Duration Of Estrus Research Articles

The evaluation of an artificial intelligence system for estrus detection in sows

BackgroundGood estrus detection in sows is essential to predict the best moment of insemination. Nowadays, a technological innovation is available that detects the estrus of the sow via connected sensors and cameras. The collected data are subsequently analyzed by an artificial intelligence (AI) system. This study investigated whether such an AI system could support the farmer in optimizing the moment of insemination and reproductive performance.M&MThree Belgian sow farms (A, B and C) where the AI system was installed, participated in the study. The reproductive cycles (n = 6717) of 1.5 years before and 1.5 years after implementation of the system were included. Parameters included: (1) farrowing rate (FR), (2) percentage of repeat-breeders (RB), (3) farrowing rate after first insemination (FRFI) and (4) number of total born piglets per litter (NTBP). Also, data collected by the system were analyzed to describe the weaning-to-estrus interval (WEI), estrus duration (ED) and the number of inseminations used per estrus. This dataset included 2261 cycles, collected on farms B and C.ResultsIn farm A, all parameters significantly improved namely FR + 4.3%, RB − 3.75%, FRFI + 6.2% and NTBP + 1.06 piglets. In farm B, the NTBP significantly decreased with 0.48 piglets, but in this farm the insemination dose was too low (0.8 × 109 spermatozoa per dose). In farm C, only the NTBP significantly increased with 0.45 piglets after the implementation of the system. The WEI as determined by the system varied between 78 and 90 h, being 10–20 h shorter in comparison with the WEI as determined by the farmer. The ED, determined by the system ranged from 48 to 60 h, and was less variable as compared to the ED as assessed by the farmer. The mean number of inseminations per estrus remained similar over time in farm B whereas it decreased over time from approximately 1.6–1.2 in farm C.ConclusionThe AI system can help farmers to improve the reproductive performance, assess estrus characteristics and reduce the number of inseminations per estrus. Results may vary between farms as many other variables such as farm management, genetics and insemination dose also influence reproductive performance.

Studies on socio- economic status of donkey owners and reproductive parameters of jennet in Marathwada region of Maharashtra, India

The present study was conducted in eight district of Marathwada region, Maharashtra, India. The eighty three donkey owners were selected using pre-tested semi-structured interview schedule and socio-economic variables of donkey owners ware studied. The parameters for the study consist of age at puberty (AP), age at first service (AFS), age at first estrus (AFE), estrus cycle duration (ECD), estrus duration (ED), age at first covering (AFC), age at first conception (AFCO), no. of services/conception (NS), age at first foaling (AFF), service period (SP), foaling interval (FI), gestation period (GP), lifetime no. of foaling (LNF) were2.70±0.02 yrs., 2.79±0.02 yrs., 2.77±0.03 yrs., 6.86±0.084 days, 23.80±0.55days, 2.96±0.01yrs, 5.9±0.07yrs., 1.82±0.06, 4.44±0.01 yrs., 1.14±0.01 yrs., 2.25±0.01 yrs., 340.8±0.27 days and 5.98±0.07, respectively. At the end of the study it is concluded that the efforts are needed to improve socio-economic condition of the farmers along with systematically eliminating identified constraints. Hence sincere efforts should be made to increase awareness of the donkey owners for health care, Vaccination and regular medication and Scientific rearing practices.

Effects of intravaginal administration of prostaglandin F2α on luteolysis and subsequent estrus in Shiba goats (Capra hircus)

AbstractThis study examined the effects of intravaginal administration of prostaglandin F2α (PGF2α) on luteolysis and subsequent estrus in cycling goats. Goats with functional corpus lutea received one of five treatments: 2 mg of PG intramuscularly (IM2 × 1; n = 6), 2 mg of PGF2α intravaginally (IVG2 × 1; n = 7), 4 mg of PGF2α intravaginally (IVG4 × 1; n = 7), and 1 or 2 mg of PGF2α intravaginally 8 h apart (IVG1 × 2 group; n = 6 and IVG2 × 2; n = 8). Blood samples were collected at 24‐h intervals from 0 to 7 days after PGF2α administration. Estrus was checked twice daily during the experiment. The proportion of goats with complete luteolysis (reduction of progesterone concentrations to <1 ng/mL until 48 h after treatment) in the IVG2 × 1 group (28.6%) was significantly lower than in the other groups (IM2 × 1; 100%, IVG4 × 1; 57.1%, IVG1 × 2; 87.5%, IVG2 × 2; 100%, respectively). For goats completing luteolysis, there was no significant difference in the onset and duration of estrus among the groups. These results suggest that intravaginal administration of PGF2α can be applied as an alternative to intramuscular administration.

Basic reproductive parameters of Kathiawari horses reared under arid zone region

The current study was undertaken with an aim to record and analyse the data related to basic reproductive parameters such as length of estrus cycle, estrus duration, pre-ovulatory follicle size at ovulation, day of ovulation, length of gestation and days of occurrence of foal heat in respect of Kathiawari mares for a period of thirteen consecutive breeding seasons (2010-2023). The mares were monitored closely for their estrus signs, examined with transrectal ultrasonography for the size of the follicle variation and to determine the size of the follicle at ovulation. The mares were inseminated with the frozen thawed semen collected from Kathiawari stallions at appropriate time. This is the first time ever report that live foals have been obtained using frozen semen via artificial insemination in kathiawari horses. The data on reproductive indices of the mares of Kathiawari breed in India are scanty and there are no available reports on reproductive characteristics of Kathiawari breed until today in the literature. The results of the present findings are of much useful and may serve as a ready reckoner for the reproductive traits of Kathiawari breed reared under arid region. The differences in the reproductive parameters observed in relation to other breeds of Indian horses may be attributed to breed differences and other environmental factors.

Efficacy Evaluation of an Organic Trace Mineral (OTM) Powder Formulation on the Reproductive Performance of Heifers

Nutritional management during gestation is essential for optimizing the efficiency andprofitability of livestock production systems. Changes in maternal nutritional status may lead to such adaptations which can permanently alter the parameters of growth, physiology, and metabolism of offspring. Supplementation of essential trace minerals to pregnant cows, which are inadequate in diet to suffice the health requirement of these animals may enhance progeny performance and their health. This study investigated the impacts of supplementing Organic Trace Mineral (OTM) powder formulation on the reproductive health of heifers. The feeding experiment was performed in the Arvind Dairy Farm, Haryana, India with two groups of 6 pregnant heifer cows each (control: T0 and experimental: T1) between January and September 2022. Both groups were fed rations adjusted with regard to body weight of animals. Group T1 fed OTM at 10 gm/animal/day for 28-days and group T0 was provided access to standard basal diet only. Experimental model investigated reproductive health of heifers for the physical and clinical parameters of estrus exhibition, duration of estrus and conception rate in comparison to controls. Significant improvement observed in the physical and clinical parameters of estrus exhibition in treatment group (T1) compared to control group (T0), higher conception rate in T1 (84%) in comparison to T0 (66%); and improvement in estrus duration in T1 (27 ± 1.53 h) as compared to the T0 (31.5 ± 2.81 h), indicating supplementation of OTM to pregnant heifers has significant influence in improving reproductive health in heifers.

Some reproductive and gynecological characteristics of Morkaraman ewes

The aim of this study is to determine some reproductive and gynecological and lamb yield characteristics in Morkaraman ewes in Iğdır province, Turkey. Reproductive and fertility characteristics of Morkaraman ewes were recorded in two breeding seasons. Clinically healthy 300 Morkaraman ewes were used. Estrus duration was statistically different in the first and second breeding seasons (P=0.034). The estrus rates were 95% and 97% in seasons, respectively (P=0.211). According to the breeding seasons (first and second year), lambing rate was 90.7% and 92%, infertility rate was 5% and 3%, placental retention rate was 2.6% and 1.5%, uterine infection rate was 8.2% and 6.6%, vaginal and uterine prolapse rate was 1.8% and 2.2%, follicular cyst rate was 1.3% and 0.7%, mastitis rate was 3.7% and 2.2%, insufficient milk production rate was 2.6% and 3.6%, abortion rate was 3.2% and 4.5%, dystocia rate was 4.4% and 5.4%, congenital anomaly rate was 1.1% and 1.5%, twinning rate was 10.7% and 12%, birth weight in singleton was 3.8 kg and 3.6 kg, birth weight in twins 3.2 kg and 3.3 kg, survival rate was 94.4% and 96.5%, respectively (P>0.05). In conclusion, Morkaraman ewes show high reproductive performance, do not have many gynecological problems, and are more likely to have single births.

Monitoring estrous cycle in Brazilian dwarf brocket deer (Mazama nana) by fecal progestagen metabolites and behavior

Data on the reproductive physiology of the Brazilian dwarf brocket deer (Mazama nana) is still scarce in many aspects, such as its reproductive cycle and endocrine pattern. Therefore, this study aimed to characterize the estrous cycle (length and fecal progestagen metabolites -FPM- profile) in captive females of M. nana, by non-invasive hormonal monitoring. The study was performed with females (n = 4), housed at two different facilities: 1) in a collective enclosure at the Danilo José Galafassi Municipal Zoo, in Cascavel, Paraná, Brazil, (n = 3). 2) in an individual pen at the Deer Research and Conservation Center (n = 1), from UNESP, Jaboticabal, São Paulo, Brazil. Fecal samples were collected three times a week during two complete estrous cycles, based on behavioral observations. FPM profiles were analyzed by enzyme immunoassay (EIA). The estrous cycle length was defined as the intervals between behavioral estrus observations and fecal hormonal monitoring. The mean duration (± SEM) of the estrous cycle was 23.9 ± 0.6 days, and the mean duration of behavioral estrus was 1.6 ± 0.3 days. Mean concentrations (± SEM) of FPM for the luteal phase and inter-luteal phase were 6183.0 ± 2268.7 ng/g and 754.5 ± 216.1 ng/g, respectively.

Resumption of postpartum reproductive cyclicity and pregnancy rates after treatment with CIDR plus PGF2 α in normally calved and retained fetal membranes affected water buffaloes

An experiment was conducted to compare the estrus induction response, estrus pattern, endometrial regeneration and pregnancy rates following treatment with CIDR plus PGF2 α between normally calved (NC) and retained fetal membranes (RFM) affected water buffaloes. A total of 32 water buffaloes including 16 treated for RFM and 16 NC were selected and divided into 4 groups as I and II, and III and IV respectively. Buffaloes of group I and III were dewormed with Albendazole followed by the administration of mineral mixture in feed for 15 days. Buffaloes of all the groups were treated with CIDR intravaginally for 9 days and they received PGF2 α at 24 hours prior to CIDR withdrawal. After CIDR removal, the buffaloes of all the groups were artificially inseminated during induced estrus. Those buffaloes returned to estrus following breeding at induced estrus, were artificially inseminated twice at an interval of 24 hours. The estrus response following CIDR withdrawal was 100%. The RFM affected buffaloes had significantly longer interval to onset of estrus and shorter duration of estrus than NC buffaloes. More pronounced intensity of estrus following CIDR treatment was observed in NC buffaloes than in RFM affected buffaloes. The mean pregnancy rates obtained in NC and RFM affected buffaloes were 81.25% and 50%. Complete loss of epithelial layer, degenerative changes of endometrium and atrophic changes in the endometrial glands were observed in RFM affected buffaloes before estrus induction. After treatment, RFM affected buffaloes showed clear regeneration of endometrium and its glandular acini. It is concluded that estrus induction using CIDR plus PGF2 α might help to augment the fertility in NC and RFM affected buffaloes at field level.

Anogenital distance is associated with postpartum estrous activity, intensity of estrous expression, ovulation, and progesterone concentrations in lactating Holstein cows.

The objectives of this retrospective observational study were to determine the associations of anogenital distance (AGD) with (a) postpartum estrous activity, (b) diameter of the preovulatory follicle, (c) intensity of estrous expression, (d) postestrus ovulation, (e) corpus luteum (CL) size, and (f) concentrations of progesterone at estrus and on d 7 after estrus. Lactating Holstein cows (n = 178; 55 primiparous, 123 multiparous) were enrolled into the study during the first postpartum week. All cows were continuously monitored by a pedometer-based automated activity monitoring (AAM) system for estrus. Postpartum estrous activity was assessed using the AAM estrus alerts, in which cows with at least one true estrus alert (i.e., a relative increase in steps from each cow's baseline detected by the AAM and the presence of at least one follicle >15 mm, a CL <20 mm, or no CL detected by ultrasound) by the first 50 d in milk (DIM) were considered to have commenced estrous activity. At the estrus alert >60 DIM, ovulation was determined by ultrasound at 24 h, 48 h, and 7 d after estrus, and blood samples were collected at estrus alert and on d 7 after estrus for progesterone analysis. The AGD was measured from the center of the anus to the base of the clitoris and classified as either short- or long-AGD using 2 cut-points of 148 mm (predictive of the probability of pregnancy to first insemination; short-AGD, n = 115; long-AGD, n = 63) and 142 mm (the median AGD; short-AGD, n = 90; long-AGD, n = 88). Regardless of the cut-point used, early postpartum estrous activity by 50 DIM (67 vs. 54%), duration of estrus (11.6 vs. 9.7 h), and preovulatory follicle diameter (20 vs. 19 mm) were greater in short-AGD than in long-AGD cows. Increased peak of activity at estrus in short-AGD cows (354 vs. 258% mean relative increase) was affected by an interaction between AGD and parity in which multiparous long-AGD cows had lesser relative increase in activity than primiparous cows (217 vs. 386%, respectively). Mean progesterone concentration at estrus was lesser in short-AGD (0.47 vs. 0.61 ng/mL) than in long-AGD cows. The ovulatory response at 24 h did not differ, but at 48 h (91 vs. 78%) and on d 7 after estrus (97 vs. 84%) it was greater in short-AGD cows. Although CL diameter on d 7 after estrus did not differ, short-AGD cows had greater progesterone concentration 7 d after estrus than long-AGD cows (4.1 vs. 3.2 ng/mL, respectively). In conclusion, greater proportions of short-AGD cows commenced estrous activity by 50 DIM, had larger preovulatory follicles, exhibited greater duration of estrus, had reduced progesterone concentration at estrus, had greater ovulation rates and progesterone concentration 7 d after estrus compared with long-AGD cows, with no difference in CL size between AGD groups. Because all the differences in physiological characteristics of short-AGD cows reported herein favor improved reproductive outcomes, we infer that these are factors contributing to improved fertility reported in short-AGD cows compared with long-AGD cows.

PSVI-3 Reproductive Performance of Gilts Enrolled in the Batch Farrowing Ovugel Program Compared with Normal Breeding on Estrus Expression

Abstract The objective was to compare the fertility (pregnancy and farrowing rates, total number of piglets born) of gilts enrolled in the Batch Farrowing OvuGel Breeding Program to control gilts receiving multiple inseminations upon expression of estrus. Four breeding groups of DNA F1 gilts were blocked by heat-no-service date, body weight and age. Altrenogest was fed (15 mg/gilt/day) to gilts for 14 days. Gilts not expressing estrus prior to altrenogest (n = 16) were divided equally between treatments. The last altrenogest feeding (LAF) was designated day 0. Treatment groups were: Control (n = 182) and Batch Farrowing OvuGel Breeding Program (OG, n = 182). Control gilts were inseminated upon detection of estrus and received additional inseminations at 24-hour intervals for the duration of estrus. Treatment OG gilts that first expressed strong signs of pre-estrus and/or standing estrus on day 6 post-LAF (n = 143) were administered OvuGel and received a single insemination 20 hours post-OvuGel regardless of estrus status. Treatment OG gilts that expressed standing estrus prior to day 6 (n = 10) and for the first time on days 7–8 (n = 22) post-LAF did not receive OvuGel, but were inseminated upon detection of estrus and received additional inseminations at 24-hour intervals for the duration of estrus. Treatment OG gilts that had not expressed estrus by day 8 (n = 7) were administered OvuGel and inseminated once 20 hours later. There were no differences in pregnancy rate (P &amp;gt; 0.89, 94.0% for both OG and control), farrowing rate (P &amp;gt; 0.34), or total number of piglets born per litter (P &amp;gt; 0.83, OG = 16.3, control = 16.2) between OG and control gilts. These data indicate gilts placed on the Batch Farrowing OvuGel Breeding Program had similar fertility as gilts that received multiple inseminations upon the detection of estrus.

Determination of estrus duration based on cervical mucus characteristics in Aceh cattle using camera-equipped artificial insemination endoscope

This study aimed to determine the length of the estrus period in Aceh cows based on changes in the characteristics of cervical mucus observed using a camera-equipped artificial insemination (AI) endoscope. This study used twelve healthy and reproductively sound cows aged 4-6 years. All cows were synchronized using prostaglandin F2α (PGF2α) injected intramuscularly twice, 11 days apart. Estrus detection was conducted 24 hours following the second injection of PGF2α three times daily for 30 minutes, respectively. Estrous cows were then subjected to the examination of their cervical mucus at 0, 6, 12, and 18 hours after the beginning of estrus. This study showed that out of 12 samples, only eight cows exhibited estrus signs. Characteristics of cervical mucus of cows at 0 and 6 hours of estrus were transparent. At 12 hours of estrus, five cows showed transparency, and the remaining three cows showed cloudy cervical mucus. Meanwhile, at 18 hours of estrus, all sampled cows showed cloudy cervical mucus then regarded as the end of the estrus. That means the estrus length of Aceh cows in this study was 15.75 ± 3.11 hours. It can be concluded that the determination of the duration of estrus in Aceh cows based on changes in the characteristics of the cervical mucus can be carried out using an AI endoscope with a camera. For further research, it is suggested to apply this estrus detection technique in the implementation of AI and determine the pregnancy rate.

The efficiency of estrus synchronization protocols and artificial insemination in the Abergelle goat on-station and on-farm conditions of Northern Ethiopia

ABSTRACT This study was conducted to investigate the effect of different estrus synchronization protocols followed by artificial insemination on estrus response and the conception rate of Abergelle goats. Three estrus synchronization protocols: (i) the standard protocol associating progestogens, gonadotropins and prostaglandins (P4 + eCG + PGF2α), (ii) single injection of prostaglandin (PGFS), (iii) double injection of prostaglandin (PGFD) were evaluated and compared to a control group that did not receive a hormonal treatment. Estrus behaviour was monitored in all does and those in estrus were inseminated. The estrous response was significantly higher in P4 + eCG + PGF2α does than in counterparts in PGFS and PGFD groups (p < 0.001). Results also revealed an earlier onset of estrus in the PGFD-treated group, a longer duration of estrus for second- and third- parity -does and an earlier onset of estrus in animals having a 3.5 body condition score. Even if the conception rate (CR) was highest when using the PGFD protocol, the lowest kidding rate (KR) was obtained when using this same treatment. The P4 + eCG + PGF protocol yielded the highest litter size. Farmers’ perception surveys revealed that a higher proportion of goat keepers used a controlled mating system and had culling practices and farmers selected PGFD as a preferred protocol.

The Indonesia’s Racehorse Reproductive Performance

The need for equestrian sport is increasing for local horse grading with Thoroughbred horses used for racehorses. Pamulang Equestrian Centre is one of the horse farms in Indonesia that acts as a pioneer in creating local Indonesian racehorses. The purpose of this paper is to explain the reproductive performance of the Indonesian Kuda Pacu Indonesia (KPI) through a case study at Pamulang Equestrian Centre. Primary data was obtained directly from the documentation and interviews of the farmers. Meanwhile, secondary data was collected from literature studies. Horse farming at Pamulang Equestrian Centre was the result of breeding horses G3 with G3, G3 with G4, G4 with G4, G3 or G4 with KPI that produced KPI. Horse breeding was carried out annually during the breeding season, from August to January. The reproductive performance of male and female KPI at Pamulang Equestrian Centre was mating time from August to January, at the age of first estrus was 12-15 months, the first mating age was 4 years, estrus duration was 7 days, and duration of gestation was approximately 11 Months.

Technology Adoption Using PGF2 Alpha for Breeding

The productivity and health level of goats kept are still relatively low. This is because the maintenance system carried out by farmers is still traditional and there is no touch and technology adoption. The limited scale of ownership coupled with the spread of cage locations makes it difficult to detect estrus/estrus, the absence of superior males also causes a decrease in the genetic quality of livestock. This study aims to find a method of breeding in sheep using reproductive engineering mating techniques to obtain an applicable goat breeding model. Research Design 10 ewes that are not pregnant, prepared for natural mating with the joint bull mating model. The treatment for the ewes was prepared for estrus synchronization reproductive technology using prostaglandins with two doses. The livestock group was induced by intramuscular estrus as much as 0.5; 1; 1.5; and 2 cc per head using the hormone PGF2 alpha (lutalyse). The injection is done with two injections (double injection) with an interval of 11-12 days. Two days after the application of the hormone, the goat showed estrus, then observed the percentage of estrus, estrus intensity and estrus strength. The results showed that all doses that had been given gave good results on the onset of estrus, standing heat, duration of estrus, intensity of estrus and after the second injection with a distance of 11 days all treatments showed 100 percent estrus. Days 14 to 18 after treatment were the peak period with the highest intensity of estrus and standing heat in goats. Giving a dose of prostaglandin 2 ml has been effective and more economical in estrus synchronization to produce quality estrus symptoms.

LH pattern and ovarian response in ovsynch-synchronized superovulated goats induced to ovulate with GnRH or hCG

The intention of the present investigation was to compare a GnRH agonist and hCG as ovulation inducing agents to apply fixed-time insemination in ovsynch synchronized superovulated goats. Three groups of 17 does of the Boer goat breed were synchronized, superovulated and ovulation induced with a GnRH analog, hCG or physiological saline, followed by mating and non-surgical embryo collection. Part of the does were provided with subcutaneous progesterone implants after mating to compensate for frequently occurring premature corpus luteum regression. Estrus detection was conducted with aproned bucks, ovarian function was monitored sonographically and by progesterone analyses and blood samples were drawn to generate LH profiles. Practically all does responded to treatment and occurrence and duration of estrus as well as the ovulatory response were unaffected by treatment. The LH surge provoked by administration of the GnRH analog buserelin emerged within 1.0 h and was closely synchronized, significantly more so than after administration of hCG or physiological saline, commencing after 11.8 and 14.9 h, respectively, with no significant differences amongst each other. It would seem that hCG is not effective in bringing about a LH surge. The interval between commencement of the LH surge and ovulation was, across treatment groups, 24.2 h with no significant difference among groups. Ovulatory response and yield of transferable embryos obtained by nonsurgical collection were modest with no significant differences among groups.

Comparison of GnRH and hCG effects on oestradiol, progesterone and premature luteolysis in Ovsynch-synchronized ewes.

The purpose of this study was to ascertain whether premature luteolysis can be alleviated by substituting the ovulation inducing agent hCG for GnRH. Seventy-two hours after the end of artificial insemination (AI), pluriparous Awassi ewes were randomly assigned to one of three treatment groups of 13 ewes each. First group received 37.5µg of the GnRH analog Lecirelin, the second 1000I.U hCG and the third group served as a control (received 1ml of physiological saline solution). Blood samples were collected at daily intervals after GnRH treatment and analysed for plasma oestradiol and progesterone concentrations. Ovarian follicles were monitored ultrasonically at the time of GnRH administration, 60hr and 84hr later. Pregnancy was diagnosed ultrasonically at Day 35 after AI. Number and size of ovarian follicles did not differ (p>.05) among treatment groups. Onset and duration of oestrus were not affected by treatment (p>.05). No significant differences (p>.05) were recorded in oestradiol and progesterone concentrations between the treatment groups during the inspection period. Premature luteolysis became evident in ewes with longer oestrous durations by Day 6.25 after AI and amounted to 7.69%, 18.18% and 23.07% in GnRH, hCG and Control groups respectively. Pregnancy rates increased to 92.31% and 81.82% in GnRH and hCG groups, compared to 76.92% in the Control group. The results indicate that GnRH was more effective in reducing premature luteolysis than hCG. Substituting hCG for GnRH as an ovulation inducing agent was of no avail.

Efficiency of Copper and Selenium during Estrus Synchronization on Estrus Behaviour, Estradiol and Progesterone Concentration in Salem Black Goats

Background: Copper and selenium were proven modulaters of reproductive function in ruminants under dietary supplementation. Their effects under pareneral administraton during estrus synchronization are not clearly defined. On this background the present was aimed to evaluate the effect of copper and selenium on estrus associated responses in goats. Methods: Thirty adult female Salem black goats were selected. On day ten of the estrus cycle, 250 µg of cloprostenol injection was given intramuscularly to all the animals and assigned to five groups. GI: control, GII: 4 µg of Buserelin, GIII: 20 mg cupric chloride, GIV: 10 mg sodium selenite and GV: copper plus selenium injections were administrated. Whole blood was collected for seven days for hormone assay. Estrus was detected using aproned bucks. Result: There was no significant (p greater than 0.05) difference in estrus response, onset and duration of estrus between groups. The progesterone concentration decreased significantly (p less than 0.05) from day 0 (before PGF2α) to day 1 (after PGF2α) in all groups. There was a significant (p less than 0.05) increase in estradiol and progesterone concentration in the GnRH group compared to other groups. Parenteral administration of copper and selenium did not significantly improve estrus behavior, estradiol and progesterone concentration in Salem black goats. GnRH was once again proved to be effective in the improvement of estrus associated responses in goats.

Estrus and fertility responses in acyclic ewes treated with short, medium or long-term GnRH-PGF2α-GnRH protocols supplemented with intra-vaginal progesterone therapy

The present study was conducted with the aim to compare the effectiveness of the short-term (5 days), moderateterm (8 days) and long-term (12 days) progesterone therapy in the form of intravaginal AVIKESIL-S® progesterone sponge developed by CSWRI, Avikanagar (Rajasthan), during modified GnRH-PGF2α-GnRH treatments during non-breeding season (May-July) in crossbred (Nali×Rambuillet) ewes. The seasonal anestrus ewes were enrolled into four groups. In Group 1 (n=50), ewes were treated with GnRH on day 0, PGF2α on day 5, and second GnRH on day 7 plus progesterone supplementation with intravaginal progesterone sponge from day 0 to day 5 while in Group-2 (n=50), ewes were treated with GnRH on day 0, PGF2α on day 8, and second GnRH on day 9 plusprogesterone supplementation with intravaginal progesterone sponge from day 0 to day 8. Further, in Group 3(n=50), ewes were treated with GnRH on day 0 and PGF2α on day 12 and second GnRH on day 13 plus progesteronesupplementation with intravaginal AVIKESIL-S® sponge from day 0 to day 12. Group 4 (n=50), comprised ofuntreated control animals. Results showed that estrus synchronization rate (%) was significantly higher in Group 2and Group 3 in comparison to Group 4 (control). There was significant difference in the duration of estrus, pregnancy rate, lambing rate in Group 2 as compared to Group 4 (control) but prolificacy and fecundity were not statistically significant (p&gt;0.01) among the groups during out of breeding season. Thus, modified Ovsynch protocol with 8-day progesterone therapy is better for augmenting fertility in crossbred ewes during non-breeding season.

Продължителност на еструса и половия цикъл при кобили от породата Хафлингер

A study of the duration of oestrus and estrous cycles in mares from Haflinger breed (HB) and the influence of some factors was conducted. The records used for this study were from the breeding registers of the mares from the State Stud farm Kabiuk near Shumen, covering a period of 11 years (2009 to 2020). In the study were included 15 mares with 110 estruses and 22 estrous cycles. With the mares from Haflinger breed, the average duration of oestrus is 5.52 ± 0.26 days and the length of the estrous cycle is 24.21 ± 1.13 days. The year (P<0.001), month (P<0.001), season (P<0.05), and length of the estrous cycle - the year of fertilization (P<0.05) had reliable influence on the duration of oestrus. In Haflinger mares, the shortest estrus is in the middle and at the end of the breeding season (March: 4.39 ± 0.46 days, July: 3.33 ± 0.82 days). Its duration increases during the winter season and reaches its peak in the middle of spring (February: 5.96 ± 0.51 days, April: 8.37 ± 0.72 days).

Ovarian follicular dynamics in peripubertal Malabari goats

The aim of this study was to characterise the follicular dynamics in first two oestrous cycles of peripubertal Malabari goats. Transrectal ultrasonography was carried out on alternate days of oestrous cycles after first observed oestrus. Follicular studies revealed presence of two to five wave cycles with predominant three and four wave patterns. The interwave interval for ovulatory wave was longer than preceding waves in three and five wave cycles. The diameter of largest follicles in wave 1 was larger than follicles of subsequent waves of three, four and five wave cycles. The largest follicles in each wave could be observed from day 3 to day 13 of oestrous cycle. Majority of ovulations occurred on day 20 of oestrous cycles and short cycles were more in first oestrous cycle. The overall mean per cent of single and double ovulations were 56.3 and 43.8 and mean ovulatory follicle size was 6.59 ± 0.11 mm in peripubertal goats. The mean length of first and second oestrous cycle was observed as 17.72± 0.79 and 20.19± 0.43 days, respectively and mean duration of first and second oestrus was 36.88 ± 2.44 and 40.13 ± 1.84 h, respectively. The study revealed that predominant wave pattern was three and four waves in peripubertal Malabari breeds. The first oestrous cycle length was shorter and characterised by higher percentage of single ovulations with smaller periovulatory follicle size. Larger ovulatory follicles and double ovulations were observed in second oestrous cycle.