Superovulatory Response of Zebu Cows Treated with pFSH in a Single Subcutaneous Injection Followed by an Additional Intramuscular Sub‐Dose 48 h Later

The aim of this study was to evaluate whether an additional intramuscular (im) injection of pFSH would increase the embryo production in zebu cows superovulated with a single subcutaneous (sc) pFSH injection. Twenty‐one Nelore cows were treated with a progesterone vaginal implant (Controlled Internal Drug Relased – CIDR B^®) and injected im with 2.5 mg estradiol benzoate. Four days later, cows were assigned randomly into three groups and superovulated with pFSH. Groups A and B received single sc injections of 400 and 320 IU, respectively; Group C received multiple im injections of 400 IU in decreasing doses at 12‐h intervals over 4 days. In the morning (07:00 am) of day 3 after starting superovulation, cows received im 150 mcg cloprostenol and Group B was additionally injected im with 80 IU of pFSH. CIDR‐B was withdrawn in the afternoon (07:00 pm). Cows were inseminated 48 and 62 h after the cloprostenol injection. Embryo collection and corpora lutea (CL) estimation were done 7 days after insemination. Alternation of treatments (crossover design) occurred at a 60‐day interval. There was no significant difference (p > 0.05) of CL counts among treatments. The total (transferable and no transferable) number of recovered embryos from Group A (6.9 ± 1.5) was not different from Group C (9.8 ± 1.2), whereas Group B (5.7 ± 1.5) was lower than Group C (p < 0.05). The number of transferable embryos from Groups A (2.4 ± 0.7) and B (1.7 ± 0.6) was lower (p < 0.05) than Group C (4.6 ± 1.2). Lesser (p < 0.05) embryo production from Group B was related to lower recovery rate (46.4%), compared with Groups A (65.1%) and C (81.7%). It was concluded that an additional im subdose of pFSH, injected 48 h after a single subcutaneous (sc) dose of pFSH, does not improve the embryo production in zebu cows.     

Embryo Production in Superovulated Goats Treated with Insulin Before or After Mating or By Continuous Propylene Glycol Supplementation

Seventeen adult and cyclic Moxoto goats were synchronized using 60 mg MPA vaginal sponge for 11 days and 50 μg cloprostenol, 48 h before sponge removal, and superovulated with 120 mg pFSH i.m. in decreasing doses at 12 h intervals for three consecutive days. In seven goats, 0.2 IU/kg BW/day of long acting insulin was subcutaneously injected at same time as pFSH, and in the other five goats, the same dose of insulin was injected for three consecutive days starting 24 h after mating. Finally, five goats were supplemented with an oral dose of 80 ml/goat/day of propylene glycol continuously during the experiment. The animals were flushed at 7 days after mating and the embryos were classified based on International Embryo Transfer Society criteria. Blood samples were collected every 3 days for insulin assay. Administration of insulin raised the insulin levels of the goats (p < 0.05), whereas in the group treated with propylene glycol, insulin rate was different only between FSH treatment and after mating (p < 0.05). Similar rates of recovery for total (80.05 ± 9.78%) or transferable structures (61.03 ± 15.13%) were obtained. Treatment was not influenced (p > 0.05) by responsiveness to superovulation, which averaged 64%. By contrast, insulin treatments were shown to increase the number of embryos considered excellent with respect to goats supplemented with propylene glycol (p < 0.05). When insulin was given before mating, a strong relationship (r = 0. 90) (p < 0.05) between number of transferable embryo and ovulations was observed in the animals. In conclusion, superovulated goats treated with low doses of exogenous insulin resulted in an enhancement in embryo quality, which was related to changes in circulating insulin concentrations.     

Active immunization against inhibin improves superovulatory response to exogenous FSH in cattle

The effect of active immunization against inhibin on the response to superovulatory treatment by porcine FSH (pFSH) was investigated in cattle. Japanese black cows were sc injected with 1 mg of porcine inhibin alpha-subunit fragment (1-26) conjugated with rabbit serum albumin (inhibin-immunized group; n=14) or rabbit serum albumin alone (control group; n=12) in Freund's complete adjuvant. Booster injections (half the amount of the primary injection) were given 35 and 70 days after the primary injection. All cows were superovulated three times with pFSH. Three days after each injection of the antigen, a progesterone-releasing intravaginal device (CIDR-B) was inserted vaginally into all animals and left in place for 10 days. Forty-eight hours before CIDR-B removal, all animals were sc injected with 30 mg pFSH dissolved in 40% polyvinylpyrrolidone, and im injected with 750 microg of PGF2alpha at CIDR-B removal. Cows were artificially inseminated twice during estrus, and ova or embryos were collected 7 or 8 days after estrus. The number of corpora lutea, the number of ova or embryos and the number of transferable embryos in inhibin-immunized cows (12.1+/-1.2, 11.1+/-1.3 and 6.2+/-1.0, respectively) were significantly greater than those in the controls (8.2+/-1.0, 5.7+/-1.1 and 3.1+/-0.7, respectively). These results indicate that active immunization against inhibin enhanced ovarian response to the usual superovulatory treatment in cattle. Therefore, immunization against inhibin may be a useful approach for improving the response to superovulation in cattle.     

Ovulatory Response and Embryo Yield in Jakhrana Goats Following Treatments with PMSG and FSH

Superovulatory response and embryo production efficacy were investigated in adult (age 2–4 years, average body weight: 27–43 kg) cycling Jakhrana goats (n = 15) under semi-arid environmental conditions of India by administering different superovulatory regimens. Goats were reared under semi-intensive system of management in established farm conditions. To synchronize oestrus, a luteolytic dose of carboprost tromethamine (Upjohn, UK) was administered intramuscularly to all does at the dose rate of 5μg per kg body weight in a double dose schedule with an interval of 11 days. For superovulation, 750 IU of PMSG (Folligon, Intervet, Boxmeer, Holland) per goat was administered intramuscularly 24 h before administering a second dose of luteolytic agent in five does (treatment 1). FSH (Sigma, St. Louis, MO, USA) 12.50 IU per goat was administered intramuscularly in a decreasing daily dose schedule (2.50, 2.50; 1.875, 1.875; 1.25, 1.25; 0.625, 0.625) at 12 h intervals over four days, initiated 48 h before administering second dose of carboprost tromethamine in 5 does (treatment 2). FSH (Super-Ov, Ausa Intern, USA) was administered at a uniform dose rate of 8.33 units per goat intramuscularly at 24 h intervals over three consecutive days (total dose was 25 units), initiated 48 h before administering a second dose of carboprost tromethamine in 5 does (treatment 3). To synchronize ovulation in responders, human chorionic gonadotrophin (hCG, Chorulon, Intervet) was injected intramuscularly at a dose rate of 500 IU in each goat on the day of oestrus appearance. Goats were laparotomized 72–82 h following the onset of synchronized oestrus and their genitalia were flushed using a standard collection procedure. Variability (p > 0.05) in superovulatory response (number of established corpora lutea) was observed: FSH (Sigma), 11.8± 2.9; FSH (Super-Ov), 11.6±4.5; PMSG (Intervet), 8.4±2.3. A similar pattern was reflected in mean embryo and transferable embryo recovery, respectively (p > 0.05): FSH (Sigma), 8.0±1.8, 5.2±1.7; FSH (Super-Ov), 6.6±2.4, 5.4±2.4; PMSG, 5.8±1.9, 3.8±2.2. In PMSG-treated does, comparatively more unfertilized ova or retarded embryos were recovered than in FSH-treated does. The superiority of FSH preparations over PMSG was reflected in terms of total and transferable embryo production (p > 0.05). On average, five transferable embryos (excellent and good quality) were recovered per doe treated with FSH of either source. The mean ova/embryo recovery was satisfactory (55–68%). Results indicated that Jakhrana goats can be superovulated for embryo production using FSH of either source to augment productivity.     

Ovarian Response to Oestrous Synchronization Protocol Based on Use of Reduced Doses of Cloprostenol in Cyclic Goats

The objective of this study was to assess the efficacy of two reduced doses vs a high/luteolytic dose of cloprostenol on luteolytic activity and synchronization of oestrus in cyclic goats. Experiment 1, included 24 goats randomly allocated to three groups: control group (group H) received a single high dose of cloprostenol (87.5 μg; 1.0 ml; i.m.) and M and L groups, which received half (43.75 μg; 0.5 ml) and a third (26.25 μg; 0.3 ml) of the highest dose, respectively. Experiment 2, included 24 goats randomly assigned to the same experimental groups. Each group was treated using two injections of cloprostenol administered 10 days apart to synchronize oestrus. Transrectal ultrasonographic scanning (US) was performed to detect the presence, size and development of corpora lutea and ovarian follicles. Furthermore, detection of oestrus was performed every 12 h between 24 and 72 h after the second injection of cloprostenol, and the luteolytic effect was verified by US. In Experiment 1, all goats that had corpora lutea at timing of treatment regressed their corpora lutea. In Experiment 2, the occurrence of oestrus and the interval between treatment to onset of oestrus were: 100%, 49.5 ± 3.0 h; 100%, 51.0 ± 3.0 h; and 75%, 56.0 ± 3.5 h for H, M and L groups, respectively. The development of preovulatory follicles and occurrence of subsequent corpora lutea were similar among groups. In summary, the use of 26.25 μg of cloprostenol is effective for the synchronization of oestrus in cyclic goats.     

Effect of season and superstimulatory treatment on in vivo and in vitro embryo production in wood bison (Bison bison athabascae)

Two experiments were done using a two-by-two design to determine the effects of season and superstimulatory protocol on embryo production in wood bison. In Experiment 1 (in vivo-derived embryos), ovarian superstimulation was induced in female bison during the ovulatory and anovulatory seasons with either two or three doses of FSH given every-other-day (FSH × 2 vs. FSH × 3, respectively). Bison were given hCG to induce ovulation, inseminated 12 and 24 hr after hCG, and embryos were collected 8 days after hCG (n = 10 bison/group). In Experiment 2 (in vitro embryo production), ovarian superstimulation was induced in female bison during the ovulatory and anovulatory seasons with two doses of FSH, and in vivo maturation of the cumulus–oocyte complexes (COC) was induced with hCG at either 48 or 72 hr after the last dose of FSH. COC were collected 34 hr after hCG, and expanded COC were used for in vitro fertilization and culture. In Experiment 1, the number of follicles ≥9 mm, the proportion of follicles that ovulated, the number of CL, and the total number of ova/embryos collected did not differ between seasons or treatment groups, but the number of transferable embryos was greater (p < .05) in the ovulatory season. In Experiment 2, no differences were detected between seasons or treatment groups for any end point. The number of transferable embryos produced per bison was greatest (p < .05) using in vitro fertilization and was unaffected by season (1.5 ± 0.2 and 1.1 ± 0.3 during anovulatory and ovulatory seasons, respectively), in contrast to in vivo embryo production which was affected by season (0.1 ± 0.01 and 0.7 ± 0.2 during anovulatory and ovulatory seasons, respectively). Results demonstrate that transferable embryos can be produced throughout the year in wood bison by both in vivo and in vitro techniques, but the efficiency of embryo production of in vivo-derived embryos is significantly lower during the anovulatory season.     

Administration of exogenous hormones in ovulatory and embryonic response in Pelibuey sheep

The objective of this study was to evaluate the effect of two sources of commercial porcine pituitary‐derived follicle‐stimulating hormone (pFSH) and pFSH—porcine Luteinizing Hormone (pLH), including equine chorionic gonadotropin (eCG), in ovulatory and embryonic response in Pelibuey sheep. Twenty‐four Pelibuey sheep were used and were assigned randomly to four treatments (n = 6): (T1; 200 mg pFSH‐Folltropin^®); (T2; 200 mg pFSH + 300 UI eCG‐Folligon^®); (T3; 250 UI pFSH/pLH‐Pluset^®) and (T4; 250 UI pFSH/pLH + 300 UI eCG). The interval of hours from withdrawal of the device to the beginning of oestrus (BO) was lower (p < .05) in sheep treated with eCG (T2 = 8.0 ± 1.4 and T4 = 10.0 ± 2.8) than in those without eCG (T1 = 12.6 ± 0.6 and T3 = 20.6 ± 2.4). The ovulatory rate (OR) was higher (p < .05) in T1 = 15.5 ± 2.8 and T2 = 15.6 ± 1.4, compared to T3 = 8.1 ± 3.2 and T4 = 11.8 ± 2.8; a significant difference was not shown between them (T1 vs. T2 and T3 vs. T4) when including eCG. The number of non‐fertilized oocytes (NFO) was lower (p ? .05) in T1 = 0.8 ± 0.4 and T3 = 1.8 ± 1.8, compared to those that included eCG (T2 = 6.3 ± 2.4 and T4 = 2.1 ± 1.2). The number of transferable embryos (TE) was higher (p < .05) when FSH was applied (T1 = 5.8 ± 1.1), compared with (T2 = 2.6 ± 1.1, T3 = 2.3 ± 1.4 and T4 = 2.8 ± 1.5). The commercial treatments (pFSH or pFSH‐pLH) in combination with eCG did not improve OR, NFO and TE. However, the exclusive pFSH (Folltropin) treatment presented a higher OR, lower number of NFO and higher number of TE.     

Influence of different dietary zinc levels on cashmere growth,plasma testosterone level and zinc status in male Liaoning Cashmere goats

The experiment was conducted to investigate the influence of different levels of zinc (Zn) on cashmere growth, plasma testosterone and Zn profile in male Cashmere goats. Twenty‐eight male Liaoning Cashmere goats, 3 years old and body weight at 56.2 ± 2.45 kg, were assigned to four groups. The animals were fed a basal diet containing of 45.9 mg Zn/kg dry matter (DM) basis and supplemented with 0, 20, 40 or 80 mg Zn (reagent grade ZnSO₄·7H₂O) per kg DM for 90 days. There was no significant effect on growth and diameter of cashmere fibre for Zn supplemented in diets. However, the length and growth rate of wool were improved (p < 0.05) with dietary Zn. The length and growth rate of wool were higher (p < 0.05) for the groups supplemented with 40 or 80 mg Zn/kg DM compared with that of 20 mg Zn/kg DM treatment group. Plasma testosterone concentration was increased for Zn supplemented in diets, and the testosterone concentration was higher (p < 0.05) in goats fed on the diet supplemented with 40 or 80 mg Zn/kg DM compared with those fed on basal diet. Plasma Zn concentrations increased (p < 0.05) with increasing dietary Zn and supplemented with 40 and 80 mg Zn/kg DM groups improved plasma Zn concentration (p < 0.05) more than 20 mg Zn/kg DM group. Fibre Zn content was higher (p < 0.05) in groups supplemented with 40 or 80 mg Zn/kg DM compared with control group, but no difference between Zn‐supplemented groups (p > 0.05). The activity of plasma alkaline phosphatase was increased (p < 0.05) due to dietary Zn supplementation; however, no difference was found between supplemented treatment groups (p > 0.05). In conclusion, Zn content (45.9 mg Zn/kg DM) in control diet was insufficient for optimal wool growth performance, and we recommended the level of dietary Zn for such goats is 86 mg/kg DM during the breeding season and cashmere fibre growing period.     

Ovarian response and embryo yield of Angora and Kilis goats given the day 0 protocol for superovulation in the non-breeding season

The aim of this study was to compare ovarian response and embryo yield of Day 0 protocol in Angora goats (AG) and indigenous Kilis goats (KG) in the non-breeding season. A total of 16 Angora goats (AG group) and 11 Kilis goats (KG group) were used in this study. In the synchronization process, after controlled internal drug release withdrawal, when estrus signs were observed, natural mating was performed. Ovarian response was determined by synchronized laparotomy 6 days after natural mating, and number of corpora lutea (CL) was recorded. Embryos were collected and morphologically evaluated by stereomicroscope. Synchronization rates did not differ between AG (88%, 14/16) and KG group (91%, 10/11). In AG and KG groups, the proportion of CL on the right (44% and 53%, respectively) and left (56% and 47%, respectively) ovaries were similar. The CL number per animal did not differ significantly between the two breeds and was determined as 4.4 ± 0.90 in AG group and 6.4 ± 1.44 in KG group. Transferable embryo yields were significantly higher in AG group (31/42, 74%) compared to KG group (16/46, 35%) in the non-breeding season (P < 0.01). In conclusion, it is suggested that the day 0 protocol can be used for goat superovulation in the non-breeding season; however, transferable embryo yields are affected by the breed.     

Superovulation in the cow with pregnant mare serum gonadotrophin: effects of dose and antipregnant mare serum gonadotrophin serum.

The effects of pregnant mare serum gonadotrophin (PMSG) dose and PMSG antiserum on superovulation in crossbred beef cows were studied. In experiment I, three groups were treated with 1200, 2400 or 3600 IU of PMSG and 48 h later with prostaglandin (PGF). The mean numbers of corpora lutea (CL), unovulated follicles, and total ova/embryos collected increased as the PMSG dose increased. The percent of fertilized ova and transferable embryos was lowest in the highest dose group (p < 0.05). In experiment II, all cows received 2500 IU of PMSG; groups 1 and 2 were treated with sheep anti-PMSG serum at 48 h or 60 h after PGF; group 3 cows were PMSG-only controls. The number of CL was lowest and the number of unovulated follicles highest in the PMSG-only group (p < 0.05). The number of CL was higher in group 2 (anti-PMSG at 60 h) than in the control group, with the anti-PMSG at 48 h not different from the other groups. Numbers of total ova/embryos, fertilized ova, and transferable embryos were higher (p < 0.05) in both antiserum-treated groups relative to the PMSG-only group. We conclude that superovulation of beef cows with PMSG and treatment with PMSG antiserum will induce a higher superovulatory response and will result in higher CL numbers and fewer unovulated follicles. Further, the variability in the superovulatory response to PMSG treatment was still evident when PMSG antiserum was administered.     

Physicochemical characterization of goat milk produced in the Comarca Lagunera,Mexico

The purpose of this study was to determine goat milk physicochemical parameters during the feed scarcity season. An evaluation was made for 398 milk samples from 80 multiparous goats belonging to three different production systems: (S1) mechanized milking grazing pasture and harvested residue (alfalfa) and grain supplemented; (S2) system grazing native pasture; and (S3) system grazing native pasture and grain supplemented. The general averages were: fat (FT) 4.0 ± 0.20%, protein (PR) 3.3 ± 0.05%, lactose (LC) 4.9 ± 0.09%, nonfat solids (NFS) 8.9 ± 0.13%, total solids (TS) 14.5 ± 0.20%, temperature (TM) 24.6 ± 1.06°C, and acidity (pH) 6.7 ± 0.049. Most of the physicochemical components of milk were affected (p < 0.0001) by the production system × month interaction and production system × group × month interaction. The FT content was higher (p < 0.05) in S2 (4.56 ± 0.18) than in S1 (3.64 ± 0.20) and S3 (3.50 ± 0.20). LC differed (p < 0.05) in S2 (5.07 ± 0.08) than in S1 (4.77 ± 0.09) and S3 (4.70 ± 0.09). No differences were observed for the rest of the variables (p < 0.05) among the production systems. The study unveiled a higher content of FT, LC, NFS, PR, and TS for S2 than for S1 and S3. This higher content may be explained because S2 only grazed on herbs and shrubs, in contrast to S1 and S3 which were additionally supplemented with grain concentrates.     

Effect of Leptin on In Vivo Goat Embryo Production

The aim of this study was to evaluate the effect of leptin administration during superovulation on in vivo goat embryo production. Ten mature does were superovulated with 133 mg follicle‐stimulating hormone (FSH) i.m. in six descending doses at 12‐h intervals. The goats received 4.8 μg/kg human recombinant leptin s.c. (leptin group, n = 5) or phosphate‐buffered saline (PBS) (control group, n = 5) with the first and second FSH doses. The does were mated and subjected to embryo collection by transcervical technique 6 days later. The total number of cells per embryo and the number of cells with fragmented DNA were assessed in selected blastocysts by combining Hoechst 33342 and terminal dUTP nick‐end labelling (TUNEL) staining. Plasma concentrations of oestradiol (E₂) and progesterone (P₄) were determined by electrochemiluminescence from the day of FSH treatment, on the day of superovulatory oestrus and on the day before embryo collection. Compared with the control group, the does that received leptin had a higher number of transferable embryos (p < 0.005), fewer embryos classified as degenerated (p < 0.001) and fewer TUNEL‐positive cells/blastocyst (p < 0.001). The number of transferable embryos was positively correlated with E₂ concentrations on day of oestrus (r = 0.562; p < 0.01) and P₄ concentrations on the day of embryo collection (r = 0.912; p < 0.001). We concluded that in vivo leptin administration during FSH treatment improved embryo quality and affected ovarian steroidogenesis in superovulated goats.     

Efficiency of Oestrous Synchronization by GnRH,Prostaglandins and Socio‐Sexual Cues in the North African Maure Goats

This study aims to develop at different seasons, for local North African Maure goats, synchronizing protocols simultaneously to the standard ‘S’ protocol using progestagens in association with prostaglandins and gonadotropin. In late May, 40 goats were assigned to either the ‘S’ protocol or to a protocol where oestrus and ovulation were induced by the buck effect in single‐injection progesterone‐treated goats and provoking early luteolysis using prostaglandin 9 days after exposure to bucks ‘B’. During the 72 h after the treatments ended, 15 and 5 goats expressed oestrus in the ‘S’ and ‘B’ protocols (p < 0.01). Mean time to oestrus was shorter for ‘S’ than for ‘B’ goats. Ovulation rate averaged 2.1 ± 0.22 and 1.60 ± 0.35 for, respectively, ‘S’ and ‘B’ goats (p > 0.05). During mid‐September, 60 goats were assigned to either ‘S’ treatment, ‘PGF’ treatment where oestrus and ovulation were synchronized using two injections of prostaglandin 11 days apart or to ‘GnRH’ treatment where the goats had their oestrus and ovulation synchronized with a GnRH (day 0)–prostaglandin (day 6)–GnRH (day 9) sequence. More ‘S’ goats were detected in oestrus over the 96‐h period after the end of the treatments (88.8, 73.7 and 55% in ‘S’, ‘PGF’ and ‘GnRH’ treatments, respectively; p < 0.05). Mean ovulation rates were 2.3 ± 0.27, 1.33 ± 0.27 and 1.33 ± 0.27 for, respectively, ‘S’, ‘PGF’ and ‘GnRH’ goats (p < 0.001). Despite a similar ovulatory response to ‘S’ protocol, efficiency of prostaglandin and GnRH‐based treatments should be tested in mid‐breeding season.     

In vitro Release of Ovarian Progesterone is Decreased During the Oestrous Cycle and Pregnancy of Swine with Obesity/Leptin Resistance

Previous studies indicate that reproductive prolificacy of obese swine breeds is markedly influenced by embryo losses in early pregnancy. In such period, adequate secretion of progesterone (P4) by the ovary is essential for pregnancy success. This study analyses the luteal functionality during the oestrous cycle and early pregnancy of Iberian sows and Large White x Landrace females, in terms of P4 secretion after in vitro culture of luteal tissue stimulated or not with luteinizing hormone (LH). The secretion of progesterone (expressed in ng/mg of luteal tissue or ng/mgLT) of the corpora lutea of obese Iberian swine was always hampered when compared to lean genotypes, either during early oestrous cycle (110.7 ± 37.8 vs 259.7 ± 10.2 ng/mgLT; p < 0.0001), late oestrous cycle (49.0 ± 3.5 vs 75.92 ± 7.14 ng/mgLT; p < 0.0001) or early pregnancy (38.4 ± 2.1 vs 70.7 ± 5.3 ng/mgLT; p < 0.0001). The differences in basal P4 secretion remained after stimulation with LH. Finally, P4 secretion during early pregnancy of Iberian sows decreased with age and, hence, with obesity features (46.6 ± 4.2 vs 65.5 ± 4.8 ng/mgLT; p < 0.001). In conclusion, the results of the present study provide convincing evidence of a reduced luteal function during oestrous cycle and early pregnancy of sows with obesity/leptin resistance like Iberian sows, which may contribute to the low reproductive efficiency reported in this breed.     

Production of Wild Buffalo (Bubalus arnee) Embryos by Interspecies Somatic Cell Nuclear Transfer Using Domestic Buffalo (Bubalus bubalis) Oocytes

The objective of this study was to explore the possibility of producing wild buffalo embryos by interspecies somatic cell nuclear transfer (iSCNT) through handmade cloning using wild buffalo somatic cells and domestic buffalo (Bubalus bubalis) oocytes. Somatic cells derived from the ear skin of wild buffalo were found to express vimentin but not keratin and cytokeratin‐18, indicating that they were of fibroblast origin. The population doubling time of skin fibroblasts from wild buffalo was significantly (p < 0.05) higher, and the cell proliferation rate was significantly (p < 0.05) lower compared with that of skin fibroblasts from domestic buffalo. Neither the cleavage (92.6 ± 2.0% vs 92.8 ± 2.0%) nor the blastocyst rate (42.4 ± 2.4% vs 38.7 ± 2.8%) was significantly different between the intraspecies cloned embryos produced using skin fibroblasts from domestic buffalo and interspecies cloned embryos produced using skin fibroblasts from wild buffalo. However, the total cell number (TCN) was significantly (p < 0.05) lower (192.0 ± 25.6 vs 345.7 ± 42.2), and the apoptotic index was significantly (p < 0.05) higher (15.1 ± 3.1 vs 8.0 ± 1.4) for interspecies than that for intraspecies cloned embryos. Following vitrification in open‐pulled straws (OPS) and warming, although the cryosurvival rate of both types of cloned embryos, as indicated by their re‐expansion rate, was not significantly different (34.8 ± 1.5% vs 47.8 ± 7.8), the apoptotic index was significantly (p < 0.05) higher for vitrified–warmed interspecies than that for corresponding intraspecies cloned embryos (48.9 ± 7.2 vs 23.9 ± 2.8). The global level of H3K18ac was significantly (p < 0.05) lower in interspecies cloned embryos than that in intraspecies cloned embryos. The expression level of HDAC1, DNMT3a and CASPASE3 was significantly (p < 0.05) higher, that of P53 was significantly (p < 0.05) lower in interspecies than in intraspecies embryos, whereas that of DNMT1 was similar between the two types of embryos. In conclusion, these results demonstrate that wild buffalo embryos can be produced by iSCNT.     

Seasonality of oestrus,ovulation and ovulation rate of Sicilo‐Sarde sheep

This study aimed to investigate monthly changes in oestrus and ovulatory activity of Sicilo‐Sarde sheep. Experimental animals comprised 25 adult and 10 maiden ewes at the start of the experiment. For 12 consecutive months (September–August), the females were exposed to natural photoperiod and permanently kept in presence of seven aproned rams. Oestrus was checked daily and ovarian activity was monitored by monthly endoscopies during the last week of each month. Ovulation rate for a particular month was assessed as the sum of corpora lutea or corpora albicans present on both ovaries at the time of endoscopy. Proportions of ewes observed in oestrus at least once a month were lowest in March (24.3%) and highest in June and October (100%). They tended (p < 0.06) to be different according to age, dropping during summer from a common value of 100% in June to 85.7% and 90% in July and then to 57.1% and 70% in August for, respectively, the Adults and Maiden females. Overall, the experimental period, 92.5% and 83.8% of Adult and Maiden ewes ovulated at least once per month (p < 0.01) respectively. Least proportions ovulating, attained 60% and 30% in April for, respectively, Adult and Maiden ewes before peaking up at 100% again in May (p < 0.05). Mean (±SD) ovulation rate of Sicilo‐Sarde sheep is 1.40 ± 0.503. Adult females had a higher (p < 0.001) ovulation rate than Maiden sheep with respective average values of 1.51 ± 0.516 and 1.16 ± 0.373. It varied little between months and decreased in Adults from a maximum value of 1.95 in October to a minimum value of 1.16 in April. It is concluded that benchmarking seasonal variations of reproductive activity in Sicilo‐Sarde breed would be valuable in designing improved management calendars for this breed.     

Multiple Factors Affecting Superovulation in Poll Dorset in China

To expand the breeding flock of Poll Dorset sheep in China, multiple ovulation and embryo transfer breeding program was applied to the limited number of imported Australian Poll Dorset sheep. This study investigated the effects of FSH from three different manufacturers, parity (nulliparous vs multiparous), repeated superovulation, oestrus induction, corpus luteum regression and oestrus delay on Poll Dorset superovulation. The results showed that gonadotropin FSH from Canada Folltropin‐V (Ca‐FSH) was successfully used for superovulatory treatment with 160 mg–200 mg dosage per ewe and recovered 12.91 ± 7.80 embryos. Multiparous ewes for superovulation treatment were significantly better nulliparous ewes (p < 0.05). The successive superovalution treatment reduced significantly embryo collection but did not affect transferable embryo number. Ewes with natural oestrus resulted in significantly higher number of embryos (13.83 ± 4.64) and of transferable embryos (12.00 ± 5.76) than ewes with induced oestrus (7.00 ± 4.92; 4.22 ± 3.42) and unknown oestrus cycle (5.94 ± 3.38; 3.19 ± 2.56, p < 0.05). The delayed oestrus ewes at 24 h after superovulatory treatment produced significantly fewer embryos and transferable embryos (0.92 ± 1.51 vs 0.42 ± 0.90) than those with normal oestrus (p < 0.01). Furthermore, the more transferable embryos were recovered from ewes with normal corpus luteum than those with corpus luteum regression (5.88 ± 5.09 vs 3.59 ± 4.30 and 8.83 ± 5.75 vs. 6.66 ± 5.41, p < 0.01). These results suggest that in our farm practice, a comprehensive treatment method by using the Canadian FSH (Folltropin‐V), plus choosing multiparous and natural oestrus ewes with normal corpus luteum might obtain an optimum embryo collection and embryos transfer in sheep.     

Is the Production of Embryos in Small‐Scale Farming an Economically Feasible Enterprise?

The present assay attempts to evaluate the feasibility of using embryo transfer in small community farmers by in vivo study and by modelling the results obtained. From the total of 59 donor cows, 62.7% responded to treatment, with a significant difference (p = 0.002) in the percentage of the response between breeds, being 90.5% (19/21) in Holstein and 47.4% (18/38) in Brahman. A total of 283 embryos were graded as transferable, while 141 as non‐transferable, without difference in the percentage of transferable embryo by breed (p = 0.18). The mean of transferable embryos graded as class I and II was not different between Holstein and Brahman (p = 0.96 and p = 0.92, respectively); besides, no differences were observed in the other grades (non‐transferable). The highest difference in costs, regardless of its quality by breed, was seen in the lower levels of probable fertility of the embryo transferred, even reaching several hundred dollars. When modelling the expected costs for embryo produced and transferred, values can reach nearly $2000.00 when the probable fertility is only 10%. However, when the probable fertility was 60%, embryo cost was close to $300.00. This technology seems to be viable on average or high‐scale systems, having a superovulatory response between 60 and 80% with 4–6 transferrable embryos. Yet, in small‐scale farming, due to the reduced number of donors and/or recipients, the costs surpass the economical feasibility of the technique.     

Solid‐Surface Vitrification and In‐Straw Dilution After Warming of In Vitro‐Produced Bovine Embryos

Three experiments were designed to test a solid‐surface vitrification system for bovine in vitro‐produced embryos and to develop a simple method of in‐straw dilution after warming, which can be potentially used for direct transfer in the field. Experiment 1 evaluated embryo survival rates (i.e. re‐expansion and hatching) after vitrification and warming in three different solutions: VS1 (20% ethylene glycol (EG) + 20% propanediol (PROH) + 0.25 m trehalose (Tr)), VS2 (20% EG + 1M Tr) or VS3 (30% EG + 0.75 m Tr). Re‐expansion and hatching rates were higher (p < 0.05) for embryos vitrified in VS3 (72.2 ± 1.9 and 58.2 ± 0.8) than VS1 (64.4 ± 0.9 and 37.2 ± 2.5) or VS2 (68.5 ± 1.5 and 49.6 ± 1.0; p < 0.05). Experiment 2 was designed to compare two methods of vitrification: glass micropipettes or solid surface, using the VS1 or VS3 solutions. No significant differences were detected between the two methods; but re‐expansion and hatching rates were higher (p < 0.05) with VS3 (73.5 ± 3.1 and 47.1 ± 2.1) than VS1 (63.3 ± 3.3 and 39.7 ± 2.8). In experiment 3, embryos were vitrified by solid surface in VS1 or VS3 solutions and cryoprotectants were diluted in‐straw after warming in a TCM 199, 0.25 m sucrose solution or holding media. Survival rates of embryos vitrified in VS3 did not differ between those exposed to 0.25 m sucrose (74.7 ± 1.3 and 57.2 ± 2.2) or holding (77.3 ± 1.4 and 58.0 ± 2.5) medium after warming; however, survival rates of embryos vitrified in VS1 were higher (p < 0.05) in those exposed to 0.25 m sucrose (67.7 ± 2.3 and 47.0 ± 1.7) than holding medium (54.5 ± 1.0 and 27.7 ± 3.1). In conclusion, solid‐surface vitrification using simplified EG‐based solutions and in‐straw dilution with holding media may be a practical alternative for cryopreservation and direct transfer of in vitro‐produced bovine embryos.     

Techniques and success of embryo transfers in Angora goats

Thirty-five mixed-age Angora does were subjected to superovulation and oestrous synchronization and of the 34 which were subsequently entire mated, 33 were subjected to surgical egg recovery approximately five days after oestrus. These 33 donors averaged 8.8 ovulations and 2.5 large (>5 mm) follicles. All corpora lutea in six donors were undergoing premature regression. The average donor egg recovery rate, egg fertilization rate and percent of eggs transferable was 82, 87 and 81%, respectively, giving 6.8 eggs, 6.0 embryos and 5.5 transferable embryos per donor. Egg recovery was reduced dramatically when premature regressing corpora lutea were present. Recipient feral does were synchronized and 183 embryos transferred surgically to 133 recipients.

Eighty-eight (66%) of the recipients kidded producing 118 kids (64% embryo survival). The 35 potential donors produced 36 kids from their natural mating which occurred shortly after surgery. Thus the donors produced a total of 154 kids from embryo transfer and natural mating, an average of 4.4 kids/doe/breeding season. This rate of reproduction is four to five times faster than normal and confirms that the technique achieves its objective of rapidly increasing the number of offspring from selected animals.