Time Of Insemination Research Articles

Ріст кролиць материнської форми кросу Hyla NG, отриманих від різних самців, у постембріональний період онтогенезу

Goal. To study the growth dynamics of rabbits of the maternal form of the Hyla NG cross obtained from males of the progenitor form with different weight indices. Methods. The live weight and body measurements of the animals were studied by the weight and linear method. The intensity and growth parameters were determined of rabbits of the maternal form of the cross, obtained from the males of the maternal line of the maternal form of the cross Hyla GPC with different weight indices and female rabbits of the maternal line of the maternal form of the cross Hyla GPD. Three groups of female rabbits were studied, which were formed taking into account the value of the weight index of the father: group I — not more than 100 units, group II — between 100 and 120 units, group III — not less than 120 units. Results. At the age of 5 weeks, the live weight of the rabbits of the experimental groups did not differ. At the age of 9 weeks, rabbits born from males with a low body weight index had the highest live weight: it was 72.5 g more (p≤0.05) than that of group II rabbits, and 77.8 g more than that of young animals in group III. At 13 weeks of age, the live weight of group I rabbits was 136.9 g (p≤0.05) higher than the weight of their peers from group II and 68.8 g more than the weight of rabbits from group III. At 17 weeks of age, the trend persisted: Group I rabbits had the highest live weight, but peers born to males with a high body weight index narrowed the difference in live weight. At the age of 19 weeks, group III rabbits had the highest live weight and surpassed group I rabbits by 86 g, and group II rabbits by 162.4 g (p≤0.05). The absolute increase in live weight in the age periods from 5 to 9 and from 9 to 13 weeks was the greatest in rabbits of group I, while in the periods from 13 to 17 and from 17 to 19 weeks the absolute increase was greater in rabbits of group III. Average daily gains in live weight in the early period of growth were the largest in female rabbits of group I, and in the period after reaching sexual maturity, before the first insemination, female rabbits of group III exceeded other rabbits in terms of average daily gains. Conclusions. Based on the results of research, certain patterns of growth of female rabbits obtained from males with different weight indices have been established. Thus, female rabbits whose parents had a high body mass index in the early period of ontogenesis were characterized by less intensive growth, while after reaching puberty their growth accelerated, and at the time of the first insemination they had the largest live weight among their peers.

Status and Constraints Evaluation of Artificial Insemination in Bishoftu and Its Environs

Efficiency of artificial insemination service might be lower due to various challenges including poor estrus detection, inefficiency of artificial insemination techniques, and distance from AI station, poor management system, inadequate nutrition and poor quality of semen. Failure of estrus detection and improper timing of insemination has been the most known problems of in diary animals. The intention of this study was to appraise the status, challenges and the outcome. AI service beneficiaries in and around bishoftu town. In this study, a total of 287 respondents (smallholder farmers, dairy farm, Animals health professionals and Artificial Insemination Techniques) were included through structured questionnaires survey and interviewed. In to this, Retrospective data study was included in the study to evaluate the status of AI service in the study site. As the result revealed that from 269 total farmer respondents 49.1% (132/269) had got AI service on time without any interruption while 50.9% (137/269) AI users couldn’t got service on time due to lack of input, unavailability of AITs and discontinuation of service on weekends and holidays with statistically significant among kebeles (p<0.05). Bellowing, clear mucous discharge from vagina, mounting, decrease production and feed intake, restlessness and nervousness, were found to be the most common estrus manifestation observed by diary owners as holidays, lack of appropriate collaboration and communication among stake holders, and repeat breeding. In case of repeat breeding, he maximum and minimum impression of AI users toward using AI repeatedly were 43.8% (Danbi) and 33.0% (Kality) respectively with statistically insignificant among respondents (p>0.05). Generally the questionnaire survey indicated that the application of assisted reproductive biotechnologies in the study area was at infant stage surrounded with challenge full so it requires urgent involvement of stakeholders before it aggravates.

Salivary crystallization pattern: a possible unconventional tool for timing of insemination and early pregnancy diagnosis in zebu cows.

The present study assessed if salivary crystallization pattern (ferning pattern formed as a result of the higher levels of salt content in the dried sample) could be used for estrus detection and for diagnosis of pregnancy/non-pregnancy in dairy cows. Saliva and blood samples were collected from non-pregnant cycling cows (Sahiwal breed; n = 20) on alternate days from the day of estrus till next estrus. Then, all the cows were inseminated and saliva and blood sampling were continued further for a period of 22 d post-insemination. Pregnancy diagnosis was carried out on day 45 post-insemination and eight cows were found to be pregnant. The salivary crystallization pattern and estradiol:progesterone ratio during estrous cycle and during pregnancy were compared among these cows. Six types of salivary crystallization patterns were discerned; distinct patterns such as branch-like, fern-like, fir-like and combinations of these. Fern-like pattern was observed in all the cows on the day of estrus (first measurement day) and furthermore, all of the cows that subsequently became pregnant had fern-like salivary crystallization pattern at the time of insemination. Saliva of all the pregnant cows showed branch-fir type of crystallization pattern on day 16 post-breeding while only 50% of non-pregnant cows showed this pattern on day 16 of estrous cycle. The appearance of fern-like pattern was positively and significantly related to estradiol:progesterone ratio (r = 0.86; P < 0.001). The findings were validated on a separate group of cycling cows (n = 32). We can conclude that salivary crystallization pattern might serve as a non-invasive and cost effective and easy-to-use cow-side tool for estrus detection and early pregnancy/non-pregnancy diagnosis in cows upon validation on a larger sample size.

Comparing State-of-the-Art Deep Learning Algorithms for the Automated Detection and Tracking of Black Cattle.

Effective livestock management is critical for cattle farms in today's competitive era of smart modern farming. To ensure farm management solutions are efficient, affordable, and scalable, the manual identification and detection of cattle are not feasible in today's farming systems. Fortunately, automatic tracking and identification systems have greatly improved in recent years. Moreover, correctly identifying individual cows is an integral part of predicting behavior during estrus. By doing so, we can monitor a cow's behavior, and pinpoint the right time for artificial insemination. However, most previous techniques have relied on direct observation, increasing the human workload. To overcome this problem, this paper proposes the use of state-of-the-art deep learning-based Multi-Object Tracking (MOT) algorithms for a complete system that can automatically and continuously detect and track cattle using an RGB camera. This study compares state-of-the-art MOTs, such as Deep-SORT, Strong-SORT, and customized light-weight tracking algorithms. To improve the tracking accuracy of these deep learning methods, this paper presents an enhanced re-identification approach for a black cattle dataset in Strong-SORT. For evaluating MOT by detection, the system used the YOLO v5 and v7, as a comparison with the instance segmentation model Detectron-2, to detect and classify the cattle. The high cattle-tracking accuracy with a Multi-Object Tracking Accuracy (MOTA) was 96.88%. Using these methods, the findings demonstrate a highly accurate and robust cattle tracking system, which can be applied to innovative monitoring systems for agricultural applications. The effectiveness and efficiency of the proposed system were demonstrated by analyzing a sample of video footage. The proposed method was developed to balance the trade-off between costs and management, thereby improving the productivity and profitability of dairy farms; however, this method can be adapted to other domestic species.

Repeat Breeding and Its' Associated Risk Factors in Crossbred Dairy Cattle in Northern Central Highlands of Ethiopia.

The purpose of the current study was to ascertain the prevalence and incidence of repeat breeding and related risk variables in crossbred dairy cattle in the northern Central Highlands of Ethiopia. The prevalence and incidence of repeat breeding in crossbred dairy cattle were 38.4% and 36.6%, respectively, out of the total cows and heifers taken into account for this study and handled with various production strategies. Age, parity, body condition, breeding practices, milk yield, management condition, and insemination time were all substantially (P < 0.05) associated with the prevalence and incidence of repeat breeders. Repeat breeder is more common in elderly, underweight, multiparous, high-milk producing, and AI serviced cows, as well as cows kept in poor management condition. It was deduced that the production system had a significant impact (P < 0.05) on the prevalence of repeat breeders in the research area. In addition, herd size was significantly associated (P < 0.05) with the prevalence of repeat breeder in this study. Insemination time and heat detection practices were also substantially (P < 0.05) interrelated with the prevalence and incidence of repeat breeders, indicating that incorrect heat detection and/or insemination timing had an impact on these variables. Therefore, it is suggested to increase the mindfulness of farm owners, managers, and attendants about appropriate feed and feeding management, accurate heat detection, and insemination time. To reduce the incidence of repeat breeders and the associated reproductive issues, as well as the resulting financial losses on dairy farms, health, housing, and reproductive management should also be improved.

Delayed Timing of Insemination Relative to Estrus Improves Pregnancy to Artificial Insemination With Sex-Sorted Semen in Beef Heifers

Objective: The objective was to evaluate the effect of timing of artificial insemination (AI) relative to the onset of estrus on pregnancy outcome when using sex-sorted semen in beef heifers. Study Description: Beef heifers were subjected to the melengestrol acetate with prostaglandin (MGA-PG) estrous synchronization protocol and visually observed for estrus every four hours for five days following injection of PG. Following detection of estrus, heifers were inseminated with semen sorted to contain X-chromosome bearing sperm cells (4.0 × 106 live cells per 0.25 mL straw of SexedULTRA 4M). Heifers were retrospectively categorized into one of three intervals from estrus onset to insemination: 1) 12.5–15.9 hours; 2) 16.5–21.0 hours; and 3) 21.4–27.5 hours. Results: Heifers with the shortest interval (12.5–15.9 hours) from estrus onset to insemination had a similar (P > 0.10) AI pregnancy rate as compared with heifers with the interval from estrus onset to insemination of 16.5 to 21 hours. Heifers inseminated 21.4 to 27.5 hours following estrus onset achieved a greater (P ≤ 0.05) AI pregnancy rate than heifers inseminated 12.5 to 15.9 hours following estrus onset. The Bottom Line: Insemination of beef heifers with sex-sorted semen later than 21 hours after estrus onset appears to improve pregnancy rate to AI when compared to earlier insemination times.

Determination of artificial insemination timing in Banteng based on follicle size and uterine enlargement

The Banteng (Bos Javanicus d'Alton 1823) is an endemic species in Indonesia that is threatened with extinction and whose population continues to decline in the wild. The aim of this study is to determine the timing of artificial insemination (AI) in the Banteng based on follicle size and uterine enlargement. For this study, two female Banteng were used in Taman Safari Indonesia, Cisarua, Bogor. Habituation was performed to facilitate data collection. Optimal timing for AI is determined by examining the reproductive organs using Ultrasonography (USG) to detect changes in the uterus and ovaries and monitor clinical signs of estrus. Follicle size and uterine examination was performed on days -1, 0, and +1 for 3 estrus cycles. Insemination was performed 2-3 times during estrus until ovulation occurred. The results showed that the average follicle size of both Banteng was 1.09 ± 0.02 cm on day -1, 1.31 ± 0.02 cm on day 0, and 1.33 ± 0.03 cm on day +1. Artificial insemination was performed with a double dose of frozen semen when the Banteng were still rideable, and the follicle size ranged from 1.23-1.38 cm. Pregnancy was examined by ultrasound on day 21 after mating; both Banteng females were pregnant after AI. It can be concluded that AI technique can be used in captive Banteng breeding program by studying the development of follicles and uterine enlargement.

Estrus response patches, timing for artificial insemination, and GnRH protocol in Split Timed AI beef cattle

Resumo Um adesivo de detecção de estro foi usado como ferramenta para determinar o momento ideal para a inseminação artificial em tempo dividido (STAI) e a necessidade de injeção de hormônio liberador de gonadotrofinas (GnRH) no 7º dia do protocolo CO-Sinc + CIDR sem comprometer as taxas de prenhez. As vacas eram cruzadas, multíparas e lactantes (Angus x Charolês, n=216) e foram estratificadas por idades (5,9 2.5 anos), BW (581 67kg), BCS (5,3 0,8; 1-9), intervalo entre partos (78,5 15,5 dias). O grupo de tratamento CTRL = IAT (n=67) foi inseminado após 72 h após a remoção do CIDR; já no grupo tratamento TRT= IATP (n=149) as vacas foram inseminadas 72 ou 84 h após a remoção do CIDR. Todas as fêmeas receberam GnRH (100 mcg I.M.), mais um CIDR (1,38 g de progesterone) no D0, no D7 foi realizado a retirada do CIDR, aplicação de PGF2α (25 mcg I.M.) e colocação do adesivo detector de cio. Após 72 h da remoção do CIDR, uma pontuação foi atribuída ao adesivo (OS1&lt;50% removido; OS2&gt; 50% removido) de todas as fêmeas. As vacas do grupo CTRL receberam a segunda injeção de GnRH (100 mcg I.M.) às 72 h na IAT. Vacas do grupo TRT com OS2 não receberam GnRH. Às 84 h as vacas restantes do grupo TRT receberam um segundo OS, aquelas com OS1 receberam GnRH (100 mcg I.M.) e as vacas com OS2 não receberam GnRH. Amostras de sangue para concentração de progesterona foram coletadas nos D-11 e D-0 para determinar o percentual de vacas ciclando. Os dados foram analisados utilizando-se o Proc Genmod, tendo o tratamento e o técnico de IA como efeitos fixos, o touro como efeito aleatório e o BW, BCS, idade e IBP como covariáveis. Resultados: as taxas de gravidez da IAT foram semelhantes (P= 0,81) entre os grupos CTRL (45,6%) e TRT (44,8%). As taxas de prenhez tenderam a ser maiores (P=0,07) para vacas com OS2 (50,3%) do que para aquelas com OS1 (29,4%). No entanto, ao estender a IAT para 84 horas em vacas não responsivas, 82,0% das vacas TRT não receberam uma segunda aplicação de GnRH na IAT. Concluiu-se que os adesivos detectores de estro reduziram a porcentagem de vacas que necessitaram de GnRH na IAT sem comprometer as taxas de prenhez. Os adesivos de detecção de estro reduziram significativamente o número de vacas que receberam uma segunda injeção de GnRH na IAT.

Assessment of Constraints of Artificial Insemination Service in Smallholder Dairy Cattle Keepers in Kacha Bira District of Southern Ethiopia.

Artificial insemination (AI) is among the most effective reproductive biotechnologies that afford widespread propagation of genes carried by superior males. A cross-sectional study followed by a simple random sampling technique was conducted from December 2021 to May 2022 to assess the constraints of artificial insemination (AI) provision in and around Kacha Bira district, Southern Ethiopia, using a structured questionnaire. A total of 200 respondents were surveyed accordingly. In this study, the education level of farmers revealed no statistically significant difference (P > 0.05) with the identification of time of insemination. Conception failure (62.5%), unavailability of artificial insemination technicians (7.5%), dystocia (3.5%), and both conception failure and unavailability of artificial insemination technicians (4.5%) were found to be the major constraints of AI service in the study area according to dairy cattle owners' response and revealed a statistically significant difference (P < 0.05) with AI service. Although statistically significant (P < 0.05), differences in AI service interruptions during both regular working hours and weekends and holidays were also observed. Among total respondents, 20.5% of dairy cattle owners got AI service at right time, but 79.5% of them used it at the wrong time. Regarding inbreeding problems, 77.5% of dairy cattle owners responded that there was no inbreeding problem and the remaining 22.5% of farmers indicated presence of inbreeding problem of which 10.5% and 10% had a perception that local breeds had low milk production and low genetic improvement than exotic breeds, respectively. On the other hand, 11.5% of dairy cattle owners responded that local breeds have a similar level of disease resistance to that of exotic breeds (11%). 48.5% of dairy farmers reported that bellowing is the most frequent sign that they used to detect heat followed by vulval discharge (23%) and mounting on other cows (10%). Majority (78.5%) of the dairy cattle owners interviewed were found to be not satisfied with the artificial insemination services. In general, different AI technicians and cattle and dairy cattle keeper-related factors constrain the AI service and its result in survey site. Therefore, smallholder dairy cattle owners should be trained sufficiently about the AI service strategies, usage, and proper management of dairy farms and the technical constraints should be avoided in order to provide AI service sufficiently.

APPLICATION OF PROGESTERONE PROFILES IN THE ASSESSMENT OF POST ARTIFICIAL INSEMINATION FERTILITY IN CATTLE

The present study was conducted to investigate success of AI in relation to progesterone concentrations with respect to the timing of inseminations or heat detection in the field. Milk samples were collected for progesterone assay from 149 crossbred cows subjected to AI. The milk progesterone concentrations were estimated by RIA to access the reproductive status of the cows. On the day of AI, progesterone concentrations were less than 1.0 nmol/L (Low) in 51% samples and more than 3.00 nmol/L (High) in 18%. Rest 31 % samples showed intermediate progesterone (1.01 to 2.99 nmol/L) suggesting that these cows were nor in proper heat at the time of AI. On the basis of two samples (day 0 and day 10-12 post AI), 50% cows had low progesterone concentrations on the day of AI and high in the second sample, indicating that these cows were inseminated during estrus and ovulated subsequently. Whereas, 12% cows had high progesterone in both the samples suggesting that at the time of AI these cows were either in the luteal phase or had luteal cyst. Remaining 37% cow had intermediate progesterone concentrations on both the occasions suggesting that they were having either developing or regressing or malfunctioning corpora lutea or partial luteal cyst. Perusal of observations on progesterone concentrations showed that 18% of inseminations were done during luteal phase and another 30% were done at some inappropriate time of heat, thus suggesting that high proportion (48%) of cows under field conditions were inseminated while not in proper heat.

In vivo embryo development in bitches inseminated laparoscopically after ovulation time estimated based on a single progesterone determination.

Logistic and economical limitations are often the causes of dog owners not accurately monitoring the estrous cycle and the optimal insemination time. The aim of this study was to evaluate in vivo early embryonic development in bitches, after the analysis of sequential vaginal cytologies associated to single progesterone measurement and single laparoscopic insemination with high quality semen (fresh and with high spermatozoa concentration) or low-quality semen (frozen/thawed and with low spermatozoa concentration) at 48 h post- ovulation time predicted on a single progesterone measurement. Ten bitches were inseminated with 250 x 106 fresh spermatozoa (80% motility), and ten with 80 x 106 frozen/thawed spermatozoa (60% motility) in the cranial part of each uterine horn. Seven days later, ovariohysterectomy was performed and the oviducts and uterine horns and body were flushed to recover embryos and unfertilized oocytes. In 80% of the bitches inseminated with fresh and 50% of bitches inseminated with frozen/thawed semen, embryos at 2 to 8 cells stage were recovered mostly from the, oviducts. This study indicates that pregnancies can be obtained with a single laparoscopic intrauterine insemination after single serum progesterone measurement, although with a low number of embryos. This result should be taken into account in case economic or logistic restrictions that affect the possibility of owners to plan an accurate monitoring of the optimal breeding time using fresh and frozen semen.

Factors Influencing the Pregnancy Outcome of Intrauterine Insemination and Follow-up Treatment.

Many factors were reported associated with the pregnancy rate of intrauterine insemination (IUI), which played key role is still debated. The aim of this study was to explore related clinical pregnancy outcome factor in IUI cycles of non-male factor. The clinical data of 1232 IUI cycles in 690 couples experiencing infertility who attended the Reproductive Center of Jinling Hospital between July 2015 and November 2021 were retrospectively analysed. Female and male age, body mass index (BMI), anti-Müllerian hormone (AMH), male semen parameters before and after wash, endometrial thickness (EMT), artificial insemination timing and ovarian stimulation (OS) protocols were compared between the pregnant group and the non-pregnant group in order to explore any correlation. Continuous variables were analysed using independent-samples t-test, and Chi-square test was used for comparison of measurement data between the two groups. P <0.05 was considered statistical significance. There were statistically significant differences in female AMH, EMT and duration of OS between the two groups. The AMH was higher in the pregnant group than in the non-pregnant group (P < 0.01), the stimulated days was significantly longer (P < 0.05) and EMT was significantly greater (P < 0.01) in the pregnant group than in the non-pregnant group. Further analysis showed that when patients with IUI had the following conditions: AMH &gt; 4.5 ng/ml, EMT between 8 and 12 mm and letrozole + human menopausal gonadotropin stimulation with higher clinical pregnancy. However, there were no differences between the pregnant group and the non-pregnant group amongst the female and male age, BMI, hormones on baseline and day of human chorionic gonadotrophin, number of ovulated oocytes, sperm parameters before and after wash, treatment protocols and the timing of IUI (P > 0.05). Furthermore, there were 240 couples who not pregnant received one or more cycles of in vitro fertilisation/intracytoplasmic sperm injection/ pre-implantation genetic technology treatment, and another 182 couples forgo follow-up treatment. The results of the present study demonstrate that the clinical IUI pregnancy rate is correlated with the factors of female AMH, EMT and OS protocol; more studies and samples are necessary to evaluate whether other factors affect pregnancy rate.

Improving Fertility in Friesian Cows by Synchronization of Fixed Time Insemination

Improving Fertility in Friesian Cows by Synchronization of Fixed Time Insemination

The Effects of GnRH and hCG Administration on Pregnancy Rate in Postpartum Dairy Cows

This study was designed to determine the effects of GnRH administration alone at the time of artificial insemination (AI) or in combination with hCG 5 days after GnRH injection on conception rates in postpartum dairy cows. Cows in estrus, without any reproductive health problem, between days 70-120 postpartum were randomly assigned to 3 equal groups. Buserelin acetate (10 µg), was administered at the time of AI to Group I (n=40). Group II (n=40) was administered first with Buserelin acetate (10 μg) at the time of AI and then with 1500 IU of hCG on the 5th day after insemination. Group III was maintained for control purposes and did not receive any treatment. Pregnancy diagnosis was performed on day 30 post-AI by transrectal ultrasonography. Conception rates were 80% (32/40), 80% (32/40), and 57.5% (23/40) in Group I, II and III (P

Revisiting the Timing of Insemination at Spontaneous Estrus in Dairy Cattle.

Cows show spontaneous estrus over 8-20 h but become refractory to the bull about 10-12 h before ovulation. This indicates that ovulation occurs 10-12 h after the end of estrus behavior, yet spermatozoa from the bull ejaculate need to undergo maturation and capacitation for 6 to 8 h in the female reproductive tract before they are capable of fertilization. Traditionally, the onset of estrus has been considered the best timing for artificial insemination (AI) in cattle, that is, 6 to 24 h from the first signs of estrus. However, recent findings suggest this interval should be reduced to 16 to 6 h before ovulation, bringing it closer to the end of estrus. In this review, the end of estrus rather than its onset is proposed as the best guide for AI timing in dairy cattle, and physiological indicators of late estrus are discussed such as relaxation of the intravaginal part of the uterus, a lower cervical mucus viscosity and a softer pre-ovulatory follicular consistency as simple cues indicating a cow is ready for service.

Luteal function in cyclic goats treated with human chorionic gonadotropin administered by intramuscular or intravaginal routes at the time of artificial insemination.

Human chorionic gonadotropin (hCG) has been used to improve goats reproductive efficiency. This study aimed to (i) evaluate if hCG administered by the intramuscular (i.m.) or intravaginal (i.vag.) route can be detected by a rapid β-hCG test in blood plasma samples and (ii) document ovarian effects of hCG administered by both routes at the time of artificial insemination (AI) performed 60 h after oestrus synchronization in goats. Twenty-two Alpine goats received two i.m. injections of 30 μg of d-cloprostenol (Prolise®, Tecnopec, São Paulo, Brazil) 7.5 days apart. One day after the onset of oestrus (at the time of AI), the goats were randomly allocated to one of the three groups that received: control (n=7): 0.3ml of saline solution intravaginally; hCGi.m. (n=7): 300 IU of hCG (Vetecor®; Hertape-Calier, São Paulo, Brazil) i.m. and hCGi.vag. (n=8): 300 IU of hCG deposited intravaginally. Blood samples were drawn at -1, 3, 6, 9 and 24 h after as well as on days 3, 7, 10, 13, 17 and 21 after hCG treatment/AI. All animals tested negative for hCG (ECO Diagnóstica, Corinto, Brazil) at -1h, and all control animals tested negative throughout the entire blood collection period. All hCGi.m. animals tested positive from 3h until D3 post-AI but only 50% of hCGi.vag. goats tested positive during the present study. In all animals studied, mean circulating P4 concentrations increased (p < .05) from D3 to D7 after AI and then declined (p < .05) from D10 to D17 in control and hCGi.m. groups and from D17 to D21 in the hCGi.vag. group. Total cross-sectional luteal area (CLA), mean colour Doppler area (DA), DA/CLA, mean high-velocity Doppler area and HVDA/CLA all declined (p < .05) by D17-D21 in all animals studied. In summary: (i) human chorionic gonadotropin could consistently be detected in blood samples using the rapid β-hCG test only in the hCGi.m. group; and (ii) there were no significant differences in the mean pregnancy rate, circulating P4 concentrations and various luteal parameters studied among Control, hCGi.m. and hCGi.vag. dose.

Pheromones, binding proteins, and olfactory systems in the pig (Sus scrofa): An updated review.

Pigs utilize multimodal communication for reproductive and other behaviors, and chemical communication is one of the key components. The success of reproduction relies on chemical communication favored by the steroid pheromones from boar saliva. These steroids were proven to be involved in advancing puberty in gilts (the boar effect) and in promoting estrus behaviors in gilts/sows, thereby helping to detect estrus and facilitating the timing of artificial insemination. The steroid pheromones bound with carrier proteins are evidenced in the mandibular (submandibular) salivary secretions of the boar. These salivary steroids bind with carrier proteins in the nasal mucus and vomeronasal organ (VNO) of the sows, eventually triggering a cascade of activities at the olfactory and endocrine levels. Besides steroid pheromones, pig appeasing pheromones (from mammary skin secretions of sows) have also been demonstrated to bind with carrier proteins in the nasal mucus and VNO of the piglets. Thus far, four different proteins have been identified and confirmed in the nasal mucus and VNO of pigs, including odorant binding proteins (OBPs), salivary lipocalin (SAL), pheromaxein, and Von Ebner's Gland Protein (VEGP). The critical roles of the chemosensory systems, main olfactory systems and VNO, have been comprehensively reported for pigs. This review summarizes the current knowledge on pheromones, their receptor proteins, and the olfactory systems of porcine species.

Repeated pregnancy in a bitch, with a diagnosis of extensive cystic endometrial hyperplasia, after the exact determination of the optimal time for breeding

A 6-year-old bitch was presented to the clinical examination with the aim of determining the optimal time for intrauterine insemination by frozen-thawed semen. The bitch had already had two litters in the past. Extensive cystic endometrial hyperplasia was diagnosed by an ultrasound examination in the bitch. The timing of the endoscopic transcervical insemination by a combination of ultrasonographic examination of the ovaries and determining the progesterone concentrations contributed to the successful conception in the bitch. The ultrasonographic examination of the ovaries represents a non-invasive method which allowed us to view the changes on the ovaries in real time and, thus, is a very suitable method for the specification of the ovulation time in bitches. Cystic endometrial hyperplasia is considered to be a possible cause of infertility. Nevertheless, the bitch repeatedly conceived and had larger litter sizes. Moreover, a considerable reduction in the number of endometrial cysts was observed after the third pregnancy of the bitch. In the described clinical case, the influence of the cystic endometrial hyperplasia on the conception was not demonstrated.

Determination of progesterone levels in the blood of cattle by liquid chromatography-tandem mass spectrometry and the relationship of steroid concentration with fertilization

The optimal conditions for determining the concentration of progesterone in the blood plasma of cattle were selected by high-performance liquid chromatography-tandem mass spectrometry, and the relationship of the level of this progestin with fertilization after treatment of cows with hormonal preparations was studied. It was found that the time of progesterone peak release under the selected chromatography mode is within 2.7 minutes, and the optimal precursor ion is [M+H]+ m/z=315.3. The developed technique makes it possible to determine the endogenous level of the steroid in the blood of cattle with high accuracy (up to hundredths of ng/ml). Analysis of progesterone concentration in cows at the time of the final injection of the prostaglandin analogue showed that animals with different reproductive status have no significant differences in the content of this steroid. The most statistically significant indicators were obtained on the day of insemination. Thus, in infertile cows, the hormone concentration was 1.9...4.2 times lower than in fertilized cows (P&lt;0.05). The higher steroid content in fertilized animals at the time of insemination most likely reflects the ovarian response to the preovulatory release of luteinizing hormone and the readiness of the follicle for ovulation. Keywords: cattle; high-performance liquid chromatomass spectrometry; progesterone; synchronization of sexual cyclicity; fertilization; infertility.

PSIII-5 Evaluation of Gnrh Administration day in the 7 &amp; 7 Synch Protocol for Fixed-Timed Artificial Insemination in Multiparous Beef Cows

Abstract The objective was to determine the effects of a decreased interval of progesterone on the ovulatory follicle prior to fixed-timed artificial insemination (FTAI) in a 7 &amp; 7 Synch estrous synchronization protocol using estrus expression (EE), FTAI pregnancy rates (AIPR) on 37±2d, and overall pregnancy rates (OPR) after a 60d bull exposure 90±2d determined via ultrasound. Using conventional Angus semen, multiparous Angus-cross cows (n=201) from two locations were randomized by age and days post-partum into two treatments. Both treatments used a controlled internal drug releasing device (Eazi-breedTM CIDR; 1.38g progesterone) inserted intravaginally –14d of the protocol simultaneous to administration of prostaglandin F2α (PGF; 500µg cloprostenol sodium; Estrumate®). In the first treatment (7&amp;7), gonadotropin-releasing hormone (GnRH; 86µg gonadorelin; Fertagyl®) was administered on –7d. In the second treatment (8&amp;6), GnRH was administered on –6d. Both treatments were then administered PGF simultaneous to CIDR removal on 0d, 66±2h prior to FTAI and administration of GnRH. EE was determined at the time of artificial insemination using an EstrotectTM patch (Rockway Inc., Spring Valley, WI). EE was signified as a patch with 50% or more of the color rubbed off or missing. Subsequently, a patch with less than 50% of the color rubbed off, was not. AIPR, OPR and EE were analyzed by treatment using the GLIMMIX procedure on SAS 9.4 (SAS Institute Inc., Cary, NC.). There was a significant effect on EE (P=0.01), a tendency on PR (P=0.08), and no effect on OPR (P=0.53) by treatment. EE, AIPR, and OPR for 7&amp;7 were 95±2.1%, 82±3.7% and 96.7±1.7% and for 8&amp;6 were 86±4.0%, 91±3.1% and 98±1.5%, respectively. In conclusion, the altered timeframe of GnRH administration affected EE and tended to affect PR in multiparous beef cows, suggesting that GnRH administration may improve PR when administered 6d, instead of 7d, prior to CIDR removal.