Veterinary Obestrics and Gynaecology

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Browsing Veterinary Obestrics and Gynaecology by Subject "Boran"

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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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    Estrus Response of Boran and Boran-Holstein Crossed Cattle to Pgf2α and Pregnancy Rates to Sexed and Conventional Semen, Holeta, Ethiopia
    (2020-06) Galma, Boneya; Dr. Tefera Yilma, Dr. Tilaye Demissie
    The study was conducted majorly to evaluate pregnancy rate to sex sorted semen and high grade non sex sorted imported semen in a 2X2 factorial design in Boran and Boran X Holstein cross cows and heifers. The effect of some animal related factors which may affect pregnancy rate and heat characteristics of different breeds and party were evaluated. A total of 71cows/heifers consisting of 36 Boran and 35 Boran x Holstein of which 49 were cows and 22 heifers were purposively selected and synchronized using PGF2, twenty five Boran (69.4%) and twenty seven Boran x Holstein cross (77.1) were responded to PGF2 and exhibited estrus. When response to PGF2 was compared by parity, 65.3% cows (n=32) and 90.9% heifers (n=20) exhibited estrus. Parity has statistically significant (P<0.05) effect on estrus response in which heifers showed higher response rate than cows whereas, breeds, body condition score and treatment (response at single or double PGF2) did not show significant effects on estrus response (P>0.05). Average duration of estrus was significantly longer in Boran x Holstein cross breed than Boran breed. However, average interval to onset of estrus and duration of standing estrus were not significant differ (P>0.05) by both breed and parity. A multivariable logistic regression model including the breed, parity, body condition score, treatment, semen type and their interactions was evaluated. Parity and semen type showed significant variation (P<0.05) on the pregnancy rate. On pregnancy detection, 54.1% Boran and 57.6% cross breed cattle were found pregnant of which 46.8% were cows and 72.2% were heifers to both types of semen. The pregnancy rate was 66.6% to conventional semen and 46.1% to sexed semen. It could be concluded that sexed semen could be a better option to improve number of replacement heifers. Similarly, high grade imported semen may help speeding up genetic improvement when used on Boran heifers. However, data from large number of animals should better be generated. Heifers were well responded to than cows; duration of estrus was longer in Boran breeds than crossbred and heifers was higher conception rates than 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.
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    Quality of semen and its implication on fertility of breeding bulls: a multiparametric analysis using computer assisted semen analyzer and functional tests of semen produced at livestock development institute
    (Addis Ababa University, 2022) Kefelegn Seyoum; Prof. Alemayehu Lemma
    Various factors are believed to influence the quality of semen in breeding bulls. Among them breed, bull selection and management, diseases and evaluation methods are believed to be the most important one. Poor semen evaluation, such as used in the conventional methods that do not address aspects of the complex spermatozoon structure and subsequent fertilization process implies the production of semen with low conception rate compromising success of artificial insemination. Reports confirm that the Ethiopian Livestock Development Institute (LDI) uses the conventional method and produces semen characterized by low conception rate. A multiparametric semen evaluation using advanced technology and functional tests that sets a higher standard for approval would improve the quality of semen. Accordingly, a computer based integrated semen analysis system, and acrosomal and plasma membrane integrity tests were applied on semen collected from 14 breeding bulls (Boran = 4, Boran* Holstein Frisian Crosses = 4 and Holstein Frisian = 6). Bulls were additionally investigated for incipient general and reproductive diseases. After the initial conventional assessment, semen was evaluated using advanced multiparametric method at fresh, chilled and frozen stages for various semen quality parameters. There were significant (P < 0.05) breed differences between Boran and Holstein Frisian breeds in scrotal circumference (33.20 Vs 38.40cm), testes volume (254.40 Vs 367.50cm3), testes weight (264.10 Vs 381.40g), semen volume (9.81 Vs 11.39ml), pH (6.31 Vs 6.58), spermatozoa head abnormality (5.02 Vs 3.42%), Hypo osmotic swelling reactivity (39.55 and 49.46%) and acrosome intact live spermatozoa (43.29 and 49.67%), respectively. Total sperm morphological abnormality (18.10%) were significantly (P < 0.05) higher in the Crosses. Motility was significantly higher (82.5%, P < 0.05) in fresh Boran semen while the same parameter was higher in chilled (70.2%) and frozen (42.9%) semen from HF bulls. All kinematic parameters (VCL, VAP, VSL, ALH, BCF, LIN, STR, and WOB) were significantly different (P<0.05) at all stages of semen production among the three breeds, being lower for Cross breed bulls. The ISAS method and the functional tests applied in this study invalidated some of the values of sperm parameters from the conventional method. Moreover, results of HOST, acrosome integrity and sperm morphological defects were associated with one or more of sperm motion characteristics which were not revealed if only conventional method was used. With minimum cut-off values (total motility=40% and progressive motility=15%) in frozen semen, nearly 56% of semen produced at LDI failed to fulfill the minimum approval requirements by ISAS. This was very apparent in semen of Cross bulls for both parameters (total motility 33.1 Vs 12.9% progressive motility) and to that of total motility (33.9%) in Boran semen. All bulls investigated were found to have no general and/or reproductive health problems that influenced the quality of semen. It is therefore plausible to assume that poor semen quality resulting from absence of a more rigorous evaluation method could be one of the factors contributing to the low conception rate at the field level. The significance of introducing advanced methods of semen evaluation is incontrovertible; however, this finding has to be complemented with more field studies and investigation of risk factors in the female individual to get a complete picture. As LDI is bearing a huge national responsibility in advancing the cross breeding program based on AI, it becomes invariably mandatory to start using state of the art methods of breeding soundness examination and semen evaluation.