End Of Estrus Research Articles

Використання колпоцитоскопії для визначення оптимального часу осіменіння у нутрій

The article is devoted to the finding a way to determine optimal time for insemination of nutria. This gives an opportunity to improve reproduction what will improve profitability of nutrition as an animal industry.Known for today’s ways to determine optimal time for insemination of nutria have shortcomings, what limits their use. To this end we tested vaginal cystoscopy (colposcopy). This method is not so expensive, it is simple and easy to use. It allows you to define a clear relationship between cytological picture of vaginal smears and hormonal status in a specific period of the sexual cycle.We installed, that in the picture of vaginal smears from the beginning to the middle of proestrus, we can see erythrocytes and parabasal cells, which have a large nucleus, which occupies almost half of the cytoplasm. With a growing level of estrogens instead of basal cells appear intermediate cells reduces the numbers of erythrocytes.During the transition period of the proestrus stage to the estrus stage vaginal swab is characterized by reducing the number of intermediate cells and increase in the number of surface cells. Also we can see non-nuclear cells. Clearly it is visible contours of cells. The appearance of surface cells coincides with the stage of ovulation of the sexual cycle.The same picture of vaginal swab with lots of surface cells we can see in second, sometimes on third day after childbirth. So, the first two days after childbirth is conductive to fertilization period in nutria.In the end of estrus the vaginal swab has changes again: appear epithelial cells with a small nucleus, also we can see many leucocytes.So, the one of the main characteristics of vaginal swab in the period of ovulation in nutria is appearance of non-nuclear surface cells with clear contours and semitransparent cytoplasm. In the development perspective the use of colposcopy to assess the condition of the fetus and the course of pregnancy for further develop methods of diagnosis and prevention of pathologies in ante-, intra- and postnatal periods of development of nutrias puppies.

"Waktu dan Kemerahan Vulva Saat Inseminasi Buatan Merupakan Faktor Penentu Angka Kebuntingan Sapi di Sumatera Barat (TIME AND REDDISH SIGN OF VULVA DURINGARTIFICIAL INSEMINATION AS A DETERMINANT FACTORS ON CONCEPTION RATE OF COW IN WEST SUMATERA) "

An experiment was conducted to evaluate determinant factors on conception rate of local and crossbreedcow at West Sumatera. There were 162 cows of four AI center at parity-0 to 4TH parity (P-4), inseminatedusing frozen semen of four different bulls (simental,brahman, limousine and Bali cattle). All fed similarityat four AI centers and location to observation of sign of estrus in high land and low land in West Sumatera.All data were analyzed using analyzed of variance in Randomized Block Design (RBD) in factorial as afactor A was time of inseminated; parity;sign of vulva,breed and two location as a replication. Resultsofthis study showed that there were no interaction between time of insemination, breed, parity and thereddish sign of vulva (P>0.05) on conception rate. On the contrary,there were significantly different(P>0.05) on conception rate by time of insemination. The highest conception rate wasfound at the end ofestrus 13–18 h (68.91%),local cow (71.82%), P-3 (67.19%) and reddish sign of vulva (74.25%). It wasconcluded that the effects,both inseminationtime and reddish sign of vulva might be the important factorto get the highest conception rate of the cows.

Studies of Sociosexual Interactions in Rats in an Externally Valid Procedure: Are They Relevant for Understanding Human Sexual Behavior?

When a prolonged observation of groups of rats in a seminatural environment is used as testing procedure, different behavioral patterns are shown compared with what observed in a pair housed in a small cage. Males and females copulate simultaneously, they show a promiscuously and random copulatory pattern. Females remain completely receptive from the first lordosis displayed in the period of behavioral estrus until the last. There is no reduction in paracopulatory behaviors and no increase in rejections towards the end of estrus. Female paracopulatory behavior and receptivity change in a most abrupt way at both initiation and termination of behavioral estrus. It appears that, in the seminatural environment, males copulate in bouts, and males do not pursue the females unless they are fully receptive. Non-sexual, social behavior including affiliative and nonaffiliative interaction among rats is rather unrelated to sexual activities in both sex.

Estrus synchronization in microminipig using estradiol dipropionate and prostaglandin F2α.

The induction of pseudopregnancy by the exogenous administration of estradiol dipropionate (EDP) was investigated in cyclic Microminipigs (MMpigs) and the effects of exogenous administration of prostaglandin (PG) F2α on estrus exhibition were assessed in pseudopregnant MMpigs. In experiment 1, ovariectomized MMpigs were given a single intramuscular injection of 0.5, 1.5, or 2.5 mg of EDP. The estradiol-17β level at each of these doses was significantly higher 1 to 3 days after EDP administration than on the day of the injection. In experiment 2, animals were given 1.5 mg of EDP once at 9 to 12 days after the end of estrus (D0) and then no (1.5 mg × 1 group), one (D0 and D4; 1.5 mg × 2 group), or two (D0, D4 and D7; 1.5 mg × 3 group) additional treatments. The pseudopregnancy rate was significantly higher in the 1.5 mg × 3 than in the 1.5 mg × 1 group. In experiment 3, PGF2α was administered twice between 26 and 28 days after EDP treatment to five pseudopregnant gilts with a 24-h interval between the two injections. Estrus after PGF2α treatment and LH surge were observed in 100% and 80% pseudopregnant MMpigs, respectively. The interval from the day of the first PGF2α treatment to the onset of estrus was 6.5 ± 0.2 days. These results indicate that multiple EDP treatments are required for induction of pseudopregnancy in MMpigs and estrus exhibition can be controlled in MMpigs by treatment with EDP and PGF2α.

Priapism Following hCG Administration In A Cat

Abstract Priapism, defined as a persistent and painful penile erection in the absence of sexual excitation, is an uncommon disorder of cats that usually requires penile amputation and perineal urethrostomy. This report describes a case of priapism in a short-haired Persian male cat aged 3 years. The condition had appeared after attempted mating with a female at the end of oestrus and the time of referral to the authors was 10 days after onset. Previous treatment had consisted of corticosteroids and local lubricants. On physical examination, the cat appeared bright and alert; the penis was erect but the colour was normal; blood analysis excluded viral pathologies. The cat history revealed that he had been treated with 500 IU hCG i.m. because he had to mate with three queens in a short period of time. In consideration of the mild symptoms, conservative treatment was adopted. The condition resolved in about 40 days. This is the first report of priapism following hCG administration in a cat and indicates that the misuse of this gonadotropin might cause potentially harmful side effects.

Failure of a single dose of medroxyprogesterone acetate to induce uterine infertility in postnatally treated domestic cats

In mice and sheep, neonatal administration of progesterone or progestins inhibited development of uterine glands. The aims of the present study were (1) to describe uterine gland development on postnatal Days 6 to 8 and (2) to evaluate the effects of a single postnatal administration of a progestin on reproduction and adult uterine glands morphology and function in domestic cats. Necropsy was performed on three 1-week-old female cats which had died unrelated to this study. Ten female kittens were randomly assigned within the first 24 hours of birth to: medroxyprogesterone acetate 10 mg/animal subcutaneously (MPA; n = 6) or placebo (PLC; n = 4) and followed up until puberty when they were mated. Twenty-four days after the end of estrus, ovulation and pregnancy were diagnosed by serum progesterone measurement and ultrasonography, respectively. Then, all the cats were ovariohysterectomized. After necropsy or surgery, the excised organs were histologically evaluated. Seven queens ovulated (4 of 6 MPA and 3 of 4 PLC; P > 0.1) and were pregnant (P > 0.1). Four MPA cats presented endometrial hyperplasia and one of them developed a pyometra. The 1-week-old females presented uterine glands in the stage of budding and incipient penetration of the glandular epithelium into the underlying stroma. The MPA-treated queens revealed that the area occupied by uterine glands per square-micrometer (0.55 ± 0.2 vs. 0.49 ± 0.2; P > 0.1) and the height of the glandular epithelium (μm; 24.5 ± 6.7 vs. 24.4 ± 7.2; P > 0.1) did not differ from those of the PLC group. Neither significant gross nor microscopical differences were also found for ovaries (P > 0.1). It is concluded that 1-week-old kittens had an incipient stage of uterine gland development and that a single postnatal supraphysiological dose of MPA did not alter uterine adenogenesis in this species. Furthermore, this treatment seemed to predispose to uterine disease without prevention of fertility.

Effect of copulation on estrus duration and ovulation time in goats

The objective of the present study was to evaluate the effect of copulation on estrus duration and ovulation in goats. During the fall season, 14 multiparous Boer does were estrous synchronized with controlled internal drug release (300 mg), maintained in the vagina for 7 days, and received 50 μg of intramuscular GnRH device insertion and 5 mg of natural intramuscular PGF2α at device removal. The does were randomly divided into two equal groups: a treatment group (TRE; n = 7) and a control group (CON; n = 7). The TRE group received two copulas by fertile bucks within the first 4 hours of estrus onset, and the CON group received only mounts by the same males equipped with canvas aprons. Estrus detection was performed every 12 hours after controlled internal drug release removal within the first 24 hours and then every 4 hours for 5 days. Estrus was defined when a doe accepted mounting by the bucks equipped with canvas aprons. Each doe in estrus got the first transrectal ultrasonography at 24 hours after estrus onset and then every 4 hours until all the preovulatory follicles ovulated. Estrus onset for the TRE and CON groups was 40.3 ± 17.4 (mean ± standard deviation) and 43.3 ± 12.2 hours (P = 0.72), respectively. Estrus duration for the same groups was 28.6 ± 5.4 and 36.7 ± 5.3 hours (P = 0.02), respectively. The mean ovulation time for the TRE and CON groups was 31.4 ± 2.2 and 35.7 ± 3.7 hours (P = 0.04), respectively. The proportion of ovulations that occurred after the end of estrus in the TRE group was higher than in the CON group (86% vs. 33%, respectively; P = 0.05). The number of ovulations for the TRE group was 2.1 ± 0.7; for the CON group, there were 2.2 ± 0.5 ovulations (P = 0.92). It was concluded that copulation by a buck at the beginning of estrus reduced estrus duration and hastened the ovulation time in Boer goats.

Effect of natural mating or laparoscopic artificial insemination in superovulated Santa Inês ewes on superovulatory response, fertility and embryo viability

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.

Short communication: Comparison of estrus characteristics in Holstein heifers by 2 activity monitoring systems

Two activity monitoring systems—Heatime (SCR Engineers Ltd., Netanya, Israel) and IceTag (IceRobotics Ltd., Edinburgh, UK)—were compared on their ability to detect and quantify estrus expression. Holstein heifers (n=57) were fitted with Heatime (HT) and IceTag (IT) sensors from 12 mo of age until confirmation of pregnancy. Upon detection of high activity by HT, ovaries were scanned by ultrasound, a blood sample was collected for analysis of plasma estradiol, and signs of estrus (clear vaginal mucus, uterine muscle tone, visual mounting activity, standing to be mounted, or rump showing signs of repeated acceptance of mounts) were recorded. Because only estrus episodes detected by HT (n=111) were further evaluated, only the positive predictive value was measured. Heifers were housed in groups of 24 in a freestall pen. Data were analyzed using Proc CORR and GLM of SAS (SAS Institute Inc., Cary, NC). The positive predictive value was 84.7% (94/111) for HT and 98.7% (74/75) for IT. Estrus duration was recorded by HT as 14.3±4.1h [mean ± standard deviation (SD)] and by IT as 15.0±4.0h; duration measurements were correlated (r=0.60). The mean duration difference was 0.74±3.52h. Recordings of onset and end of estrus by IT were 3.5±4.3h and 2.9±4.9h earlier than those by HT. The overlap in duration was 9h. Measurements of estrus intensity were correlated (r=0.63). Peak activity was 77.3±19.5 index value (approximately 7.7 SD from basal activity) on HT. The relative increase in activity measured by IT was 360±170% baseline value. Measurements of intensity and duration from HT were correlated (r=0.64) but those from IT were not (r=0.13). Plasma estradiol concentration (11.2±4.6pg/mL) was not correlated with preovulatory follicle diameter or with duration or intensity of estrus. Diameter of preovulatory follicle (15.7±2.6mm) had no correlation with duration of estrus and was only weakly correlated with intensity measured by either system. Baseline steps/hour was negatively correlated with intensity from both sensors (r=−0.37 and −0.70 for HT and IT). Estrus episodes accompanied by 2 or 3 of the monitored signs of estrus had greater intensity and duration on HT but not on IT. Preovulatory follicle diameter and plasma estradiol concentration did not influence occurrence of estrus signs. Results indicate that both systems identified estrus precisely, with correlated characterization and similar timing. In contrast, relationships with plasma estradiol concentration and signs of estrus require further investigation.

Facets of Estrus Behavior in Surti Buffaloes

The Investigation was undertaken on sixteen healthy Surti buffaloes to document and characterize female sexual/estrus behavior in Surti buffaloes maintained at Livestock Research Station, Navsari Agricultural University, Navsari, Gujarat. Perusal of data revealed that in about 56.25 per cent of animals showed estrus during morning while remaining 42.75 percent in the evening time. Result of this study indicated that restlessness, frequent urination and sniffing of vagina, chin resting, chasing, bellowing, being mounted by others, mounting others and tail raising was the estrus specific signs in Surti buffaloes. The overall estrus duration, onset of estrus to ovulation and estrus duration after end of estrus were 22.19 ± 0.75, 31.50 ± 0.87 and 9.31 ± 0.48 hrs, respectively.

Sociosexual behaviours in cycling, intact female rats (Rattus norvegicus) housed in a seminatural environment

Groups of 3 males and 4 females were housed in a seminatural environment for a period of 8 days. Female sociosexual behaviours were recorded and analysed from the beginning of behavioural oestrus (defined as the first lordosis response observed in the environment) until the end of oestrus (defined to occur at the moment of a lordosis that was not followed by another one within 60 min). The duration of behavioural oestrus varied between 4.05 and 10.87 h, with a mean of 7.41 ± 0.49 h. In order to analyse changes in behaviour during oestrus, the entire period was divided in 5% segments for each female. The frequency and/or duration of some behaviours changed during the period of oestrus, while others remained stable. Most remarkable among the latter are the frequency of lordosis and the lordosis quotient. From the start of oestrus until the end, the females responded with lordosis to every male mount. Rejections were most frequent at the beginning of the period of oestrus. Then there was a decline, and thereafter rejections remained at a low level, even when the end of oestrus was approached. Paracopulatory behaviours reached a maximum towards the end of the first quarter of the oestrus period. There was no evident decline at the end of oestrus. Females having a high frequency of lordosis showed more paracopulatory behaviours and were pursued more by the males than females with low lordosis frequency. When the behaviour of females with a large number of offspring was compared to that of females with a low number of offspring, no difference in sexual behaviours was found. Comparisons between the females’ behaviour in response to preferred (either defined as the male producing the largest number of lordosis responses or as the male that was most sniffed by the female) and non-preferred males revealed a few minor differences. Location of behaviour was also analysed. Comparisons were made between the environment’s open area and burrow and between different sectors in these parts. Some important differences were found. This is the first detailed description of female rat sociosexual behaviour during the entire period of behavioural oestrus in a seminatural environment.

Qualidade do corpo lúteo e do embrião de ovelhas Santa Inês superovuladas com FSH associado à rbST

Avaliou-se o efeito da somatotropina bovina recombinante (rbST) sobre a qualidade do corpo lúteo e do embrião e sobre a concentração de progesterona (P4), em ovelhas da raça Santa Inês doadoras de embriões. Foram utilizadas 13 doadoras, distribuídas aleatoriamente em dois grupos, G1 (n=7) e G2 (n=6). Em ambos os grupos, as doadoras foram sincronizadas com implante vaginal por 14 dias, receberam 100µg de PGF2α (Ciosin®) no sétimo dia e foram superovuladas, a partir do 12º dia, com 250UI de FSH (Folltopin-V®) em seis doses decrescentes. No dia da retirada do implante, as doadoras do G2 receberam 125mg de rbST (Boostin®) e foram cobertas por macho Santa Inês a cada 12 horas até o final do estro. No sexto dia após a primeira cobrição, foram avaliadas, por laparoscopia, a resposta superovulatória e a quantidade e a qualidade dos corpos lúteos. Após as avaliações, as colheitas embrionárias foram realizadas por laparotomia. A administração da rbST no protocolo de superovulação promoveu aumento significativo (P<0,05) no número de corpos lúteos do tipo I (9,00 x 5,28) e na qualidade embrionária (4,33 x 2,00).

Treatment of queens in estrus and after estrus with a GnRH-agonist implant containing 4.7 mg deslorelin; hormonal response, duration of efficacy, and reversibility

Although slow release GnRH-agonist implants have been shown to effectively suppress the estrous cycle in queens, there are still several remaining questions about their use: if the probability and frequency of estrus induction because of initial stimulation is dependent on the stage of cycle when animals are treated, if all effects are reversible, and to what extent fertility is regained after the end of efficacy. The latter is of major interest to cat breeders who want temporary suppression of estrus in breeding animals. Twenty queens (14 with known fertility) were treated with a 4.7 mg deslorelin implant; hormonal changes (progesterone [P4], and estradiol [E2]) and behavioral changes with special respect to estrus signs and subsequent fertility were assessed. Group A cats (N = 10) were treated 3.2 ± 0.8 days after the beginning of estrus and estrus stopped 4.1 ± 2.5 days after treatment. Estrus induction was observed in one queen 6 days after treatment, and one queen showed estrous signs 138 and 155 days after treatment. Progesterone increased significantly after treatment in all animals until day 14, then slowly decreased reaching basal levels on day 56 without any further increase. Group B cats (N = 10) were treated 7 days after the end of estrus; nine cats had P4 > 1.5 ng/mL and basal E2, one cat (B10) had basal E2 and P4. In cat B10 estrus induction occurred after treatment, but in none of the others; however, E2 increased in all group B cats 1 day after treatment but reached pretreatment concentrations on Day 7 again and remained basal. The implant was still effective in one animal of the estrus group with a duration of efficacy >1102 days, in the others duration of efficacy varied between 483 and 1025 days. Eight queens were mated afterwards and gave birth to a healthy litter with 3.3 ± 1.5 kittens. This study proves that (1) the incidence of estrus induction—although very low—is highest after treatment in estrus or postestrus, (2) the duration of efficacy varies between 16 and 37 months, and (3) estrus suppression is reversible and animals remain fertile after the treatment effect has expired.

8 DURATION OF ESTRUS AND TIME OF OVULATION IN SUPEROVULATED SANTA INÊS EWES

The aim of this study was to determine the intervals between sponge removal and the onset of estrus, sponge removal and the first detected ovulation, and onset of estrus and the first ovulation, and also to determine the duration of estrus, in superovulated Santa Inês ewes subjected to natural mating (NM) and AI. The trial was done in July and February at Cachoeiras de Macacu–Rio de Janeiro (22°27′S, 43°39′W). Fifteen non-pregnant Santa Inês ewes, age 3.4 ± 1.4 years, weighing 47.8 ± 6.3 kg, with 3.3 ± 0.4 body condition score (scale of 1 to 5), were randomly assigned to 2 groups. Both groups were superovulated using the same protocol and were mated in a crossover design by NM and laparoscopic AI. Estrus was synchronized using intravaginal sponges (60 mg of medroxyprogesterone acetate; Progespon®, Schering Plough Animal Health, São Paulo, Brazil) inserted (Day 0) and maintained for 6 days. On Day 5, the ewes received IM injections of 300 IU of eCG (Novormon®, Schering Plough Animal Health) and 0.0375 mg of cloprostenol (Prolise®, Tecnopec, São Paulo, Brazil). Twelve hours after sponge removal, 0.025 mg of gonadorelin acetate (Gestran®, Tecnopec) was administered IM. Superovulation started 60 h after sponge removal and consisted of 5 IU kg–1 of porcine FSH (pFSH; Pluset®, Hertape Calier, Minas Gerais, Brazil) IM in 6 decreasing doses (25, 25, 15, 15, 10, and 10%) at 12-h intervals. At the first pFSH dose, new sponges were inserted. At the fifth pFSH dose, 0.0375 mg of cloprostenol was administered IM and the sponges were removed. After the sponge removal, the NM group was exposed to rams twice per day for mating, until the end of estrus. In the AI group, estrus was detected using a teaser with the penis diverted. The females were permitted to be mounted twice per day until the end of estrus, and were inseminated with frozen–thawed semen 24 and 36 h after the end of superovulation. The follicular development and ovulation time were observed using real-time ultrasonography (8.0 MHz Pie Medical®, Aquila Vet, Tokyo, Japan) at 12-h intervals. For statistical analysis, a Student’s t-test was performed (5% significance level) using the BioEstat program. Results are presented as mean ± standard deviation. The time from sponge removal to onset of estrus and the duration of estrus did not differ between NM and AI groups (31.79 ± 5.94 v. 25.25 ± 10.38 h and 29.89 ± 11.54 v. 26.66 ± 8.67 h, respectively). The time from sponge removal to ovulation and from onset of estrus to the first ovulation were shorter (P < 0.001) in the NM group (32.11 ± 12.72 v. 56.48 ± 15.39 h and 8.61 ± 5.99 v. 32.25 ± 18.57 h, respectively). The time from sponge removal to ovulation in July and February was 56.07 ± 7.27 versus 56.83 ± 20.72 in the AI group and 29.54 ± 0.56 versus 33.83 ± 19.02 in the NM group, respectively, suggesting that the season of the year in a tropical region did not influence the ovulation time for each treatment. Possibly, the mechanical stimulation induced by the contact of the penis with the vagina fornix and by the accessory sex glands fluids in mating hastened the ovulation time in the NM group. The service can shorten the time of ovulation.

Embryo production and recovery in goats by non-surgical transcervical technique

The objective of this study was to evaluate the efficiency of non-surgical embryo collection in goats. Five lactating Saanen goats were tested alternately in a cross-over design for two treatments (T1 and T2). In both treatments, intravaginal progesterone devices were inserted (day 0/6p.m.) and removed six days later (day 6/18:00p.m.) and 22.5μg cloprostenol were administered by intravulvosubmucosal via (day 0). From day 4 (18:00 p.m.), goats received six decreasing doses of FSH (250–400IU) at 12h interval. Three doses of 50mg flunixin meglumine were administered on days 9, 10, and 11. In T1 and T2, animals received two doses of saline or 250mg of rbST on day 0 and on first detection of estrus, respectively. Goats were mated until the end of estrus and uteri were flushed by cervical route seven days after first mating. The embryo collection interval was 60days. Percentage of flushing medium recovered was close to 100% in both treatments. Total number of ova (18.4±9.4 and 15.7±11.0) and viable embryos (13.4±4.1 and 8.2±3.0) were similar (P>0.05) for T1 and T2, respectively. Short-term progesterone protocol was efficient for superovulation in lactating Saanen goats but association with rbST did not enhance embryo recovery or quality. Non surgical flushing by cervical via was efficient to recover flushing medium and embryos in goats.

Follicle-stimulating hormone to substitute equine chorionic gonadotropin in the synchronization of ovulation in Santa Inês ewes

The substitution of equine chorionic gonadotropin (eCG) by follicle-stimulating hormone (FSH) in protocols for synchronization of ovulation in Santa Inês ewes was assessed. Ten females were submitted to the insertion of intravaginal sponges containing 60 mg medroxyprogesterone acetate for 10 days; after this period sponges were withdrawn and the animals were randomly divided into two groups. Group 1 (n = 5): intramuscular injection of 0.5 mL d-cloprostenol and 300 UI eCG; Group 2 (n = 5): intramuscular injection of 0.5 mL d-cloprostenol and 20 mg FSH. Interval between sponge withdrawal and estrus beginning was 27.7 h and 35.9 h for eCG and FSH, respectively. Interval between sponge withdrawal and the end of estrus was 55.8 h for eCG treatment and 55.6 h for FSH treatment. Estrus length was 29.3 h and 19.6 h, for eCG and FSH treatments, respectively. The biggest follicle and the second in size measured 0.74 cm and 0.54 cm for eCG treatment, whereas for the FSH treatment they measured 0.73 and 0.50 cm. The interval between the beginning of estrus and ovulation was similar within all groups: 21.0 h for eCG treated ewes and 25.2 h for the ones treated with FSH. Ewes treated with eCG presented an interval of 47.5 h between sponge withdrawal and ovulation, while the ones treated with FSH presented a 61.1 h interval. Ovulation occurred 8.3 h before the end of estrus in the eCG group. On the other hand, ewes treated with FSH ovulated 5.5 h after the end of estrus. Estrus and ovulation were efficiently synchronized in Santa Inês ewes by using long-term progestogen protocol associated to the administration of 20 mg FSH, along with Prostaglandin F2α (PGF2α) at the moment of sponge withdrawal, thus substituting the use of eCG.

Follicular growth monitoring in the female cat during estrus

Follicular growth in the feline ovary is usually detected indirectly, through behavior observation, vaginal smears, or more invasively, by estradiol assay in blood. This study was designed to describe follicular dynamics by transabdominal ultrasonography. Secondly, the stage of follicular growth was associated to behavioral and vaginal changes. Ovarian ultrasonography was performed during nine anovulatory and 12 ovulatory cycles. Forty-eight follicles were followed during anovulatory cycles: on the first day of estrus behavior, 4.8 ± 0.2 follicles (2 to 7 per female) of 2.3 ± 0.01 mm mean diameter were present. Follicular growth continued at a rate of 0.2 ± 0.04 mm per day. At least one follicle in the cohort reached a diameter greater than 3.0 mm. Maximal follicular growth (when one follicle of the cohort reached the maximal diameter observed for the whole estrus) was reached 3.8 ± 0.3 days after the onset of estrus with the largest follicle reaching a diameter of 3.5 ± 0.04 mm. Growth of the various follicles within a cohort was not exactly synchronous. When no ovulation took place, the follicular diameter decreased by 0.1 ± 0.01 mm per day until the end of estrus. The first day after the end of behavioral estrus, the diameter of the largest follicle in each cohort was 2.7 ± 0.05 mm. No correlation was found between follicular development and either vaginal smear characteristics, or time elapsed since the onset of estrus. When ovulations were mechanically induced after one follicle had reached 3.0 mm in diameter, artificial insemination produced normal pregnancy rate and litter size: four pregnant females out of nine, and 2 to 4 kittens per litter. Ultrasonography proved thus to allow the monitoring of follicular growth in the female cat, with low correlation with behavior and vaginal smear modifications. Further studies are needed to evaluate the interest of an ultrasonographic ovarian follow-up to determine the optimal moment for ovulation induction prior to artificial insemination.

Maternal Obesity and Overnutrition Is Associated with Reduced Systemic Progesterone During the Estrous Cycles of Adult Female Offspring and a Marked Increase in Insulin Resistance at Midpregnancy.

Previously published studies from our laboratory and others have demonstrated that maternal undernutrition (MU) and overnutrition (MO) alter fetal growth and development during intrauterine life, predisposing offspring to similar metabolic disturbances in postnatal life. We have recently demonstrated that MO predisposes nonpregnant female offspring to hyperphagia, increased obesity, and insulin resistance as adults. Further, we have reported that MU of ewes is associated with increased oxidative base lesions within DNA of mid-gestational (Day 78) fetal oogonia in sheep. More recently we have reported that female offspring born to MU ewes exhibited consistently reduced circulating progesterone concentrations during their estrous cycles, and reduced fertility when compared to female offspring born to ewes fed to NRC requirements. This study evaluated the impact of MO on systemic progesterone concentrations during an estrous cycle, fertility, and insulin resistance of adult female offspring at midgestation. Adult nonpregnant female offspring (2-3 years old) born to obese (OB) overnourished ewes fed 150% of NRC recommendations (n = 10), or 100% of NRC (Controls; CON, n=7) from 60 days prior to conception to term were utilized in this study. During an estrous cycle, ewes were bled daily from one estrus (Day 0) to the next, and serum collected and frozen at -80°C until analyzed for progesterone (P4) via validated RIA. At the second estrus, ewes were hand mated to an intact ram at 12hr intervals until the end of estrus. Conception rates and fetal numbers (singles and twins) were determined via real time ultrasonography, and pregnant ewes were subjected to an intravenous glucose tolerance test (IVGTT) at midgestation (75 ± 1 day). Plasma glucose and insulin was measured in triplicate by colorimetric assay and validated RIA, respectively. Estrous cycle length was reduced (P < 0.05) in the offspring of OB vs. CON ewes (17.2 ± 0.2 days vs. 18.0 ± 0.1 days). Further, serum progesterone concentrations were decreased (area under the curve, P < 0.05) during the estrous cycle of offspring from OB versus CON ewes. Baseline glucose and insulin concentrations were greater (P < 0.05) in offspring from OB vs. CON ewes, (64.03 ± 3.97 vs. 54.68 ± 1.30 mg/dL and 7.01 ± 2.18 vs. 3.43 ± 0.15 mIU/L, respectively). During the IVGTT, glucose concentrations remained greater (area under the curve; P < 0.01) than those of offspring from CON ewes during the post infusion period. Plasma insulin concentrations of OB offspring during IVGTT were also markedly increased (P < 0.03) when compared to offspring from CON ewes. These data suggest that the decrease in systemic progesterone exhibited by the OB offspring during their estrous cycles may contribute to the shortened estrous cycle lengths observed in this group. In spite of the decrease in circulating progesterone of OB offspring, however, conception rate and fecundity remained unaffected. Maternal overnutrition also resulted in a marked insulin resistance at midgestation in offspring of OB vs. CON ewes, suggesting that the F2 generation could exhibit the same metabolic alterations as their mothers resulting in a transgenerational programming effect. Supported in part by NIH INBRE #P20RR016474. (platform)

Effect of the short-term progestagen treatments plus PMSG prior ram introduction on the estrus synchronization and the fertility of Ile de France ewes

The aim of the present study was to evaluate the effect of the short-term progestagen treatments plus PMSG prior ram introduction on the estrus synchronization and the fertility of Ile de France ewes in the beginning of mating season. The study was carried out with 36 pure-bred ewes (aged 4-6 years) during April 2009. The ewes were divided in 3 groups (n=12 for each group): group I - vaginal sponge impregnated with 30mg FGA for six days, as at the time of placement of sponge 125 ?g cloprostenolum was put i.m At the time of removal of the sponge 250 UI PMSG was put i.m.; group II- the same as the I group, but without cloprostenolum treatment: III group - control. The teasers were introduced to ewes 24h after the sponge removal and ewes in estrus was inseminated artificially. The following parameters were studied: effect of estrus synchronization (EES) ewes in estrus was recorded twice daily for the first 6 days after sponge removal; onset, end and duration of estrus for group I and II, fertility (at first estrus) and fecundity (calculated after lambing). The data for fertility and fecundity for the control group was obtained as ewes were fertilized during 30 days from the begging of the breeding. A significant effect of both schemes to estrus synchronization was determined F=33,33, P&lt;0,001). The EES, fertility and fecundity for group I, II and III were - 91,66%, 63,64% and 142,0%; 91,66%, 45,45% and 140,0 %; 8,33%, 91,66% and 140,0% respectively. The mean onset, end and duration of estrus was 51,27 h, 77,45 h and 27,27h for the I group and 57,82h, 87,27h and 29,45 h respectively for the II group. We conclude that the scheme applied for the first group is better to use for estrus synchronization in the beginning of mating season.

167 EVALUATION OF SUPEROVULATORY RESPONSE IN Santa Inês EWES BY ULTRASONOGRAPHY AND LAPAROSCOPY

The development and use of non-invasive techniques would reduce risks of surgery sequels on the same animal and use of the donor could be optimized. The aim of this study was to evaluate the accuracy of ultrasonography performed prior to embryo collection to estimate superovulation response in sheep. Fifteen pluriparous Santa Inês sheep, 2 to 5 year old, with an average body weight of 46.79 ± 6.00 kg and body condition score of 2.96 ± 0.32 (1 to 5 scale) were allocated into 3 groups (GI, GII, GIII) in a cross-over design. In GI, intravaginal sponges (60 mg of medroxyprogesterone acetate; Progespon®, Schering Plough Animal Health, São Paulo, Brazil) were inserted (Day 0) and maintained for 14 days, and the superovulatory (SOV) protocol started on Day 12. In GII and GIII, intravaginal sponges were inserted (Day 0) and maintained for 6 days. On Day 5, the animals were treated with 300 IU of eCG (Novormon 5000®, Schering Plough Animal Health) and 5 mg of dinoprost (Lutalyse® Pfizer Animal Health, São Paulo, Brazil) i.m. Animals in GIII received 0.025 mg of gonadorelin acetate (Gestran-Plus®, Tecnopec, São Paulo, Brazil) i.m. 12 h after sponge withdrawal. In GII and GIII, the SOV protocol started 48 h after sponge removal and a new sponge was inserted immediately after its removal. The SOV protocol in all groups consisted of 200 mg of pFSH (Folltropin-V®, Tecnopec) administered in 6 decreasing doses given every 12 h (50/50, 30/30, and 20/20 mg). At the time of the fifth dose of pFSH, 5 mg of dinoprost was administered i.m. and the sponges were removed. Animals were bred by a sexually mature ram twice a day until the end of estrus. Prior to embryo collection, an ultrasonographic evaluation (5 MHz, Aloka SSD-500, Tokyo, Japan) was performed to determine the number of CL present on both ovaries. The number of CL was further evaluated by laparoscopy, when it was possible to detect poor responders or even non-ovulating animals. Statistical analysis was performed using all tests at the 95% confidence interval by SAEG program. Results are presented as mean ± SE. The number of CL was not different among all groups. The total number (GI, GII, and GIII) of CL determined by ultrasonography (9.09 ± 5.01) was not different (P &gt; 0.05) from that observed by laparoscopy (8.87 ± 5.25). A significant correlation (r = 0.56, P &lt; 0.0005) between evaluation performed by ultrasonography and laparoscopy was observed. These results suggest that ultrasonography can be used to determine the response to the superovulatory protocol. As embryo collection in sheep is performed mainly by surgical techniques, the implementation of non-invasive techniques such as ultrasonography could avoid unnecessary surgeries on animals that did not respond to the SOV protocol, therefore preventing early culling of embryo donors. Financial support: Fopesq/Proppi and Faperj (E26/171.065/2006).