Veterinary Obestrics and Gynaecology

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Browsing Veterinary Obestrics and Gynaecology by Subject "conception rate"

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    EFFECT OF BREED, PARITY AND BODY CONDITION ON OVARIAN RESPONSE AND CONCEPTION RATE OF BORAN AND ZEBU-HOLSTEIN CROSSBRED DAIRY COWS SUBJECTED TO OVSYNCH OR CO-SYNCH PROTOCOL
    (2018-06) Alebachew, Tilahun; Dr. Tilaye Demissie, Dr. Alemayehu Lemma; Dr. Tefera Yilma
    A study was carried out to evaluate the effect of parity, breed and body condition on ovarian response and conception rate of Boran (n=17) and Zebu-Holstein cross (n=18) dairy cows bred by Ovsynch or Co-synch timed artificial insemination. Ovarian response (ovulation and luteolysis) and pregnancy diagnosis were made by ultrasound and progesterone assay. For progesterone assay blood samples were collected at day 0, 5, 7, 9, 15 and day 21 of the experiments. The overall ovulation rate was 85.7%, of which 90% and 80% in Ovsynch and Co-synch, respectively. In this study, body condition, breed, and parity did not influence ovulation rate in both protocols (P>0.05). The overall conception rate was 60%, (55% in Ovsynch and 66.7% in Co-synch). Conception rate was relatively higher in Boran (70.6%) compared to crossbred (50%). However, the difference in conception rate was not statistically significant (P>0.05). Conception rate was significantly higher in primiparous (73.7%) compared to multiparous dairy cows (43.8%) (P <0.05). Conception rate was not influenced by body condition and breed in both protocols. The mean diameter of corpus luteum was 18.3±1.31 mm for animals with good body condition while it was 11.84±0.93 for those with low to moderate body condition and mean difference of corpus luteum was statistically significant (P<0.05). However, breed and parity did not influence mean size of corpus luteum. Twenty-seven cows (77.1%) had functional corpus luteum on day seven of the treatment (progesterone >1 ng/ml) and the progesterone was reduced to less than 1 ng/ml in 22 cows (81.5%) on day nine after PGF injection. In five cows (18.5%) the progesterone remained at levels greater than 1 ng/ml after PGF2α treatment (day 9). The result of this study demonstrated that conception was higher in Boran cows than Zebu-Holstein cross. Based on the result, it could also be concluded that both Ovsynch and Co-synch can give acceptable level of conception with the established TAI protocols.
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    OVARIAN FOLLICULAR DYNAMICS AND EFFECT OF BREED ON CONCEPTION RATE TO ARTIFICIAL INSEMINATION WITH FROZEN SEMEN IN MARES
    (2018-06) Ararsa, Duguma; Dr. Alemayehu Lemma
    Equine reproduction is unique by having long behavioral estrus and variations in ovarial follicular dynamics. Additionally, differences in time of breeding between breeds and individuals of mares made difficulty to standardize breeding time. There were a limitted data on equine reproduction and breeding in Ethiopia. An experimental study was conducted at Balderas sport horses and recreational center, Addis Ababa, Ethiopia from January to June, 2018 to determine ovarian follicular dynamics and evaluate conception rate to frozen semen in local and exotic cross breed mares. A daily transrectal ultrasonography was carried out to evaluate uterine changes and ovarian structures for 2-3 consecutive estrus cycles. Inseminations were done post ovulation within an average of 6-9h using frozen thawed semen. The mean (+SEM) of cross sectional uterine diameter were 44.4+0.5mm and 45+0.5mm for local and cross breed mares respectively; whereas endometrial fold development indicated 3.1+0.1 in local and 2.8+0.1 scores in cross breed mares with significant difference at P<0.05. The mean (+SEM) of preovulatory follicle diameter in local and cross breed mares indicated 49.1+1.0mm and 50.1+0.8mm respectively. Fast growth of dominant follicles in cross breed shorten interovulatory interval than local breed mares with length of estrus, 7.0+0.9 days for local and 6.1+0.6 days for cross breed mares. A positive correlation of teasing scores, uterine diameter and endometrial fold scores with diameter of developing dominant follicles in the present study has been used to estimate time of eminent ovulation. The overall conception rate to frozen semen was 15/21 (71.43%) with 8/11 (72.73%) in cross breed and 7/10 (70%) local breed mares. Conception rate increased significantly with increased number of services/conception with an overall mean +(SEM) of 2.2+0.2 services/conception. More number of services/conception were required for local breed (2.7+0.2) than cross breed mares (1.8+0.3) and again for lower body condition scores than higher condition scores of mares. In conclusion, measuring a cross sectional uterine diameter, endometrial folding scores and teasing scores with developing dominant follicles and their correlation were good parameters to determine relative time of ovulation and breeding in mares; whereas good management of mares for improved body conditions could require to decrease number of services per conception.