No abstract

Communication [Comunicação]Viable offspring after successful non-surgical embryo transfer in goats [ Nascimento de fetos viáveis após transferência de embriões não-cirúrgica em caprinos]

The objective of this study was to evaluate the efficiency of two doses of PGF associated or not to hCG on the associated reproductive parameters in dairy goats. A total of 29 goats received two doses of 30μg d-cloprostenol latero-vulvar at a 10 day intervals (Day 1 and Day 10). The does were allocated according to body weight and body condition score into two treatments, to receive hCG (250IU) or saline at estrus onset. After the second dose of PGF, estrus was monitored and ultrasound exams were performed twice daily. All does were inseminated 16h after estrus onset. Blood collection was performed every day for progesterone assay. The use of hCG at estrus onset did not affect any studied parameter and therefore the data were pooled.

This study evaluated the effect of two mating methods (GNM: natural mating or GAI: laparoscopic artificial insemination) on superovulatory response, fertility and embryo yield in superovulated ewes. Fifteen non-pregnant Santa Inês ewes were superovulated and either mated by GNM or GAI in a crossover design. Oestrus was synchronised using intravaginal progestagen sponges for 6 days and on Day 5, 300 IU eCG and 0.0375 mg d-cloprostenol were given. Twelve hours after sponge removal, 0.025 mg gonadotropin-releasing hormone was administered. Superovulation started 48 h after gonadotropin-releasing hormone treatment, using 5 IU/kg follicle-stimulating hormone (pFSH). At the first pFSH dose, new sponges were inserted. At the fifth dose, 0.0375 mg cloprostenol was administered and the sponges were removed. The GNM was mated with rams every 12 h, until the end of oestrus. The ewes of GAI were laparoscopic inseminated with frozen–thawed semen 36 and 48 h after sponge removal. Ultrasonography was performed every 24 h from the beginning of oestrus synchronisation treatment and every 12 h from the second sponge removal to 2 days after the last pFSH dose. Six to seven days after mating, the number of corpora lutea (CL) was evaluated by laparoscopy and the females with > 4 CL were subjected to embryo collection. The interval from sponge removal to ovulation was shorter (P < 0.05) in the GNM. The overall superovulatory response was 63.3% (19/30), with 60.0% and 66.7% in GNM and GAI, respectively (P > 0.05). The number of recovered structures (6.4 ± 2.4 vs 4.5 ± 3.0), recovery rate (74.0 ± 16.0 vs 52.3 ± 26.5%), number of transferable embryos (3.0 ± 2.9 vs 3.6 ± 2.0) and viability rate (47.2 ± 45.3 vs 77.4 ± 37.1%) did not differ between GAI and GNM (P > 0.05). However, the GAI group showed a higher (P < 0.05) number of unfertilised oocytes (3.1 ± 3.1) and a higher non-fertilisation rate (47.1 ± 45.3%) than the GNM (0.9 ± 2.1 and 11.5 ± 21.5%). The mating method did not affect the superovulatory response, and production of viable embryos although the non-fertilisation rate has been inferior for the AI group.

The use of three different gonadotropins was tested for estrous induction in dairy goats during the non-breeding season. All does received an injection of 30 μg of d-cloprostenol and intravaginal sponges containing 60mg of medroxyprogesterone acetate (MAP) for 6 d plus 20 IU of porcine FSH (pFSH), 200 IU of eCG or 250 IU of hCG 24h before sponge removal. In Experiment 1 (n=24), ovarian ultrasound parameters were recorded and cervical mucus was evaluated daily for 5 d after sponge removal or until ovulation. In Experiment 2 (n=80), reproductive efficiency of artificially inseminated or naturally mated does was assessed. The mean interval from sponge removal to ovulation (73.5±23.7 h), number of ovulations (1.6±0.7) and ovulatory follicle diameter (7.2±0.8 mm) did not vary (P >0.05) among the three groups. At ovulation, cervical mucus had crystalline-striated to striated (22.2%), striated to striated-caseous (72.2%) and striated-caseous to caseous (5.6%) appearance. The largest follicle diameter was greater (P <0.05) in does with crystalline (6.7±1.4 mm), crystalline-striated (7.2±1.1 mm) or striated (7.3±1.3 mm) mucus than in those with striated-caseous (5.3±1.4 mm) or caseous (4.5±1.1 mm) mucus. Percentage of animals exhibiting estrus (92.5%) and conception rate (60.8%) were similar (P >0.05) among the three gonadotropins groups. Results of this study support the use of eCG (200 IU), hCG (250 IU) and pFSH (20 IU) for the estrous induction protocols in dairy goats during the non-breeding season. Cervical mucus evaluation can be used as an additional method to determine the optimal time for artificial insemination in goats.

The effect of hCG administration on accessory corpus luteum (ACL) formation, CL area, and plasma progesterone (P4) concentration (ng/mL) seven days after breeding was studied in nulliparous Santa Inês sheep. Intravaginal 60 mg MAP sponges were inserted into ewes for six days and 300 IU eCG i.m. and 30 µg d-cloprostenol latero-vulvar were administered 24 h before sponge removal. Ewes were naturally bred and, seven days after first mating (Day 0; D0), were treated with either 250 IU hCG (hCG group; n = 7) or 1 mL saline solution (control group; n = 7). Blood was collected to determine plasma P4 concentrations and sonograms were performed on Days 7, 10, 13, 16, 19, and 22. Number of CL on D7 was similar (P > 0.05) between hCG (1.3 ± 0.5) and control (1.3 ± 0.5) groups; however, on D13, it was greater (P < 0.05) in the hCG group (2.3 ± 0.5) than in the control group (1.3 ± 0.5). A greater (P < 0.05) luteal tissue area was detected in hCG-treated ewes (n = 4) on Days 16 to 22 than in the animals in the control group (n = 7). Plasma P4 concentration on D13 to D22 was higher (P < 0.05) in hCG-treated animals than in control ewes. Administration of hCG seven days after estrus onset efficiently induced accessory CL formation in ewes, increasing luteal tissue area and plasma P4 concentration.

No abstract

This study evaluated the effect of the protected fatty acid inclusion during estrus synchronization on reproductive parameters. Goats (n = 32) received progestagen sponges for 6 days and 200 IU equine chorionic gonadotropin and 30 µg d-cloprostenol were given on Day 5. No difference was found among control (C), 1% protected fatty acid inclusion (C + 1%) or 4% protected fatty acid inclusion (C + 4%) groups, respectively, in estrus (100.0, 100.0 or 90.9%), estrus duration (31.6 ± 12.3; 43.2 ± 12.9 or 40.8 ± 14.1 h), animals ovulating (100.0, 90.0 or 100.0%) or ovulation rate (1.3 ± 0.5; 1.1 ± 0.3 or 1.2 ± 0.4). The interval from sponge removal to ovulation and from estrus to ovulation, respectively, were shorter for C + 4% (45.2 ± 8.0 h; 18.3 ± 11.0 h) compared with C (56.3 ± 12.6 h; 30.6 ± 10.5 h) or C + 1% (57.7 ± 8.7 h; 30.3 ± 11.1 h). The average ovulatory follicle diameter was smaller for C + 4% (6.2 ± 0.7 mm) than C (7.5 ± 0.8 mm), but similar to C + 1% (7.0 ± 1.5 mm). Insulin, insulin-like growth factor 1, glucose and progesterone concentrations were similar among groups. The inclusion of protected fatty acid during synchronization treatment promoted no benefits on ovulation rate, but 4% anticipated the ovulation time.