Veterinary Obestrics and Gynaecology

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Browsing Veterinary Obestrics and Gynaecology by Subject "Conception rate"

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    Association of Subclinical Mastitis and Lameness with Reproductive Performance and Subclinical Endometritis in Zebu X Friesian Crossbred Dairy Cows In And Around Jimma Town Dairy Farms, Ethiopia
    (Addis Ababa University, 2023) Nuraddis Ibrahim; Prof. Fekadu Regassa; Dr. Tefera Yilma; Prof. Tadele Tolosa
    A longitudinal observational study was conducted to assess the association of subclinical mastitis and lameness with reproductive performance and subclinical endometritis in crossbred dairy cows. The California Mastitis Test and cytobrush technique were used to screen for subclinical mastitis and subclinical endometritis, respectively. Samples positive for subclinical mastitis were subjected to bacteriological analysis. Lameness in cows was also assessed using a 5-point locomotion scoring system. Analysis of progesterone and cortisol concentrations in blood serum of cows was performed using electrochemiluminescence immunoassay “ECLIA”. A total of 84 clinically healthy cows were tested for subclinical mastitis using the California Mastitis Test. The prevalence of subclinical mastitis at cow level was 51.2% (43/84). The prevalence of subclinical mastitis in 108 lame cows was 53.7% (58 of 108). Based on the results, the 192 cows according to the study were divided into the following four groups: Group I (n=43) cows with subclinical mastitis, Group II (n=50) are lame cows, Group III (n=58) lame cows with subclinical mastitis and Group IV (n=41) healthy cows (control group). Lame cattle are also classified as no lameness, mild lameness, moderate lameness, lameness, and severe lameness. Mean number of days from calving to first mating interval was highly significantly longest in lame cows with subclinical mastitis (122.71±28.6) than for lame cows (120.98±31.3), subclinical mastitis cows (120.51±24.5) and healthy cows (85.15±28.3) (P<0.05). Mean number of services per conception was significantly highest in lame cows with subclinical mastitis (3.66±1.31) than lame cows (3±1.6), subclinical mastitis cows (2.51±0.83) and healthy cows (1.59±0.81) (P<0.05). Cows clinically lame had a longest calving to first service interval when compared with cows which were never lame and those mildly lame. The difference was significant (P<0.05). Lowest conception and pregnancy rates at first services were observed in lame cows with subclinical mastitis. Cows that were clinically lame had a lowest conception rate at first services than cows that were never lame and mildly lame, although the difference was not statistically significant (P>0.05). Clinically lame cows had a lowest pregnancy rate at first services than cows that were never lame and mildly lame (P<0.05). Risk factors analysis revealed that prevalence of subclinical mastitis, lameness and in lame cows with subclinical mastitis significantly differed with the parity and body condition score (P<0.05). The present study revealed that subclinical mastitis and lameness were significantly and directly associated with subclinical endometritis (P<0.05). Progesterone concentrations highly decreased in lame cows with subclinical mastitis than in subclinical mastitis and lameness alone while the cortisol concentrations also highly increased in lame cows with subclinical mastitis. The major bacterial isolate was Staphylococcus aureus. In conclusion these results provide further evidence that combined occurrence of subclinical mastitis and lameness inflict harmful effects on fertility and hormonal profiles of dairy cows than those diagnosed with mastitis and lameness alone, emphasizing the relevance of mastitis and lameness control programs in dairy farms.
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    Comparison of Conception Rate of Frozen Semen from Two Extenders and Methods of Early Pregnancy Diagnosis Using Ultrasonography, And Progesterone Analysis in Dairy Cattle
    (2019-06) Abiy, Shimelis; Alemayehu Lemma (Prof), Dr. Tilaye Demissie
    Semen extenders used in Ethiopia are imported and expensive. Pregnancy detection is mostly through rectal palpation. This study was designed to compare conception rates of frozen semen prepared by commercial (Bioxcell) and homemade (Tris egg yolk) extenders. Further, evaluate advanced methods of early pregnancy diagnosis (18th to 22nd days post AI) using Progesterone analysis and Ultrasonography. Post-thaw semen viability, forward motility, live percent and morphological abnormality were 67±2.6%; 43.59±3.7%; 47.22±1.8% and 42.12±1.26% for TEY preserved semen, respectively; while the same parameters were 68.11±2.6%; 40.83±4.0%; 46.52±1.7% and 41.64±1.1% for Bioxcell preserved semen, respectively. HOS test was higher in TEY (8.87±0.72) extended semen than that of BioXcell extended semen (4.45±1.20%). A total 120 animals were included for both study, 48 animals for conception rate of semen extenders (14 heifers and 34 cows) were equally grouped and inseminated (24 by Bioxcell – G-I and 24 by Tris egg yolk – G-II). First service conception rate was 50% for G-I and 70.8% for G-II. Though conception rate was higher in G-II, there were statistically non significant but higher values between the groups. Nevertheless, conception rate was higher for both heifers and cows within G-II (71.42% and 70.58% in G-II compared to 42.85% and 52.94% in G-I). From a total of 72 animals inseminated for early pregnancy detection, pregnancy was confirmed on Days 18th and 22nd by RMPT and serum P4 analysis 42(58.4%) and 37(51.4%) respectively, and on Day 28th Ultrasonography 32 (44.5%) post AI. Although pregnancy detection with RMPT was statistically non significant but the values was higher between the tests. RMPT was the most sensitive (88.9%) but less specific (72.2%) taking Ultrasonography as a gold standard. Pregnancy later performed by transrectal palpation on Day 40 post AI showed 27 (37%) indicating the presence of corpus luteum and early embryonic mortality. RMPT was found to be relatively cheaper, and easier to apply under field condition. Results comparable to ultrasonography can be found if the test is repeated 7-8 days later. In conclusion, semen extenders can be locally prepared to mitigate the cost commercial extenders with even better conception results. Diagnosis of pregnancy can also be made at an earlier stage using a RMPT under the field conditions of Ethiopia.
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    Evaluation of Biochemical Determinants of Successful Conception in Dairy Cows in and around Bishoftu, Ethiopia
    (Addis Abeba University, 2024) Kutelo Kussia; Prof. Alemayehu Lemma
    The influence of biochemical characteristics of cervical mucus at the time of estrus were evaluated on conception rates of normal-cycling and repeat-breeding dairy cows. A total of 62 Holstein-Friesian dairy cows, 38 normal-cycling and 24 repeat-breeding cows, were included in the study. Vaginal electrical resistance (VER) was measured before artificial insemination and cows were categorized into three VER groups (150-180, 181-220 and >220 Ω). The cows were also grouped into three body weight ranges (300-350, 351-400 and 401-450 kg). Cervical fluid parameters including pH, spinnbarkeit, sperm penetration and crystallization patterns were measured or scored and pregnancy was diagnosed by ultrasonography after 30 days post-AI The overall conception rate was 54.84% with a significant difference (P<0.05) between normal cycling cows (63.2%) and repeated breeders (41.7%). The mean (±SD) VER was in the order of 219.03±66.17Ω and 221.67±41.77Ω for normal-cycling and repeated breeding cows, respectively. The average pH and spinnbarkeit value of cervical fluid were 7.38±0.32, 5.76±2.2cm in normal cycling and 7.32±0.27, 5.85±3.77cm in repeat breeder cows, respectively. The mean(±SD) VER of pregnant and nonpregnant cows were 202.15±31.15Ω and 241.79±73.56Ω, respectively. Body weight, timing of insemination and VER showed significant effects (P<0.05). Conception rates were highest for cows weighing 351- 400 kg(75%), inseminated 7-12 hours (71.43%) after standing estrus and VER of 181-220 Ω 84.21%). Interestingly, although there was some tendency for influence of the cervical fluid pH, this was not statistically significant, but sperm penetration, spinnbarkeit value and crystallization patterns of cervical fluid did (P<0.05). Cows with normal sperm penetration (72.2%), spinnbarkeit of 7-9 cm (87.5%) and typical crystallization patterns of cervical mucus (76.47%) had comparatively higher conception rates. In conclusion, sperm penetration, spinnbarkeit, vaginal electrical resistance and crystallization pattern are useful predictors of optimal insemination timing in Holstein cows.
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    Modulation of ovarian function to improve suitability for reproductive biotechnology application in local and crossbred Cattle
    (Addis Ababa University, 2022) Tilaye Demissie; Prof. Alemayehu Lemma; Dr. Tefera Yilma; Dr. Tamrat Degefa
    Ovarian function is influenced by various intrinsic and extrinsic factors. Breed related variations, nutrition; local environmental conditions are among the major sources of differences in response to application of reproductive biotechnologies. It is of paramount importance to understand specific ovarian functions amenable to modifications in order to improve suitability for advanced technologies such as fixed time artificial insemination (FTAI), ultrasound guided ovum pickup (OPU) and in vitro embryo production (IVP). In the first part of this study, estrus sign/s that best correlate with the time of ovulation and pregnancies rate to insemination at FTAI was evaluated in 27 Boran*Holstein crossbred dairy heifers. The second part explored ovarian response to estrus synchronizing hormones by cow realated factors and pregnancy rate to FTAI after ovulation synchronization using GnRH and PGF2α with or without progesterone augmentation (CIDR vaginal insert) in native Borans and Boran*Holstein crossbred dairy cows. The third part assessed the effect of CL, follicle ablation, administration of different doses/frequency of FSH, and different coasting period in Boran cows. Result indicated that, the frequency of occurrence of various estrus signs, length of estrus, and onset of estrus, was not affected (P>0.05) by estrus type. Irrespective of estrus type, standing estrus (r=1, P<0.05), and mounting other heifers (r=0.87, P<0.05) showed a strong positive correlation with ovulation time. Ovulation rate and pregnancy rate on day 32 was significantly higher (P<0.05) in cows that received CIDR augmentation to the double GnRH and PGF2α protocol compared to those that did not. When time of insemination was considered conception rate to insemination 19h post second GnRH administration was significantly higher (P<0.05) for Ovsynch group compared to Cosynch group. Presence of CL did not influence mean number of follicles aspirated, oocyte recovery rate, and quality of oocyte and cleavage rate. Divided dose of 175 IU FSH and 350 IU FSH ignificantly (P<0.05) improved the mean number of medium and large follicles compared to single dose while the 48h coasting period significantly improved (P<0.05) oocyte grade, oocyte maturation rate and cleavage rate. It could be concluded that standing estrus best predict ovulation time. Insemination scheduled at 19h of standing estrus significantly increase conception rate as this sign best correlates with the mean time of ovulation. Further, CIDR priming to the synchronization protocol greatly improve ovulation rate and subsequent pregnancy. Follicular ablation and administration of divided doses of FSH prior to OPU and a coasting period of just 48hr improves follicular population and oocyte recovery rate. Hwever, future studies are recommended to answer why Boran cows’ with morphologically smaller CL than Boran*Holstein cows have larger amount of progesterone than Boran*Holstein. Why some heifers that ovulated to D0 GnRH did not ovulate to D9 GnRH. As some of the CL that were present at day of start were lost at PGF2α the effect of stages of estrus cycle at the start of hormone treatment shoud be assessed both in Boran and Boran*Holstein cattle.