Time Of Insemination Research Articles

A multivariate model for the prediction of pregnancy following laparoscopic artificial insemination of sheep.

The causes of variation in the success of laparoscopic artificial insemination (AI) in sheep are not well understood. As such, this study incorporated the contributions of multiple male and female factors relevant to the success of AI into a comprehensive prediction model for pregnancy success. Data from Merino ewes (N = 30 254) including age, uterine tone (1; pale/flaccid-5; turgid/pink), intra-abdominal fat (1; little to no fat present-5; high fat), time of insemination and sire used, were recorded during AI. A subset of semen per sire (N = 388) was thawed and assessed for volume, subjective motility, sperm concentration, and morphology. Sperm motility (CASA), viability and acrosome integrity (FITC-PNA/PI), membrane fluidity (M540/Yo-Pro), mitochondrial superoxide production (Mitosox Red/Sytox Green), lipid peroxidation (Bodipy C11), level of intracellular reactive oxygen species (H2DCFDA) and DNA fragmentation (Acridine Orange) were also assessed 0, 3 and 6h post-thaw. Logistic binomial regression revealed sperm concentration (P < 0.001), CASA parameters at 0h (PCA3; P = 0.03), viable acrosome intact sperm at 6h (P = 0.02), abnormal morphology (P < 0.001), uterine tone (P < 0.001) and intra-abdominal fat (P = 0.03) of ewes influenced likelihood of pregnancy. Results generated will help standardise the pre-screening and selection of semen and ewes prior to artificial breeding programs, reducing variation in the success of sheep AI.

Impact of bovine herpesvirus-1 infection on fertility in dairy cattle

Bovine herpesvirus-1 (BoHV-1) is endemic in the UK dairy herd and can have an important negative impact on fertility. As well as being the cause of infectious pustular vulvovaginitis and infectious balanoposthitis, BoHV-1 can reduce conception rate following introduction of the virus in contaminated semen at the time of artificial insemination. Its ability to cause abortions, particularly in the last trimester, is well-documented and the incidence of abortions can be high following the introduction of infection to naïve herds. The impact of BoHV-1 on herd fertility will depend on the degree of herd immunity, route of infection and strain of BoHV-1. Vaccination has been shown to reduce spread of BoHV-1 within and between herds, and to significantly reduce the risk of abortion. In light of the cost of a single abortion, and the impact of BoHV-1 on milk yield, routine vaccination against BoHV-1 offers a cost-effective control strategy suitable for most UK dairy herds.

A Survey Study on Management Practices Associated With Voluntary Waiting Period and Its Effects on Reproductive Performance of dairy cows in Iranian Dairy Farms.

Voluntary waiting period (VWP), housing systems and the presence of a veterinarian are effective factors on reproductive performance of a dairy farm. This study aimed to investigate the management practices associated with VWP and its effects on reproductive performance. A total of 136,943 records of 21,756 cows that calved between 1990 and 2013 were used. A questionnaire was also conducted with the farms involved to determine if they adjust the timing of insemination based on the body condition score (BCS) of the cows, postpartum health situation (PPHS) or environmental factors such as heat stress and season. The impact of changing the VWP selectively, the presence of a veterinarian and the type of barn on reproductive outcomes like days open (DO), number of services per conception (NSPC) and days to first service (DFS) was examined using a linear mixed model. This model considered animals and herds as random factors and management practices as fixed factors in the analysis. Among herds that reported altering the VWP based on heat stress, DFS significantly increased (61.68±0.68 vs. 58.4±0.83) while DO (119.70±1.86vs. 126.9±2.29) and NSPC (1.98±0.04vs. 2.48±0.05) reduced compared to herds that did not alter the VWP. Our results showed that farms with a full-time veterinarian had a better reproductive performance than those with part-time care (p < 0.05). Housing system was significantly associated with fertility traits, so that cows in free-stall barns were more fertile than those kept in open-shed barns. The obtained results from this study indicated that management decisions to selectively altering the VWP led to difference in DFS and improved reproductive performance.

Factores que influyen en la inseminación artificial con semen fresco en alpacas (&lt;i&gt;Vicugna pacos&lt;/i&gt;)

The aim of the study was to evaluate factors that affect the fertility of artificial insemination (AI) with fresh diluted semen in alpacas. In Exp. 1, females with preovulatory follicles with diameters ≥7-≤ 9 or ≥10-≤12 mm were inseminated; in Exp. 2 the females were inseminated at 24, 26, 28 and 30 h after ovulation induction; In Exp. 3, alpacas were inseminated with semen at four concentrations: 15, 25, 35 and 45x106 sperm/ml; and in Exp. 4, using the best results from the previous experiments, 350 alpacas were inseminated in two peasant communities. Semen was collected by the post-copulatory method, using ejaculates with motility ≥60%, diluted in Tris-glucose-citric acid and egg yolk. Alpacas with preovulatory follicles ≥7 mm were selected for AI. Ovulation induction was done with a GnRH analogue and pregnancy diagnosis was made 30 days after service. Pregnancy rate was not affected by follicular size. AI 24 to 26 h after ovulation induction obtained a higher pregnancy rate (50 and 55%, respectively; p&lt;0.05) compared to those inseminated at 28 and 30 h (35 and 30%). AI with 15x106 sperm/ml resulted in low pregnancy rates (30%) compared to 35 and 45x106 sperm/ml (50 and 55%, respectively). In the peasant communities, 55% pregnancy rate was obtained. The results suggest that the success of AI with fresh semen in alpacas is highly dependent on sperm dose and timing of insemination.

Cryopreservation of bovine sperm causes single-strand DNA breaks that are localized in the toroidal regions of chromatin

BackgroundSperm cryopreservation is widely used in the cattle industry, as it allows for disassociating the localization of sires and the collection of semen from the timing of artificial insemination. While freeze-thawing is known to impair sperm DNA integrity, whether the damage induced consists of single- (SSB) or double-strand breaks (DSB) has not been determined. In addition, no previous study has addressed if DNA breaks preferentially reside in specific genome regions such as those forming the toroid linker regions, or are rather spread throughout the regions linked to protamines. The main aim of the present work, therefore, was to elucidate the type and localization of the DNA damage generated by cryopreservation and to evaluate its impact on artificial insemination outcomes in cattle.ResultsThe incidence of SSB and DSB was evaluated in 12 ejaculates before and after cryopreservation with the Comet assay, and the localization of the DNA breaks was assessed using pulsed-field gel electrophoresis (PFGE). Before cryopreservation, the incidence of SSB was 10.99% ± 4.62% and involved 20.56% ± 3.04% of sperm cells, whereas these figures significantly (P < 0.0001) increased up to 34.11% ± 3.48% and 53.36% ± 11.00% in frozen-thawed sperm. In contrast, no significant differences in the incidence of DSB were observed (P > 0.990) before and after cryopreservation (before: incidence of 13.91% ± 1.75% of sperm DNA affecting 56.04% ± 12.49% of sperm cells; after: incidence of 13.55% ± 1.55% of sperm DNA involving 53.36% ± 11.00% of sperm cells). Moreover, PFGE revealed that the percentage of sperm DNA fragments whose length was shorter than a toroid (< 31.5 kb) was greater (P < 0.0001) after (27.00% ± 4.26%) than before freeze-thawing (15.57% ± 4.53%). These differences indicated that the DNA breaks induced by cryopreservation affect the regions condensed in protamines, which are structured in toroids. On the other hand, in vivo fertility rates were associated to the incidence of SSB and DSB in frozen-thawed sperm (P = 0.032 and P = 0.005), but not with the size of the DNA fragments resulting from these breaks (P > 0.05).ConclusionCryopreservation of bovine sperm generates single-strand DNA breaks, which are mainly located in protamine-condensed toroidal regions. The incidence of DNA breaks in cryopreserved sperm has an impact on cattle fertility, regardless of the size of generated fragments.

Optimizing timing for intrauterine insemination (IUI) in donor sperm cycles: pre- versus post-ovulation insemination in natural cycles

Purpose To investigate whether pregnancy outcomes of natural cycle intrauterine insemination (IUI) with donor sperm can be improved by performing insemination after confirmation of ovulation. Methods This retrospective cohort study evaluated 751 couples undergoing 1170 cycles of artificial insemination with donor sperm (AID) in natural cycles between January 2018 and January 2021. Patients underwent AID either within 6–12 h after spontaneous luteinizing hormone (LH) surge (pre-ovulation group) or after ovulation was confirmed by ultrasound (post-ovulation group). Propensity score matching was performed to account for differences in baseline characteristics between groups. The main outcome measures of this study were clinical pregnancy rate and live birth rate. Results After propensity score matching, each group comprised 216 cycles. No significant differences were observed between the pre-ovulation and post-ovulation groups in terms of clinical pregnancy rate (30.6% vs 27.3%, respectively, p = .458) and live birth rate (25.0% vs 22.7%, respectively, p = .651). However, upon excluding cases of luteinized unruptured follicle syndrome (LUFS) from the pre-ovulation group, the clinical pregnancy rate (33.5% vs 27.3%, respectively, p = .043) and live birth rate (27.4% vs 22.7%, respectively, p = .039) were significantly higher in the pre-ovulation group. Conclusions For fertile women undergoing AID in natural cycles, pre-ovulation insemination timing yielded superior pregnancy outcomes compared to post-ovulation insemination when ovulation was achieved. However, due to the occurrence of LUFS, pre- and post-ovulation AID resulted in comparable overall pregnancy outcomes in natural cycles.

Cervix-Deep Rectal Temperature Differential on the Day ofOvulation is Correlated With Embryo Recovery Results in Mares.

Variations in temperature throughout the reproductive tract have been noted in many species. A recent study found the cervix-rectum temperature differential (CR-TD) in cattle was related to fertility. The present study aimed to assess the CR-TD in mares around the time of ovulation and relate it to embryo recover. Over 52 cycles, mares were inseminated with a fertile stallion and embryo recovery was undertaken on Day 7 post ovulation. Further 10 control mares were not inseminated. Rectal and cervical temperatures were measured using a precision thermometer on four or five occasions: the day of deslorelin administration and insemination, the day before ovulation, the day of ovulation (Day 0), the day after ovulation and, for inseminated mares, before embryo recovery on Day 7. One-way ANOVA showed that the CR-TD was significantly lower on the day of ovulation in the 36 positive cycles, in which an embryo was recovered, versus the 16 in which the embryo flush was negative (0.21 ± 0.17 vs. 0.40 ± 0.09°C; p < 0.001). Control cycles showed equivalent CR-TD to positive (0.13 ± 0.22 vs. 0.21 ± 0.17°C; p = 0.196) but not negative cycles (0.13 ± 0.22 vs. 0.40 ± 0.09°C; p < 0.001). A positive embryo recovery was associated with lower CR-TDs from the time of insemination and deslorelin to the day after ovulation compared to the day of embryo flushing (RM ANOVA; p < 0.001; Pairwise comparisons; p ≤ 0.01, in all cases). Rectal or cervical temperatures per se showed no significant differences between positive, negative or control cycles at any time point. In conclusion, a thermoregulatory process occurs close to ovulation which results in a lower CR-TD in cycles that produced an embryo versus those which did not. Further characterisation of TDs within the reproductive tract of the mare would increase our understanding of the conditions required for optimum fertility.

Optimising Laparoscopic Artificial Insemination in Lohi Sheep: Effects of Timing, Sperm Concentration and Body Condition on Fertility Outcome in Subtropical Climates.

The objective of this study was to determine the optimal timing, sperm concentration, and body condition score (BCS) for laparoscopic artificial insemination (LAI) in the subtropical Lohi sheep breed. In Experiment 1, Lohi ewes (n = 80) were synchronised through progestin-sponges (day 0-day 11), administering PGF2α (d-cloprostenol 75 μg/mL; i.m. @ 75 μg /ewe) on day 09 and eCG (i.m. @ 300 IU/ewe) on day 11. Ewes were divided equally into four groups (n = 20 each) and then LAI was performed at 48 (T48), 60 (T60), 72 (T72) and 96 (T96) hours post-sponge removal using 200 million sperm/insemination. In Experiment 2, ewes (n = 81) were synchronised as in Experiment I. Following synchronisation ewes were divided into four groups, each subjected to LAI employing varying sperm concentrations: 10 (S10; n = 21), 20 (S20; n = 20), 50 (S50; n = 20), or 100 (S100; n = 20) million per insemination. Inseminations were performed within a time window of 48-60 h post-sponge removal, based on the findings from Experiment 1. In both experiments ewes were categorised according to BCS, that is, medium 3 and high > 3. Results of Experiment 1 revealed a quadratic response that ewes inseminated at 60-h post-sponge removal exhibited significantly higher pregnancy and twinning rates (p = 0.02). The results of Experiment 2 revealed that sperm concentration had a quadratic effect, 50 million sperm per insemination resulted in maximal pregnancy rates (p = 0.01). Additionally, ewes with medium BCS (≤ 3) had higher pregnancy rates than high BCS (> 3) ewes. In conclusion, ewes with medium BCS (≤ 3) are ideal candidate for LAI and can be inseminated at 60 h with minimal sperm 50 × 106/dose post-sponge removal to achieve a maximum pregnancy rate.

Adjusting the timing of inseminations to the time lag on luteolysis alerts results in higher conception in dairy cattle

Dairy cow fertility is a complex trait that depends on the cow's physiological status, the farm's environmental and management conditions, and their interactions. Already the slightest improvement in fertility can positively impact a farm's profitability and sustainability. In research, milk progesterone (P4) has often been used as an accurate and feasible way to identify a dairy cow's reproduction status. Moreover, in Europe and Canada, it has been used to improve fertility management on commercial farms as it allows to accurately identify reproduction issues, pregnancy and the optimal insemination window. An on-farm P4 device (OPD) automatically samples, measures and monitors the milk P4 concentration of individual cows. To this end, the P4 data is smoothed to be robust for measurement errors and outliers, and fixed thresholds are used to estimate the time of luteolysis preceding ovulation, thereby generating a luteolysis alert (LA). By smoothing the P4 data, the OPD introduces a time lag on the LA. Variation in this time lag is not considered in the estimation of the optimal insemination window that is advised to the farmer. Ignoring this variation might decrease the accuracy of the optimal insemination window and, therefore, decreases the likelihood of conception. We hypothesize that considering the length of the time lag and adapting the advice accordingly improves the conception rate. This observational retrospective study uses an extensive data set from 17 commercial dairy farms that are equipped with an OPD. We estimated the time lag on the alerts and evaluated their relationship with the interval from LA to insemination for successful (n = 3721) and unsuccessful inseminations (n = 3896) separately. Results showed that the probability of conception increases when a longer LA time lag is compensated with a shorter interval from LA to insemination and vice versa. In addition, for successful inseminations, we found a clear negative relation between the time lag and the interval from LA to insemination and the interval was significantly shorter when the time lag of the LA was longer. This negative relation between time lag and interval from LA to insemination was less pronounced for unsuccessful inseminations. Additionally, we evaluated the conception rates for inseminations that are performed too early, in time or too late with respect to the optimal insemination window advised by the OPD, in function of their associated time lags. We found that, for inseminations that were preceded by a short time lag (<8 h), the conception rate was 17.5 percentage points higher when cows were inseminated later than advised. Likewise, when inseminations were preceded by a long time lag (≥24 h), we found that the conception rate was 13 percentage points higher when cows were inseminated earlier than advised. Our results suggest that farmers using an OPD could potentially increase their conception success by compensating the variable time lag on the LA by adapting the interval from alert to insemination accordingly. This could be used to develop reproductive management strategies to improve reproductive performance on those farms, which can positively impact their sustainability.

PSIII-19 Effects of insemination time and semen sorting on conception rate to AI in beef cattle

PSIII-19 Effects of insemination time and semen sorting on conception rate to AI in beef cattle

Evaluation of estrus detection by cervical monitoring and pregnancy rates in ovsynch and co-synch treated Anatolian buffalo heifers

The aim of this study was to assess the relationship between the occurrence and intensity of estrous expression and the success of artificial insemination in Ovsynch and Co-synch treated Anatolian buffalo heifers, employing a novel approach utilizing smartphone-based endoscopic inspection of the cervix uteri. Twenty-seven Anatolian buffalo heifers (n=27) were utilized for the study. In the Ovsynch synchronization protocol (n=15), GnRH (buserelin acetate, 12 μg) was administered on day 0, PGF2α (cloprostenol, 500 μg) on day 7, and GnRH (buserelin acetate, 12 μg) on day 9, with artificial insemination conducted 16-20 hours after the second GnRH application. For the Co-synch protocol (n=12), GnRH (buserelin acetate, 12 μg) was administered on day 0, PGF2α (cloprostenol, 500 μg) on day 7, and GnRH (buserelin acetate, 12 μg) along with artificial insemination on day 10. At the time of artificial insemination, estrous expression was categorized as intense, moderate, weak, or negative. Pregnancies were confirmed between 40 to 70 days after artificial insemination using either pregnancy-related glycoprotein or ultrasonography examinations.Intense, moderate, weak, and negative estrus intensities were observed at rates of 20%, 20%, 26.7%, and 33.3%, respectively, in the Ovsynch group and 41.7%, 58.3%, 0%, and 0%, respectively, in the Co-synch group (P

P-190 Impact of low lactate culture media in embryo development and IVF outcomes

Abstract Study question Can low lactate culture media improve embryo utilization rate in artificial reproductive technology (ART) cycles? Summary answer Embryos cultured in low lactate media showed a significant improved blastocyst utilization rate compared to embryos cultured in standard culture media. What is known already Culture media plays a key role in the embryonic development in the IVF lab. Currently, different culture medias are commercially available, yet no consensus on the most suitable media composition has been reached. Recently, minimizing metabolic stress for the embryo to enhance implantation and pregnancy rates has been suggested. Research on the metabolism of mammalian preimplantation embryos revealed that excess lactate in the culture medium, in addition to pyruvate and glucose, can burden metabolic efficiency, as embryos naturally produce lactate during energy production. Study design, size, duration The prospective, monocentric study was designed and conducted at the Kinderwunsch Institut Schenk GmbH (Dobl, Austria). A total of 60 women with an average age of 32.5 undergoing ICSI (intracytoplasmic sperm injection) treatment were included. All of them had at least 6 mature (MII) oocytes at time of insemination. Sibling oocytes were cultured in two different culture medias and outcomes were compared. Patients undergoing preimplantation genetic testing were excluded. Participants/materials, setting, methods Mature (MII) oocytes of each patient (total 621 MII oocytes) were inseminated by ICSI and then equally split into two culture medias: standard (313 oocytes) and low lactate (308 oocytes) covered with mineral-oil overlay and incubated in time-lapse under the same conditions. A total of 428 embryos were obtained. Embryos were evaluated using morphokinetic criteria. The fertilization rate, embryo utilization rate, pregnancy rate and time to Blastocyst were analyzed. Main results and the role of chance No differences were observed in the number of fertilized oocytes (n = 211 and 217 in the standard and low lactate media, respectively). The overall embryo utilization rate was significantly different (p &amp;lt; 0.008) resulting in 52% in standard media and 64.3% using low lactate media. Interestingly, age stratification (18-30; 31-35; 36-41) revealed overall higher embryo utilization rates when using low lactate media in all age groups. Blastocyst utilization rate was significantly different (p &amp;lt; 0.007) 43,1% and 58,05% in the standard and low lactate media, respectively. Regarding the time to blastocyst, it was observed that in the standard culture media 80% of the blastocysts reached blastocyst stage on D + 5 whereas in the low lactate media 92,07% reached blastocyst stage on D + 5, which was also significantly different (p &amp;lt; 0.001). No differences in pregnancy and live birth rates were observed. Limitations, reasons for caution The number of patients may be seen as a study limitation. Results should be confirmed with a bigger sample size. Wider implications of the findings Low lactate media could help improve IVF outcomes due to higher embryo utilization rate leading to better cumulative pregnancy rates. Excessive lactate concentration in culture media could negatively influence embryo metabolism. Trial registration number not applicable

P-118 Behavior of the second polar body and its relationship to subsequent embryonic development, embryo ploidy status and viability in human embryos

Abstract Study question Can the behavior of the second polar body (PBII) be an indicator of embryo viability? Summary answer The behavior of PBII was shown to possibly reflect the viability of human embryos depending on the type of its behavior. What is known already Lately, time-lapse incubators have become widely available. Using time-lapse imaging, second polar bodies (PBII) can be observed from the time of extrusion to the first cleavage, exhibiting a variety of behaviors such as morphologically static, moving like an amoeba, shrinking, fragmenting and ruffling (Shimura et al, Hum Reprod:38,Suppl_1,2023). Although the ploidy and morphology of the first polar body have been variously reported to reflect the quality of embryos after fertilization, there are few studies on PBII, which is thought to directly reflect the state of oocyte after sperm entry, and its relationship to the subsequent embryonic development and embryo viability. Study design, size, duration Retrospective study involving 282 ICSI zygotes derived from 69 ART treatment cycles from January to August 2019. Zygotes were classified into two groups according to the type of PBII behaviors (Group1: static, Group2: others), and developmental outcome was compared (Study1). The relationship between the type of PBII behaviors and ploidy in 64 biopsied blastocysts from 11 cycles in which one or more euploid embryos were obtained between August 2021 and October 2023 was examined (Study2). Participants/materials, setting, methods Time-lapse imaging was performed in EmbryoScope® or Geri®. Study1: Zygotes with morphologically static PBII (n = 70) and PBII showing various behaviors (n = 212) were classified into Group1 and Group2, respectively. The rates of irregular division, good quality embryos, and the time from the PBII extrusion and pronuclear breakdown to the first cleavage were compared between groups. Study2: Biopsied blastocysts were classified according to the type of PBII behavior, and the euploid rates were examined. Main results and the role of chance Study1: The incidence of irregular divisions at the first cleavage was 21.4% (n = 15/70) in Group1 and 28.3% (n = 60/212) in Group2. Good quality embryos at the early cleavage stage were cryopreserved/transferred on Day-2/3 according to our clinic policy, and only those that were not cryopreserved or freshly transferred on Day-2/3 were extendedly cultured up to Day-7. Of those, the rate of good quality blastocysts was 32.4% (n = 12/37) in Group1 and 22.5% (n = 32/142) in Group2. Meanwhile, the rate of good quality embryos at the early cleavage stage was significantly higher in Group1 than in Group2 [P &amp;lt; 0.001; 58.6% (n = 41/70) in Group1, 35.4% (n = 75/212) in Group2]. The utilization rate for cryopreservation and embryo transfer was also significantly higher in Group1 than in Group2 [P &amp;lt; 0.05; 64.3% (n = 45/70) in Group1, 48.1% (n = 102/212) in Group2]. The time elapsed from the pronuclear breakdown to the first cleavage was significantly longer for Group2 than for Group1 [P &amp;lt; 0.05; 2.57 ± 0.42h in Group1, 3.07 ± 1.90h in Group2]. Study2: There were 20 euploid embryos in embryos with PBII showing static, amoebic and shrinking behavior (37.0%; n = 20/54), whereas there were no euploid embryos in embryos with ruffling and fragmenting PBII (0%, n = 0/10) (P &amp;lt; 0.05). Limitations, reasons for caution Categorizing PBII behavior is difficult and requires some proficiency because it varies widely including time-based changes. For the conventional IVF-derived embryos examined in Study2, time-lapse imaging was mostly started after PBII extrusion to allow sufficient insemination time. Wider implications of the findings This study showed that good quality embryos tended to have morphologically static PBII, and that euploid embryos were absent in embryos with PBII showing certain types of behavior. The behavior of PBII may be a new indicator for embryo assessment, but further clarification is needed for clinical use. Trial registration number not applicable

A field investigation of the impact of the interaction between IBR vaccination and insemination time in cow herd: Reproductive and economic perspectives

A field investigation of the impact of the interaction between IBR vaccination and insemination time in cow herd: Reproductive and economic perspectives

Ultrasound Imaging and Ovarian Follicles Growth of Mares at Nirwana Equestrian Club

Mares in the estrus cycle by the form of reproductive determine the precision of ovulating time so that efficient to the appropriate time of artificial insemination for breeding. The determination requires supporting medical equipment such as Ultrasonography during the ovulation. This research was conducted to know the ovarian follicle imaging of mares during estrus with Ultrasonography that helps through presume ovulation and the appropriate time to proceed with artificial insemination. This observation was conducted at Nirwana Equestrian Club Semarang, from October until December 2023. The sampling is collected by purposive sampling method where the sample is specifically the mares while in their estrus symptom. The collected data and information are processed descriptively using laboratory equipment such as Ultrasonography. The observation collected the mares physical estrus symptoms such as urination, vulvar pulsination, and vaginal fluid discharge. Significant development was observed from the initial follicle size of 5.34 cm to 5.61 cm in one of the samples with the examination interval within 18 hours before the occurrence of the corpus luteum. The results were proved by 9 samples of mares that had been measured with ultrasound during their estrus, and undergoing pregnancy by one attempt of artificial insemination. The optimum time for artificial insemination for mare is during ovulation where the effective precision is supported by ultrasonography.

Cattle Artificial Insemination Service in Developing Countries: Efficiency, Major Challenges and Economic Loss: A Review

This review paper summarizes information on the efficiency, major challenges and economic loss of cattle Artificial Insemination (AI) service in developing countries. Efficiency of AI service can be measured by number of services per conception (NSC), conception rate at first insemination, and calving rate (CR). The optimum recommended NSC for profitable dairy cow ranges from 1.0-2.0. The averages of NSC of the conventional AI (1.73) and fixed time AI (1.78) in the reviewed publications were in the ranges of the recommendations of NSC. The NSC varies with animal breeds, animal factor (body condition score, age and parity), semen factor (handling procedure and quality), inseminator factor (knowledge, skill and experience), production systems, management level provided and AI breeding methods. The NSC and calving rate vary with conventional AI and fixed time AI breeding methods. Likewise, calving rate (CR) is influenced by poor semen quality, poor semen handling procedure, inadequate insemination skill, poor oestrus detection and wrong time of insemination. The average success rate (CR) of conventional AI (35.15%) in the reviewed publications is far below the success rates reported in some developing countries. Nevertheless, widespread use and longtime use of AI service on selected genotype(s) can cause cattle biodiversity loss. Dairy producers incur additional costs when cows fail to conceive at their first AI services. Moreover, challenges of AI service comprised of feed scarcity, animal diseases, climate change, poor AI infrastructure, poor livestock husbandry practices, weak livestock extension systems and incapability of Artificial Insemination Technicians (AITs). This calls designing suitable interventions to improve the efficiency of AI services. Adequate feed and high level of management should be provided to the breedable cows and heifers. AI service centers should be established as per the recommended number of breedable cows and heifers. AI inputs including AITs should be always available at each AI service center, and proper AI service recording should be practiced. Sexed semen should be used to enhance the number of replacement heifers, and capacity building should be provided to AITs and community cattle breeders. Radio, television and printed medias should be used to enhance the awareness of the community cattle breeders. Frequent extension support is essential for the success rate of the AI service.

Factors at Insemination and Subsequent Conception of Cattle under Heat-Stress Tie-Stall Environments

This research aimed to compare the conception rates among AI at 12, 24, and 36 h after estrus in cattle living in tie-stall barns in a tropical environment. The second study was to determine factors at insemination at 24 h after estrus, including secondary signs of estrus behavior, reproductive tract characteristics, and heat-stress factors, in relation to conception. The study was conducted on 22 tie-stall dairy farms in Chiang Mai, Thailand. After secondary signs of estrus were observed, all farmers were informed for data collection at the insemination time. Repeated logistic regression models were used to determine factors associated with conception. The results revealed that cattle inseminated 24 h after estrus detection had the highest conception rate (67.5%). The study also found that cattle with three or two secondary estrus signs before insemination had a higher risk of conception than those with only one sign. Interestingly, there was an increased risk of conception when sticky or no cervical mucus was observed during insemination (OR = 6.85 and OR = 5.96, respectively). Moreover, increases in body temperature and ambient relative humidity were related to a decrease in the chances of conception. This study recommends delaying insemination to 24 h after the initiation of secondary estrus signs. Multiple signs of estrus, sticky cervical mucus, and lower body temperature increased conception risk in dairy cattle living in tie-stall barns in a heat-stress environment.

Effect of prostaglandin treatment on the estrus behaviour, follicular and luteal morphometry and serum hormone profile in sub-estrus buffaloes during non-breeding season.

Sub-estrus buffaloes do not exhibit estrus signs despite being cyclic contributing to extended service periods and inter-calving intervals causing significant economic loss. The present study described the effect of synthetic prostaglandin (PGF2α) on estrus behaviour, follicular and luteal morphometry, and serum estradiol (E2) and progesterone (P4) profile in sub-estrus buffaloes during the non-breeding season. The incidence of sub-estrus was 38.4% during the non-breeding season. The sub-estrus buffaloes (n = 33) were divided into two groups, viz., Control (n = 16) and PGF2α treatment (Inj. Cloprostenol 500 μg, i.m., n = 17). Estrus induction response was significantly greater in the treatment (100 vs. 18.75%, p < .001), and a relatively greater proportion of animals conceived in the treatment group (29.41 vs. 6.25%, p = .08). The time elapsed to induction of estrus and insemination following treatment was significantly lower in the treatment group than control. A significant increment in the follicle diameter (9.72 ± 0.45 vs. 13.00 ± 0.45 mm, P < .0001) and serum estradiol (E2) concentration (66.01 ± 11.92 vs. 104.9 ± 13.21 pg/mL, p = .003) observed at the post-treatment period in the PGF2α treatment group. At the same time, CL diameter was reduced significantly at a higher regression rate in the PGF2α treated buffaloes than those of control. Of the responded buffaloes, only 30% showed high-intensity estrus attributed to the expulsion of cervico-vaginal mucus (CVM), uterine tonicity, micturition, and mounting response by a teaser bull. From this study, it can be concluded that the administration of PGF2α could induce estrus in the sub-estrus buffaloes during the non-breeding season. Behavioural changes, along with sonographic observation of POF, regressing CL, and serum E2 and P4 concentration would be useful to determine the right time of insemination in sub-estrus buffaloes during non-breeding season.

Supplementation during pregnancy on the production and metabolic profile of Polwarth sheep

The aim of this study was to evaluate the effect of supplementation during different stages of pregnancy on the development and productive performance of Polwarth sheep. Fifty-three adult ewes under synchronised pregnancy were submitted to a supplement of 1.5% body weight with commercial feed during the different stages of pregnancy on natural pasture: NS - no supplementation, SIG - supplemented during the initial third of pregnancy, SMG - supplemented during the middle third of pregnancy, SFG - supplemented during the final third of pregnancy, and STG - supplemented throughout pregnancy. The ewes were weighed at the time of laparoscopic insemination, at every third stage of the pregnancy, and two days before the expected lambing date, at which time the body condition score and metabolic markers were evaluated. The pre-lambing weight of the STG ewes was greater than that of the SFG and SMG ewes, which were, in turn, greater than the SIG and NS ewes. Body condition was superior in the STG and SFG ewes. Lamb survival was greater in the STG and SFG ewes, and lower in the SMG, SIG and NS ewes. Beta-hydroxybutyrate was lower in the SFG and STG ewes. Supplementation during the final third and throughout pregnancy increases the rates of survival and production in the lambs, with supplementation only during the final third of gestation being less costly for the production system.

Machine Learning to Predict Pregnancy in Dairy Cows: An Approach Integrating Automated Activity Monitoring and On-Farm Data.

Automated activity monitoring (AAM) systems are critical in the dairy industry for detecting estrus and optimizing the timing of artificial insemination (AI), thus enhancing pregnancy success rates in cows. This study developed a predictive model to improve pregnancy success by integrating AAM data with cow-specific and environmental factors. Utilizing data from 1,054 cows, this study compared the pregnancy outcomes between two AI timings-8 or 10 h post-AAM alarm. Variables such as age, parity, body condition, locomotion, and vaginal discharge scores, peripartum diseases, the breeding program, the bull used for AI, milk production at the time of AI, and environmental conditions (season, relative humidity, and temperature-humidity index) were considered alongside the AAM data on rumination, activity, and estrus intensity. Six predictive models were assessed to determine their efficacy in predicting pregnancy success: logistic regression, Bagged AdaBoost algorithm, linear discriminant, random forest, support vector machine, and Bagged Classification Tree. Integrating the on-farm data with AAM significantly enhanced the pregnancy prediction accuracy at AI compared to using AAM data alone. The random forest models showed a superior performance, with the highest Kappa statistic and lowest false positive rates. The linear discriminant and logistic regression models demonstrated the best accuracy, minimal false negatives, and the highest area under the curve. These findings suggest that combining on-farm and AAM data can significantly improve reproductive management in the dairy industry.