Hormonal Protocols Research Articles

In vitro fertilization outcomes in women with antiphospholipid antibodies circulation

Background: Antiphospholipid antibodies (aPL) have a multifaceted effect on the hemostatic system, damaging all its protective links.Aim: To study the effect of APA on outcomes of assisted reproductive technologies (ART).Study design: We examined 267 women with infertility, who planned pregnancy using ART. They included 178 women with IVF failure (I group) and 89 women with pregnancy after the IVF program (II group). The comparison group consisted of 80 pregnant women after IVF (male factor); a control group included 80 pregnant women with physiological pregnancy. Results of study demonstrated a high frequency of aPL circulation in a group of women with IVF failures. Overall, the proportion of aPL among all 267 women who planned pregnancy with ART was 32.6%. Elevated levels of aPL in the structure of causes of IVF failures (group I) were observed in 42.1% of them. Among women whose pregnancy occurred with ART (II group) the rate of APA was 19.1%. In the comparison group, in 6.3% of cases, aPL circulation was observed. In the control group, the rate was 3.4%.Conclusion: Considering the high percentage of aPL circulation in the case of IVF failures, authors think that high titers of aPL are a temporary contraindication for IVF. Patients with a history of aPL circulation are required to receive anticoagulant therapy from the first days of the hormonal protocol. The drug of choice is a group of low molecular weight heparins (LMWH). An individual approach is extremely important with the possible identification of causes of IVF failures and selective therapy, which leads to a significant improvement in the outcomes of the IVF program.

Cervical relaxation for non-surgical uterus access in Santa Inês ewes

ABSTRACT The present study was composed by two experiments aiming to develop a cervical dilation technique for non-surgical access to Santa Inês ewe’s uterus. In Experiment 1, thirty ewes underwent four epidural treatments. The three experimental treatments used 2.0mg/kg ketamine. The group receiving this drug alone was denominated KG, whereas other group had ketamine associated with 0.1mg/kg morphine (KM) and KX a third group had ketamine associated with 0.05mg/kg xylazine (KX). Control treatment was 1mL/7.5kg saline solution epidurally (CON). Cervical dilation was evaluated in both experiments by attempting to pass a metal rod through the cervix. In Experiment 2, three different hormonal protocols for cervical dilation were tested in thirty ewes. Epidural anesthesia with 2.0mg/kg ketamine was the control treatment (KG) and was combined with hormonal treatments: Misoprostol (MI); Oxytocin + Estradiol (OE); Misoprostol + Oxytocin + Estradiol (MOE). In Experiment 1 transposition rate was not different among groups. In Experiment 2, OE presented the highest rate (90%) while MOE presented 86.2%, MI 68.9% and CON 62.1%. The study developed a pharmacological protocol that increased cervical transposition making the non-surgical access to the uterus feasible in Santa Inês ewes.

Resynchronization with the G6G protocol: A retrospective, observational study of second and later timed artificial inseminations on commercial dairy farms.

We recorded conception rates and estimated pregnancy rates following second and later timed artificial inseminations (TAIs) after hormonal resynchronization on commercial dairy farms, using the so-called G6G protocol (PGF day-0; GnRH 2, 8days; PGF 15, 16days, GnRH 17days; TAI 18days), and the 5-day Ovsynch protocol or 5DO (GnRH day 0; PGF 5, 6days; GnRH 7days; TAI 8days). In four farms, both protocols were implemented in parallel, and these 1,368s and later TAIs were used for the protocols' comparison based on logistic regression (544 TAIs in primiparous; 824 in multiparous cows; 1,024 TAIs after G6G [600 TAIs in multiparous and 424 in primiparous]; 344 TAIs after 5DO [224 TAIs in multiparous and 120 in primiparous]; 280 TAIs during the hot season; 1,088 during the cool season). Conception rate (CR) was 31.7%±12.0% among all cows, 35.1%±10.7% among cows resynchronized with the G6G protocol and 21.8%±9.7% among cows resynchronized with the 5DO protocol (p<0.0001). CR among all cows was lower during the hot season (19.3%±8.4%) than during the cool season (34.9%±10.6%; p<0.0001), and similar seasonal results were observed with G6G protocols. Logistic regression showed significant effects on CR in second and later TAIs by protocol (OR=0.514; 95% CI 0.385-0.686; p<0.0001) and season (OR=0.486; 95% CI 0.350-0.676; p<0.0001). Parity did not influence CR after second and later TAIs (p>0.1), and no interaction with season or resynchronization protocol was found. Estimated pregnancy rates based on these CR data from both hormonal protocols suggest that G6G can be effectively used for second and later TAIs and highlight the importance of considering protocol and season when designing strategies for second and later timed AIs on dairy farms.

Intramammary infusion of lipopolysaccharide promotes inflammation and alters endometrial gene expression in lactating Holstein cows

The objective of the current study was to evaluate the effects of 2 intramammary infusions of lipopolysaccharide (LPS) on inflammatory and reproductive parameters and endometrial gene expression of lactating Holstein cows. At 35 ± 7 d in milk, 20 cows were submitted to a Double Ovsynch program and randomly assigned to control (n = 11) and LPS (n = 9) treatments. Cows from the LPS treatment received 2 intramammary infusions of 25 µg of LPS after morning milking on d 5 and 10 post-AI, whereas control cows were infused with only saline. Blood samples were taken and ultrasound scanning of the ovaries was performed during the entire study before and after AI to determine haptoglobin, tumor necrosis factor-α, and progesterone concentrations as well as response to the hormonal protocol and corpus luteum diameter. Milk yield was evaluated and samples were taken for somatic cell count at 0, 10, 24, 34, and 96 h relative to each infusion. Rumen-reticular temperature was recorded using a rumen-reticular bolus logger and summarized hourly. On d 15 post-AI, uterine flushing for conceptus recovery and endometrial biopsies were performed. Samples of endometrium from cows with positive embryo recovery (control = 5; LPS = 6) were submitted to mRNA extraction and quantitative reverse-transcription PCR analysis of 96 target genes. Haptoglobin concentrations in plasma were greater for LPS treatment (control = 0.24 ± 0.07, LPS = 0.89 ± 0.06 optical density), but tumor necrosis factor-α concentrations were similar (control = 0.67 ± 0.11, LPS = 0.46 ± 0.11 ng/mL) between treatments. Lipopolysaccharide reduced milk yield after treatment (control = 34.3 ± 1.5, LPS = 29.4 ± 1.6 kg/d), whereas somatic cell count (log) was greater in LPS-treated cows until 34 h after infusions (control = 2.3 ± 0.1, LPS = 3.3 ± 0.1 cells/mL of milk). Rumen-reticular temperature of LPS cows was elevated between 5 and 10 h after each infusion compared with control cows (control = 39.5 ± 0.1, LPS = 40.1 ± 0.1°C). Progesterone concentration after AI was unaffected by treatment or pregnancy status as well as corpus luteum diameter and conceptus length on d 15. Lipopolysaccharide treatment altered the expression of 13 key genes in the endometrium (mostly upregulated), whereas another 17 tended to be modulated. Modified gene expression included genes related to immune response (PTX3 = 2.34-fold increase; IL6 = 3.42-fold increase; and TCN1 = 2.52-fold increase), adhesion molecules (CADM3 = 1.93-fold increase; MMP19 = 1.49-fold increase; EMMPRIN = 1.20-fold increase; SELL = 1.91-fold increase), Wnt signaling pathway (WNT2, FZD4, and FZD7, all <1.5-fold increase), and interferon-stimulated genes (BMP15 = 0.27-fold decrease; ISG15 = 2.17-fold increase, and MX2 = 2.23-fold increase). In summary, intramammary infusions of LPS were able to trigger an inflammatory response with no effect on corpus luteum diameter and concentration of progesterone in plasma. However, a limited but important set of modulations in the endometrium gene expression at d 15 of gestation was found.

Effect of estrous cycle phase on vulvar, orbital area and muzzle surface temperatures as determined using digital infrared thermography in buffalo

The objective of this study was to evaluate variations in the orbital area, muzzle and vulva surface temperatures and progesterone (P4) concentrations during follicular and luteal phases in Murrah buffalo and whether these temperatures are influenced by the weather patterns. Forty cows were submitted to P4-based hormonal protocol. After P4 device withdrawal transrectal ultrasonography and infrared digital thermography were performed daily until day 16 and on days 20, 24, 28 and 32 to follow the ovulation as well as the vulva, orbital area and muzzle temperatures. In addition, the weather variables were evaluated, as well as rectal temperature (RT) and P4 and cortisol concentration. Vulva, muzzle and orbital area temperatures correlated positively with RT and with weather data. Greater temperatures of the vulva, orbital area and muzzle were detected during the period of estrus. The vulvar surface temperature (VST) was not influenced to a great extent by weather factors during the morning, so this period was chosen to evaluate the influence of the phase of the estrous cycle on VST. The VST was less during days 16, 20, 24 and 28 (diestrus) and P4 concentration was inversely proportional to the VST. Muzzle, orbital area and RT, however, were not of the same pattern. Negative correlations were observed between VST and P4 concentrations. It is concluded that VST undergoes changes during the reproductive phases, correlating with P4 concentration. The weather factors influence the temperatures of the body surface areas, and the morning is the most desirable time to perform the thermographies.

Endometrial Histomorphometric Changes Under the Influence of Different Hormonal Protocols to Prepare Non-cyclic Mares as Embryo Recipients

Endometrial Histomorphometric Changes Under the Influence of Different Hormonal Protocols to Prepare Non-cyclic Mares as Embryo Recipients

Hormonal stimulation in 4 to 7 months old Nelore (Bos taurus indicus) females improved ovarian follicular responses but not the in vitro embryo production

The inclusion of pre-pubertal bovine females in reproductive management could allow in vitro embryo production and reduce generation interval, thereby causing faster genetic gain of the herd. However, oocytes of pre-pubertal females have lower competence, blastocyst production, and pregnancy rates than those collected from pubertal animals. This study aimed to evaluate the effect of an induced hormonal stimulation on the serum concentrations of Anti-Mullerian hormone (AMH) and FSH, ovarian responses, ovum pick up (OPU), and in vitro produced embryos (IVP) from oocytes obtained from four-to seven-months old Nelore female cattle. In a crossover design, these females were randomly allocated into: 1) Treated Group (TG, n = 9): the animals were subjected to a hormonal protocol (implanted progesterone device, estradiol benzoate, LH, and FSH) from Day 0 (the start of the treatment) to Day 7 (OPU day), and 2) Control Group (CG, n = 9): the females did not receive any hormonal stimulation, but they had ablation of their largest follicles on Day 2 of experiment. Blood collection for serum FSH measurements was done on Days 5, 6, 7, and 8, and collection for serum AMH measurements was done on Days 5 and 8. As hypothesized, TG had higher serum FSH concentrations (p < 0.05) on Day 5 (1.16 ± 0.31 ng/mL), Day 6 (1.21 ± 0.45 ng/mL), and Day 7 (0.95 ± 0.26 ng/mL) than CG (0.56 ± 0.17 ng/mL on Day 5, 0.60 ± 0.25 ng/mL on Day 6, and 0.60 ± 0.14 ng/mL on Day 7). However, serum AMH concentrations were neither significantly different (p > 0.05) between CG and TG, nor between the collection days. Hormonal stimulation also increased (p < 0.05) total follicular population (20.0 ± 4.95 CG vs 26.66 ± 4.24 TG), ovarian diameter (13.08 ± 1.0 mm CG vs 14.81 ± 1.38 mm TG) and number of follicles ≥2.5 mm (6.88 ± 2.14 CG vs 11.55 ± 4.09 TG). In TG, grades I and II oocytes predominated, whereas, in CG grades III and IV oocytes were more abundant (p < 0.05). No significant increases (p > 0.05) in the cleavage (49.33% CG vs 51.42% TG), cleavage > 4 cells (9.33% CG vs 16.19% TG), and blastocysts rates (1.33% CG vs 8.57% TG) were seen in TG. This hormonal protocol increased serum FSH concentrations that possibly contributed to increases in the observed follicle, as well as improving oocyte quality. This exogenous hormonal stimulation increased available oocytes numbers for IVP, despite no increase in the in vitro embryo production efficiency.

Application of hormonal subdoses at acupoint Hou Hai in estrus synchronization protocols of goats

The objective was to evaluate the efficacy of hormonal subdoses at acupoint Hou Hai in estrus synchronization of goats. Sixty-nine females goats received intravaginal sponges containing 60 mg of medroxyprogesterone acetate for seven days and were randomly distributed among three treatments: T1 (n = 23): application of 125 ?g of PGF2? on the sixth day (D6) and 300 UI of eCG on the seventh day (D7), both intramuscularly (IM); T2 (n = 23) and T3 (n = 23): application 37.5 ?g of PGF2? at D6 and 90 UI of eCG at D7, applied by Hou Hai acupuncture and false acupuncture (IM), respectively. The goats were subjected to hormonal protocol and monitored for the coverage and evaluation of reproductive parameters. The data were subjected to normality analysis, followed by appropriate statistical tests for each variable. Greater numbers of estrus goats were obtained in treatments one (T1 = 100%) and three (T3 = 91.3%) (p &lt; 0.05). No difference was observed (p &gt; 0.05) for sponge removal intervals at the beginning (35.9 h) and end (59.8 h) of estrus, and for the duration of estrus (24.7 h), gestation rate at 30 (77%) and 60 (76.7%) days, and prolificacy (1.9). The use of PGF2? and eCG in subdoses applied to the Hou Hai acupoint or false acupoint was efficient in synchronizing estrus in goats, based on the rate of gestation and prolificity of the animals.

Synchronization treatments previous to natural breeding anticipate and improve the pregnancy rate of postpartum primiparous beef cows

Timed AI has become a potential tool to bypass postpartum acyclicity, yet only a small percentage of the world bovine herd is inseminated. Most females are still subjected to bull mating; therefore, the frequent occurrence of postpartum anestrus may compromise their reproductive efficiency. Thus, the aim of this study was to develop an approach that allows the early conception of postpartum primiparous beef cows that are exposed to natural breeding (NB). For this purpose, 350 primiparous Nelore cows 35–65 d postpartum were allocated into three groups: Control (no hormonal treatment), TNB (hormonal protocol for timed-NB without equine chorionic gonadotropin; eCG) and TNB + eCG (hormonal protocol for TNB with eCG) groups. The protocol for TNB consisted of the insertion of a 1-g progesterone device and the intramuscular (IM) administration of 2 mg estradiol benzoate on D-9 (nine days before bull exposure), followed by device removal and the administration of 1 mg estradiol cypionate IM on D0. An additional 300 IU of eCG was given only to TNB + eCG cows. All cows were exposed to bull mating from D0 to D105. Pregnancy was checked by ultrasonography every 50 d, gestational age was estimated, and the number of new gestations every 21-d cycle (P21, P42, P63, P84 and P105) was predicted. Control cows had lower pregnancy at P21 (5.7%c, 7/123) than TNB (30.4%b, 35/115) and TNB + eCG (51.8%a, 58/112; P = 0.001) cows. Pregnancy rate increased across P42, P63 and P84 (P = 0.001) but remained higher for TNB + eCG cows. Regarding time to conception, the TNB + eCG cows achieved a greater than 50% pregnancy rate within the first days after bull exposure, while the TNB and Control cows took more than 40 d and 90 d to achieve 50% pregnancy rates, respectively. At the end of the breeding season (BS), TNB + eCG cows had a 21% higher pregnancy rate than the Control cows and a 16% higher rate than the TNB cows. The probability of conceiving increased 1.5-fold for cows treated with TNB (P = 0.0079) and 2.2-fold for cows additionally treated with eCG (P < 0.0001). The average interval between the onset of the BS and conception was reduced (P < 0.0001) for the TNB + eCG cows (26.5 ± 3.8c) compared to the TNB (35.7 ± 4.1b) and Control (64.7 ± 3.9a days) cows. Thus, the use of TNB, especially when associated with eCG, efficiently improved the early conception of postpartum primiparous beef cows after exposure to NB. The increased number of cows conceiving early in the BS is crucial to improve reproductive efficiency by reducing the interval between parturitions and improving the number of pregnant cows at the end of BS, thus resulting in greater farm income.

Evaluation of buffaloes' follicular dynamics and stress state under different ovulation synchronization protocols.

The aims of the present study were to analyze the effect of different hormonal protocols using an implant containing Norgestomet, at the ovulation synchronization in buffaloes and to verify the effect of the stress caused by manipulation of the herd during the experiment. Twenty-four female Murrah breed buffaloes, lactating, multiparous, aged from three to eight years, with a body condition score of 3.5 or higher (0 to 5) and with more than 45 days post partum, were used. These females were randomly distributed into one of the three groups (group 1, group 2 and group 3) with eight subjects in each. On day 0 (day 0), all animals received an ear progesterone implant with 3.0 mg of Norgestomet and an intramuscular (IM) injection with 2.0 mg of estradiol benzoate (EB). The implants were removed after nine days (day 9) and one single dose of PGF2α (0.15 mg d-cloprostenol, IM) was administered to all animals. On the same day, the group´1 and group 3 buffaloes were treated with 500 UI of eCG (IM). Two days later (day 11), 1000UI of hCG (IM) were administered to the group 1 and group 2 buffaloes. After the implant had been removed, an ultrasound evaluation was performed every 12 h, in order to access the ovarian follicular dynamics, using an Aloka 500 equipment with a 5 MHz transrectal probe. Blood samples were also taken on days 0, 9 and 11 to determine the plasmatic concentrations of cortisol and progesterone. No difference was observed in the ovulation rate (group 1: 62.5%, group 2: 50%, group 3: 75%). However, the size of the preovulatory follicles and the plasmatic concentration of cortisol had (P < 0.05). G3 was the most efficient group in promoting the ovulation synchronization, which suggests that this protocol can be used in Fixed Timed Artificial Insemination programs (FTAI) among postpartum, lactating Murrah breed buffaloes’.

Intensified use of TAI and sexed semen on commercial farms.

The livestock sector has achieved many technological advances, which have resulted in continued improvements in animal production systems and in the reproductive efficiency of herds. The associated use of reproductive biotechnology and genetic improvements combined with adequate sanitary and nutritional management are essential conditions for sustainable intensified animal production and financial autonomy within farms. Timed artificial insemination (TAI) represents one of the strategies with the greatest impact of expansion in providing genetic improvements and increased reproductive efficiency at a decreased cost. Despite the high proportion of cows receiving TAI, this market still exhibits considerable potential for expansion. After a TAI procedure, approximately 40 to 60% of females become pregnant. This result can vary depending on such factors as the hormonal protocol employed, female category, body condition score, ovarian status, farm management and aspects related to bulls and semen. The fertility and genetic quality of the bull plays an important role in the herd because a single bull can influence the entire production system. Another important strategy is the use of sex-sorted semen associated with TAI, primarily when associated with management practices to improve the pregnancy rate. This paper presents a review of the intensification of TAI, supplying practical information regarding the implementation of TAI commercial programs.

Oral progesterone supplementation for beef cattle after insemination in TAI programs

Abstract: The objective of this work was to evaluate the effects of supplementation with melengestrol acetate (MGA), after timed artificial insemination (TAI), on the conception rate of Nellore cows, according to cyclicity during the protocol, estrus expression between intravaginal device withdrawal and insemination, and diameter of the largest follicle at the time of insemination, in order to identify predictors of the use of MGA. Multiparous lactating cows (577) were subjected to a hormonal protocol for ovulation synchronization. On day -2 of the protocol, the animals were painted with a marker on the base of their tail. On day 0, they were evaluated for estrus expression; the preovulatory follicle diameter (POFD) was measured by ultrasonography, and the artificial insemination was performed. The animals were assigned to two experimental groups according to the supplementation or not with 0.50 mg MGA, between 13 and 18 days after TAI. Pregnancy diagnosis was performed using an ultrasound examination 35 days after TAI. A positive effect of the treatment with MGA on the conception rate occurred generally in animals in anestrus, irrespective of the estrus expression. For animals treated with MGA, only those with POFD greater than 14 mm showed better conception rates that the control group.

Follicular response and oocyte production following variations in ovarian stimulation in goats

In this study, goats were subjected to ovarian stimulation protocols to evaluate possible differences in ovarian follicular responses and oocyte production. Two experiments were conducted to assess the effects of hormonal protocol duration (seven or twelve days) and number of follicle stimulating hormone (FSH) applications (one or five doses). All animals received intravaginal sponges saturated with 60 mg medroxyprogesterone acetate and an application of 125 μg cloprostenol 72 h before the sponges were removed. For ovarian stimulation, 120 mg FSH was applied in a single dose 36 h before laparoscopic follicular aspiration (LOPU) or in five doses (30, 30, 20, 20, and 20 mg) at 12 h intervals, with the last dose applied 36 h before LOPU. In the first experimental phase, ultrasonography was performed to monitor follicular number and diameter, and in the second phase, the animals received LOPU to count the follicles and cumulus-oocyte complexes (COCs) and for morphological classification. There was no significant effect (P > 0.05) of any variable or combination of variables on follicle number on Day (D) 0 or D3/D8 (day of LOPU). However, evaluation at D6/D11 revealed an effect (P < 0.05) from the protocol duration with the highest number of small follicles resulting from the short protocol. There was also an effect (P < 0.05) of FSH dose number on the resulting number of medium and large follicles, with more medium follicles recovered after a single dose and more large follicles after multiple doses. There was no effect of any variable (P > 0.05) on the diameters of the large, medium, and small follicles, except for the D4/D9 evaluation, which showed a combination effect for large follicles (P < 0.05). In the second phase, no variable had an effect on the number of follicles visualized or aspirated, number of COCs recovered, recovery rate, morphological quality of COCs in grades 1, 2, 3, and 4, or rate of viable COCs. Thus, all four protocols efficiently stimulated the ovarian response and oocyte production of goats, although the short protocol (7 days) with a single dose of FSH was most efficacious based upon the greater number of medium-sized follicles available for aspiration, the shorter time, and greater practicality of execution.

Effect of serum paraoxonase-1 (PON1) activity on follicular development and pregnancy rate in cattle

Paraoxonase-1 (PON1) activity has been associated with improvement in ovarian function in early postpartum dairy cows and improved in vitro embryo development. The aim of the current study was to evaluate the potential association among PON1 activity and follicular growth, diameter of the preovulatory follicle and pregnancy per artificial insemination (AI) service in cattle. In Experiment 1, cows (n=33) were subjected to an estradiol-progesterone based protocol to control time of ovulation. Starting on Day 8 of the protocol, follicular growth and serum PON1 activity were monitored. Cows were separated according to the occurrence of ovulation into two groups: Ovulatory (Ov; n=22) and Anovulatory (Anov; n=11). The serum activity of PON1 was not different between Ov and Anov cows (P=0.94). In addition, using a regression model there was no effect of serum PON1 activity on the diameter of dominant follicle (r2=0.00; P=0.99). In Experiment 2, cows (n=193) were submitted to the same hormonal protocol as in Experiment 1. On the day of the timed artificial insemination (TAI), the diameter of dominant follicle was evaluated and blood samples were collected for analysis of PON1 activity. According to the serum PON1 activity, cows were divided into three groups: Low (<70U/mL), Medium (70–90U/mL) or High (>90U/mL) PON1 activity. The overall pregnancy rate was 62.7% (121/193), with no difference among PON1 activity groups. Additionally, using a regression model there was no effect of serum PON1 activity on the diameter of the preovulatory follicle (r2=0.03; P=0.65) and pregnancy rate (r2=0.005; P=0.94). The results of this study indicate that there is no effect of serum PON1 activity on the diameter of preovulatory follicle or establishment of pregnancy in cows submitted to time of ovulation synchronization protocols.

Improvement of Fertility in Postpartum Anooestrus Buffaloes by using Different Hormonal Protocols during Non Breeding Season

The study was conducted on 40 postpartum anooestrus buffaloes randomly divided into four equal groups during non-breeding season. The buffaloes were selected based on ovarian inactivity, good body condition score and overall good health. Group I was administered Ovsynch protocol + Progesterone impregnated intravaginal device (PRID). Group II was administered PRID which was removed on 7th day and GnRH 10 μg i/m was given on day of AI. Group III was administered Ovsynch protocol and Group IV was kept as untreated control. 100, 80, 80 and 00 % animals responded in groups I, II, III and IV respectively. Fix timed AI was performed in all responded buffaloes. Calcium, phosphorous, cholesterol and protein level increased (p&gt;0.05) in respect of pregnant animal than the non-pregnant animals, the rise was more in Group I than the other Groups.The conception rate was found to be 70.00, 50.00, 62.50 and 00.00 % in Group I, II, III and IVrespectively. The overall conception rate was observed to be significantly higher in Group I, i.e., Ovsynch + PRID followed by Group III, i.e. Ovsynch protocol alone in postpartum anooestrus buffaloes during nonbreeding season. It can be concluded that ovsynch with progesterone based protocol is very effective for oestrus induction and improved conception rate in postpartum anooestrus buffaloes during non breeding season.

Morfología de testículos de la tuvira (Gymnotus spp.) Sometida a la reproducción por diferentes protocolos hormonales

The aim of study was to analyze the testis morphology of males tuviras (Gymnotus spp.) submitted to reproduction by different hormonal inducers. Forty male tuviras (40g ± 5.0) were used approximately in a completely randomized design with four treatments and 10 replicates; each animal was considered a repetition. For hormonal protocol establishment were tested three inducers: crude extract of carp pituitary (EBHC), equine chorionic gonadotropin (ECG), synthetic analogue of gonadotropin-releasing hormone (GnRH-a) and the control group was administered saline solution at 2%. The three hormones and control were applied in two doses (preparatory and final induction). Ten males per treatment were euthanized for macroscopic and microscopic analysis. It was determined volumetric proportion occupied by the components of testicular parenchyma (seminiferous tubules and intertubular tissue) and quantified populations of spermatogonia type A, type B, primary spermatocytes, secondary spermatocytes, spermatids, Sertoli cells (S) and lumen measurement . The results indicated that the hormone GnRH-a showed a higher capacity to promote the final maturation of the testes (P &lt; 0.05), followed by eCG hormone. The EBHC hormone failed to promote the final maturation in males tuviras.

OvSynch Protocol and its Modifications in the Reproduction Management of Dairy Cattle Herds - an Update.

Current knowledge about the function of the reproductive tract and appropriate use of hormonal drugs affords control of the oestrus cycle of cows. One of the hormonal protocols is OvSynch, which enables artificial insemination (AI) to be performed at the precise optimum time without control of the ovaries and uterus. Use of such protocols in reproductive management allows oestrus cycles to be synchronised and cows to be effectively inseminated without oestrous detection, which is time-consuming and difficult in farms with numerous cows. Therefore, OvSynch has become the first management tool for AI and is an alternative method to heat detection. Over the 20 years since its first implementation, OvSynch has been modified many times to improve its reproduction outcomes and widen its use. Besides its original use for heat synchronisation, it is also used in many ovarian disorders as a therapeutic method. This review article describes the possibilities which OvSynch provides, its current modifications, various applications, and the advantages and disadvantages of its use in practice.

ANTIOXIDANT STATUS OF THE FOLLICULAR LIQUID AND ITS RELATION WITH THE QUALITY OF EMBRYON IN INFERTILITY PATIENTS PASSING THROUGH THE PROCEDURE OF EXTRACORPORAL FERTILIZATION

The aim of the study is to evaluate the antioxidant properties of the follicular fluid with a new chemiluminescent method in women with a reduced ovarian reserve and tubal factor of the infertility, undergoing in vitro fertilization (IVF) procedure, and to compare the obtained data with embryo quality. Material and methods. Samples of the follicular fluid were obtained during oocyte sampling in 16 women with a reduced ovarian reserve and 16 women with a tubal peritoneal factor of the infertility. Patients in both groups were matched for the age, body mass index and hormonal stimulation protocol (short protocol). The antioxidant activity of the follicular fluid was measured by the method of luminol-activated chemiluminescence using 2,2’-azobis (2-amidinopropane) dihydrochloride as a source of radicals. The total antioxidant activity (AOA) and antioxidant activity due to the action of proteins (AOA-b) were determined. Results. The kinetic curve of chemiluminescence of the follicular fluid is similar in shape to the curve of the antioxidant activity of the blood plasma. As in blood plasma, antioxidant activity is caused by uric acid and proteins - albumins and globulins. As a result of the study, three groups of patients were identified, whose AOA significantly differed: patients with low embryo quality and decreased antioxidant activity, AOA 11.4 ± 2.5 mM ascorbate (n = 16); patients with a good quality embryo, AOA 21.4 ± 3.8 mM (n = 10); patients with a low embryo quality and an elevated AOA of 33.7 ± 2.9 mM (n = 6). Conclusions. Based on the comparison of AOA (in ascorbate units) with the quality of the embryo, three areas can be proposed: 1) a zone of reduced antioxidant activity (less than 15 μM, oxidative stress) - these patients had embryos of poor quality; 2) the zone of normal AOA (15-30 μM) - the patients received good quality embryos; 3) zone of increased AOA (more than 30 μM, antioxidant stress) - embryos of poor quality. Thus, it can be assumed that optimal development of embryos in the follicle requires the optimal value of antioxidant activity, since both its reduction (oxidative stress) and increase (antioxidant stress) adversely affect the quality of the embryo and the outcome of IVF. These data correspond to the modern concept that optimal development of the oocyte requires an optimal level of production of reactive oxygen species.

Fertility of lactating Holstein cows submitted to a Double-Ovsynch protocol and timed artificial insemination versus artificial insemination after synchronization of estrus at a similar day in milk range

Our objective was to compare the AI submission rate and pregnancies per artificial insemination (P/AI) at first service of lactating Holstein cows submitted to a Double-Ovsynch protocol and timed artificial insemination (TAI) versus artificial insemination (AI) to a detected estrus after synchronization of estrus at a similar day in milk range. Lactating Holstein cows were randomly assigned to receive their first TAI after a Double-Ovsynch protocol (DO; n = 294) or to receive their first AI after a synchronized estrus (EST; n = 284). Pregnancy status was determined 33 ± 3 d after insemination and was reconfirmed 63 ± 3 d after insemination. Data were analyzed by ANOVA and logistic regression using the MIXED and GLIMMIX procedures of SAS (SAS Institute Inc., Cary, NC). By design, days in milk at first insemination did not differ between treatments (76.9 ± 0.2 vs. 76.7 ± 0.3 for DO vs. EST cows, respectively), but more DO cows were inseminated within 7 d after the end of the voluntary waiting period than EST cows (100.0 vs. 77.5%). Overall, DO cows had more P/AI than EST cows at both 33 d (49.0 vs. 38.6%) and 63 d (44.6 vs. 36.4%) after insemination, but pregnancy loss from 33 to 63 d after insemination did not differ between treatments. Primiparous cows had more P/AI than multiparous cows 33 and 63 d after insemination, but the treatment by parity interaction was not significant. Synchronization rate to the hormonal protocols was 85.3%, which did not differ between treatments; however, synchronized DO cows had more P/AI 33 d after insemination than synchronized EST cows (54.7 vs. 44.5%). In summary, submission of lactating Holstein cows to a Double-Ovsynch protocol and TAI for first insemination increased the percentage of cows inseminated within 7 d after the end of the voluntary waiting period and increased P/AI at 33 and 63 d after first insemination resulting in 64 and 58% more pregnant cows, respectively, than submission of cows for first AI after detection of estrus at a similar day in milk range. We conclude that, because the proportion of synchronized cows did not differ between treatments, DO cows had more P/AI than EST cows because of an intrinsic increase in fertility after submission to a fertility program.

The effect of circulating progesterone on magnitude of the GnRH-induced LH surge: Are there any differences between Bos indicus and Bos taurus heifers?

This study evaluated the effects of differing circulating progesterone (P4) levels on the luteinizing hormone (LH) surge profile following treatment with gonadotropin releasing hormone (GnRH) in B. indicus (Nelore, n = 13) and B. taurus (Holstein, n = 16) heifers. All heifers were synchronized with a hormonal protocol to induce either a Low or High circulating P4 environment at the time of GnRH treatment. Heifers were randomly assigned to a 2 × 2 factorial design composed by two genetic groups (B. indicus and B. taurus) and two levels of circulating P4 concentrations (Low or High). Blood samples were collected every 30 min from −30 to 210 min and at 270 min after GnRH treatment. As expected, mean P4 concentration was greater for cows in the High than in the Low P4 group (P = 0.0008) and in Bos indicus than in Bos taurus heifers (P = 0.06). Despite genetic group, the area under the curve of LH release was greater in the Low-P4 than in High-P4 concentration group (P < 0.0001). Interestingly, it appears that High P4 concentrations had a more pronounced effect on LH peak in B. indicus than in B. taurus heifers, as indicated by the interaction (P = 0.01) between genetic group and P4 levels. In conclusion, circulating P4 concentration have a great impact on the GnRH-induced LH surge of both B. indicus and B. taurus heifers, but it does not explain the much lower LH peak in B. indicus with low circulating P4. Thus, more studies are essential to uncover some of the underlying physiological factors other than circulating P4 that are limiting LH release following a GnRH treatment in B. indicus cattle.