Induction Of Estrus Research Articles

EFFECT OF TOCOPHEROL AND SELENIUM ON THE PERFORMANCE OF BUSERELIN FOR ESTRUS INDUCTION IN LATE SEASON ANESTRUS MARES (EQUUS CABALLUS)

The aim of this study was to determine the effect of tocopherol and selenium on the performance of buserelin (GnRH analogue) for estrus induction in anestrus mares. A total of 18 seasonally anestrus mares were divided into three equal groups (n=6 in each) after ovarian scanning. Mares in group A (treatment group) were treated with tocopherol and selenium intramuscularly along with daily dose of buserelin. Mares which came into heat within ten-day buserelin protocol, further injections of buserelin for those mares were stopped. Mares in group B were treated with buserelin intramuscularly only for ten days. Mares which came into heat within ten-day buserelin protocol, further injections of buserelin were stopped. Blood/serum was collected from each experimental mare kept in different groups (A-C) at days 1, 11, 12, 13 and 14. Onset of estrus signs was 83.3, 33.3 and 0% in group A, B and C, respectively, that was significant (P<0.05) among groups. Follicular dynamics were 20.24±3.00, 14.59±2.24 and 10.35±0.63mm in groups A, B and C, respectively with significant (P˂0.05) difference. Change in serum E2 contents was significantly (P˂0.05) different among groups A, B and C whereas progesterone concentration showed non-significant difference among groups.

Induction of Oestrus and Fertility Response using Bromocriptine, Cabergoline and eCG Plus hCG Treatment Protocols in Female Dogs

Background: Reproductive pattern of dog is quite different from other mammalian species. A major difference between canine and other mammalian species is that in dog oestrus period is followed by long inter-oestrus interval (period of sexual quiescence), described as monocyclic animal. There are several reproductive problems encountered by the dog breeders and pet owners causing prolonged whelping interval. Anoestrus is thought to be one of the undiagnosed ovarian disorders responsible for prolonged oestrus interval in canine. Anoestrus of variable duration (2 to 10 months) following each oestrus cycle in female dogs is frequently observed. The approaches for the management of reproductive problems due to ovarian disorders encountered by the dog breeders and pet owners needs to be explored to optimize whelping interval. Hence, the current study aimed to study the Induction of oestrus and fertility response using bromocriptine, cabergoline and eCG plus hCG treatment protocols in female dogs.Methods: The study was conducted in 28 apparently healthy female dogs at TVCC college of veterinary science and Animal Husbandry Jabalpur and at door step of pet owners or dog breeders during the period of 2018-19. Dogs used in the study were divided into small, medium and large breeds. Pomeranian and Pug breeds included under small breeds; German shepherd, Labrador, Siberian husky, Dalmatian, ND and Doberman under medium breeds whereas Great dane, Rottweiler, Bullmastiff and Saint Bernard included under large breeds. The animals were selected irrespective of breeds with the history of anoestrus up to two month or more after whelping. The selection of anoestrus dog was made based on the ratio of cells in vaginal cytology and serum progesterone estimation.Result: Our results shows that the oestrus and fertility response following hormonal treatments in anestrous female dogs was significantly (p less than 0.01) higher than the oestrus induction in all treatment groups (71.48% in Group-I, 85.70% in Group-II and 71.48% in Group-III) as compared to control (14.28%).The breeding was recorded in 83.33% of dogs in cabergoline treatment followed by 100% in eCG plus hCG and 80% in bromocriptine with the conception rates of 100%, 80% and 75%, respectively in three groups. Serum progesterone (P4) profile were statistically significant (P less than 0.05) in all the treatment groups (I, II and III), but not in control group and the exflotive veginal cytology were found significantly (P less than 0.05) higher in induced than the non-induced animals of same group.

Canid Reproductive Biology: Norm and Unique Aspects in Strategies and Mechanisms.

Simple SummaryThe family Canidae, composed of dog-like species such as wolves, foxes, and jackals, demonstrates a significant variety in reproductive biology. In general, female canids experience very long periods of ovarian inactivity during the year; however, there are diverse patterns with regard to seasonality between species, as well as within an individual species depending on geographic region or housing status. Understanding of these differences is critical to the development of assisted reproductive technologies for canid conservation efforts. This review summarizes the current knowledge of canid reproduction, including reproductive cyclicity, seasonal breeding, male sperm traits, and recent developments in assisted reproductive technologies for canids.The reproductive physiology of canids is unique compared to other mammalian species. Specifically, the reproductive cycle of female canids is characterized by extended periods of proestrus and estrus followed by obligatory diestrus and protracted ovarian inactivity (anestrus). Although canid reproduction follows this general pattern, studies have shown variations in reproductive biology among species and geographic regions. Understanding of these differences is critical to the development of assisted reproductive technologies including estrus induction, gamete rescue, and embryo production techniques for canid conservation efforts. This review summarizes current knowledge of canid reproduction, including estrus cyclicity, seasonality, and seminal traits, with the emphasis on species diversity. The application of reproductive technologies in wild canid conservation will also be discussed.

Herbal Combo Therapy’ for Oestrus Induction in Postpartum Anoestrus Cows

The research was aimed at studying the effect of a ‘Herbal combo therapy’ (HCT) on induction of oestrus and enhancement of fertility in postpartum anoestrus (PPA) in crossbred cows. Crossbred cows (n = 24) which were diagnosed for true anoestrus condition were utilized for the study. All the cows were dewormed and randomly divided into two groups (i) Control group (n = 10): No treatment schedule and (ii) Treatment group (n = 14): HCT involving a sequential administration of Raphanus sativus, Aloe vera, Moringa oleifera, Cissuss quadrangularisis and Murraya koenigii for a period of 20 days. The animals which expressed oestrus signs during the experimental period were inseminated and pregnancy was confirmed. Diameter of the largest follicle was documented on the initiation day of experiment and at the end of the experimental period or on the day of expression of induced oestrus. Perusal of the data revealed that 71.4 per cent of the PPA animals responded to the HCT by expressing oestrus signs within the experimental period as against 10.0 per cent in control group. The follicular diameter significantly increased in HCT group (11.8 + 2.4 mm) than the control group (9.6 + 0.8 mm). The overall conception rate among the PPA cows treated with HCT was much higher (57.1%) than the control group (10.0%). Steroidogenic activity, rich nutrient source and anti-inflammatory properties of HCT would have potentiated the follicular development and thereby induced oestrus and improved conception rate in anoestrus cows.

Vascular Perfusion of the Preovulatory Follicle and its Relationship in Pregnancy Establishment during Natural and Induced Estrus in Buffaloes

Background: In buffaloes, little attention has been devoted on the haemodynamics of preovulatory follicle (POF) and serum estradiol profiles and their relationship with conception rate following AI at natural and induced estrus. Methods: Sixty healthy pleuriparous graded Murrah buffaloes were selected and divided into two groups, viz., Group I and II. Group I buffaloes were artificially inseminated twice at an interval of 24 hours during natural estrus. Estrus induction was done using PIVD and PGF2α in group II buffaloes and AI was performed 48 h and 72 h after the withdrawal of PIVD. The blood flow of the preovulatory follicle (POF) and early pregnancy were assessed in both the groups by Doppler ultrasonography.Result: On statistical analysis, the mean (± SE) of spectral indices revealed there was an increased blood flow to the POF during induced estrus (Group II) when compared to natural estrus (Group I). The conception rate observed was 66.67 and 58.33 per cent in group I and II, respectively. It is concluded that increased vascular perfusion to POF resulted in almost similar conception rates in induced and natural estrus following AI in buffaloes.

The effect of ovulation induction of GnRH following a short-term estrous induction protocol in Saanen goats

The current study was to compare the effect on the ovulation time and estrus parameters of a GnRH agonist (buserelin acetate) administered 24 or 36 h following a short-term estrus induction and synchronization treatment in non-lactating Saanen goats during the transitional period. Goats received 20 mg FGA sponges during 6 days plus 300 IU eCG and 125 µg d-cloprostenol 24 h prior to sponge removal. After removal of the sponges, goats were given either 1 ml physiological saline (0.9% NaCI) solution (Group 1 ; n = 9) after 12 h, 0.004 mg GnRH (buserelin acetate, Group 2 ; n = 10) after 24 h or 0.004 mg GnRH (Group 3 ; n = 10) after 36 h. The follicle development and ovulation in the ovaries were monitored by transrectal ultrasonography starting from the sponge application until the fifth day of the estrus cycle. Blood samples were collected on the same days to determine the plasma concentrations of progesterone (P4) and estradiol (E 2 ). As no statistical differences was detected in any synchronization parameters, ultrasonic evaluations and plasma P4 and E 2 concentrations among all groups, thus averages were assessed. The total estrus response, duration of the induced estrus, interval from sponge removal to onset of the induced estrus, time occurrence of ovulation from sponge removal and estrus onset to ovulation were recorded to be 93.10%, 33.66 ± 2.85 h, 27.48 ± 2.71 h, 48.05 ± 1.24 h and 21.51±2.37 h, respectively. The total ovulation rate, total number of ovulations per doe, largest follicle diameter and second largest follicle diameter were recorded to be 93.10%, 2.01±0.22, 6.85 ± 0.26 mm and 6.12 ± 0.24 mm, respectively. Results of this study indicate that administration of GnRH at 24 h or 36 h after sponge removal does not affect plasma P4 and E 2 concentrations, estrus parameters and ovulation time in estrus induction and synchronization in goats during the transition period.

Effect of Janova, Sepia and Ovsynch Protocol on Blood Biochemical Profile and Fertility in Postpartum Anoestrus Cows

Background: Anoestrus is still one of the most prevalent reproductive disorders in dairy cows despite technological advances in animal husbandry. Evaluation of blood biochemical profile is of diagnostic value to determine disease or health status of animal. The current study was aimed to evaluate the effect of different therapeutic regimen on blood biochemical profile, oestrus induction response and conception rate of anoestrus cows.Methods: Thirty two postpartum anoestrus cows randomly allocated to four groups as G0 (negative control), GI, GII, GIII, GIV and 8 normal cyclic as GV (positive control). Dewormer and mineral mixture administered to GI, GII, GIII, GIV while group GII, GIII and GIV additionally received janova, sepia and Ovsynch protocol respectively.Result: Different therapeutic protocols have variable effects on blood biochemical parameters. Overall oestrus induction response in G0, GI, GII, GIII, GIV and GV is 0.00, 50, 62.5, 75, 87.5 and 100.00 per cent respectively with corresponding conception rate of 0.00, 75, 80, 66.66, 57.13 and 75.00 per cent. On the basis of findings it can be concluded that aforesaid therapeutic regimens have definite bearings on fertility and can be used to manage postpartum anoestrus in cows.

Effect of GnRH treatment following a short-term estrous induction protocol on estrus and ovulation in Saanen goats, during the transitional period

The objective of this study was to compare the effect on the ovulation time and estrus parameters of a GnRH agonist (buserelin acetate) administered 24 or 36 h following a short-term estrus induction and synchronization treatment in non-lactating Saanen goats during the transitional period. Goats received 20 mg FGA sponges for 6 days plus 300 IU eCG and 125 μg d-cloprostenol 24 h prior to sponge removal. After removal of the sponges, goats were given either 1 ml physiological saline (0.9% NaCI) solution (Group1; n = 9) after 12 h, 0.004 mg GnRH (Group2; n = 10) after 24 h or 0.004 mg GnRH (Group3; n = 10) after 36 h. The follicle development and ovulation in the ovaries were monitored by transrectal ultrasonography starting from the sponge application until the fifth day of the estrus cycle. Blood samples were collected on the same days to determine the plasma concentrations of progesterone (P4) and estradiol (E2). No statistical differences among groups were detected in any synchronization parameters, ultrasonic evaluations and plasma P4 and E2 concentrations. The evaluation of pooled data showed that the response of Saanen goats to treatments was comparable to the results of other published trials. Results of this study indicate that administration of GnRH at 24 h or 36 h after sponge removal, at the end of a short estrus induction and synchronization protocol, does not affect plasma P4 and E2 concentrations, estrus parameters and ovulation time in goats, during the transition period.

Effect of Estrus Induction on Blood Biochemical and Mineral Profiles and Fertility Rate in Retained Fetal Membranes Affected and Normally Calved Riverine Buffaloes

Background: Calving to conception interval is abnormally extended by the occurrence of retained fetal membranes (RFM) by altering the blood biochemical and mineral milieu in cows. Hence this experiment was conducted in RFM affected and normally calved (NC) buffaloes by inducing estrus with CIDR plus PGF2α protocol to study the blood biochemical and mineral profiles and to correlate them with fertility rate. Methods: Buffaloes (n=64) at 45-60 days postpartum including 32 treated for RFM and 32 NC from field were equally divided into groups I and II and groups III and IV, respectively. Buffaloes of groups I and III were initially dewormed and administered 35-50 g mineral mixture daily orally for 15 days in the concentrate feed. Then, buffaloes of all the groups were treated with CIDR plus PGF2α. After CIDR removal, all the buffaloes were artificially inseminated twice at 48 and 72 hrs. Blood was collected during different stages of treatment from all the buffaloes to assess the blood biochemical and mineral status. The animals returned to estrus following FTAI were again inseminated during subsequent estrus. Pregnancy diagnosis was done at 60 days post-AI and conception rates for induced estrus and overall of two cycles were calculated.Result: In all the groups, blood glucose, total protein, triglycerides, cholesterol and phosphorus levels increased from the time of selection to 10 days post-AI. There was an altered calcium phosphorus ratio in RFM affected buffaloes (1:1) at the time of selection. CIDR plus PGF2α protocol influenced the blood biochemical constituents and brought the calcium and phosphorus ratio as 2:1 and improved the fertility in riverine buffaloes. The overall conception rate was 62.50, 37.50, 87.50 and 75.00 per cent, in group I, II, III and IV buffaloes, respectively.

Monitoring Plasma Metabolic Profile, Fertility in Normal and Estrus Synchronized Suckled Kankrej Cows

Background: Postpartum fertility in dairy bovines is one of the important criteria of sustainable dairy industry and economy of farmers. The Kankrej, a dual purpose zebu cattle, is known for its endurance, but is slow breeder with very late maturity, prolonged postpartum anestrous/subestrous and thereby calving interval. These peculiarities necessitate scientists to adopt fixed time AI (FTAI) protocols of estrus synchronization for improving their reproductive efficiency. Hence this study was aimed to assess the fertility and plasma metabolic profile of normal and synchronized anestrous/ subestrous suckled Kankrej cows of an organized farm.Methods: The study involved 36 parturient Kankrej cows of the University Farm that were maintained under identical nutritional and managerial practices. Blood samples were collected in heparinized vacutainers from all the animals on the day of calving and then at 10 days interval till 90 days for plasma metabolic profile. Animals monitored by per rectal palpation 10 days apart around day 70-80 postpartum revealed 30 cows to be anestrous or subestrous, which were randomly allocated to five different estrus synchronization protocols at day 90-92, each with six cows and a group of six cows that exhibited estrus and were bred by day 70-90 served as normal control. The treatment protocols included Ovsynch, CIDR, Ovsynch + CIDR, Cosynch and double PGF2α together with estimation of plasma metabolites on day 0, 7, 9/10 (AI) and then at 10 days interval up to day 40 post-AI. Result: The mean plasma total protein levels varied non-significantly, while total cholesterol and triglycerides varied significantly (p less than 0.01) between intervals until 90 days postpartum in most of the groups with gradual increase in the mean values from the day of calving. The estrus synchronization protocols, however. did not alter the plasma profile of these constituents. The estrus induction response with Ovsynch, CIDR, Ovsynch + CIDR, Cosynch and PGF2α treatment was 66.66, 83.33, 50.00, 66.66 and 66.66% and the conception rates at induced estrus 16.66, 33.33, 16.66, 50.00 and 50.00%, respectively. In normal cyclic control group, the conception rate at first cycle was 33.33%. The plasma total cholesterol and triglycerides were higher in conceived than non-conceived cows, particularly during early postpartum period and post-AI. It was concluded that CIDR, Cosynch and PGF2α protocols were better for estrus induction and conception rate in anestrous and subestrous suckled Kankrej cows, although they did not influence the plasma metabolic profile.

116 Differences between 5- and 6-day progestogen-based oestrus induction protocol in Saanen and Toggenburg goats

Hormonal oestrus induction treatment is an important tool for the success of reproductive biotechniques in anoestrus goats. In the nonbreeding season, oestrus induction can be performed by the use of several protocols, including those varying in their duration. This study aimed to compare short-term (for either 5 or 6 days) progestogen-based oestrus synchronization protocols in dairy [Toggenburg (n=12) and Saanen (n=12)] goats during the nonbreeding season. This study was performed in Minas Gerais State, Brazil (21°35′S and 43°15′W), with 12 nulliparous (12–14 months old) and 12 pluriparous (2–4 years old in final third of lactation) goats, all with body condition scores (BCS) of 3.0 to 3.5. They were equally assigned to both treatments according to their order of parturition, BCS, and breed. On a random day (Day 0), 24 goats received an intravaginal device of 60mg of medroxyprogesterone acetate (Progespon®, Zoetis) which remained for 5 (G5; n=12) or 6 (G6; n=12) days. On Day 5, goats from both groups received 30µg of cloprostenol intramuscularly (IM) (Prolise®, ARSA S.R.L.) and 200IU of equine chorionic gonadotrophin (eCG) IM (Novormon®, Schering Plough Animal Health). Both groups received cloprostenol and eCG on the same day (regardless of device removal) to ensure they were administered at the same follicular wave. Both device insertion and removal were performed in the morning. Ultrasound evaluations were performed every 12h from device removal to ovulation detection. Ovulations were considered as the average interval between the last observation of follicles and the first exam in which it was no longer seen. The normal distribution of variables was determined by Shapiro-Wilk test and homocedasticity by Levene’s test. All variables were not normally distributed and thus analysed by Mann–Whitney U test, with P<0.05 considered significantly different. Values are presented in median±interquartile range. There was no difference between G5 and G6, respectively, in the interval to oestrus (48.0±0.0 vs. 48.0±12.0h), interval from oestrus onset to ovulation (18.0±9.0 vs. 18.0±12.0h), interval from device removal to ovulation (66.0±18.0 vs. 66.0±24.0h), number of ovulated follicles (2.0±2.0 vs. 2.5±2.0), or mean diameter of ovulated follicles (6.6±1.6 vs. 6.6±1.4mm). All ovulations were detected in the morning. In conclusion, our data demonstrate that short-term hormonal treatment for 5 or 6 days is similarly efficient to induce synchronous oestrus in Saanen and Toggenburg goats. This research was supported by EMBRAPA (Project 20.19.01.004.00.03.001) and CNPq (314952/2018-7).

Examination of oestrus-dependent alterations of bovine cervico-vaginal mucus glycosylation for potential as optimum fertilisation indicators.

Oestrus is the period in the sexual cycle of female mammals where they become most receptive to mating and are most fertile. Efficient detection of oestrus is a key component in successful reproductive livestock management programmes. Oestrus detection in cattle is most often performed by visual observation, such as mounting behaviour and standing heat, to facilitate more successful prediction of optimal time points for artificial insemination. This time-consuming method requires a skilled, diligent observer. Biological measurements using easily accessible biomolecules in the cervico-vaginal mucus could provide an alternative strategy to physical methods of oestrus detection, providing an inexpensive means of rapidly and accurately assessing the onset of oestrus. In this study, glycosylation changes in cervico-vaginal mucus from three heifers following oestrus induction were investigated as a proof of concept to assess whether potential glycosylation-based trends could be useful for oestrus stage indication. Mucus collected at different time points following oestrus induction was immobilised in a microarray format and its glycosylation interrogated with a panel of fluorescently labelled lectins, carbohydrate-binding proteins with different specificities. Individual animal-specific glycosylation patterns were observed, however each pattern followed a similar trend around oestrus. This unique oestrus-associated glycosylation was identified by a combination of relative binding of the lectins SNA-I and WFA for each animal. This alteration in cervico-vaginal mucus glycosylation could potentially be exploited in future to more accurately identify optimal fertilisation intervention points compared to visual signs. More effective oestrus biomarkers will lead to more successful livestock reproductive programmes, decreasing costs and animal stress.

The Effect of Gonadotropin Releasing Hormone Administration on Fertility and Embryonic Loss in Goats during the Anoestrus Period

Background: Following the induction of oestrus out of season in small ruminants, low fertility and variations in fertility rates are associated with embryonic losses. One of the main causes of embryonic loss is luteal dysfunction. Gonadotropin Releasing Hormone (GnRH) supports the luteal structure, and increasing progesterone levels may be beneficial in terms of promoting embryonic life. The main objective of the present study was to evaluate the efficacy of GnRH administration following an oestrus induction protocol in the anoestrus season for preventing embryonic loss in goats having failure to conceive during the season. Materials, Methods & Results: In the study, 106 Damascus goats aged 3-5 years and weighing 45-60 kg were used. The oestrus of 106 goats in the anoestrous group was stimulated with progesterone and pregnant mare serum gonadotropin (PMSG) treatment. Out of breeding season, goats were divided into the 4 following groups: GnRH0 (n = 27), GnRH7 (n = 26), GnRH0+7 (n = 27) and control (n = 26). In each goat, an intravaginal sponge (IS) containing 20 mg of fluorogestone acetate (FGA) was placed into the vagina and left for 9 days. With the withdrawal of the sponge, 550IU PMSG and 125 μg of d-cloprostenol were injected intramuscularly. Oestrus detection was made via teaser bucks for 3 days starting 24 h after withdrawal of the IS. Eighteen bucks known to be fertile were used for breeding. Goats in the oestrus period were mated via natural breeding. The GnRH analogue lecirelin was injected intramuscularly at breeding in the GnRH0 group, on day 7 post-breeding in the GnRH7 group, and both at breeding and on day 7 post-breeding in the GnRH0+7 group. No injections were given to the control group. Blood samples for progesterone measurement were taken by jugular vena puncturing on days 3, 6, 7, 10, 13, 16, and 19 after breeding from 10 randomly chosen goats in all groups. The goats with a level of > 3.5 ng/mL of progesterone on day 21 post-breeding were evaluated as pregnant. Pregnancy was also viewed on day 50 after breeding by real-time ultrasonography (USG) with a 5-7.5 MHz convex probe. The oestrus rate was 96.23% (102/106) in the goats. The rates of onset of oestrus between 36-48 h, 48-60 h and 60 h and beyond were 38.7% (41/106), 21.7% (23/106) and 35.8% (38/106), respectively. The total pregnancy rate was 35.8% (38/106). There were no statistically significant differences (P > 0.05) found for the pregnancy rate, embryonic death rate or progesterone concentration of the groups. However, serum progesterone levels were statistically different in the GnRH7 group compared with the control group (P < 0.05).Discussion: After synchronisation, various anti-luteolytic strategies can be used to support corpus luteum development and elevate progesterone concentration in the luteal phase to decrease embryonic loss and increase reproductive performance. Therefore, application of GnRH to support the luteal structure and to increase progesterone levels may be beneficial in terms of supporting embryonic life. The results showed that GnRH treatment on the day 7 post-breeding following oestrus induction, including FGA and PMSG, can increase serum progesterone levels in Damascus goats in the anoestrus period. However, following oestrus induction in the anoestrus period, it was seen that GnRH treatment at breeding or on day 7 after breeding did not have any positive effect on embryonic loss or reproductive performance. In conclusion, it was considered that this protocol could be implemented successfully, yielding a 35% pregnancy rate in Damascus goats in the anoestrus period, but embryonic loss must be deeply studied in detail.

Induction and synchronization of oestrus in sheep and goats

Different methods for oestrus induction and synchronization in domestic small ruminants have been developed. Seasonality and female’s status are important factors for choosing the most appropriate treatment. In the case of females during breeding season, prostaglandins can be used since functional corpus luteum must be present in the ovaries, while during non-breeding season females should be treated with progesterone-based treatments, accompanied by equine chorionic gonadotrophin (eCG), releasing hormones and other compounds. Significant spread of oestrus synchronization during and after the breeding season has been achieved by the use of intravaginal sponges impregnated with synthetic analogues of progesterone. However, the effect of hormonal drugs on the female reproductive system may manifest differently depending on the initial functional state of reproductive organs and the hormonal status, and negative consequences can be observed when drugs are wrongly administered. In addition, insufficient knowledge about the patterns of change in the reactivity of the nervous sexual centers and the corresponding reactions of the body to the administration of hormones reduces their effectiveness, which limits the widespread use. In general, the induction and synchronization of oestrus in small ruminants is an currently important direction of scientific research and an urgent problem of sheep and goat breeding, but the proposed methods require further improvement by reducing the costand increasing biosecurity and predictability of the result.

Studies on Efficacy of 7D CIDR-GNRH Protocols for Induction of Ovulatory Estrus in Anestrus Buffaloes

Studies on Efficacy of 7D CIDR-GNRH Protocols for Induction of Ovulatory Estrus in Anestrus Buffaloes

110 Pregnancy rate and embryo viability in response to chorionic gonadotrophins given for oestrus induction and gonadotrophin-releasing hormone 5 days after timed laparoscope-aided insemination of lactating and non-lactating goats

Gonadotrophins are included in oestrous/ovulation synchronization (E/OS) regimens when breeding early in the transitional phase to promote follicular development. However, the time of use has been a matter of debate. Hence, the objective of this study was to determine whether equine and human chorionic gonadotrophins (eCG and hCG, respectively) given 24h before or 24h after concurrent removal of intravaginal progestagen (P4) and prostaglandin (PGF2α) delivery influences pregnancy rate (PR) and/or embryo viability (EV). Relatedly, the influence of gonadotrophin-releasing hormone (GnRH) 5 days post-breeding (dpb) on PR and/or EV was also considered. A prospective randomised control trial was conducted using lactating and non-lactating Alpine breed goats of different parity, average±s.e. age, and bodyweight (3.7±2.6), and (52.5±7), respectively. Goats were time-bred at 48h after P4 removal by laparoscopy (LAI; n=75) or by natural service (NS; n=29) during the early transitional breeding phase in mid-September through mid-December (corresponding to 12:12h daylight/darkness). E/OS used an intravaginal device containing 300mg of P4 for 12±1d. At P4 removal, 2mL of PGF2α was administered IM. Twenty-four hours before (E) or 24h after (L) P4 removal, an IM dose of 1.5mL containing 120IU of eCG and 60IU of hCG was given. A third control (C) group (n=38) was not exposed to gonadotrophins. GnRH analogue was given (n=51) 5 days after insemination, and the remaining goats (n=53) received an IM dose of 2mL of saline solution. PR was evaluated at 18 to 24 (dpb) by non-return to oestrus (NRE), at 30 dpb by pregnancy-specific protein B (PSPB), and at 40 dpb by ultrasound imaging (UI). EV was determined from the difference between pregnancy outcomes for NRE and PSPB, and PSPB and UI. Statistical analysis (JMP/SAS vs.11; SAS Institute Inc.) were obtained using logistic regression. All concomitant variables (i.e. parity, bodyweight, days of P4 exposure, and lactation were not influenced by PR or EV; P>0.07). The overall PR was 71% for LAI and 69% for NS and, as shown in Table 1, was similar (P>0.49) at all times (at 18 to 24, 30, and 40 dpb). Likewise, the breeding procedure did not influence the levels of EV at 30 or 40 dpb. E/OS protocol or the use of GnRH 5 dpb did not affect PR or EV at any of the time points evaluated. Table 1. Main effect mean comparisons and logistic model probabilities for pregnancy rate (PR) and embryo viability (EV) by main treatment effect Response variable (days post-breeding) Breeding procedure E/OS Protocol Gonadotrophin LAI NS P> Control Early Late P> GnRH Placebo P> PR at 18–24 77 72 0.49 76 73 78 0.83 78 74 0.49 PR at 30 68 66 0.65 66 65 70 0.82 71 64 0.43 PR at 40 69 69 0.78 66 69 73 0.77 73 66 0.43 EV at 30 89 90 0.94 86 94 90 0.65 92 87 0.46 EV at 40 88 95 0.42 86 89 94 0.73 92 87 0.43

114 Short-term hormonal protocol efficiency either with or without equine chorionic gonadotrophin to promote oestrous synchronization in cyclic dairy goats

The use of equine chorionic gonadotrophin (eCG) in oestrous induction protocols is associated with antibody production against eCG. Moreover, there are important equine welfare issues involved in its production and the development of viable protocols without eCG in dairy goats is essential. The aim of this study was to assess oestrus and ovulatory responses of short-term oestrous synchronization protocol with or without eCG in nulliparous (NUL) and multiparous (MUL) dairy goats during the breeding season. On a random day of oestrous cycle (Day 0), Alpine (n=10 NUL and 10 MUL), Nubian (n=10 NUL and 10 MUL), and Saanen (n=10 NUL and 6 MUL) goats received 30μg of d-cloprostenol intramuscularly (IM) and an intravaginal sponge containing 60mg of medroxyprogesterone acetate, which was maintained for 6 days (Day 6). At 24h before sponge removal (Day 5), goats received IM 200IU of Novormon 5000 (G-eCG) or saline solution (G-Control). NUL and MUL goats of each breed were assigned equally into one of the two treatments. Transrectal ultrasonography was used to assess ovarian parameters, and teaser goats detected oestrus every 12h from sponge removal to ovulation or until 96h after sponge removal. The results are described as mean±s.e.m., and categorical results are presented as percentages. The normal distribution of the residues of all variables was determined by the Shapiro-Wilk test and for homoscedastic by Levene test. To evaluate interaction between treatments and parity order, the general linear model (GLM) was applied. Parametric variables were subjected to Student’s t-test. Nonparametric variables were analysed by Mann–Whitney test, Chi-squared test, and Fisher’s exact test. Values of P<0.05 were considered significant. According to the breed and parity order, Nubian and Saanen goats showed no difference (P>0.05) in reproductive parameters. Alpine goats had a longer (P<0.05) interval from sponge removal to onset of oestrus (SROE) in MUL (61±14.0h) than NUL (38.5±12.7h), longer interval from onset of oestrus to ovulation (IEOV) in NUL (33.5±11.9h) than MUL (19.5±13.4h), and the number of ovulations was greater (P<0.05) in MUL (2.2±0.9) than in NUL (1.3±0.5). In goats either receiving eCG or not, Alpine and Nubian goats had no difference (P>0.05) in SROE, IEOV, interval from sponge removal to ovulation (SROV), percentage of animals that ovulated, diameter of the ovulatory follicle, and number of ovulations. Saanen goats had a higher (P<0.05) percentage of animals that ovulated in G-eCG (87.5%) than G-control (25.0%). Regardless of parity order and breed, SROV was longer (P<0.05) in G-control (73.2±9.8h) than in G-eCG (65.1±10.2h), and the percentage of animals that ovulated was greater (P<0.05) in G-eCG (96.4%) than in G-control (67.9%). In summary, in short-term protocols for oestrous synchronization in cyclic dairy goats, the addition of eCG led to a shorter interval from sponge removal to ovulation and increased number of animals that ovulated. This research was supported by CNPq (310166/2012-8) and Embrapa (20.19.01.004.00.03.001).

Estradiol benzoate priming during induction of estrus with Vitex-castus extract in dogs

This study compared two methods of estrus induction between dogs (using vitagnus and vitagnus-estradiol). A total of 10 adult cyclic female Shih tzu Terrier mix breed dogs at anestrus stage were selected and divided into two groups. The first group (VAC) received vitagnus for five weeks (90 mg daily, PO). The second group (VAC-E2) was treated with vitagnus and estradiol benzoate. Estradiol benzoate was injected at the beginning of each week (0.01 mg/kg, IM). Blood sampling for evaluation of steroid hormones and vaginal smears were taken weekly. The sings and return to the estrus with the number of puppies were recorded. In the VAC group, 60%, and in the VAC-E2 group, 80% of dogs returned to the follicular phase after five weeks. In the VAC-E2 group, signs of estrus appeared 7 to 10 days and a mating process started 4 to 6 days earlier than those in the VAC group. The average number of delivered puppies was 4. These symptoms were confirmed by the cytology of the vagina. There was no significant difference in the estradiol and progesterone levels between groups. The mean concentration of estradiol significantly changed between weeks 1 and 4, 1 and 5, and 2 and 5 (p < 0.05). The progesterone level in the VAC-E2 group on week five was higher than that in other weeks. In conclusion, the administration of estradiol benzoate before vitagnus improved induction of estrus in dogs.

Efficacité d’un traitement intravaginal à base de progestérone chez des vaches croisées &lt;em&gt; Bos indicus &lt;/em&gt; x &lt;em&gt; Bos taurus &lt;/em&gt;

L’étude a eu pour objectif d’évaluer l’efficacité d’un traitement combiné à base de progestérone intravaginale sur l’induction de l’oestrus de femelles croisées au Cameroun. Un total de 116 vaches Goudali (Bos indicus) x Charolaises (Bos taurus) ayant mis bas au moins une fois, sans antécédent pathologique, avec une note d’état corporel supérieure à 2, ont été sélectionnées dans des élevages du département de la Vina (arrondissement de Nyambaka). Elles ont été rassemblées dans un ranch et réparties en lots de 10 animaux. Le protocole d’induction et de synchronisation des chaleurs a consisté en la pose d’un dispositif intravaginal à base de progestérone (Prid Delta) pendant huit à neuf jours. Vingt-quatre heures avant son retrait, une injection de cinq millilitres de prostaglandine F2alpha (Dinoprost, Enzaprost) a été administrée. Au moment du retrait, 500 UI de gonadotropine chorionique équine ont été injectées. Cinquante-six heures après le retrait, l’insémination a été effectuée à heure fixe avec de la semence de taureaux Gyr et Brahman. Les taux d’induction de l’oestrus et de synchronisation, de rétention du dispositif intravaginal, de gravidité en première insémination, de fécondité, et d’avortement ont été respectivement de 100 %, 100 %, 56,0 %, 51,7 %, et 4,3 % (en % des vaches traitées). Le Prid Delta s’est révélé efficace pour l’induction des chaleurs et l’obtention de gravidités chez les vaches Goudali x Charolaises.

Effects of immunization against inhibin α-subunit on ovarian structures, pregnancy rate, embryonic and fetal losses, and prolificacy rate in goats where estrus was induced during the non-breeding season

The objectives of the study were to determine the dose-dependent effects of active immunization against inhibin α-subunit (AIINHA) on ovarian dynamics, concentrations of progesterone (P4), pregnancy rate (PR), embryonic and fetal losses (EFL), and prolificacy during the non-breeding season when there was imposing of a progestin-based treatment regimen to induce estrus in Beetal goats. Goats (n = 30) were randomly assigned into following groups: 1) saline (G-CON-0 mg; n = 10), 2) small dose (G-AIINHA-0.5 mg; n = 10), and 3) large dose (G-AIINHA-1 mg; n = 10). The primary administration of inhibin immunogen was administered at Day -48, followed by another administration at Day -20, and subsequently there was induction of estrus using a progestin based treatment regimen that included a single administration of progestin-containing sponge and PGF2α at Day -8. The sponge was removed, and GnRH was administered at Day -3 followed by breeding (Day 0) at standing estrus. Results indicated mean diameter of the follicles, size of pre-ovulatory follicles and corpora lutea, and post-breeding P4 concentrations were greater (P < 0.05) in the goat does of the G-AIINHA-0.5 than G-CON-0 group. The PR, and EFL, however, did not differ (P> 0.05) among groups, whereas prolificacy rate was greater (P = 0.04) in goat does of the G-AIINHA-0.5 than G-CON-0 groups. The data from this study indicate G-AIINHA-0.5 is the recommended dose of inhibin immunogen to enhance the reproductive performance during non-breeding season in Beetal goats when estrus is induced using a progestin-based treatment regimen.