Induction Of Estrus Research Articles

Induction of estrus as a strategy to improve the economic efficiency of the sheep flock

Productivity and profitability in sheep production systems are strongly influenced by the reproductive capacity of the flock.
 Objective: To evaluate the use of reproductive biotechnologies (e.g., the induction of estrus) and its impact on the economic efficiency and the productive and reproductive performance of technified sheep production systems, during the seasonal anestrus.
 Design/Methodology/Approach: Four-hundred recently weaned (60 days postpartum) ewes of the Katahdin breed were randomly divided into two treatments: T1 = natural mating (n= 200) and T2 = induction of estrus (n=200). Estrus was induced through the application of intravaginal sponges, impregnated with 20 mg of chronolone, plus the injection of 400 IU of Equine Chorionic Gonadotropin. The aim was to evaluate the reproductive and economic efficiency of the flock.
 Results: The induction of estrus during the seasonal anestrus recorded increases (p<0.001) in prolificacy (32%), fertility (86%), and kilograms of lamb weaned per year per ewe (48%), while decreases (p <0.05) were recorded in the number of open days (25%), calving interval (11%), cost per open days (23%), and the kilograms of lamb required per ewe per year (10%).
 Study Limitations/Implications: The constant variations in the price of supplies and services caused changes in the economic indicators.
 Findings/Conclusions: The use of reproductive biotechnologies (such as estrus induction) has a positive impact on production units, improving their profitability.

Effect of estrus on vaginal and vulvar temperature following induction of estrus during winter and summer in anestrus Murrah buffalo and heifer

Effect of estrus on vaginal and vulvar temperature following induction of estrus during winter and summer in anestrus Murrah buffalo and heifer

Influence of Blood Glucose, Total Protein and Haemoglobin at The Time of Induced Estrus on Conception Rate on Anestrus Crossbred Cows

The present study was conducted to evaluate the influence of blood glucose, total protein and haemoglobin at the time of induced estrus on conception rate in 30 postpartum anestrus crossbred dairy cows. The cows were treated with progesterone intravaginal (CIDR) based estrus induction protocol with double fixed timed inseminations at 12 and 24 h after injection of last GnRH. estrus induction response was 100% with majority of the cows (80%) showed intermediate intensity of estrus. On the day of first AI, blood was collected from all the animals for the estimation of glucose, total protein and haemoglobin. The mean time to onset of estrus from the time of removal of CIDR was 44.85 ± 7.23 h. The overall conception rate in the present study was 30 % (9/30). In the present study, the mean values of glucose, total protein and haemoglobin at the time of estrus were 43.81 ± 1.14 mg/dl, 7.78 ± 0.24 g/dl and 8.68 ± 0.22 g/dl respectively. The mean glucose, total protein and haemoglobin levels in the anestrus cows which were included in the study are lower than the normal range. There is no significant different in the biochemical parameters among the cows showing weak, intermediate and intense intensity of estrus. Similarly, there is no significant difference in the biochemical parameters between the cows that conceived and cows not has not conceived. The findings in the present study clearly indicates that poor nutritional status may be the cause for the anestrus condition of the animal under field conditions.

Synchronization of ovulation (FTET) in Turcana sheep as embryo recipients

Due to the fact that the farm wants to crossbreed sheep with meat breeds, it was opted for the fastest solution to bring genetic progress, namely embryo transfer, using sheep from the Turcan breed as embryo recipients and those from the Suffolk breed as embryo donors, so that finally the batch of receivers after parturition will produce a production of Suffolk lambs. Following the selection of recipients considering the standard criteria that include: general health, functional integrity of the genital tract and cyclic activity of the ovaries, two groups were formed for the induction and synchronization of estrus. The first batch consisted of 20 sheep and the second batch of 20. The first batch was subjected to a P4-PG-PMSG protocol and the second batch to the P4-PG-GnRH protocol. The two protocols consisted of the insertion of intravaginal sponges with flugestone acetate in a concentration of 20mg, to induce the progesterone phase, for 13 days, day 0 of the protocols being represented by the day when the progesterone sponges were applied. In continuation of the protocol, Prostaglandinf2α was used on day 12 in a double dose, in the morning and in the evening at a distance of 12 hours in a dose of 0.6 ml/administration/animal. On day 13, the progesterone sponges were removed and PMSG (Folligon) was administered in the case of the first batch at a dose of 600 IU/animal, and in the second batch GnRH (Receptal) was administered at a dose of 12 μg/animal ( 3ml/animal) followed by a dose of 600 IU HCG (Chorulon) 24 hours after GnRH administration. Ovulation was accurately assessed at the time of embryo transfer through laparotomy, due to the highlighting of the ovaries and their macroscopic analysis in the operative field, after identifying the CL on the ovary, their appearance and the number of CL on the ovary. However, the assessment of the rate of entry into heat was assessed 24 hours after the end of the protocol by biostimulating the receptors with the help of detector rams, thus the ewes that entered in estrus at 12 – 24 hours, 24 – 48 of hours or over 48 hours after completing the protocol. The results obtained in the case of the first batch having the highest rate of entering in estrus between 24 - 48 hours being 40%, followed by a rate of 30% between 12 - 24 hours, the lowest rate being 20% that entered in estrus after 48 hours, the second batch with GnRH had the highest rate of entry into estrus of 60% in the first 12-24 hours and the rate at 24-48 hours, respectively those that entered heat after 48 hours was 20%. Compared between the two groups, there were differences in the timing of ovulation assessment, as in the case of the first group with PMSG, a 60% ovulation rate was assessed with well-developed CL, 10% presented CL but these were unsuitable for embryo transfer, 10% presented ovarian cysts, and 10% did not ovulate, in the case of the second batch an ovulation rate of 60% was assessed and the rate of 40% represented the animals that did not ovulate, the difference between the two batches being the fact that it is observed in the case of the first batch rate of 10% with ovarian cysts, which indicates that the PMSG-based pharmaceutical is causing ovarian cysts. In conclusion, the therapeutic protocol used in the off-season for the induction of estrus and ovulation in Turcan sheep, in this study, resulted in the detection of estrus in 90% of the ewes subjected to the protocol, and the ovulation rate was 80% (60% with CL well developed and 20% were with poorly developed CL), regarding the first batch, and regarding the second batch 100% of ewes in oestrus were detected, but 60% of them ovulated with CL well developed. These results can be largely attributed to the reproduction seasonality of the sheep.

Development of a new protocol for estrus induction and synchronizationin multiparous weaned sows

Estrus induction and estrus synchronization with P.G. 600 to improve the reproductive performance of multiparous sows is a standard protocol. However, its nonavailability in India and higher cost warrants development of new protocols without compromising the reproductive performance. The present study compared the efficacy of two different protocols for estrus induction and synchronization in multiparous sows. The sows (n=80) were randomly divided into two groups. In group-I, sows (n=40) were injected with P.G. 600 (equine chorionic gonadotropin [eCG] 400 I.U. and human chorionic gonadotropin [hCG] 200 I.U.) and in group-II, P.G. 450 (eCG 300 I.U. and hCG 150 I.U.) intramuscularly. Reproductive performance parameters, including estrus induction, treatment to estrus induction interval, estrus duration, farrowing rate, live born piglets/litter, stillborn piglets, total piglets born/litter, litter size at weaning and pre-weaning mortality were analyzed between two groups. Estrus induction and farrowing rate were numerically higher in group-II but statistically nonsignificant. Treatment to estrus induction interval was 55.59 h and 55.57 h, respectively in group-I and group-II. Similarly, total litter size at birth and litter size at weaning were non-statistically higher in group-II as compared to group-I. In conclusion, the present study demonstrated that estrus induction and synchronization can be successfully achieved in multiparous sows with P.G. 450 and this will reduce the cost of hormonal treatment and optimize the reproductive efficiency in Indian condition.

Comparative evaluation of natural tupping with fixed-time laparoscopic and cervical insemination techniques using chilled semen in estrous synchronized sheep

The present study was conducted in crossbred ewes to compare the efficiency of different artificial insemination techniques with natural tupping following fixed time artificial insemination using fresh semen. Crossbred ewes (n=29) were randomly divided into three groups with 10 animals in natural tupping (NT) and laparoscopic artificial insemination (LAI) groups and nine animals in cervical artificial insemination (CAI) group. Ewes in all the treatment groups were subjected to the same estrus induction protocol: insertion of intravaginal progesterone sponges for 10 days followed by an intramuscular injection of 500 IU eCG at the time of sponge withdrawal. Immediately after removal of sponges, animals of NT group were kept with proven breeding rams up to 72 h. Fixed time cervical or laparoscopic insemination was done at 48 h after sponge removal. The insemination was repeated 12 h later in CAI group. The pregnancy and lambing rates were significantly higher in NT group (90%, 90%), than CAI group (55.5%, 55.5%) and LAI group (20%, 10%). The prolificacy rate was significantly higher in CAI group (180%) than NT group (111.1%) and LAI group (100%). The serum progesterone concentration was higher in pregnant ewes on day 10, day 17 and day 35 than non-pregnant ewes. The fixed time cervical insemination following intravaginal progesterone sponges for 10 day+eCG protocol resulted in better pregnancy rate and prolificacy rate in crossbred ewes during breeding season.

CASE REPORT: A SUCCESSFUL STRATEGY FOR TREATMENT OF RETAINED FETAL MEMBRANES COMBINED WITH PUERPERAL METRITIS IN A DAIRY COW

A Holstein dairy cow on a farm located in central Taiwan gave birth after 281 days of gestation; however fetal membranes were not expelled until 12[Formula: see text]h post-parturition. Preventive antibiotics of ceftiofur (750[Formula: see text]mg) combined with flunixin (750[Formula: see text]mg) were administered intramuscularly for three consecutive days. On day 11 postpartum, expulsion of partial fetal membranes and reddish-brown vaginal discharge with an offensive odor were reported. Intrauterine lavage using 800[Formula: see text]ml of sterile saline and 500[Formula: see text]ml of 0.2% chlorhexidine solution was performed, followed by intrauterine infusion with 300[Formula: see text]ml of 0.5% povidone iodine. On day 21 postpartum, a vaginal discharge score (VDS) of 3 was graded by Metricheck[Formula: see text] and uterine cytology revealed 76.1% polymorphonuclear neutrophils (PMNs), all of which suggested endometritis. An additional intrauterine infusion of 0.5% povidone iodine was subsequently prescribed, followed by two low doses of PGF[Formula: see text] to control uterine infection. On day 49 postpartum, a VDS of 0 with a proportion of 3.8% PMNs was revealed, indicating available criteria for breeding. Estrus induction and timed artificial insemination were scheduled and pregnancy was confirmed 33 days after artificial insemination. In summary, we have demonstrated a successful two-step treatment for a Holstein having retained fetal membranes (RFMs) combined with puerperal metritis (PM) to have a favorable result of 65 days open.

Ruling out Efficacy of Hormonal Protocols alone or Fortified with Mineral and Bypass Fat for Treatment of Postpartum Anoestrus in Cattle

Background: High milk production and excellent fertility is a dream of livestock owners.The major reproductive disorders which lead to decrease the productivity and reproductive ability of farm animals is postpartum anestrous.Recently, kisspeptin was reported as game changer in the animal reproduction. Kisspeptin increases the number of follicles at wave emergence, oestrus response rate and duration of oestrus. Thus, indicating its potentiality for induction of oestrus in anestrous animals. Methods: The present study was conducted to compare the efficacy of Ovsynch and kisspeptin protocol and need of fortification for treatment of postpartum anestrous.Fifty postpartum anestrous cows were selected. The animals were divided into four treatment groups (10 cows in each) and treated with Ovsynch (Group I), Ovsynch fortified with mineral mixture (MM) and bypass fat (BPF) (Group II), kisspeptin (Group III) and kisspeptin fortified with MM +BPF (Group IV). The remaining 10 cows served as control (Group V). The oestrus response was recorded on the basis of behavioral signs, physical signs and clinico-gynaecological changes. The blood was collected following treatment for hormonal estimation. The pregnancy was confirmed on day 45 post AI using ultrasound. Result: The oestrusresponse was pronounced in Ovsynch as compared to kisspeptin groups. Further, fortification has enhanced the response. The serum oestrogen concentration increased following treatment and was significantly high on day of onset of oestruswith highest concentration in group II. The results indicate Ovsynchdistinguishly succeeded in addressing postpartum anestrus with fortification enhances fertility response.However, kisspeptin also emerged as a potent candidate for the resumption of cyclicity.

Comparative Efficacy of Different Oestrous Synchronization Protocols on Estrus Induction Response and Conception Rate in Repeat Breeder Dairy Cows

Repeat breeding is one of the exasperating reproductive disorders of dairy cows which results in heavy economic loss to dairy farmers. The present research was conducted to compare the efficacy of different oestrous synchronization protocols in repeat breeder cows under field condition. A total of 50 repeat breeder cows formed the experimental animals for the present study. The repeat breeder cows were randomly and equally assigned to one of the five groups. viz. CIDR (Group I; n=10), Ovsynch (Group II; n=10), Ovsynch+CIDR (Group III; n=10), Ovsynch+CIDR+Vitamin AD3E&H (Group IV; n=10) and Control (Group V; n=10) and bred accordingly. The pregnancy status was checked 45 days post insemination by rectal palpation. The estrus induction response and conception rate in all five groups are compared and analysed. Though cows from all groups expressed estrus, there was significant difference (P≤0.05) in their duration of estrus which was high in Group IV. The overall conception percentage obtained in Group I, II, III, IV and V were 30, 40, 60, 80 and 20 per cent, respectively. In this study, the highest overall percentage of conception rates were recorded in group IV (80.00) followed by group III (60.00) when compared to groups II (40.00), I (30.00) and Control (20.00). Hence, it is concluded from the present study that Ovsynch+CIDR+Vitamin AD3E&H protocol resulted in better estrus expression, duration and conception rate for treatment of repeat breeder cows under field conditions than other protocols.

CASE REPORT: A SUCCESSFUL TREATMENT STRATEGY FOR CYSTIC OVARIAN DISEASE IN A DAIRY COW

A 5-year-old multiparous lactating Holstein cow was reported to have cystic ovarian disease with a history of whitish vaginal discharge on the 80th day postpartum. On the 83rd day postpartum, transrectal ultrasonography revealed a thick-walled cystic structure with visible cobwebs in the cavity, measuring 4.2[Formula: see text]cm × 3.4[Formula: see text]cm in diameter on the right ovary. The serum progesterone (P4) concentration was 6.82[Formula: see text]ng/mL, leading to a diagnosis of luteinized follicular cyst. Transvaginal aspiration of the cyst was performed to decrease the compression of ovarian stroma by the cyst, followed by intramuscular administrations of cloprostenol and buserelin. A 1.9[Formula: see text]cm diameter corpus luteum was detected on the right ovary nine days after aspiration, with a serum P4 concentration of 1.29[Formula: see text]ng/mL. Continual hormone treatment was followed, consisting of an injection of buserelin and an intravaginal progesterone-releasing device inserted for seven days. After seven days, two corpora lutea were noted on the right ovary with an average diameter of 2.8[Formula: see text]cm and 1.8[Formula: see text]cm, respectively. The device was removed and the cow showed a P4 concentration of 11.22[Formula: see text]ng/mL on that day. Estrus induction was conducted with two low doses of cloprostenol followed by an injection of gonadorelin, to induce a complete luteolysis and the following ovulation to fit a fixed-timed artificial insemination (AI). Pregnancy was confirmed 33 days after AI. Although the number of days open was 102 in this case, it took a total of 19 days from treatment to pregnancy.

Changes in Mineral Profiles in Progesterone-based Estrus Induction Protocols and their Relationship with the Phases of Estrous Cycle in Kangayam Cows

Background: For the successful reproduction in Kangayam cows, adequate nutrition containing sufficient quantum of minerals is necessary. Minerals are important cofactors in majority of the metabolic and immune reactions and hormone synthesis that could affect reproduction. Present study was planned to analyse whether mineral levels change in different treatment days following estrus induction and corresponding changes in stages of the estrous cycle. Methods: Non pregnant, pluriparous Kangayam cow (n=70) were allotted to control and different treatment protocols (each consist of 10 cows) based on the transdermal (PNC based groups) and transvaginal application of progesterone (CIDR based group) with a shot of PGF2α one day preceding the day of progesterone removal. Ovulation was induced either using estradiol benzoate or buserelin acetate. Mineral profiles were analysed on the day of progesterone application (APP), removal (REM), AI and 10 days post insemination (10 DPAI). Result: It indicated that changes in the mineral levels between the treatment days especially on the day of AI and 10DAPAI could be correlated with the corresponding follicle and luteal phases and it could be concluded that there were significant changes especially in selenium, manganese, zinc and copper levels between the treatment days in each group which could be extrapolated to have specific roles in stages of estrous cycle. Among these minerals copper levels could be correlated to affect the steroid concentration by altering its metabolism thereby its clearance in Bos indicus breed ie Kangayam breed of Tamil Nadu.

Assessing the acceptability of hormone-based estrus induction / synchronization protocols to overcome anestrus in buffaloes

Five hundred dairy households in the rural areas of Punjab state were interviewed through comprehensively designed questionnaires to assess the knowledge and experience of farmers regarding the hormone-based strategies to overcome anestrus and getting the buffaloes pregnant. About 81.8% dairy households were unaware (P<0.05) about any estrus induction or synchronization hormonal protocol and majority (65.5%) of these belonged to households with <5 animals. Out of households having awareness about hormonal protocol use in buffaloes, the majority (58.2%) belonged to households with >15 animal. Out of dairy farmers using hormonal protocols, the proportion of illiterate was 14.8%. Out of dairy farmers not aware about hormonal protocols, the proportion of illiterate was 52.3%. Data analysis of 91 dairy households who had used hormonal protocols revealed summer (65.9%) and anestrus (82%) as the major underlying reasons for their use in buffaloes. Low success rate (20.2%), high cost (50%) and non-availability of doctor (29.7%) were the reasons for the irregular use of hormonal protocols. The success rate of hormonal protocols under field condition in terms of conception was 47.1%. In summary, the major bottlenecks in acceptability of hormone-based therapeutics strategies under filed conditions are illiteracy, high cost of therapeutics strategies and lack of awareness in buffalo farmers especially in households with <5 animals.

Association of MTNR1A and GDF9 gene allelles with the reproductive performance, response to oestrus induction treatments and prolificacy, in improved and non-improved local indigenous sheep breeds.

Sheep farming plays a crucial role for Mediterranean countries, wherefrom a plethora of dairy products is produced. Yet, numerous indigenous sheep breeds in temperate latitudes such as the Mediterranean present a serious drawback that milk production is impaired by the seasonality of reproduction. Towards the efforts for reduction of this phenomenon, the purpose of this study was to evaluate and compare different oestrus synchronization treatments, as well as to associate two genes alleles', namely the MTNR1A and the GDF9, with the response to those treatments. Three indigenous breeds were investigated (Florina, Chios and Karagouniko sheep) and inside each breed three different oestrus synchronization treatments were applied (A: intravaginal sponges, B: GNRH use and C: male effect). In group A, Florina ewes expressed oestrus at 90% in July and fecundity was 85%. Karagouniko and Chios ewes exhibited an oestrus expression of 100% with fecundity rates at 95% and 99%, respectively. In group B, Florina ewes expressed oestrus at 60% with fecundity at 57%, Karagouniko ewes expressed oestrus at 65% with fecundity at 54%, whereas Chios breed animals expressed oestrus at 87% with fecundity rate at 85%. In group C, 68% of the Florina breed expressed oestrus 20-25 days post ram induction, whereas this proportion was 84% and 94%, for Karagouniko and Chios breed, respectively. For the molecular analysis, partial segments of the two genes were sequenced and analysed, whereas alleles were scored based on the detected SNPs. All frequencies of the four detected SNPs in MTNR1A gene were statistically and significantly different in ewes that expressed oestrus in comparison with ewes that did not express oestrus in Florina and Karagouniko breeds concerning all treatments. Two SNP's were detected in GDF9 gene, G1 and FecG , from which, only the FecG mutation exhibited statistically significant difference in twins and triplets than in singles in Florina and Karagouniko breeds.

Increase of Body Temperature Immediately After Ovulation in Mares.

To successfully inseminate mares, precise detection of ovulation time is crucial, especially when using frozen-thawed semen. Monitoring body temperature, as has been described in women, could be a noninvasive way to detect ovulation. The objective of this study was to investigate the relationship between the time of ovulation and the variation of body temperature in mares based on automatic continuous measurements during estrus. The experimental group included 21mares for 70analyzed estrous cycles. When the mares showed estrous behavior, they were administered intramuscular deslorelin acetate (2.25mg) in the evening. At the same time, monitoring of body temperature using a sensor device fixed at the left lateral thorax was started and continued for over 60hours. In 2-hour intervals, transrectal ultrasonography was performed to detect ovulation. Estimated body temperature in the 6 hours following ovulation detection was on average 0.06°C +/- 0.05°C (mean+/-SD) significantly higher when compared with body temperature at the same time on the preceding day (P=.01). In addition, a significant effect of PGF2α administration for estrus induction on the body temperature was found, being significantly higher until 6hours before ovulation compared to that of uninduced cycles (P=.005). In conclusion, changes in body temperature during estrus in mares were related to ovulation. The increase in body temperature immediately after ovulation might be used in the future to establish automatized and noninvasive systems to detect ovulation. However, the identified temperature rise is relatively small on average and hardly identifiable in the individual mares.

Kangal Koyunlarında Farklı Formlarda Verilen Vitamin ve Mineral Desteğinin Plasenta ve Doğum Ağırlığı ve Reprodüktif Performansa Etkisi

The objective of this study was to evaluate the out-of-season reproductive performance and lamb birth weight of Kangal ewes orally administered a bolus of vitamin and mineral premix or mineral premix given as injection with at 40-45 days postpartum during the anestrous period. In total, 78 primiparous Kangal ewes with were randomly allocated to three experimental groups. Estrus induction protocol was performed and a ram was introduced to the ewes at the 80th days postpartum. Ewes in the group 1 a dose of 2 mL of injectable mineral solution at 40-45 days before oestrous synchronisation, was administered at once (n = 25). As for group 2, at 40-45 days before oestrous synchronisation, a mineral bolus was given orally once (n = 27). To the ewes in the group 3 a dose of 2 mL of physiological saline was given once to the animals (n = 26) simultaneously with group 1 and group 2. Reproductive parameters such as estrus and pregnancy rates; single, twin, triplet, and multiple pregnancy rates; litter size; embryonic mortality; fecundity; and dystocia rates were evaluated. In addition, the placentas were weighed to evaluate the effect of mineral supplements on placentation. There were no significant differences between the groups in terms of parameters above (p>0.05). However, the rate of dystocia was significantly lower in group 2 compared to Groups 1 and 3 (p<0.05). In conclusion, as a result, it was determined that slow-releasing boluses could not produce efficacy during the throughout pregnancy.

A Circular Economy Approach to Integrate Divergent Ruminant Production Systems: Using Dairy Cow Feed Leftovers to Enhance the Out-of-Season Reproductive Performance in Goats.

Based on a circular economy approach, we evaluated the possible effect of targeted supplementation with leftover feed from dairy cows (i.e., intensive system) on the reproductive performance of crossbred/rangeland goats (i.e., extensive system) in arid Northern Mexico. During the deep-anestrous season (i.e., March-April, 25° North), multiparous goats (n = 38) with a similar body weight (BW) and body condition score (BCS) were randomly assigned to two groups: (1) supplemented group (SG; n = 19; BCS: 1.76 ± 0.07; BW: 43.7 ± 1.8 kg), receiving 400 g goat d-1 of dairy-cow-feed leftovers prior to grazing; and (2) non-supplemented group (NS; n = 19; BCS: 1.76 ± 0.06; BW: 44.3 ± 2.5 kg). Both groups were directed to the rangeland for a period of ≈8 h. While the experimental period lasted 36 d, the experimental breeding considered 11 d (d0-d10). The anovulatory status of goats was ultrasonographically confirmed on days -20, -10, and -1 prior to male-female interaction. Previously, bucks were separated for 3 weeks from the experimental females and received exogenous testosterone every third day (i.e., 50 mg i.m.) prior to mating. With respect to the response variables, namely BW, BCS, blood glucose levels (BGLs), estrus induction (GIE, %), latency to estrus (LTE, h), estrus duration (ED, h), and luteal tissue volume (LTV, mm), no differences (p > 0.05) occurred between experimental groups. However, the response variables, namely goats ovulating (GO, %; 78.9 vs. 47.3), total number of corpuses luteum (TNCL, n; 27 vs. 13), ovulation rate (OR, n; 1.42 vs. 0.73), multiple ovulation (MO, %; 73.3 vs. 55.5), and pregnancy rate on d 36 (PRd36, %, 68.4 vs. 36.8), favored (p < 0.05) the SG over the NS goats. Our results demonstrate that connecting the circularity of two divergent ruminant production systems (i.e., cow-intensive and goat-extensive) by using dairy cows' feed leftovers as a targeted supplementation strategy in anestrous goats under a marginal-rangeland production system enhanced out-of-season reproductive outcomes (i.e., ovulation rate and pregnancy rate), thus benefiting marginal goat producers and their families.

Influence of hormonal induction of estrus and/or ovulation on embryo transfer success

The recipient mare is one of the most important elements in an equine embryo transfer program. Mare selection at the time of transfer is based on a number of established criteria such as uterine and cervical tone, absence of endometrial oedema after ovulation and the presence and morphology of the corpus luteum. However, recent studies suggest that other factors, such as estrus duration, have a favorable influence on pregnancy rates. The aim of the study was to determine if the pregnancy rate in recipient mares was influenced by estrous length, induction of estrus with prostaglandin F2alpha and/or induction of ovulation with hCG. Retrospective data from a commercial embryo transfer program in Northern Germany, was analyzed. A total of 1051 embryos were transferred into 880 recipient mares (2-24 years of age) during 2021. Recipient mares were evaluated ultrasonographically daily, from first signs of estrus until ovulation was detected. For the analysis of estrus length, mares were classified according to the number of days that edema was detected ultrasonographically into the following groups: short (1-3 days), medium (4-6 days) and long (7-9 days) estrus. Estrus was induced in 852 (81.06%) and ovulation was induced in 676 (64.31%) cycles. Overall pregnancy rate at day15 post-ovulation was 76.21% (801/1051). Spontaneous estrus had a lower pregnancy rate (70.85%) compared to estrus induced by prostaglandins (77.46%) (p=0.052). Nonetheless, there were no significant differences in embryo transfer success between spontaneous (79.2%) and hCG-induced (74.55%) ovulation (p=0.096). The duration of estrus had no influence on pregnancy rates when evaluating the 1051 embryo transfers. However, when evaluating each estrus length group individually, in the medium and long estrus groups there was a significant effect of ovulation induction on pregnancy rates (p=0.007, p=0.042 medium and long estrus, respectively), suggesting that hCG-induction reduced the success rate vs spontaneous ovulations (71.99% vs 84.05%) in medium length estrus, while increasing pregnancy rate in the long length group (80.85% vs 60.71%). These data suggest that the importance of estrus length on successful embryo transfer rate may be associated with factors such as estrogen exposure and ovulation. In long estrus cycles, ovulation induction may be beneficial in preventing lack of ovulation or estrogen overstimulation. However, a minimum duration of estrogen exposure is necessary to optimize gestation rates. Further studies are needed to evaluate the possible causes of these effects.

Assessing the efficacy of probiotics in augmenting bovine reproductive health: an integrated in vitro, in silico, and in vivo study.

The aim of this study was to isolate and characterize bovine-vaginal probiotics genotypically and phenotypically using in silico and evaluate their in vivo performance in buffaloes with endometritis. For the in vitro isolation and characterization, vaginal swabs were collected from 34 cows and 17 buffaloes, and 709 primary bacterial isolates with probiotic activity were obtained using MRS agar media. Two isolates Lactiplantibacillus plantarum KUGBRC (LPKUGBRC) and Pediococcus pentosaceus GBRCKU (PPGBRCKU) demonstrated optimum in vitro probiotic activities as compared to Lacticaseibacillus rhamnosus GG including, acid production, secretion of fatty acids and exopolysaccharide, cell surface hydrophobicity, self-aggregating and co-aggregating capacity with pathogens, anti-microbial activity and bacteriocin-like compounds against pathogens Escherichia coli and Staphylococcus aureus in cell-free supernatant and absence of hemolytic activity. Their phenotypic capacity was confirmed by analyzing the whole genome sequencing data and identifying genes and pathways associated with probiotic properties. These probiotic isolates have shown no virulence genes were discovered in their genomic study. In vivo study of 92 buffaloes suffering from clinical endometritis with purulent cervico-vaginal mucus (CVM) were randomly allocated 40 × 108 CFU/ml LPKUGBRC and PPGBRCKU and 40 ml Normal saline. The LPKUGBRC reduced the duration between administration of probiotic to induction of healthy estrus significantly. However, no effect was observed on pregnancy rate. These results suggest that LPKUGBRC and PPGBRCKU probiotic bacteria demonstrate probiotic efficiency and adaptability. Further sourced from the same niche as the targeted infection, they offer a distinct advantage in targeting the specific microbial population associated with endometritis. The findings of this study highlight the potential of LPKUGBRC and PPGBRCKU probiotics in treating endometritis and suggest further exploration of their clinical applications.

Subcutaneous Administration of Melatonin Resumes the Cyclicity and Improves Conception Rate in Anestrus Buffalo Heifers

The present study was aimed to see the effect of subcutaneous injection of melatonin @ 18 mg/50 kg b.wt. on estrus induction and conception rate in anestrus buffalo heifers (n=24). Among the heifers treated with melatonin (n=14), 6 (42.86 %) animals showed behavioral estrus within 4-28 days of treatment as compared to none in control group (n=10). The first service conception rate was 33.33 % (2/6) in the melatonin treated buffaloes, while none of the buffalo exhibited estrus/conceived in control group. It is concluded that melatonin @ 18 mg/50 kg b.wt. can be used to induce the estrus in anestrus buffalo heifers with satisfactory conception rate.

Development and evaluation of an injectable slow-release progesterone formulation for estrus synchronization in ewes out of the breeding season.

This study was aimed at developing a type of slow-release progesterone micro-particles useable in a single intramuscular injection for estrus synchronization in non-breeding season ewes. A total of 66 ewes were randomly assigned into four groups: CIDR (n = 16): exposed to intravaginal CIDR for 12 days, and three experimental groups, i.e., T100 (n = 16), T150 (n = 17) and T200 (n = 17), receiving a single intramuscular injection of 100, 150 and 200 mg slow-release progesterone, respectively. Blood sampling was performed on all ewes at five different times, and the ELISA method measured progesterone levels. No significant differences were observed in progesterone levels among the groups in each sampling time. More than 90% of ewes in the CIDR, T100 and T150 groups and all those in T200 showed estrus behaviour, and the rate was not significantly different between groups. The difference in the mean interval from progesterone treatment to estrus was also insignificant. The parturition rate declined by increasing the dose of injected progesterone; although it was similar in CIDR and T100 groups, it decreased significantly in T150 and T200 . Since our injectable progesterone formulation was successful in the induction and synchronization of estrus in ewes out of the breeding season, it can be applied as an alternative to the conventional progesterone containing intravaginal devices.