) by follicular waves. The mean (±SEM) number of days from the emergence of cohort follicles to ovulation of dominant follicle of the ovulatory wave was significantly (P<0.05) greater (10.80±1.03 days) for two wave cows than three-wave cows (7.50±0.70 days). The mean (±SEM) diameter of the preovulatory follicle was significantly (P<0.05) larger for cows with two waves (14.29±1.36mm) than for cows with three waves (12.30±1.01mm). The mean (±SEM) growth rate of the dominant follicle that finally ovulated was significantly (P<0.05) higher (1.16±1.2mm/day) in the three-wave cycle than in two-wave cycles (0.85±0.1mm/day). The mean (±SEM) serum concentrations of estrogen and progesterone were 28.73±6.56 pg/ml and 0.88±0.40 ng/ml, respectively during the proestrous and estrous. While during the late diestrous cycle, serum estrogen and progesterone were 11.01±1.61pg/ml and 2.67±0.12 ng/ml, respectively. 87.5 % of cows were found conceived on ultrasound 32 days after insemination. In conclusion, based on ovarian follicular dynamics, serum estrogen and progesterone pattern, and conception rate repeated ovum pick does not significantly affect the fertility of Boran cows. Boran cows were characterized by a higher incidence of two-wave cycles.
  • No Thumbnail Available
    Item
    Prevalence, Major risk factors and Response to Hormonal therapy of Phantom Cow Syndrome in urban/peri-urban dairy farms in Bishoftu town
    (Addis Ababa University, 2023) Onneta Regasa; Prof. Alemayehu Lemma; Dr. Tilaye Demissie
    Phantom cows that are non-pregnant and not returning to estrus within 21-24 days post insemination cause a serious reproductive management challenge for the smallholder and huge economic loss for the dairy producer. A clinical survey and therapeutic experimental study were conducted to determine the prevalence of phantom cow syndrome, determination risk factors and possibility of treatment using reproductive hormones in 25 dairy farms in and around Bishoftu town. Relevant data were collected through clinical evaluation of animals, record analysis reproductive indices and experimentation. The overall incidence of phantom cow syndrome was 11.9%; (86/720). Proportional incidences in small, medium and large farms were 47.5%, 11.8% and 5.8%, respectively. There was a significant difference (P < 0.05) between the different farm sizes. Presence of diseases such as Pyometra, metritis, luteal cyst, and cow related factors such as daily milk yield, age, parity, and body condition were found to be the major risk factors of PCS. There was a significant difference (P<0.05) in the incidence of PCS with respect to age, herd size, and parity. Return to estrus and pregnancy were highly improved in treated phantom cows with relatively higher pregnancy rate (75%) observed when cows were treated with PGF2 alpha and uterine lavage when there is endometritis. Early pregnancy diagnosis (between days 17 and 24) either with ultrasound or non-pregnancy test using a rapid P4Gold test was instrumental in restoring cyclicity in phantom cows. The prevalence of PCS in this study is relatively high; showing more non-productive animals are being kept in the dairy system. Many of the risk factors identified in this study are more common in the small holder dairy farms thus need to be considered during optimizing the production system. The use of a more accurate method of early pregnancy detection and treatment of phantom cows with reproductive hormones can contribute to the reduction of incidence of PCS by increasing submission rate for cows that fail to be pregnant during the preceding service. Therefore, proper diagnosis of phantom cows and their early treatment using hormones can potentially reduce the overall impact of PCS