RESUMO
The aim of this study was to evaluate the effect of supplementing bovine semen freezing extender with different concentrations of iodixanol on post-thaw sperm characteristics. Six ejaculates of three Nellore bulls were pooled and diluted in commercial extender (BotuBov®) and then divided into 4 groups: control group (without adding iodixanol); groups G1.5, G3, or G6 according to the concentration of iodixanol solution (RedCushion®). After dilution, the samples were cooled and frozen. Post-thaw semen evaluation included sperm motility by CASA immediately after thawing and after 60 min of incubation at 37°C, flow cytometry analysis for integrity of plasma and acrosomal membranes, membrane destabilization and translocation of phosphatidylserine, mitochondrial membrane potential, and formation of intracellular anion superoxide ( O 2 - ), hydrogen peroxide (H2 O2 ), and membrane lipid peroxidation. The group G6 presented significantly higher (p < .05) total and progressive motility, percentage of plasma and acrosomal membrane integrity, and H2 O2 than control and group G1.5. Furthermore, group G6 showed lower (p < .05) lipid peroxidation than control. In addition, regardless of the concentration used, the percentage of spermatozoa without phosphatidylserine translocation was higher (p < .05) in all iodixanol supplemented groups. In conclusion, iodixanol supplementation preserved the motility and integrity of sperm membranes during cryopreservation and protected against lipid peroxidation.
Assuntos
Preservação do Sêmen , Sêmen , Masculino , Animais , Bovinos , Congelamento , Antioxidantes/farmacologia , Fosfatidilserinas , Motilidade dos Espermatozoides , Preservação do Sêmen/veterinária , Crioprotetores/farmacologia , Espermatozoides , Análise do Sêmen/veterinária , Criopreservação/veterinária , Suplementos NutricionaisRESUMO
Artificial insemination using cooled-transported semen has marked importance in equine breeding programs around the world, and the high value of mules has generated avid interest in donkey semen biotechnology. However, donkey semen cools poorly in commercially available equine extenders. Therefore, this study aimed to develop approaches to improve the ability of donkey semen to tolerate cooling. Ejaculates of seven donkeys (n = 21) were cooled at 5°C for 48 h in three different extenders (milk-based, SM; sodium caseinate-based, SC; or egg yolk-based, EY) in the presence or absence of seminal plasma (centrifugation, C). Sperm motility, plasma membrane integrity (PMI), plasma membrane stability (PMS), mitochondrial membrane potential (HMMP), intracellular hydrogen peroxide (H2O2), and intracellular superoxide ( O 2 - ) were assessed before, 24 h, and 48 h post-cooling. In addition, 15 mares (163 estrous cycles) were randomly inseminated with semen from two jacks (Jack 1, n = 90; Jack 2, n = 73) previously cooled for 24 h under one of the treatments (SM, SC, EY, SM-C, SC-C, or EY-C). Groups EY, SC-C, and EY-C (P < 0.05) demonstrated superior sperm analytical parameters to SM at 24 and 48 h. Centrifugation positively affected sperm analytical parameters in cooled donkey semen extended in SM and SC (P < 0.05). Mares bred with semen extended in SC (67%, 18/27), SC-C (89%, 24/27), EY (89%, 25/28), or EY-C (74%, 20/27) had significantly greater conception rates than mares bred with SM (33%, 9/27; P < 0.05). Mares bred with SM-C had intermediate conception rates (59%, 16/27). In conclusion, SC and EY improved the cooling ability and fertility of donkey semen in horse mares, and centrifugation positively affected donkey semen extended in SM.
RESUMO
This study aimed to evaluate the in vitro antimicrobial activity of essential oils (EO) from Ocimum basilicum (basil), Rosmarinus officinalis (rosemary), and Cymbopogon citratus (lemongrass) on endometritis-causing microorganisms in mares. Serial concentrations of the EO from 30.00 mg/mL to 0.47 mg/mL were tested. The major compounds of O. basilicum EO were linalyl acetate (33.32 wt.%) and citronellal (25.06 wt.%); of R. officinalis EO were borneol (26.48 wt.%), trans-ß-ocimene (16.76 wt.%), camphene (12.45 wt.%), and α-phellandrene (11.08 wt.%); and of C. citratus EO were geranial (45.96 wt.%) and neral (32.62 wt.%). Regarding antimicrobial activity, C. citratus EO has had the highest inhibition percentage (73.9%), followed by O. basilicum (67.2%) and R. officinalis (58.7%). P. aeruginosa was the only pathogen unable to establish the minimum inhibitory concentrations (MIC) and minimum bactericidal concentration (MBC) values for the studied EO. The EOs were effective against all other microorganisms (S. equi, S. aureus, K. pneumoniae, E. coli, and C. Albicans). In conclusion, the EOs of O. basilicum, R. officinalis, and C. citratus have presented in vitro antimicrobial activity against microorganisms causing endometritis in mares.
Assuntos
Anti-Infecciosos , Endometrite , Doenças dos Cavalos , Óleos Voláteis , Animais , Anti-Infecciosos/farmacologia , Endometrite/tratamento farmacológico , Endometrite/veterinária , Escherichia coli , Feminino , Cavalos , Óleos Voláteis/farmacologia , Staphylococcus aureusRESUMO
The objectives of this study were: (1) to assess uterine features and serum progesterone concentrations of acyclic mares synchronized and resynchronized with intravaginal progesterone release device (IPRD), and (2) to compare pregnancy rates and losses of cyclic and acyclic embryo recipient mares treated with different synchronization protocols. In Experiment 1, mares (n = 12) received estradiol for 3 days (E2-3d), and then 24 h after the last injection, an IPRD was inserted and kept in place for 9 days. Three days after IPRD removal, mares were treated with E2-3d, and then a new IPRD was inserted and maintained for three days. Serum progesterone concentrations were assessed 2, 6, and 12 h after insertion and removal of IPRD, and then daily from the insertion of the first IPRD to one day after removal of the second IPRD. Experiment 2 was conducted with embryo recipient mares randomly assigned to four groups: (1) Cyclic: mares (n = 75) had ovulation confirmed after receiving a single dose of histrelin when a periovulatory follicle was first detected, (2) LAP4: acyclic mares (n = 92) were treated with E2-3d and then administered a single dose of LAP4 24 h after the last estradiol injection, (3) IPRD: acyclic mares (n = 130) were treated with E2-3d and an IPRD for 4-8 days, and (4) RE-IPRD: acyclic mares (n = 32) were synchronized as in the IPRD group but not used for embryo transfer (ET), then 8 to 15 days later, the mares were resynchronized with E2-3d and an IPRD for 4-8 days. In vivo-produced Day-8 embryos were collected and transferred 4-8 days after ovulation or progesterone treatments. Mares in IPRD and RE-IPRD groups had the intravaginal device removed immediately before ET, and then a new IPRD was inserted right after ET. Pregnancy diagnosis was performed at 5, 30, and 60 days after ET. Once pregnancy was confirmed, mares in the three acyclic groups received weekly injections of LAP4 (1.5 g) until 120 days of pregnancy. Mares in IPRD and RE-IPRD groups had the device removed three days after the first pregnancy diagnosis. In Experiment 1, progesterone concentrations increased rapidly starting 2 h after insertion of IPRD (p < 0.05); then, concentrations plateaued well above pregnancy maintenance until removal on days 9 and 3, respectively. Progesterone concentrations were reduced to baseline 24 h after IPRD removal (p < 0.05). For experiment 2, there was no difference in pregnancy rates across groups (65-74%) or pregnancy losses by 60 days of gestation (7-12%) (p > 0.05). In conclusion, the IPRD used herein resulted in a rapid increase and a sharp decline in progesterone concentrations upon its insertion and removal, respectively. Finally, our results demonstrated that IPRD could be a compatible alternative to LAP4 to synchronize and resynchronize acyclic embryo recipient mares.
RESUMO
This study compared the postthaw semen parameters of stallions with high and low body condition score (BCS) and evaluated associations between body morphometric parameters and postthaw semen parameters. Twenty stallions were split into Low BCS (BCS<7, n = 11) and High BCS (BCS ≥7, n = 9) groups, and underwent a complete morphometric analysis (e.g., neck scores and circumference, crest neck height, body weight, and height), and subcutaneous body fat thickness (SFT) at the tail head, withers, shoulders, and retroperitoneal space. A fasted oral sugar test (OST) was conducted on all stallions. One ejaculate from each stallion was frozen with a commercial egg yolk-based extender. Postthaw sperm motility parameters, plasma membrane integrity, mitochondrial membrane potential, hydrogen peroxide and intracellular superoxide production, and lipid peroxidation were analyzed for all stallions. The circumference at 25% and 50% of the neck's length were larger for High-BCS stallions (P < .05). There were no differences between groups for the neck crest height (P > .05). Stallions with High BCS had greater SFT at the tail head than stallions with Low BCS (P < .05); however, there were no differences between groups in the SFT at the shoulders and withers (P > .05). All stallions had resting blood glucose below the cutoff for equine metabolic syndrome. There were no differences between groups for resting glucose concentrations or for a peak at 30 or 60 minutes after initiation of the OST (P > .05). There were no differences in sperm parameters between groups (P > .05). Collectively, the findings of the present study suggest that High BCS or Low BCS in the presence of normal OST do not explain post-thaw semen parameters.
Assuntos
Preservação do Sêmen , Sêmen , Tecido Adiposo , Animais , Criopreservação/veterinária , Cavalos , Masculino , Preservação do Sêmen/veterinária , Motilidade dos Espermatozoides , AçúcaresRESUMO
The goal of this study was to compare the efficiency of histrelin acetate (GnRH analog) and human chorionic gonadotropin (hCG) to hasten ovulation in Brazilian Northeastern jennies (Equus africanus asinus). Thirty cycles of ten jennies were randomly assigned in one of the three groups: G0 (control group), saline; G1, 250 µg of histrelin acetate; G2, 2500 IU of hCG. Jennies were evaluated by transrectal palpation and ultrasonography, and had the administration of an ovulation-inducing agent when a follicle measuring between 29 and 32 mm of diameter was diagnosed. Jennies were monitored every 6 hours by transrectal ultrasonography until ovulation. The interval between prostaglandin administration and ovulation was lower (P < .05) in jennies from the G1 (145.2 ± 34.6 hours) and G2 (147.4 ± 27.3 hours) groups compared with the control cycle (220.0 ± 41.8 hours). Both treatments (G1, 41.15 ± 3.5 hours; G2, 37.8 ± 2.5 hours) also reduced (P < .05) the interval that jennies took to ovulate after the administration of the ovulation-inducing agent compared with the control (81.8 ± 28.8 hours). All jennies from G1 and G2 ovulated up to 48 hours after ovulation induction, whereas 100% of jennies in the control cycle ovulated later (>48 hours from the administration of saline). In conclusion, both histrelin acetate and hCG at the used dose are efficient ovulation-inducing agents in jennies promoting ovulation up to 48 hours after administration.
Assuntos
Equidae , Ovulação , Acetatos , Animais , Brasil , Gonadotropina Coriônica , Feminino , Hormônio Liberador de Gonadotropina/análogos & derivadosRESUMO
This study aimed to evaluate the antioxidant properties of coenzyme Q10 (CoQ10) during cryopreservation of semen obtained from stallions having good and bad semen freezing ability (GFA vs. BFA, respectively). Forty ejaculates (nâ¯=â¯20 stallions) were split into five centrifugation and five freezing extenders containing different concentrations of CoQ10 (0, 25, 50, 75 and 100⯵mols/L). If CoQ10 was added to the centrifugation extender, the freezing extender had no CoQ10 added; similarly, if CoQ10 was added to the freezing extender, the centrifugation extender had no CoQ10. Semen cryopreserved on extenders containing no CoQ10 served as the control. After post-thaw total sperm motility (TM) assessments, the stallions were classified as GFA (i.e., decrease of ≤25% in TM, nâ¯=â¯7) or BFA (i.e., decrease of ≥40% in TM, nâ¯=â¯5). Stallions not fitting (nâ¯=â¯8) this enrollment criteria had samples discarded. After that, two straws for each extender were thawed at 37⯰C for 30â¯s; one straw was immediately used for evaluation of sperm kinetics, plasma membrane integrity, non-capacitated spermatozoa, reactive oxygen species production, mitochondrial activity and lipid peroxidation. The second straw was kept at 37⯰C for 30â¯min and subjected to the same assessments. Expectedly, sperm motility parameters were significantly lower for stallions with BFA. There were no effects of CoQ10 concentration or time for all parameters evaluated in the group with GFA when compared with the control extender (pâ¯>â¯0.05), except lipid peroxidation (pâ¯<â¯0.05). However, stallions with BFA had improved sperm parameters for samples processed with extenders containing CoQ10 (particularly 75⯵mols/L) (pâ¯<â¯0.05), except for the reactive oxygen species production and mitochondrial potential (T0) in which there were no differences between the groups (pâ¯>â¯0.05). In summary, 75⯵mols/L appears to be the optimal dose of Co-Q10, particularly, when added to the centrifugation extender.
Assuntos
Criopreservação/veterinária , Cavalos/fisiologia , Preservação do Sêmen/veterinária , Ubiquinona/análogos & derivados , Animais , Congelamento , Masculino , Ubiquinona/farmacologiaRESUMO
This study compared hormone treatments given to mares during anestrus, spring transition, and different stages of the estrous cycle, by assessing uterine features and pregnancy rates after embryo transfer (ET). Embryo recipient mares (nâ¯=â¯160) were equally arranged as follows: G1-spontaneous ovulation (control), G2-anestrus, G3-spring transition, G4-early estrus, G5-estrus, G6-diestrus, G7-early diestrus treated with a dose of dinoprost, and G8-early diestrus treated with two doses of dinoprost. At treatment initiation (Day-4), G2-7 were given dinoprost and estradiol-17ß, thereafter, estradiol-17ß was repeated on Days-3,-2, and -1. On Day0, mares received long-acting altrenogest. Then, each mare had one ET performed from Dayâ¯+â¯3 to Dayâ¯+â¯8 after altrenogest. Immediately before the ET, mares received a boost of altrenogest and had uterine features assessed. Pregnant mares on each of the checks (by 7, 30, 60, and 120d after ET) were maintained on weekly injections of LA-P4 until 120d. G8 received similar management, but dinoprost was repeated on Day-3. G1-G6 and G8 displayed uterine edema and satisfactory pregnancy rates ≥65%. Repeating dinoprost to G8 likely ensured proper luteolysis and response to estrogen as determined by higher uterine edema scores and pregnancy rates than G7 (pâ¯<â¯.05). Our results were consistent with previous studies and other successful commercial ET programs (except G7), thus, demonstrating the usefulness of the hormone treatments described herein to synchronize embryo recipient mares with donor mares. Thus, we foresee that other groups may use the strategies described herein for the management of embryo recipient mares.