Oestrous Ewes Research Articles

The Effect of Prolactin on Gene Expression and the Secretion of Reproductive Hormones in Ewes during the Estrus Cycle.

Prolactin (PRL) plays an important role in animal follicle development and ovulation. However, its regulatory effects on the different stages of the estrus cycle in ewes are unclear. In this study, bromocriptine (BCR, PRL inhibitor) was used to study the effect of PRL on the secretion of reproductive hormones and gene expressions in order to explore its regulatory effects on the sexual cycle of ewes. Eighty healthy ewes with the same parity and similar weights were randomly assigned to the control group (C, n = 40) and the treatment group (T, n = 40, fed bromocriptine). After estrus synchronization, thirty-one ewes with overt signs of estrus were selected from each group. Six blood samples were randomly obtained by jugular venipuncture to measure the concentration of PRL, estrogen (E2), progesterone (P4), luteinizing hormone (LH), follicle-stimulating hormone (FSH), and gonadotropin-releasing hormone (GnRH) in the proestrus, estrus, metestrus, and diestrus. At the same time, we collected the ovaries of the six ewes in vivo after anesthesia in order to detect follicle and corpus luteum (CL) counts and measure the expression of hormone-receptor and apoptosis-related genes. The results show that PRL inhibition had no significant effects on the length of the estrus cycle (p > 0.05). In proestrus, the number of large and small follicles, the levels of E2, FSH, and GnRH, and the expressions of ER, FSHR, and the apoptotic gene Caspase-3 were increased (p < 0.05); and the number of middle follicles and the expression of anti-apoptotic gene Bcl-2 were decreased (p < 0.05) in the T group. In estrus, the number of large follicles, the levels of E2 and GnRH, and the expressions of the StAR, CYP19A1, and Bcl-2 genes were increased (p < 0.05), and the number of middle follicles was decreased (p < 0.05) in the T group. In metestrus, the number of small follicles and the expression of LHR (p < 0.05) and the pro-apoptotic gene Bax were increased (p < 0.05); the number of middle follicles was decreased (p < 0.05) in the T group. In diestrus, the number of large follicles, middle follicles, and CL, the level of P4, and the expressions of PR, 3β-HSD, StAR, Caspase-3, and Bax were increased (p < 0.05); the number of small follicles and the expression of Bcl-2 were decreased (p < 0.05) in the T group. In summary, PRL inhibition can affect the secretion of reproductive hormones, the follicle count, and the gene expression during the estrus cycle. These results provide a basis for understanding the mechanisms underlying the regulation of the ewe estrus cycle by PRL.

Особенности гормональной регуляции индуцированного полового цикла овцематок

The purpose of the study is to identify patterns of changes in the content of progesterone, FSH, LH and free estriol under various options for inducing the reproductive cycle of ewes with hormonal drugs. Objectives: during the period of spring anaphrodisia, to stimulate sexual oestrus in ewes using a double injection of estrofan; during the same period, to stimulate sexual estrus in ewes according to the follimag-progestamag, surfagon scheme; to study the nature of changes in the content of sex hormones in the blood serum of ewes during the implementation of the specified schemes for stimulating sexual heat; to identify the pattern of dynamics of sex hormones in ewes during an induced sexual cycle. The study was conducted in the Orenburg Region in April 2022 on Romanov breed ewes. Three groups of ewes of 12 heads each were formed. The age of the sheep is 3–5 years, live weight is 30–35 kg. The experiment was carried out against the background of fortification of sheep with E-selenium. In groups I (control) and II, animals were administered E-selenium on the 1st and 11th days of the experiment, in group III – on the 1st and 8th days. Hormonal stimulants were not used in the control; in group II, sheep were administered estrofan on days 1 and 11 and surfagon on the 13th day of the experiment; in group III, follimag was used on the 1st day, progestamag and surfagon on the 8th day. To determine the hormone content, blood was taken from the jugular vein from all animals on the 1st, 8th, 11th, 13th, and 14th days of the experiment. When stimulating sexual heat in ewes during seasonal anaphrodisia, the most pronounced hormonal response was obtained using injections of follimag and progestamag with surfagon at weekly intervals. When using this regimen, the levels of free estriol and LH reached their maximum values by the 11th day from the start of stimulation, creating optimal conditions for ovulation. After stimulating sexual heat in ewes, it is advisable to begin mating or insemination on the 10th–11th day.

Factors and Treatment of Anestrus in Ewes

In normal circumstances, the average time of estrus cycle is 22 days, and the duration is about 1-4 days, which has obvious and typical external estrus characteristics. However, there are also some ewes, the regularity of estrus is not in line with the normal estrus of the ewe, influenced by physiological, nutritional composition, disease, age, stress and other factors. Whether abnormal estrous ewes are frozen sperm mating, fresh sperm mating or not, their conception rate is significantly lower than the normal estrous ewe individual or groups. This paper gives a brief and detailed introduction to the reasons for the occurrence of non-estrus and abnormal estrus in several ewes. The growth hormone stimulating estrus of ewes has long become a necessary technical method in the sheep industry. This technical method has improved the breeding rate of ewes and the economic profit of the farm, and has been widely promoted and applied in many farmers.

Effect of GnRH and hCG Treatment Following a Short-Term Estrus Synchronization Protocol on Ovulation and the Fertility in Merino Ewes, During the Breeding Season

This study aimed to compare the effect of hCG or GnRH administered 36 h following a short-term estrus synchronization treatment on the ovulation time and pregnancy rates of Merino ewes during the breeding season. The estrus cycles of ewes were synchronized with an intravaginal sponge containing 60 mg of medroxyprogesterone acetate for 6 days, and an injection of 400 IU of eCG and 125 µg of d-cloprostenol 24 h before sponge removal. Thirty-six h after the sponge removal, ewes were injected intramuscularly either 1 ml of physiological saline solution (control-group; n=14), 100 IU of hCG (hCG-group; n=14) or 0.004 mg of buserelin acetate (GnRH-group; n=14). The estrus behavior was observed using teaser rams and the ovulation time was monitored using transrectal ultrasonography twice daily for 96 h after the sponge removal. Ewes in estrus were allowed a single mating using fertile rams. Estrus response was higher (P&lt;0.05) in the control group (92.86%) than in the GnRH group (50.00%). The interval from sponge removal to ovulation and from hCG to ovulation were shorter in the control group than in the hCG group (70.55, 80.83 h; 34.55, 44.83 h, respectively, P&lt;0.05). In conclusion, administration of hCG or GnRH at 36 h following a short-term estrus synchronization protocol did not affect estrus behaviors, ovarian findings and pregnancy rates in ewes during the breeding season.

Evaluation of the efficiency of estrus synchronization protocols combined with natural service and ultrasonography on ewe reproductive performance during non-breeding season.

Estrus synchronization is an important assisted reproductive technology to improve the reproductive performance in ewes. Various protocols have been used with variable success rates, however; literature regarding field applicable estrus synchronization is meagre. The present study was designed with the aim to evaluate the estrus synchronization protocols on reproductive performance in ewes using different hormones. Experimental ewes were divided randomly into three groups (n=15). Ewes of all groups received intravaginal sponge for 12 days. Subsequently, NP4-GnRH and NP4-eCG groups received 8 µg of buserelin acetate or 200 IU of eCG intramuscularly, respectively on day 12 whereas NP4-Insulin group received insulin 0.2 IU/kg body weight subcutaneously for three consecutive days started on the day of sponge removal. Estrus detection commenced 24 h after sponge removal in NP4-GnRH and NP4-eCG groups and 24 h following last injection of insulin in NP4-Insulin group. The ewes in estrus were separated and pen mated. The conception rate was determined by ultrasonography. The estrus response and conception rates were 71.43, 92.86 and 53.85%, and 70.00, 84.61, and 71.43%, respectively in NP4-GnRH, NP4-eCG, and NP4-Insulin groups. The lambing rates were the same as the conception rates. The single and multiple birth rates were 71.41, 36.36 and 60.0%, and 28.57, 63.64, and 40.0% whereas prolificacy was 128.57, 190.91, and 140.00%, respectively in NP4-GnRH, NP4-eCG, and NP4-Insulin groups. In conclusion, the estrus synchronization protocol including intravaginal progesterone sponge and eCG was found to be more effective under field conditions.

Sexual behaviour of young rams is improved and less stressful after intranasal administration of oxytocin

The aim of this study was to determine if intranasal administration of oxytocin modifies sexual behaviour and the stress response in young rams during sexual tests with ewes in oestrus. Ten rams were used in a cross-over design. At Day 0, the control group (CG, n = 5) received isotonic saline spray intranasally, and the treated group (OTG, n = 5) received oxytocin (24 IU) intranasally, 40 min before the sexual test. At Day 15, the groups were reversed. In each sexual test (20 min) with an oestrous-induced ewe, the sexual behaviour of the young rams was recorded. Serum cortisol concentrations were determined before and after the test. Less flehmen was observed in the OTG, but mounts with ejaculation were increased. The OTG presented lower serum cortisol concentration than the CG. In conclusion, intranasal administration of oxytocin modified the sexual behaviour of rams, evidenced by a decrease in flehmen behaviour and an increase in mounts with ejaculation, making sexual activity more efficacious. In addition, the treatment decreased the stress response of the rams in the sexual tests. Therefore, intranasal administration of oxytocin could be used to increase sexual activity in rams, and with less stress, providing better welfare 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.

Estrous, ovulation and reproductive responses of ewes synchronized with a long interval prostaglandin–based protocol for timed AI

The aim was to characterize and assess the reproductive performance of a long interval prostaglandin (PG)–based protocol for timed AI (TAI) at different times. During breeding season three experiments were done involving 622 Merino ewes, 11 rams, and five androgenized wethers per 100 ewes. All ewes were estrus synchronized with two PG injections 15–day apart (PG15): Day −15 and 0 (Hour 0). Estrous distribution respect to Hour 0, estrous response and synchrony after Hour 0, and interval from Hour 0 to estrus detection (PG–estrus) was evaluated (Experiment I; n = 105 ewes). Interval from estrus detection to ovulation (estrus–ovulation) and from Hour 0 to ovulation (PG–ovulation) was determined (Experiment II; n = 12 ewes). Visual–physical score of cervical mucus at TAI, non–return to service to Day 23 (NRR23), fertility, prolificacy, and fecundity to Day 60 in four cervical fresh semen TAI groups was evaluated (Experiment III; n = 505 ewes; 107 nulliparous-398 multiparous). Three groups with single service at 56 (Control), 44 or 68, and one with double service at 44 and 68 ± 1.5 h after Hour 0 (PG15–56, PG15–44, PG15–68, and PG15–44/68 groups, respectively) were tested. Ninety-eight-point one percent of the ewes showed estrus from Hour −48 up to 84 respects to Hour 0. Twenty percent of them showed estrus from Hour −48 up to 0, and 78.1 % from Hour 12 up to 84 (Experiment I). The largest proportion of ewes in estrus was observed between Hour 36 and 60 (80.5 %). PG–estrus interval was 54.1 ± 10 h (means ± SD). Estrus–ovulation interval was 32.4 ± 5.8 h, and PG–ovulation interval was 77.0 ± 16.6 h (Experiment II). Ewe parity did not affect any of the reproductive variables (P > 0.05; Experiment III). There were no significant differences (P > 0.05) between Control and different groups in mucus score (2.18 ± 0.08, 2.02 ± 0.07, 2.14 ± 0.09, 2.25 ± 0.10), NRR23 (76.0, 71.9, 78.6, 79.4 %) or fertility (66.4, 64.1, 66.7, 73.8 %; PG15–56, PG15–44, PG15–68 or PG15–44/68 groups, respectively). Prolificacy in PG15-44 group was lower (1.07 ± 0.03; P < 0.05) than other groups (1.27 ± 0.05, 1.23 ± 0.05, 1.20 ± 0.04), and fecundity than PG15–44/68 group (0.84, 0.69, 0.82, 0.89), without differences among other groups (PG15–56, PG15–44, PG15–68 or PG15–44/68 groups, respectively). We concluded that any time between 56 and 68 h after PG15 protocol could be used to perform cervical TAI using fresh semen, without benefits of a double TAI service at 44 and 68 h.

FEATURES OF EFFECTIVE BREEDING METHODS TO IMPROVE THE REPRODUCTION ABILITY OF KAZAKH ROUGH-WOOLED SHEEP

The article presents the materials of the most valuable quality of fat-tailed sheep, along with high precocity, regular fertility is the high viability of the offspring, which serves as an objective criterion for their adaptive ability to various paratypes factors and to study the reproductive productivity of Kazakh fat-tailed sheep in two flocks, 1165 freshly received ewes were cervically inseminated sperm of Kazakh fat-tailed rams. Ewes in natural estrus were detected once daily in the morning from 7 to 8 a.m. with the aid of the teaser rams. Sperm from 6 sire-rams was collected with the aid of an artificial vagina. Double cervical insemination was performed at 9-10 a.m. and 4-5 p.m. On average 78% or 921 ewes out of 1165 inseminated lambed ranging from 76% to 81% in two flocks. Total of 1080 lambs were born, or 117.3 lambs per 100 lambed ewes. Body weights in the single newborn ram and ewe lambs were 5.04±0.07 (n=108) and 4.44±0.07 kg (n=98), while in the twin males and females were 3.94±0.08 (n=20) and 3.79±0.09 kg (n=18), respectively. It is concluded that Kazakh fat-tailed sheep have a high reproductive capacity.

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.

A Recognition Method of Ewe Estrus Crawling Behavior Based on Multi-Target Detection Layer Neural Network.

There are some problems with estrus detection in ewes in large-scale meat sheep farming: mainly, the manual detection method is labor-intensive and the contact sensor detection method causes stress reactions in ewes. To solve the abovementioned problems, we proposed a multi-objective detection layer neural network-based method for ewe estrus crawling behavior recognition. The approach we proposed has four main parts. Firstly, to address the problem of mismatch between our constructed ewe estrus dataset and the YOLO v3 anchor box size, we propose to obtain a new anchor box size by clustering the ewe estrus dataset using the K-means++ algorithm. Secondly, to address the problem of low model recognition precision caused by small imaging of distant ewes in the dataset, we added a 104 × 104 target detection layer, making the total target detection layer reach four layers, strengthening the model's ability to learn shallow information and improving the model's ability to detect small targets. Then, we added residual units to the residual structure of the model, so that the deep feature information of the model is not easily lost and further fused with the shallow feature information to speed up the training of the model. Finally, we maintain the aspect ratio of the images in the data-loading module of the model to reduce the distortion of the image information and increase the precision of the model. The experimental results show that our proposed model has 98.56% recognition precision, while recall was 98.04%, F1 value was 98%, mAP was 99.78%, FPS was 41 f/s, and model size was 276 M, which can meet the accurate and real-time recognition of ewe estrus behavior in large-scale meat sheep farming.

Synchronization of estrus using progesterone injections followed by human menopausal gonadotropin in ewes.

Serial progesterone injections followed by human menopausal gonadotropin (hMG), instead of equine chorionic gonadotropin (eCG), were used to synchronize estrus in ewes. Shal ewes (n = 189) were assigned into five groups and each group was divided into two sub-groups to receive gonadotropins including eCG (300 IU; intra-muscular) or hMG (one ampoule; subcutaneously, SC). All ewes received prostaglandin (PG) F2α six days after introducing ram (day 0). Ewes received 0 (control), one, two, three or four injections of progesterone (50.00 mg; SC), 72 hr apart. The first progesterone was injected at the time of PG injection. Ewes in treatment groups received gonadotropins 48 hr after the last progesterone injection. Control group ewes received gonadotropins, at the time of PG injection. Mating was recorded after introducing fertile rams. Data were analyzed using GLM and GENMOD procedures in SAS. The incidence of estrus was less in control and ewes received a single progesterone (34.20%) compared to ewes received two (64.10%), three (81.10%) and four injections (68.40%) of progesterone. Time to estrus was earlier in control (45.70 ± 4.41 hr) than progesterone-treated groups (63.60 ± 1.79 hr). Fertility (51.30%) and fecundity (78.40%) of ewes received three progesterone injections were significantly greater than other progesterone-treated groups. There was no significant difference in reproductive indices between eCG and hMG sub-groups. In conclusion, during the non-breeding season, three injections of progesterone, three days apart, starting six days after ram exposure, in association with hMG, 48 hr after the last progesterone injection, could provide a sound reproductive performance in Shal ewes.

Sex or maternal care? Nursing oestrous ewes prefer to interact with rams over their lambs

In some sheep production systems, the ewes are induced to come into oestrus whilst nursing their lambs. After that, mothers and offspring are usually moved into a paddock with sexually active rams leading to a conflict between sexual and maternal motivations. The aim of this study was to determine if a nursing oestrous ewe prefers its lamb or a sexually active ram in a two-choice test with full physical contact. During the breeding season, 23 multiparous Corriedale ewes nursing single lambs were induced to come into oestrus 72 days after parturition. Twenty ewes came into oestrus and were tested in a two-choice test with full physical contact between their single lamb and a sexually active ram. The latency to enter into a contact area surrounding each stimulus (ram or lamb) and the time spent in each area were recorded for 3 min. The number of vocalisations emitted by the lambs and the sexual behaviour displayed by the rams were also recorded. One nursing oestrous ewe did not enter any defined area and was excluded from the analysis, which included 19 tests. Nursing oestrous ewes entered earlier (X2 =8.05; P = 0.005; Survivance test) and stayed longer (Z = −2.74; P = 0.006; Wilcoxon Signed-Rank test) in the ram's contact area than in the lamb's contact area. During the test, rams almost always displayed sexual behaviours when ewes entered their contact area (17/19 tests). The lambs vigorously vocalised during the test (19.7 ± 2.5 bleats/test), but the number of vocalisations was not related to the time the ewe spent near the lamb or the ram. In conclusion, nursing oestrous ewes strongly prefer sexually active rams over their lambs during the breeding season. This result gives rise to a greater understanding of sexual behaviour in the ewe, which may very well impact the reproductive management of sheep.

PSI-6 The Influence of a Single Administration of Prostaglandin on Estrus Synchronization in Range Sheep Production

Abstract Administration of a single injection of prostaglandin after ram introduction has previously been reported as an effective method to synchronize estrus in ewes housed in a dry lot setting. The objective of this study was to investigate the effectiveness of a single injection of prostaglandin administered at the beginning of the breeding season after ram introduction, on estrus synchronization in range ewes. Western Whiteface cross ewes, of which thirty-six were ½ blood South African Meat Merino (SAMM) and seventeen ¼ blood SAMM (total n=53) were assigned to one of two treatments: control (CON; n=26) or one injection of prostaglandin (PG; n=27). Ewes were utilized in a complete randomized block design and were stratified by SAMM percentage, body condition score (BCS) and age. Ewes assigned to PG treatment were administered 3 mL of prostaglandin IM (Lutalyse, Zoetis Animal Health) approximately 60 h after rams were introduced with ewes. Rams (n=4) were applied with marking paint and placed with ewes on (d 0: December 21) and remained for the duration of the 56 d breeding season for natural service. Ewes were observed for estrus twice daily at 0730 h and 1700 h for d 0-10 and d 16-21 of the breeding season, by an experienced evaluator. At lambing, birth weight, sex, and type of birth was recorded. The MIXED and GLIMMIX procedures of SAS were used to analyze estrus response, ewes bred in the first 5 d of the breeding season, days to lambing, lambing date, number of lambs born, and lamb weight. South African Meat Merino percentage was included as an independent variable but was found to be nonsignificant and was removed from the statistical model. The proportion of ewes bred during the first 5 d of the breeding season was not different among the two treatments (P ≥ 0.60). There was no difference between the PG ewes and the CON ewes for the date of estrus (P ≥ 0.82). There was no difference between the PG ewes and the CON ewes for the lambing date (P = 0.60). Treatment did not influence days to lambing (P ≥ 0.25). The number of lambs born per ewe tended to be influenced by treatment (P &amp;lt; 0.08), with PG ewes tending to have more lambs than CON ewes. Lamb weights were not different among treatments (P ≥ 0.50). In conclusion, the administration of a single PG injection after ram exposure did not influence estrus expression, days to lambing, or lambing date, however, PG ewes did tend to have more lambs.

A Lightweight Neural Network-Based Method for Detecting Estrus Behavior in Ewes

We propose a lightweight neural network-based method to detect the estrus behavior of ewes. Our suggested method is mainly proposed to solve the problem of not being able to detect ewe estrus behavior in a timely and accurate manner in large-scale meat sheep farms. The three main steps of our proposed methodology include constructing the dataset, improving the network structure, and detecting the ewe estrus behavior based on the lightweight network. First, the dataset was constructed by capturing images from videos with estrus crawling behavior, and the data enhancement was performed to improve the generalization ability of the model at first. Second, the original Darknet-53 was replaced with the EfficientNet-B0 for feature extraction in YOLO V3 neural network to make the model lightweight and the deployment easier, thus shortening the detection time. In order to further obtain a higher accuracy of detecting the ewe estrus behavior, we joined the feature layers to the SENet attention module. Finally, the comparative results demonstrated that the proposed method had higher detection accuracy and FPS, as well as a smaller model size than the YOLO V3. The precision of the proposed scheme was 99.44%, recall was 95.54%, F1 value was 97%, AP was 99.78%, FPS was 48.39 f/s, and Model Size was 40.6 MB. This study thus provides an accurate, efficient, and lightweight detection method for the ewe estrus behavior in large-scale mutton sheep breeding.

Farmers' Characteristics Associations with the Knowledge for Sheep Estrus Detection in Batur Village, Banjarnegara, Indonesia

The accuracy of the estrus detection was important in sheep breeding management. This study aimed to determine the correlation between the farmers’ characteristics and the knowledge on estrus detection of their sheep. The data were collected by interviewing 33 farmers, who have raised sheep with a breeding system for at least two years of experience in Batur Village, Banjarnegara, Indonesia. The farmers’ knowledge for estrus detection was divided into three-level, namely low, medium, and high levels. The results showed that the farmers’ knowledge for estrus detection was 51.5%, 27.3%, and 21.2% on the low, medium, and high levels, respectively. There was a significant relationship between formal education, informal education, number of sheep, the sheepfold position, stay duration in the sheepfold, and the ram ownership for mating toward knowledge of estrus detection level. It can be concluded that there is a relationship between farmer characteristics in Batur Village and the ability to detect estrus in ewes, which is dominated at low levels, so it is necessary to increase farmers' knowledge regarding estrus detection.

Evaluation of hormonal protocols for induction of synchronized estrus on reproductive indices in Kangal-Akkaraman ewes during the outbreeding season

The objective of this study was to assess the effect of human chorionic gonadotropin (hCG) and gonadotropin-releasing hormone (GnRH) treatment before sponge insertion and anti-Müllerian hormone (AMH) concentration in ewes which were either pregnant or non-pregnant during the previous breeding season. In the study, 375 (3–6-year-old) Kangal-Akkaraman ewes that conceived or did not conceive in the preceding breeding season, and 36 rams (3–6-year-old) were used. The sheep were randomly divided into 5 equal groups. Blood samples were taken before stimulation (day −4), the day stimulation was initiated (day 0), after stimulation (day 9), on the mating day (days 11–12). AMH concentrations were measured in the samples taken on − 4th day. As a conventional method, a sponge containing 20 mg of flugeston acetate (Chronogest® CR, MSD, Turkey) was placed intravaginally (day 0) into to study ewes. The ewes were intramuscularly administered 131.5 µg prostaglandin F2α (Estrumate, MSD, Turkey) and 600 IU equine chorionic gonadotropin (Chronogest® PMSG 6000, MSD, Turkey) simultaneously with sponge removal 9 days after insertion. No other treatment was applied to group 5 which served as control. Ewes in groups 1, 2, and 3 received an intramuscular injection of GnRH (4.2 µg of Buserelin acetate, Receptal, MSD, Turkey) at the time of insertion of progesterone sponge. GnRH or 600 IU hCG (Chorulon®, MSD, UK) was administered 4 days prior to sponge insertion for the ewes in the groups 2, and 3, respectively. As for the group 5 group, hCG (instead of GnRH) was administered to the ewes at the beginning of the progesterone treatment. Ewes in estrus were detected with a teaser ram and taken into a different pen with rams. Transrectal ultrasonography (Mindray DP50/Vet/US, rectal probe) was achieved during days the 30–35 following mating. Transabdominal ultrasonography was achieved during days 60–65 to detect late embryonic and early fetal death. The estrus rate was 71.19 % out of breeding season for all ewes. The pregnancy rate on day 30 post-mating was 32 % in the control group and was 31.00 %. No significant differences were observed between groups for pregnancy rates on day 30. The mean pregnancy rate in sheep that conceived and did not conceived in the preceding breeding season of the study was 32.03 % and 32.06 % respectively (P > 0.05). After treatments, AMH concentrations in non-pregnant were significantly higher than pregnant ewes (P < 0.005). In conclusion, although the AMH concentration is significantly higher in non-pregnant ewes, the AMH concentration may not be a suitable biomarker to predict induction success outside breeding season. Progesterone-based protocols may achieve an acceptable reproductive outcome in lactating ewes and the ones which experienced infertility.

Correlation analysis of serum reproductive hormones and metabolites during multiple ovulation in sheep

BackgroundThe establishment of non-invasive diagnostic method for multiple ovulation prediction is helpful to improve the efficiency of multiple ovulation. The blood hormones and metabolites would be suitable indexes for this subject.MethodsIn this study, 86 estrus ewes (65 of induced estrus (IE) and 21 of spontaneous estrus (SE)) were selected and the blood samples were collected at the day before follicle-stimulating hormone (FSH) injection (1st) and before artificial insemination (2nd). The serum reproductive hormones ofFSH, luteinizing hormone (LH), 17β-Estradiol (E2), progesterone (P4) and anti-Mullerian hormone (AMH) were measured through enzyme linked immunosorbent assay (ELISA) and the untargeted metabolomics analysis was processed through LC–MS/MS. The embryos were collected after 6.5 days of artificial insemination.ResultsIn total, 975 and 406 embryos were collected in IE and SE group, respectively. The analysis of reproductive hormones showed that concentrations of FSH, E2 and AMH were positive correlated with the embryo yield while concentrations of LH and P4 were negative correlated in both group at 1st detection. At 2nd detection, the trends of reproductive hormones were similar with 1st except P4, which was positive correlated with embryo yield. The metabolomics analysis showed that 1158 metabolites (721 in positive iron mode and 437 in negative iron mode) were detected and 617 were annotated. In 1st comparation of high and low embryonic yield populations, 56 and 53 differential metabolites were identified in IE and SE group, respectively. The phosphatidyl choline (PC) (19:0/20:5) and PC (18:2/18:3) were shared in two groups. In 2nd comparation, 48 and 49 differential metabolites were identified in IE and SE group, respectively. The PC (18:1/18:2) and pentadecanoic acid were shared. Most differential metabolites were significantly enriched in amino acid, fatty acid metabolism, digestive system secretion and ovarian steroidogenesis pathways.ConclusionsThis study showed that FSH, P4, AMH, the PC relevant metabolites and some anomic acids could be potential biomarkers for embryonic yield prediction in ovine multiple ovulation. The results would help to explain the relation between blood material and ovarian function and provide a theoretical basis for the multiple ovulation prediction.

The effect of dietary energy levels on the sexual puberty of ram lambs

Aim of study: To evaluate the effect of different feeding levels on body weight changes, sexual behavior activities, and spermatogenesis characteristics of testis tissue in immature Iranian breed lambs. Area of study: University of Tabriz, Iran. Material and methods: A total of 40 (start of experiment, 4; after 6 months, 12; 9 months, 12; sexual behavior, 12) two-month-old immature ram lambs were divided into three equal groups and were fed for eight months with three different concentrate mixtures formulated using conventional ingredients based on barley grain. Lambs received the same amount of crude protein with three levels of energy. The diet of the low-energy (LE) group had an energy of 10% lower than the control group, which received a diet with optimum energy of 100% according to the NRC. Lambs in the high-energy (HE) group were fed diets with an energy of 10% higher than the optimum energy group. In each group, four lambs were castrated in three steps, including the ages of 2 (start of treatment), 6, and 9 months. Body weight and scrotal circumference were recorded monthly. Sexual behaviors toward estrus ewes were evaluated for 30 min, and the testes were analyzed histologically. Main results: The lambs in the LE group had lower body weight and smaller scrotal circumference than HE group (p&lt;0.05). Sexual behaviors in the HE group occurred at an earlier age, such as mount and mounts with ejaculation, as the external presentations of puberty (p&lt;0.05). Research highlights: Underfeeding of pre-pubertal animals delayed puberty, while high-plane feeding advanced puberty.

The Effect of Progestin Source on Some Reproductive Performance in Akkaraman Ewes

This study was conducted to determine the effect of progestin source on some reproductive performance, lamb birth weight and lamb mortality rate in Akkaraman ewes. A total of 40 Akkaraman sheep breed with similar body weight (51.3 ± 1.5 kg) and at least two parturitions were used as experimental animals. In all ewes, the intramuscular injection of PGF2α (2.5 mg) was administered 96 hours before estrus synchronization to obtain corpus luteum regression. The ewes were allocated randomly into two groups according to body weight and ages. Estrus of ewes in the first group (n=20) were synchronized with an intra-vaginal CIDR device containing 0.30 g of natural progesterone. Estrus of ewes in the second group (n=20) were synchronized with an intra-vaginal sponge containing 30 mg flugestone acetate (FGA). CIDR and sponge were withdrawn following 12 days and 600 IU PMSG were injected intramuscularly. After 24 hours from injections, all ewes were introduced to Akkaraman rams and ewes in estrus were recorded. There were no significant differences between natural and synthetic progesterone applications in terms of estrus rate, gestation rate and duration of gestation in Akkaraman ewes. Additionally, lamb birth weight and lamb mortality rates were similar in both experimental groups. However, the application of CIDR increased the total and multiple lamb birth rates of Akkaraman ewes (P