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W.s Youn - One of the best experts on this subject based on the ideXlab platform.

  • Embryo recovery and transfer for the production of transgenic goats from Korean native strain, Capra hircus aegagrus.
    Small Ruminant Research, 2000
    Co-Authors: N.z Fang, G.d Zheng, K.b Oh, W.s Youn
    Abstract:

    During the breeding season in Korea (September 1997 to April 1998), a goat embryo recovery and transfer program using a Korean native strain (Capra hircus aegagrus) was performed for the production of transgenic goats. Donors were synchronized with norgestomet implants and superovulated by a combined treatment with FSH and hCG. The treatment regime induced a consistent and efficient superovulation Rate of 90% from donors with an ovulation Rate of 12.1 0.5. 50.5% of the recovered oocytes/embryos were fertilized and most of them were at the 1-cell stage. After DNA microinjection, a total of 188 embryos were immediately transferred to naturally cycling or hormonally synchronized recipients with two or three embryos per animal. There was a tendency for the pregnancy Rate of naturally cycling recipients to be higher (38.9%) than that of hormonally synchronized recipients (25.7%). When the recipients were classified into a two or three embryo-received group, the embryo viability was markedly decreased from 58.3% in two embryo-received group to 35.3% in three embryoreceived group, without an increase in the Kidding Rate. This resulted from a high occurrence of abortions or stillbirths from the multiple-pregnant recipients which had received three embryos. This indicated that the transfer of two embryos per recipient is highly recommendable for an optimal embryo survival in Korean goats. Altogether, 188 embryos were transferred to 71 recipients and two transgenic Korean goats were produced from 25 offspring. # 2000 Elsevier Science B.V. All rights reserved.

Youn - One of the best experts on this subject based on the ideXlab platform.

  • Embryo recovery and transfer for the production of transgenic goats from Korean native strain, Capra hircus aegagrus.
    Small ruminant research : the journal of the International Goat Association, 2000
    Co-Authors: Fang, Zheng, Oh, Youn
    Abstract:

    During the breeding season in Korea (September 1997 to April 1998), a goat embryo recovery and transfer program using a Korean native strain (Capra hircus aegagrus) was performed for the production of transgenic goats. Donors were synchronized with norgestomet implants and superovulated by a combined treatment with FSH and hCG. The treatment regime induced a consistent and efficient superovulation Rate of 90% from donors with an ovulation Rate of 12.1+/-0.5. 50.5% of the recovered oocytes/embryos were fertilized and most of them were at the 1-cell stage. After DNA microinjection, a total of 188 embryos were immediately transferred to naturally cycling or hormonally synchronized recipients with two or three embryos per animal. There was a tendency for the pregnancy Rate of naturally cycling recipients to be higher (38.9%) than that of hormonally synchronized recipients (25.7%). When the recipients were classified into a two or three embryo-received group, the embryo viability was markedly decreased from 58.3% in two embryo-received group to 35.3% in three embryo-received group, without an increase in the Kidding Rate. This resulted from a high occurrence of abortions or stillbirths from the multiple-pregnant recipients which had received three embryos. This indicated that the transfer of two embryos per recipient is highly recommendable for an optimal embryo survival in Korean goats. Altogether, 188 embryos were transferred to 71 recipients and two transgenic Korean goats were produced from 25 offspring.

L J Dawson - One of the best experts on this subject based on the ideXlab platform.

  • 151 influence of chorionic gonadotrophin breeding procedure and gonadotrophin releasing hormone on pregnancy embryo viability and Kidding Rate of lactating alpine goats time inseminated during the early transitional reproductive phase
    Reproduction Fertility and Development, 2020
    Co-Authors: M Calle, L J Dawson, M Rojas, E Loetz
    Abstract:

    Oestrus and ovulation synchronisation (E/OS) regimens containing equine chorionic gonadotrophin (ECG) are used for follicular stimulation during the early transitional reproductive phase and goat anestrus. However, the effects of ECG when applied at different times are unknown. Thus, the objective was to evaluate the influence of ECG, breeding procedure, and gonadotrophin-releasing hormone (GnRH) on pregnancy, embryonic viability, and Kidding Rate in dairy goats. We used 41 alpine goats (mean ± standard deviation: 3.82 ± 1.2 years old; 57.0 ± 6.0 kg of bodyweight; 1.75-2.25 body condition score; 195 ± 16.7 days in milk; range of 1-4 Kiddings). This study took place during the transitional phase (12 h of daylight, 12 h of dark) in September (35.9° N, 97.3° W) using controlled internal drug release intravaginal inserts (300 mg of progestagen; P4) for 11, 12, or 13 days with a 2-mL intramuscular dose containing 10 mg of dinoprost tromethamine at P4 removal. The E/OS protocols differed on the time when the 1-mL intramuscular dose of P.G. 600© (Merck Animal Health; 120 and 60 IU of ECG and human chorionic gonadotrophin, respectively) was given (i.e. early = 24 h before P4 removal; late = 24 h after P4 removal), and the traditional control group did not receive P.G. 600. Time breeding, either by laparoscopic-aided insemination using frozen-thawed semen (n = 28) or natural (n = 13), was scheduled 48 h after P4 removal. To improve embryo survival, 5 days post-breeding (dpb) 21 goats received 1 mL of GnRH analogue intramuscularly as 50 µg mL−1 gonadorelin diacetate tetrahydRate, and 20 control goats received 1 mL of placebo intramuscularly. Pregnancy Rate (PR) was evaluated at d 18-24 by non-return to oestrus, d 30 by pregnancy-specific protein B, and d 40 by ultrasound. Kidding Rate was determined for females with at least one newborn. Logistic regression was used to establish statistical significance. Days of P4 exposure did not influence any response variable (P > 0.20). Table 1 summarises the results; age influenced all PR evaluations. The number of Kiddings and administration of GnRH at 5 dpb had a significant effect on PR, whereas bodyweight, days in milk, E/OS protocol, and breeding procedure were not influential. Embryo viability and Kidding Rate were not influenced by any variable. In short, P.G. 600 had no bearing on any response variable analysed. Late-lactating goats can be evaluated early in the transitional breeding phase using PR at 18-24, 30, or 40 dpb. As indicated by the lack of effect on embryo viability at 30 and 40 days, the mechanism by which GnRH increases PR was not by decreasing embryo mortality. Table 1.Logistic model independent variable probabilities on response variables1 Response variable Age (years) BW Kidding DIM E/OS protocol GnRH Breeding procedure PR 18-24 d 0.02 0.65 0.15 0.52 0.37 0.21 0.30 PR 30 d 0.01 0.56 0.05 0.58 0.61 0.05 0.39 PR 40 d 0.001 0.12 0.01 0.60 0.62 0.02 0.35 EV 30 d 0.62 0.96 0.61 0.63 0.30 0.32 0.36 EV 40 d 0.44 0.90 0.26 0.36 0.46 0.17 0.40 KR 0.83 0.93 0.63 0.86 0.42 0.29 0.35 1BW = body weight; DIM = days in milk; E/OS = oestrus/ovulation synchronisation; GnRH = gonadotrophin-releasing hormone; PR = pregnancy Rate; EV = embryo viability at 30 and 40 d; KR = Kidding Rate.

  • Evaluation of melatonin and bromocryptine administration in Spanish goats: II. Effect on seasonal cashmere growth, yield and fiber characteristics of does
    Small Ruminant Research, 2003
    Co-Authors: T. Wuliji, L J Dawson, A. Litherland, A. L. Goetsch, Tilahun Sahlu, Ryszard Puchala, Terry A. Gipson
    Abstract:

    Abstract Manipulation of spring breeding in Spanish goats could improve reproductive efficiency, Kidding Rate and cashmere production. Spanish female goats (15 does and 65 doelings) were used to determine the effects of melatonin treatment on cashmere fiber growth Rate, length and characteristics during spring breeding. Treatments were as follows: control (C); melatonin implant (MI) and with a bromocryptine (225 mg) implant (MIB); and oral administration of 3 mg per day of melatonin (MO) or with bromocryptine (MOB). Cashmere growth Rate was monitored by monthly clipping of fiber in a 10 cm ×10  cm patch on the mid-side of goats from February 1999 to January 2000. Mean daily clean fiber growth Rate (mg per day) was greater (P

  • evaluation of melatonin and bromocryptine administration in spanish goats i effects on the out of season breeding performance in spring Kidding Rate and fleece weight of does
    Small Ruminant Research, 2003
    Co-Authors: T. Wuliji, L J Dawson, A. Litherland, A. L. Goetsch, Tilahun Sahlu, Ryszard Puchala, Terry A. Gipson
    Abstract:

    Abstract The demand for meat goats in the USA is increasing, particularly in the Christmas and Easter holiday season. Manipulation for spring breeding in goats could increase productivity of flocks, enhance profitability and elevate the supply of meat goats at a time when demand is high. Four Spanish bucks were conditioned for 2 months to long day photoperiod (16 h light:8 h dark), followed by a single melatonin implant (18 mg, 6-week release period). Eighty Spanish female goats (15 does and 65 doelings) were allotted to five treatments: control (C); melatonin implant (MI); melatonin and bromocryptine (225 mg, 60-days release period) implants (MIB); oral administration of melatonin (MO, 3 mg per day); and oral administration of melatonin and the bromocryptine implant (MOB). After the fifth week of melatonin administration, does were randomized and bred in three single-sire groups for a 35-days period. Melatonin administration elevated serum melatonin level ( P P P

E Loetz - One of the best experts on this subject based on the ideXlab platform.

  • 151 influence of chorionic gonadotrophin breeding procedure and gonadotrophin releasing hormone on pregnancy embryo viability and Kidding Rate of lactating alpine goats time inseminated during the early transitional reproductive phase
    Reproduction Fertility and Development, 2020
    Co-Authors: M Calle, L J Dawson, M Rojas, E Loetz
    Abstract:

    Oestrus and ovulation synchronisation (E/OS) regimens containing equine chorionic gonadotrophin (ECG) are used for follicular stimulation during the early transitional reproductive phase and goat anestrus. However, the effects of ECG when applied at different times are unknown. Thus, the objective was to evaluate the influence of ECG, breeding procedure, and gonadotrophin-releasing hormone (GnRH) on pregnancy, embryonic viability, and Kidding Rate in dairy goats. We used 41 alpine goats (mean ± standard deviation: 3.82 ± 1.2 years old; 57.0 ± 6.0 kg of bodyweight; 1.75-2.25 body condition score; 195 ± 16.7 days in milk; range of 1-4 Kiddings). This study took place during the transitional phase (12 h of daylight, 12 h of dark) in September (35.9° N, 97.3° W) using controlled internal drug release intravaginal inserts (300 mg of progestagen; P4) for 11, 12, or 13 days with a 2-mL intramuscular dose containing 10 mg of dinoprost tromethamine at P4 removal. The E/OS protocols differed on the time when the 1-mL intramuscular dose of P.G. 600© (Merck Animal Health; 120 and 60 IU of ECG and human chorionic gonadotrophin, respectively) was given (i.e. early = 24 h before P4 removal; late = 24 h after P4 removal), and the traditional control group did not receive P.G. 600. Time breeding, either by laparoscopic-aided insemination using frozen-thawed semen (n = 28) or natural (n = 13), was scheduled 48 h after P4 removal. To improve embryo survival, 5 days post-breeding (dpb) 21 goats received 1 mL of GnRH analogue intramuscularly as 50 µg mL−1 gonadorelin diacetate tetrahydRate, and 20 control goats received 1 mL of placebo intramuscularly. Pregnancy Rate (PR) was evaluated at d 18-24 by non-return to oestrus, d 30 by pregnancy-specific protein B, and d 40 by ultrasound. Kidding Rate was determined for females with at least one newborn. Logistic regression was used to establish statistical significance. Days of P4 exposure did not influence any response variable (P > 0.20). Table 1 summarises the results; age influenced all PR evaluations. The number of Kiddings and administration of GnRH at 5 dpb had a significant effect on PR, whereas bodyweight, days in milk, E/OS protocol, and breeding procedure were not influential. Embryo viability and Kidding Rate were not influenced by any variable. In short, P.G. 600 had no bearing on any response variable analysed. Late-lactating goats can be evaluated early in the transitional breeding phase using PR at 18-24, 30, or 40 dpb. As indicated by the lack of effect on embryo viability at 30 and 40 days, the mechanism by which GnRH increases PR was not by decreasing embryo mortality. Table 1.Logistic model independent variable probabilities on response variables1 Response variable Age (years) BW Kidding DIM E/OS protocol GnRH Breeding procedure PR 18-24 d 0.02 0.65 0.15 0.52 0.37 0.21 0.30 PR 30 d 0.01 0.56 0.05 0.58 0.61 0.05 0.39 PR 40 d 0.001 0.12 0.01 0.60 0.62 0.02 0.35 EV 30 d 0.62 0.96 0.61 0.63 0.30 0.32 0.36 EV 40 d 0.44 0.90 0.26 0.36 0.46 0.17 0.40 KR 0.83 0.93 0.63 0.86 0.42 0.29 0.35 1BW = body weight; DIM = days in milk; E/OS = oestrus/ovulation synchronisation; GnRH = gonadotrophin-releasing hormone; PR = pregnancy Rate; EV = embryo viability at 30 and 40 d; KR = Kidding Rate.

Alvaro De Gracia - One of the best experts on this subject based on the ideXlab platform.

  • Successful artificial insemination using semen frozen and stored by an ultrafreezer in the Majorera goat breed.
    Theriogenology, 2009
    Co-Authors: Michel Batista, D. Alamo, Martin Santana, F. Cabrera, Tony Di Nino, F Gonzalez, N Castro, Alvaro De Gracia
    Abstract:

    Abstract The semen of five Majorera breed bucks was collected and processed to reach a final concentration of 200 × 106 spermatozoa/straw in the extender containing 4% of glycerol and 12% of egg yolk. Two freezing techniques were assessed: (LN) straws were frozen and stored in liquid nitrogen, and (ULF) straws were frozen and stored in the ultra-low freezer at −152 °C. Semen quality (sperm motility, acrosome integrity and abnormal sperm cells percentages) was determined for different storage times (1, 30, 90 and 365 days of cryopreservation). Thereafter, 150 Majorera goats were assigned to four experimental groups: for groups LN-1 (n = 40) and LN-6 (n = 35), the goats were transcervically inseminated with frozen-thawed semen stored for 1 and 6 months in liquid nitrogen, respectively, while for groups ULF-1 (n = 40) and ULF-6 (n = 35), the goats were transcervically inseminated with frozen-thawed semen stored for 1 and 6 months in an ultra-low freezer at −152 °C, respectively. The pregnancy Rate was determined by transabdominal ultrasound scanning; in addition, the Kidding Rate and prolificacy were recorded at parturition. In vitro results showed that the freezing protocol did not affect sperm quality with similar values for up to 1 year of cryopreservation. The Kidding Rates were not significantly different between experimental groups (43.6%, 38.5%, 42.8% and 40.0% for groups LN-1, ULF-1, LN-6 and ULF-6, respectively). In all experimental groups, the Kidding Rate and prolificacy were significantly higher (p

  • Successful artificial insemination using semen frozen and stored by an ultrafreezer in the Majorera goat breed
    Theriogenology, 2009
    Co-Authors: Michel Batista, D. Alamo, Martin Santana, F. Cabrera, Tony Di Nino, F Gonzalez, N Castro, Alvaro De Gracia
    Abstract:

    The semen of five Majorera breed bucks was collected and processed to reach a final concentration of 200 × 106 spermatozoa/straw in the extender containing 4% of glycerol and 12% of egg yolk. Two freezing techniques were assessed: (LN) straws were frozen and stored in liquid nitrogen, and (ULF) straws were frozen and stored in the ultra-low freezer at -152 °C. Semen quality (sperm motility, acrosome integrity and abnormal sperm cells percentages) was determined for different storage times (1, 30, 90 and 365 days of cryopreservation). Thereafter, 150 Majorera goats were assigned to four experimental groups: for groups LN-1 (n = 40) and LN-6 (n = 35), the goats were transcervically inseminated with frozen-thawed semen stored for 1 and 6 months in liquid nitrogen, respectively, while for groups ULF-1 (n = 40) and ULF-6 (n = 35), the goats were transcervically inseminated with frozen-thawed semen stored for 1 and 6 months in an ultra-low freezer at -152 °C, respectively. The pregnancy Rate was determined by transabdominal ultrasound scanning; in addition, the Kidding Rate and prolificacy were recorded at parturition. In vitro results showed that the freezing protocol did not affect sperm quality with similar values for up to 1 year of cryopreservation. The Kidding Rates were not significantly different between experimental groups (43.6%, 38.5%, 42.8% and 40.0% for groups LN-1, ULF-1, LN-6 and ULF-6, respectively). In all experimental groups, the Kidding Rate and prolificacy were significantly higher (p < 0.01) in multiparous than in nulliparous goats. Therefore, the in vitro results and fertility trials confirmed the efficiency of the ULF technique for freezing and storage of goat semen. © 2009 Elsevier Inc. All rights reserved.