Evaluation of synergic effects of iodixanol and trehalose on cryosurvival of electroejaculated ram semen.

The primary aim of the study was to investigate whether iodixanol and trehalose would have a synergic effect on the cryosurvival of electroejaculated ram semen. Tris-based diluter was used to prepare 9 different extenders by the addition of iodixanol or trehalose alone or varying combinations of these substances. Diluters were prepared as follows: Tris (control), Io5 (5% iodixanol), Tr25 (25 mmol/L trehalose), Tr50 (50 mmol/L trehalose), Tr50 + Io1.25 (50 mmol/L trehalose and 1.25% iodixanol), Tr50 + Io2.5 (50 mmol/L trehalose and 2.5% iodixanol), Tr50 + Io5 (50 mmol/L trehalose and 5% iodixanol), Tr25 + Io5 (25 mmol/L trehalose and 5% iodixanol) and Tr12.5 + Io5 (12.5 mmol/L trehalose and 5% iodixanol). Supplementation of the freezing extender with trehalose or iodixanol alone supported the protection of both morphological and functional integrity of ram spermatozoa and total motility at 1 and 4 hr post-thawing respectively. However, beyond these positive effects, the combination of trehalose (25 mmol/L) and iodixanol (5%) significantly increased post-thaw sperm longevity and motion properties at the end of 4-hr incubation. The results of the study clearly showed that there was positive synergic effect of iodixanol and trehalose on cryosurvival of ram semen.

Effect of the interval from follicle aspiration to initiation of lengthened FSH treatment on follicular superstimulatory and superovulatory responses and embryo production in lactating Simmental cows.

The present study evaluated follicular superstimulatory (FSS) and superovulatory (SOV) responses and in vivo embryo production in lactating Simmental cows treated with FSH starting 1 or 2 days after follicle aspiration (FA). The performance of a lengthened superovulation program, named 6dFSH-P36-hCG60, is described. At random stages of the estrous cycle, cows (n = 52) were subjected to ultrasound-guided transvaginal aspiration of all follicles ≥ 5 mm. After FA, cows were randomly assigned to one of two groups in which FSH treatments started 1 or 2 days after FA (groups FA-1D and FA-2D, respectively). Cows were superstimulated with a total of 500 µg pFSH over 6 days on a decreasing dose schedule and were pre-treated with a single dose of 400 IU of eCG 24 h before the start of FSH treatments. Follicular superstimulatory (the mean numbers of follicles ≥ 8 mm on the day of hCG treatment) and SOV responses (the mean numbers of CL and cows with ≥ 3 CL at the time of collection) were similar in FA-1D and FA-2D groups. However, when compared to FA-1D group, the number of unfertilized ova tended to decrease (0.4 vs 1.7; P = 0.065) and percentage of fertilized ova tended to increase (95.8% vs 84.6%; P = 0.066) in FA-2D group. Moreover, the mean numbers and percentages of both transferable embryos (8.0 and 77.6% vs 6.4 and 57.7%) and freezable embryos (5.3 and 51.5% vs 3.5 and 31.1%) were numerically higher in FA-2D group than FA-1D group. The results of the study suggest that starting a lengthened superovulation programs in Simmental cows 2 days after FA has potential to increase percentage of fertilized ova and the number of transferable and freezable embryos, although new studies may be needed to confirm this findings.

The effects of the thiolation with thioglycolic acid and l-cysteine on the mucoadhesion properties of the starch-graft-poly(acrylic acid).

The aim of this study is to investigate the effects of the thiolation on the mucoadhesion characteristics of the gelatinized and crosslinked wheat starch-graft-poly(acrylic acid) [(WS-g-PAA)gc] for potential use in drug delivery via vaginal route. Thiolation of (WS-g-PAA)gc was first time realized using l-cysteine hydrochloride monohydrate (CyS) and thioglycolic acid (TGA). These conjugates [(WS-g-PAA)gcth] were characterized using FTIR. The free SH group, mucoadhesion, cytotoxicity characteristics and the mechanism of the thiolation were also evaluated. To obtain fundamental data for possible application such as drug carrier, in vitro and in vivo progesterone release profiles from the mucoadhesive tablet formulations were also determined. The results showed that, vaginal tablet containing (WS-g-PAA)gc-TGA, which has not contain free SH groups in its structure, displays higher mucoadhesion than (WS-g-PAA)gc and (WS-g-PAA)gc-CyS. This tablet formulation can also be used as a drug carrier in vaginal applications.

Development of starch based mucoadhesive vaginal drug delivery systems for application in veterinary medicine.

The aim of this study was to prepare and evaluate the mucoadhesive, biocompatible and biodegradable progesterone containing vaginal tablets based on modified starch copolymers for the estrus synchronization of ewes. Starch-graft-poly(acrylic acid) copolymers (S-g-PAA) were synthesized and characterized. The vaginal tablets were fabricated with S-g-PAA and their equilibrium swelling degree (Qe) and matrix erosion (ME%) were determined in lactate buffer solution. In vitro, mucoadhesive properties of the tablets were investigated by using ewe vaginal mucosa and in vivo residence time were also investigated. In vitro and in vivo progesterone release profiles from the tablets were compared with two commercial products. Tablet formulation containing wheat starch based grafted copolymer (WS-g-PAA)gc indicated promising results and might be convenient as an alternative product to the commercial products in veterinary medicine.

Long-term effects of 900 MHz radiofrequency radiation emitted from mobile phone on testicular tissue and epididymal semen quality.

The purpose of this study is to bridge this gap by investigating effects of long term 900 MHz mobile phone exposure on reproductive organs of male rats. The study was carried out on 14 adult Wistar Albino rats by dividing them randomly into two groups (n: 7) as sham group and exposure group. Rats were exposed to 900 MHz radiofrequency (RF) radiation emitted from a GSM signal generator. Point, 1 g and 10 g specific absorption rate (SAR) levels of testis and prostate were found as 0.0623 W/kg, 0.0445 W/kg and 0.0373 W/kg, respectively. The rats in the exposure group were subject to RF radiation 3 h per day (7 d a week) for one year. For the sham group, the same procedure was applied, except the generator was turned off. At the end of the study, epididymal sperm concentration, progressive sperm motility, abnormal sperm rate, all-genital organs weights and testis histopathology were evaluated. Any differences were not observed in sperm motility and concentration (p > 0.05). However, the morphologically normal spermatozoa rates were found higher in the exposure group (p < 0.05). Although histological examination showed similarity in the seminiferous tubules diameters in both groups, tunica albuginea thickness and the Johnsen testicular biopsy score were found lower in the exposure group (p < 0.05, p < 0.0001). In conclusion, we claim that long-term exposure of 900 MHz RF radiation alter some reproductive parameters. However, more supporting evidence and research is definitely needed on this topic.

Comparison of cryoprotective effects of iodixanol, trehalose and cysteamine on ram semen.

This study was conducted to improve cryosurvival of electroejaculated (EE) ram semen in the presence of iodixanol (OptiPrep™), trehalose or cysteamine. A tris-based extender was used to prepare 12 extenders containing OptiPrep™ (Op), trehalose (Tr) or cysteamine (Cy) alone, or different combinations of these compounds. Extenders were designated as follows: Tris (control), Op1.25 (1.25% Op, v/v), Op2.5 (2.5% Op, v/v), Op5 (5% Op, v/v), Tr50 (50mM Tr), Tr100 (100mM Tr), Cy (5mM Cy), OpTr (2.5% Op and 100mM Tr), OpCy (2.5% Op and 5mM Cy), TrCy (100mM Tr and 5mM Cy), OpTrCy1 (2.5% Op, 100mM Tr and 5mM Cy) and OpTrCy2 (1.25% Op, 50mM Tr and 2.5mM Cy). A two-step dilution was used and glycerol was added at 5°C in the second step. Diluted samples were equilibrated for 1h, loaded in 0.25mL straws and frozen in a programmable freezing machine. Supplementation of 5% OptiPrep™ significantly protected post-thaw progressive motility, membrane integrity, acrosomal integrity and morphological damages. Trehalose supplementation protected membrane integrity of ram sperm; however, it did not help post-thaw motility and morphology. Supplementation of 5mM cysteamine had detrimental effect on cryosurvival of EE ram semen. These results demonstrate that the supplementation of iodixanol increases the cryosurvival of EE ram semen in a dose-dependent manner.

Effects of sildenafil citrate, isoniazid, and streptomycin on testicular tissue and epididymal semen quality in rats.

OBJECTIVE: To evaluate the effects of isoniazid (INH) and streptomycin (STR) on epididymal semen quality and testicular tissue, and to evaluate the protective effect of sildenafil citrate (SC) on possible testicular toxicity induced by STR and INH in rats. METHODS: Eighty adult male Sprague-Dawley rats were divided randomly into 8 groups including control, SC, INH, STR, STR+INH, SC+INH, SC+STR, and SC+INH+STR. After 45 days of treatment, the reproductive organ weights, epididymal semen quality, testicular histopathological findings, levels of serum nitric oxide, testosterone, follicle-stimulating hormone (FSH) and luteinizing hormone (LH) were investigated. RESULTS: SC significantly increased the epididymal sperm motility and concentration, and the levels of FSH, LH, and testosterone. The STR group had a significantly higher percentage of sperm head defect than the control group (P < .05). The INH group had lower Johnsen Testicular Biopsy Score than the control group (P < .001). Although SC and INH treatment alone did not affect the epididymal semen quality negatively, the SC+INH group had significantly higher spermatozoon tail and total morphologic defect ratios than the control group (P < .05). CONCLUSION: It has been concluded from this study that (1) SC has positive effects on spermatogenesis, sperm production, and semen quality; (2) STR affected the testicular biopsy score and spermatozoon head morphology negatively, but positively affected the other spermatologic traits; (3) INH did not effect the epididymal semen quality negatively, but decreased testicular biopsy score; and (4) SC can prevent the spermatozoon head defects induced by STR and can decrease the testicular toxicity induced by INH.

Using cell banks as a tool in conservation programmes of native domestic breeds: the production of the first cloned Anatolian Grey cattle.

The aim of this study was to clone native Anatolian Grey cattle by using different donor cell types, such as fibroblast, cartilage and granulosa cells cryopreserved in a gene bank and oocytes aspirated from ovaries of Holstein cows as the recipient cytoplasm source. One male calf from fibroblast, three female calves from granulosa cells and one female calf from cartilage cells were born healthy and at normal birthweights. No calves were lost after birth. The results demonstrated that the cloned calves had the same microsatellite alleles at 11 loci as their nuclear donors. However, the mtDNAs of the five Anatolian Grey cloned calves had different haplotypes from their donor cells and mtDNA heteroplasmy could not be detected in any of the clones. The birth of healthy clones suggests that the haplotype difference between the cell and oocyte donor did not affect the pre- or post-implantation development of the bovine nuclear transfer derived embryos in our study. The results showed that well established nuclear transfer protocols could be useful in conserving endangered species. In conclusion, somatic cell banking can be suggested as a tool in conservation programmes of animal genetic resources.

Lambing rates and litter size following carazolol administration prior to insemination in Kivircik ewes.

The effect of carazolol on the ease of penetrating the cervix during artificial insemination, lambing rate and litter size was studied using 1.5-4.0-year old Kivircik ewes in an incomplete 3 x 2 x 2 experimental design. All of the ewes in this study were synchronized for oestrus by insertion of a progesterone impregnated vaginal sponge for 12 days and administration of 400 IU PMSG at sponge withdrawal. Three methods of service were compared: natural service, artificial insemination (AI) with fresh semen, or AI with frozen semen. Two times of insemination (fixed time AI versus AI at observed oestrus) were compared on the fresh and frozen AI treatments. The absence (control) or use of carazolol (carazolol; 0.5mg/ewe i.m. 30 min before mating) was the third factor in the design and penetration of the cervix by the insemination pipette was assessed as shallow (<10mm), middle (10-20mm) or deep (>20mm). Natural service ewes were only mated at observed oestrus. Consequently, the factorial design was incomplete and there were a total of 10 treatments each represented by 30 ewes. Natural service resulted in a significantly (P<0.05) higher lambing rate and litter size (86%; 2.0+/-0.05 lambs/ewe) than AI using fresh (65%; 1.6+/-0.1 lambs/ewe) or frozen (40%; 1.4+/-0.14 lambs/ewe) semen. For AI animals the lambing rate and litter size were not significantly different when service was at a fixed time (50%; 1.5+/-0.12 lambs/ewe) or at observed oestrus (56%; 1.5+/-0.12 lambs/ewe). Carazolol did not permit complete cervical penetration in any ewe. Deep penetration of the cervix at AI was achieved in 33% of untreated (control) and 48% of carazolol treated ewes (P<0.05). However, the proportion of ewes in which penetration of the cervix and semen deposition was greater than shallow was similar for control (82%) and carazolol (85%), and lambing rate and litter size were similar for both treatments. Over the three service methods, the lambing rate was 56% for control and 63% for carazolol (NS) and litter size was similar for both treatments. It was concluded that the carazolol treatment used prior to natural mating or AI in this experiment did not improve lambing rate or litter size in Kivircik ewes.

Effects of estrous cycle stage and transport temperature of ovaries on in vitro maturation of canine oocytes.

Unlike other domestic animals, in vitro maturation (IVM) of canine oocytes still has limited success. The present study investigated the effects of estrous cycle stage and transport temperature of ovaries on in vitro maturation of canine oocytes. The donor bitches were categorized into three groups based on stage of estrus cycle: follicular (proestrus or estrous), luteal (diestrus) and anestrus. One ovary of each pair collected from 39 mature bitches was transported in Phosphate Buffer Saline (PBS) at 4 degrees C while the other was transported at 37 degrees C. A total of 1138 Grade I COCs obtained from all ovaries were grouped and matured in modified synthetic oviduct fluid (mSOF) supplemented with follicle stimulating hormone (FSH), luteinizing hormone (LH), essential and non-essential amino acids at 38.5 degrees C in a humidified 5% CO(2), 5% O(2), and 90% N(2) atmosphere for 72 h. The nuclear maturation rates were evaluated by aceto-orcein staining. Oocytes harvested from follicular and luteal ovaries have a significantly higher maturation rates (MI+MII) than the oocytes from anestrual ovaries in the 37 degrees C group (p<0.05). However, oocytes harvested from anestrual ovaries transported at 4 degrees C had the highest maturation (MI+MII) rate, and the difference between anestrual and luteal ovary groups was significant (p<0.05). The oocytes from anestrual ovaries transported at 4 degrees C have significantly higher maturation rates than those transported at 37 degrees C (p<0.0001). However, the transport temperature (37 or 4 degrees C) did not significantly affect the maturation (MI+MII) rates of oocytes harvested from the luteal (p=0.61) and follicular (p=0.48) stage ovaries. It can be concluded from this study that (1) both transport temperature and transport temperaturexestrus cycle stage interaction effected the maturation rates, while estrus cycle stage alone did not, and (2) transporting canine ovaries at 4 degrees C can improve in vitro maturation rates in oocytes harvested from anestrous ovaries.

Developmental competence of domestic cat oocytes from ovaries stored at various durations at 4 degrees C temperature.

Temporal storage of ovaries can provide opportunity to rescue oocytes from ovaries of endangered felids. The objective of the study was to examine the effect of different storage periods (2, 24 and 48h) of ovaries at 4 degrees C for maturation of cat oocytes in vitro. Ovaries were collected from 25 domestic cats at various stages of the estrous cycle by routine ovariohysterectomy following anesthesia at different local veterinary clinics, and maintained in physiological saline at 4 degrees C for 2, 24 or 48h until oocytes recovery. Selected COCs were maturated at 38 degrees C for 48h in four-well petri dishes, which included 500microL modified synthetic oviduct fluid (mSOF) medium under mineral oil in a humidified 5% CO(2), 5% O(2), and 90% N(2) atmosphere incubator. After the in vitro maturation period, there were no differences between the rate of oocytes matured at MII stages in 2 and 24h storage groups (50.7% and 48.2% respectively, p>0.05). However, the same result for the 48h group was significantly lower than the 2 and 24h groups (28.0%, p<0.001). Our results suggest that while 2 or 24h storage of ovaries at 4 degrees C does not affect the meiotic competence of oocytes in vitro, 48h storage of ovaries decrease the results dramatically.

Evaluation of short estrus synchronization methods in dairy cows.

In the present study, two new short estrus synchronization methods have been developed for lactating dairy cows. The study was completed in three consecutive phases. In experiment (Exp) 1, 32 cows, that were not detected in estrus since calving between the 50th and 84th post-partum days, were treated with PGF2alpha (PGF, d-cloprostenol, 0.150 mg), estradiol propionate (EP, 2mg) and GnRH (lecirelina, 50 microg) at 24h intervals, respectively, and timed artificial insemination (TAI) was performed 48 h after PGF. Different from Exp 1, EP and GnRH were given at 48 and 60 h, respectively after PGF in Exp 2 (n=20), instead of 24 and 48 h. Ovulations were investigated by ultrasound for 7 days starting from the day of PGF treatment, and ovulation rates were compared with the ones obtained in Exp 1. In Exp 3, cows were given the same treatments as Exp 2, but treatments started at certain estrus stages. Cows detected in estrus and with a confirmed ovulation (n=27) after the second PGF given 11 days apart were assigned to three treatment groups. Treatment was initiated at Day 3 (group metestrus, n=9), Day 12 (group diestrus, n=9) and Day 18 (group proestrus, n=9) after ovulation. All cows included in Exp 3 were TAI between 16 and 20 h after GnRH treatment. In Exp 2 and 3, blood samples were obtained once every 2 days, starting from Day 0 to the 10th day after GnRH injection, and once every 4 days between the 10th and the 22nd days after GnRH to examine post-treatment luteal development. During the study, animals exhibiting natural estrus were inseminated and served as controls (n=85). The rate of estrus was found to be significantly higher in cows with an active corpus luteum (CL) at the start of Exp 1 (72.7% vs. 30.0%, P<0.05) and the pregnancy rate tended to be higher than cows without an active CL (40.9% vs. 10.0%, P=0.08). Compared to those in Exp 1, cows in Exp 2 had higher rates of synchronized ovulation (94.1% vs. 59.1%, P=0.013). In Exp 3, estrus (P<0.001) and pregnancy rates (P=0.01) were found to be significantly higher in cows in the proestrus group than in those in the metestrus group. Comparable pregnancy rates were obtained from the first and second inseminations in Exp 1 and 3 with results from those inseminated at natural estrus (P>0.05). It was concluded from the study that the treatment in Exp 1 and 3 could result in comparable pregnancy rates after timed AI of lactating dairy cows at random stages of the estrus cycle relating to those inseminated at natural estrus, but the stage of the estrus cycle can have significant effects on pregnancy rates.

The potential fertility estimation capacity of the hypoosmotic swelling test, the thermal stress test and a modified cervical mucus penetration test in the bovine.

In this study, hypoosmotic swelling (HOS), thermal stress (TS) and modified cervical mucus penetration (mCMP) tests have been used with routine tests for the assessment of semen quality. This is the first study in which the comparison of potential fertility estimation of fore-mention three tests was performed. Bull semen samples were divided into two fertility groups (high: n=3, low: n=3), according to their post-insemination NRR (non-return rate). Prior to the tests, post-thawed spermatological characteristics were assessed after which HOS, TS and mCMP tests were carried out. In the HOS test, the ratio of swollen cells, in the TS test the motility, and in the mCMP test the number of spermatozoa penetrating the cervical mucus, were examined. The relationship between the tests and fertility was also evaluated. HOS test was carried out according to different incubation times and temperatures (37 degrees C 60 min/41 degrees C 15 min/41 degrees C 30 min/46 degrees C 15 min/46 degrees C 30 min). For TS test, samples were subjected to various temperatures for different periods (no incubation (37 degrees C)/41 degrees C 15 min/41 degrees C 30 min/46 degrees C 15 min/46 degrees C 30 min). The mCMP test were subjected to various temperatures for the same period (37 degrees C 15 min/41 degrees C 15 min). In this study, post-thawed motility was found to be similar in high and low fertility groups. However, it has been determined that acrosomal (p<0.01) and other morphological defects (p<0.05) were low in the high fertility group. When HOS test was carried out at 37 degrees C, no difference was observed between the bulls with high and low fertility, but at 41 and 46 degrees C, results of high fertility group were significantly higher than those of low fertility group (p<0.01). Similarly in TS test, the progressive motility rates of high fertility bulls was higher after thermal practices at 41 and 46 degrees C (p<0.01). In mCMP test, at 37 degrees C, the number of cells that had penetrated was similar. However, significant differences were observed in the incubation at 41 degrees C (p<0.01). It has been concluded that for the estimation of potential fertility of bulls, HOS, TS and mCMP tests, in combination with routine spermatological tests can be used and the use of further penetration distance range (PDR2) in mCMP test and higher temperatures such as 41 degrees C instead of 37 degrees C, during the incubations in the afore-mentioned performance tests, is more determinative.

Relationship between bovine fertility and the number of spermatozoa penetrating the cervical mucus within straws.

In this study, by using a recently developed test technique, the relationship between the total spermatozoa number penetrating determined sites of bovine cervical mucus in straws and potential fertility of bulls, and other spermatological characteristics were investigated. Furthermore, we aimed to determine the effect on the test results, of two different incubation temperatures (37 and 41 degrees C) and two sperm penetration distance ranges (PDRs). Frozen semen samples of six Holstein bulls were used in the study. The bulls were divided into two fertility groups (high and low fertility) according to the "non-return rates" (NRR). For the penetration test, cervical mucus was drawn into transparent plastic straws and incubated with semen at 37 and 41 degrees C for 15 min. After the incubation, straws were frozen in liquid nitrogen vapour and stored at -20 degrees C. On the evaluation day, concentrations of spermatozoa penetrated to the PDRs, each of which was 2.5 mm, between 32.5 and 35 mm (first penetration distance range, PDR1), and 50 and 52.5 mm (second penetration distance range, PDR2) distance in the straws from the open end, were measured. When compared with the low fertility group, bulls from the high fertility group showed a higher number of spermatozoa at the determined PDRs, and a significant positive correlation was found between the total number of spermatozoa at the penetration distances and the NRR scores of the bulls.

The effects of a low dose of cabergoline on induction of estrus and pregnancy rates in anestrous bitches.

This is the first report of successful induction of normal estrus and ovulation in breeder bitches with as a low dose as 0.6 microg/kg/day of cabergoline formulation marketed for use in women. Sixty-one pure breed bitches from various breeds were used in the study at their already determined periods of anestrus. Twenty-four dogs formed the control group, while 37 bitches were administered with two different doses of cabergoline (recommended dose group, n=10, 5 microg/kg/day and low dose group, n=27, 0.6 microg/kg/day). Induced estrus rates and mean treatment and proestrus durations of dogs in these two dose groups were compared. At the second phase of the study, the effects of 500 IU human chorionic gonadotropin (hCG) administered on days 1 and 3 of estrus induced by the low dose of cabergoline, on the duration of behavioral estrus, ovulation rates, pregnancy rates and the number of offspring were investigated. For this purpose, the dogs with signs of proestrus (22/27) following the treatment in the low dose group were assigned into two subgroups. Five hundred IU of hCG (Pregnyl, Organon, Turkey) was intramuscularly administered to eight of these dogs [low dose (hCG+) group] on days 1 and 3 of estrus. The remaining 14 dogs were not treated with hCG [low dose (hCG-) group]. An aqueous solution of cabergoline (Dostinex, Pharmacia, Italy) was orally administered until 2 day after the onset of proestrus or for a maximum of 42 days. Blood samples were taken daily from all treatment and 11 control bitches during the first five days of behavioral estrus to measure progesterone concentrations. In the recommended dose and low dose groups, estrus was induced between days 8-45 and 4-48 (mean: 23.63+/-14.33 and 24.41+/-14.31 days), in the ratio of 80.0 and 81.5%, respectively (p>0.05). In both dose groups, post-treatment interestrous intervals were significantly shorter than both those of the control group and their own pre-treatment interestrous intervals (p<0.05). Ovulation rates, pregnancy rates and mean number of offspring delivered by the dogs in the recommended dose, low dose (hCG-), low dose (hCG+) and control groups were found to be similar (p>0.05). However, the mean duration of behavioral estrus of the dogs in the low dose (hCG+) group was found to be significantly longer compared to dogs in all other groups (p<0.05). In both dose groups, no correlation could be found between the anestrus stages and treatment durations (p>0.05). Shortly, it has been concluded from the study that (1) normal and fertile estrus can be induced more economically in bitches during different stages of anestrus using as a low dose of 0.6 microg/kg of cabergoline formulation marketed for use in women, and that (2) hCG injections on days 1 and 3 of the estrus induced by this method has no positive effects on the ovulation rates, pregnancy rates and the number of offspring per pregnancy.

Effect of transport and storage temperature of ovaries on in vitro maturation of bitch oocytes.

In this study, the effects of ovary transport and storage temperature on in vitro maturation of bitch oocytes were investigated. Ovaries were collected from 23 mature bitches and one randomly selected ovary of each pair (n=23 pairs) was transported in physiologic saline at 4 degrees C, while the other one at 35-38 degrees C for 2-4h. A total of 316 cumulus oocyte complexes (COCs) were obtained from the 4 degrees C group and 301 COCs from the 35-38 degrees C group. All COCs were matured in modified synthetic oviduct fluid (mSOF) supplemented with follicle stimulating hormone (FSH), essential and non-essential amino acids at 38 degrees C in a humidified 5% CO2, 5% O2, and 90% N2 atmosphere for 72 h. At the end of the in vitro maturation period, nuclear maturation of oocytes was classified as germinal vesicle (GV), germinal vesicle breakdown (GVBD), metaphase I (MI), metaphase II (MII), undetermined nuclear maturation (UDNM), and MI+MII. The nuclear maturation rates to MI, MII, and MI+MII stages were 60.44%, 10.75%, and 71.20% in the 4 degrees C group and 37.20%, 7.64%, and 45.85% in the 35-38 degrees C group, respectively. The data demonstrated that oocytes obtained from ovaries transported at 4 degrees C had higher maturation rates than from the ones transported at 35-38 degrees C (p<0.001).