Lower Conception Rates Research Articles

GPX5-Enriched Exosomes Improve Sperm Quality and Fertilization Ability

Semen preservation quality affects the artificial insemination success rate, and seminal exosomes are rich in various proteins that are transferable to sperm and conducive to sperm-function preservation during storage. However, the specific effects of these proteins remain unclear. In this study, the specific effects of these proteins on semen preservation quality and fertilization capacity were investigated through a proteomic analysis of seminal exosomes from boars with high conception rates (HCRs) and low conception rates (LCRs). The results revealed significant differences in the expression of 161 proteins between the two groups, with the GPX5 level being significantly higher in the HCR group (p < 0.05). The role of GPX5 was further investigated by constructing engineered exosomes enriched with GPX5 (Exo-GPX5), which could successfully transfer GPX5 to sperm. Compared to the control group, Exo-GPX5 could significantly improve sperm motility on storage days 4 and 5 and enhance the acrosome integrity on day 5 (p < 0.05). Additionally, Exo-GPX5 increased the total antioxidant capacity (T-AOC) of sperm, reduced the malondialdehyde (MDA) level, and decreased the expression of antioxidant proteins SOD1 and CAT (p < 0.05). In simulated fertilization experiments, Exo-GPX5-treated sperm exhibited higher capacitation ability and a significant increase in the acrosome reaction rate (p < 0.05). Overall, Exo-GPX5 can improve boar semen quality under 17 °C storage conditions and enhance sperm fertilization capacity.

Effects of parity and early pregnancy on peripheral blood leukocytes in dairy cattle

Subfertility remains a major problem in the dairy industry. Only 35-40% of high-yielding dairy cows and 55-65% of nonlactating heifers become pregnant after their first service. The immune system plays a critical role in the establishment of pregnancy. However, it can also create challenges for embryo survival and contribute to reduced fertility. We conducted 2 separate experiments to characterize changes in subsets of peripheral blood leukocytes (PBL) and their phenotype over the estrous cycle and early pregnancy in heifers and cows. We used flow cytometry and RT-qPCR to assess protein and mRNA expression of molecules important for immune function. We observed that CD14+ monocytes and CD3+ T cells tended to be affected by pregnancy status in heifers, whereas CD8B+ lymphocytes and NCR1+ natural killer (NK) cells were affected during early pregnancy in cows. Changes in expression of immune function proteins appeared to be greater in heifers than cows. To compare the most striking differences between heifers and cows observed in the initial experiments, we conducted a third experiment where PBL sampled from heifers and cows were simultaneously collected and analyzed under the same experimental conditions. Our results indicate that, compared with heifers, cows had greater mRNA expression of proinflammatory cytokines (IFNG and IL6) and AHR protein along with greater percentage of MM20A+ neutrophils and myeloid cells expressing SIRPA, ITGAM and ITGAX. Moreover, animals that failed to become pregnant showed altered expression of anti-inflammatory molecules compared with cyclic and pregnant animals. Overall, these findings support the hypothesis that early pregnancy signaling alters the phenotype of immune cells in the peripheral blood and that there are differences in the peripheral immune response to pregnancy between cows and heifers. Because cows have lower conception rates than heifers, it is possible that a more proinflammatory immune status in peripheral blood may play a role in embryo loss.

Factors influencing pregnancy loss between days 30 and 70 in a single cattle herd: A comprehensive analysis of sire, cow, and other contributing factors

This retrospective study utilized a mixed-effects logistic model analysis to investigate variables associated with the probability of pregnancy loss (PL) between days 30 and 70 in a dataset comprising 9507 pregnancies from a single cattle herd over 10 years. The model incorporated fixed-effect variables including cow breed (Holstein, Crossbred, and Brown Swiss), parity (1st, 2nd, 3rd, and 4th or more), insemination seasons, insemination number (≤3 vs >3), estrus nature (spontaneous vs synchronized), postpartum problems, sire breed (Holstein, Fleckvieh, Brown Swiss, and Montbéliarde), zygote genotypic (pure vs crossbred), days in milk (DIM) at insemination, actual 305-day milk yield, and sire conception rate. Additionally, random effects included sire (n = 129), cow (n = 3463), and production years (n = 10). The results revealed that cows inseminated with Brown Swiss sires or sires with lower initial conception rates had higher PL rates. Biparous cows, cows with lower 305-day milk yield, cows inseminated later in DIM, cows receiving the 4th or subsequent insemination, and cows inseminated during winter or autumn had lower PL rates. The estrus type and zygote genotype did not significantly impact PL. The random effects of cow, sire, and production years were estimated at 0.230, 0.054, and 0.112, respectively. In conclusion, the study findings suggested that improving management practices for high-yielding cows, cows in early lactation stages, and cows exposed to thermal stress conditions, along with utilizing Brown Swiss cows and sires with high initial conception rates per insemination, could potentially decrease overall PL rates on the farm. Nonetheless, the results did not support the use of Crossbred cows, sires from different breeds, or specific sires to mitigate PL rates on the farm.

Comparison of CUMS at different pregnancy stages, maternal separation, and their effects on offspring in postpartum depression mouse models

Due to the diversity of postpartum depression (PPD) patients and the complexity of associated pathophysiological changes, most current animal models cannot accurately simulate PPD-like symptoms. In this study, we established a reliable animal model for PPD by inducing chronic unpredictable mild stress (CUMS) at different stages (pre-pregnancy, pregnancy, or postnatal) in female mice, followed by maternal separation (MS) from day 2–21 after delivery. The results for female mice subjected to pre-pregnancy stress were not statistically significant due to a lower conception rate. However, female mice exposed to CUMS during either the gestational or postnatal stage, followed by MS, successfully exhibited PPD-like symptoms. The models were deemed effective based on observed behavioral abnormalities, impaired hippocampal neuron functioning, and reduced serum concentrations of neurotransmitters (5-HT, GABA, and NE). Additionally, mice that underwent gestational CUMS followed by MS displayed a more dysfunctional hypothalamic-pituitary-adrenal (HPA) axis and more severe uterine inflammation. The study also investigated the impact of PPD on the behavior and neurodevelopment of adolescent offspring through behavioral tests, enzyme-linked immunosorbent assay (ELISA), hematoxylin-eosin (HE) staining, and western blotting (WB). The results indicated that adolescent offspring of mothers with PPD exhibited behavioral and neurodevelopmental disorders, with male offspring being more susceptible than females. Female mice exposed to both CUMS and MS during the postnatal period had more severe adverse effects on their offspring compared to the other model groups.

PiRNA expression patterns in high vs. low fertility bovine sperm

PIWI-interacting RNAs (piRNAs) are 24–32 nucleotide RNA sequences primarily expressed in germ cells and developing embryos that suppress transposable element expression to protect genomic integrity during epigenetic reprogramming events. We characterized the expression of piRNA sequences and their encoding clusters in sperm samples from an idiopathic fertility model of Holstein bulls with high and low Sire Conception Rates. The piRNA populations were determined to be mostly similar between fertility conditions when investigated by principal component and differential expression analysis, suggesting that a high degree of conservation in the piRNA system is likely necessary for the production of viable sperm. Both fertility conditions demonstrated evidence of ‘ping-pong’ activity – a secondary biogenesis pathway associated with active transposable element targeting and suppression. Most sperm-borne piRNAs were between 29-30 nucleotides in length and originated from 226 clusters across the genome, with the exception of chromosome 20. Mapping analysis revealed abundant targeting of several transposable element families, suggesting a suppressive function of sperm piRNAs consistent with their established roles. Expression of genes targeted by sperm-borne piRNAs is significantly reduced throughout early embryogenesis compared to the mRNA population. Limited transposable element expression is known to be essential for spermatogenesis, thus epigenetic regulation of this pathway is likely to influence sperm quality and fertilizing capacity.

Perceived Constraints and Strategic Recommendations by Commercial Dairy Farmers in Jabalpur, Madhya Pradesh, India

The present study was undertaken to find out the constraints faced by the commercial dairy farmers in adoption of advance dairy production practices. The Jabalpur district of Madhya Pradesh was specifically chosen for the study because it is regarded as a centre for commercial dairy farmers and has a well-established infrastructure for the development of the dairy industry. The sample consisted of 203 responders in total. The research findings revealed that the main constraints mentioned by commercial dairy farmers were the unavailability of green fodder year-round, low conception rates through artificial insemination, high cost of veterinary treatment, and low milk prices relative to production costs. Farmers suggest solutions such as increasing milk prices in proportion to feed and service costs, standardize labour costs, reducing feed material costs, and improving access to veterinary services and innovative technologies. Providing suitable solutions can improve dairy farming practices, enhance productivity, and support the economic well-being of dairy farmers

Study on the correlation of supplementation with L-citrulline on the gastrointestinal flora and semen antifreeze performance of ram.

Cryopreservation of semen can give full play to the reproductive advantages of male animals. However, in actual production, due to the poor frost resistance of sheep semen and the low conception rate, the promotion of sheep frozen semen is greatly hindered. Therefore, it is urgent to improve the frost resistance of semen to improve the quality of frozen semen. At present, most studies on improving the quality of frozen semen are based on the improvement of semen dilutions, and few studies on improving the freezing resistance of ram semen by feeding functional amino acids. Therefore, 24 Turpan black rams were divided into high antifreeze group (HF) and a low antifreeze group (LF) Each of these groups was further randomly divided into control and experimental subgroups. The control subgroup was fed a basal diet, while the experimental subgroup received an additional 12 g/d of L-Cit supplementation based on the control group for a duration of 90 days. The results showed that Following L-Cit supplementation, the experimental group demonstrated significantly elevated sperm density and VSL (Velocity of straight line), T-AOC, GSH-Px, and NO levels in fresh semen compared to the control group (P < 0.01). After thawing, the experimental group exhibited significantly higher levels of T-AOC, GSH-Px, and NO compared to the control group (P < 0.01). Additionally, the HFT group, after thawing frozen semen, displayed significantly higher HK1 protein expression compared to the control group. The number of spermatogonia, spermatocytes, and sperm cells in the HFT group was significantly higher than that in the HFC group. Moreover, 16S rRNA sequence analysis showed that Candidatus_Saccharimonas, Staphylococcus, Weissella, succinivbrionaceae_UcG_002, and Quinella were significantly enriched in the rumen of the HFT group, while Ureaplasma was significantly enriched in the HFC group. In the duodenum, Clostridiales_bacterium_Firm_14, Butyrivibrio, and Prevotellaceae_NK3831_group were significantly enriched in the HFT group, whereas Desulfovibrio and Quinella were significantly enriched in the HFC group. Under the conditions employed in this study, L-Cit supplementation was found to enhance the intestinal flora composition in rams, thereby improving semen quality, enhancing the antifreeze performance of semen, and promoting the development of testicular spermatogenic cells.

Estrategia sostenible para mejorar la eficiencia de los servicios de inseminación artificial en ganado bovino en el trópico

The aim of this study was to evaluate the efficiency of artificial insemination (AI) services in Holstein x Brahman cows under a heat induction programme. Three experiments were carried out. In Exp. 1, a retrospective analysis of the efficiency of AI insemination of 41 000 cows treated with the combination of progesterone and oestradiol benzoate or equine chorionic gonadotropin (eCG) was carried out. In Exp. 2 it was evaluated 863 cows inseminated after heat induced with progesterone and oestradiol benzoate to know the physiological events that occur before and after service in herds with a high incidence of anoestrus. Gynaecological examinations and determination of progesterone in milk were performed. The purpose of Exp. 3 was to improve the effectiveness of AI services for cows in postpartum anoestrus treated with progesterone and oestradiol benzoate combined with a technique to identify and induce the return to service of females that did not conceive. Only 30% of the cows exceeded 40% conception. The best results were obtained when using eCG (47% vs 29%). The problems associated with the low conception rate were unfertilized oestrus, embryonic mortality and anoestrus after breeding (Exp. 2). The return to service induction technique increased (p&lt;0.001) the conception rate of the second induced service and the percentage of accumulated pregnancy in the treated group compared to the control (69.0 and 32.0%, respectively) (Exp. 3).

Decline in the Conception Rate of Wild Japanese Monkeys after the Fukushima Daiichi Nuclear Power Plant Accident

We examined the conception rate of wild Japanese monkeys (Macaca fuscata) in Fukushima City that were exposed to radiation as a result of the Fukushima Daiichi Nuclear Power Plant accident in March 2011. The conception rate in the year of delivery from 2009 to 2022 was estimated by dissecting individuals that were euthanized by the government for population control as a countermeasure against crop damage. To evaluate the effects of exposure, the cumulative exposure dose for each individual was calculated using the concentration of radiocesium deposited in the soil at the capture site and the concentration of radiocesium in muscle estimated from the aggregated transfer factor. There were no significant differences in conception rates across all age classes over time. In terms of conception rates by age class, there was a significant decrease post-exposure compared with pre-exposure in the age class ≥ 8 years, but no significant differences in the age class 5–7 years. The non-ovulation rate did not significantly differ between the pre- and post-exposure periods for any age class. Body fat index, which can affect fertility, was compared between the pre- and post-exposure periods, and no significant differences were found in either age class. In contrast, the median total cumulative exposure (cumulative internal exposure + cumulative external exposure) was significantly higher in the age class ≥ 8 years compared with the age class 5–7 years. These results suggest that the total cumulative exposure dose may be one of the reasons for the lower conception rate in the post-exposure period among the age class ≥ 8 years.

Semen sexing and its impact on fertility and genetic gain in cattle.

Semen sexing is among one of the most remarkable inventions of the past few decades in the field of reproductive biotechnology. The urge to produce offspring of a desired sex has remained since traditional times. Researchers have tried many methods for accurate semen sexing, but only the flow cytometry method has proved to be effective for commercial utilization. However, there were always concerns about the effects of sexed semen, especially on fertility and the rate of genetic gain. Some concerns were genuine because of factors such as low semen dosage in sexed semen straws and damage to sperm during the sorting process. Various researchers have conducted numerous studies to find out the effect of sexed semen on fertility and, in this article, we reflect on their findings. Initially, there were comparatively much lower conception rates (∼70% of conventional semen) but, with refinement in technology, this gap is bridging and the use of sexed semen will increase over time. Concerning genetic gain with use of sexed semen, a positive effect on rate of genetic progress with the use of sexed semen has been observed based on various simulation studies, although there has been a mild increase in inbreeding.

Relationships between antral follicle count and reproductive characteristics of embryo-recipient mares

Mares (n = 77) were evaluated by antral follicle count (AFC) and selected as embryo recipients. Cyclic recipients received embryos between days 4-6 after ovulation. The acyclic recipients received an intramuscular (i.m.) protocol with 5mg of estradiol benzoate (EB) on the day of donor ovulation (D0; D-4 recipient), 3mg of EB on the following day (D1; D-3 recipient), and 3mg of EB (D2; D-2 recipient). Furthermore, 1500mg of progesterone (P4) i.m. given on D0 of the recipient (D4 donor) followed by 1500mg of P4 on the day of ET (D4-6 recipient). On the ET day, the AFC and animals’ weight, body condition score (BCS), corpus luteum diameter, age and degree of uterine edema (UE) were measured. Pregnancy was confirmed on days 12 and 30. Low AFC was defined as ≤11 follicles (n = 43 mares) and high AFC as >11 follicles (n = 34 mares). Data were analyzed by a mixed effect model, including AFC group, reproductive seasonality, and season (P ≤ 0.05). UE was influenced (P = 0.05) by reproductive seasonality. The conception rate was higher (P = 0.016) in recipients with low (79.07 %) than high AFC (61.76 %) and higher (P = 0.005) in cyclic (81.40 %) than anestrus (58.82 %) mares. In addition, we observed a tendency (P = 0.06) for the interaction of AFC*reproductive seasonality, showing that high*anoestrus recipients had the lowest conception rate (37.50 %b) compared to high*cyclic (83.33 %a), low*anoestrus (77.78 %a) and low*cyclic (80 %a). The conception rate was higher in cyclic recipients with low AFC. Furthermore, UE was influenced by reproductive seasonality and mares in anestrus showed a higher degree of UE than cyclic mares.

Effects of Various Non-genetic Factors on Fertility Traits in Murrah Bulls in an Organized Herd

Background: In a herd going through improvement by selective breeding, bulls contribute more than half of the genetic gain due to higher selection intensity and wider coverage through AI. On the other side, meritorious sires might have a lower fertility due to various reasons which would render them less fit in their contribution to genetic improvement. Thus dairy buffalo breeders must find a delicate balance between production and reproduction superiority for selection of sires, for which an accurate assessment of genetic and non-genetic component of conception is essential. Methods: Present study was conducted on thirty five years data comprising of 5349 AI records on 1302 Murrah buffaloes using 86 bulls maintained and semen analysis of cryopreserved semen samples of 130 Murrah maintained at ICAR-National Dairy Research Institute Karnal were analyzed to study bull conception rate and sperm quality traits. Data were classified into four periods; four seasons of AI viz., Summer (April-June), rainy (July-September), autumn (October-November), winter (December-March); five parity (first, second, third, fourth, fifth and above) and five female AI number (1,2,3,4 and ³ 5 AI) to study the conception rate. Age at freezing (Years), period of freezing and season of freezing were analysed to observe their effects on semen quality traits. Mixed model analysis (SAS 9.3) and the analysis of variance were used to see the effects of various factors on conception rate as well as on semen quality parameters. Result: The analysis of variance revealed that period of AI and season of AI had significant (P less than 0.05) effect on conception rate while parity and female AI number were not found to affect the conception rate of bulls. For seminal parameters, acrosome integrity and HOST were significantly affected by age at freezing. Season affected all the semen quality traits while the effect of period of freezing was found to be non-significant for all the traits. Over all autumn season was found to be most suitable with respect to better seminal parameters. Considering season of AI, rainy season (July-September) had the lowest conception rate. The overall conception rate (%) in the study was 38.43±0.99; where Sires showed a wide variation for conception rate ranging from 20.00% to 60.46%. Concluding with the fact that there exists variation among bull fertility that can be utilized for not only herd conception rates but also be used as a criteria for bull selection and evaluation.

Mastitis impact on high-yielding dairy farm's reproduction and net present value.

Poor udder health can have a negative impact on milk production and reproductive performance, which reduces the net present value (NPV) of dairy farms. The aim of this study is therefore to investigate the relationship between clinical mastitis and NPV and the financial impact of impaired reproductive function. For this purpose, 473 dairy cows were included in our study, 146 cows with clinical mastitis (CM group) and 327 clinically healthy cows (CH group) from a high-yielding dairy farm in Romania, milking approximately 780 dairy cows with an average milk production of 46 kg milk/day. We found that, in contrast to CH cows, CM cows had a significantly lower conception rate at first service (58.2% vs. 41.7%, p < 0.05), third service (45.3% vs. 30.2%, p < 0.05), and total services (49.2% vs. 36.4%, p < 0.05). However, this positive effect was not observed for the average days open, which were significantly lower in CM cows than in CH cows (112 ± 4.3 days vs. 142 ± 3.1 days, p < 0.05). The fact that the non-pregnant CH cows had higher somatic cell counts (>400,000 SCC/mL) in their milk around artificial insemination (AI) and 1 month earlier than the pregnant cows (<250,000 SCC/ml) supports the idea that poor uterine health affects the reproductive activity of high-yielding cows. However, by using the UW-DairyRepro$ decision support tool, we found that despite the impairment of reproductive function in dairy cows, the largest negative impacts on NPV are still the cost of milk loss (US$14,439.4/farm/year) and treatment costs (US$4,380/farm/year). We considered the costs associated with poor reproductive function in the CM group (US$3,577/farm/year) as an additional cost of mastitis. Finally, it appears that the impact of mastitis on reproduction is associated with a lower chance of conception than it is with a daily risk of services.

The proteomic landscape of sperm surface deciphers its maturational and functional aspects in buffalo.

Buffalo is a dominant dairy animal in many agriculture-based economies. However, the poor reproductive efficiency (low conception rate) of the buffalo bulls constrains the realization of its full production potential. This in turn leads to economic and welfare issues, especially for the marginal farmers in such economies. The mammalian sperm surface proteins have been implicated in the regulation of survival and function of the spermatozoa in the female reproductive tract (FRT). Nonetheless, the lack of specific studies on buffalo sperm surface makes it difficult for researchers to explore and investigate the role of these proteins in the regulation of mechanisms associated with sperm protection, survival, and function. This study aimed to generate a buffalo sperm surface-specific proteomic fingerprint (LC-MS/MS) and to predict the functional roles of the identified proteins. The three treatments used to remove sperm surface protein viz. Elevated salt, phosphoinositide phospholipase C (PI-PLC) and in vitro capacitation led to the identification of N = 1,695 proteins (≥1 high-quality peptide-spectrum matches (PSMs), p < 0.05, and FDR<0.01). Almost half of these proteins (N = 873) were found to be involved in crucial processes relevant in the context of male fertility, e.g., spermatogenesis, sperm maturation and protection in the FRT, and gamete interaction or fertilization, amongst others. The extensive sperm-surface proteomic repertoire discovered in this study is unparalleled vis-à-vis the depth of identification of reproduction-specific cell-surface proteins and can provide a potential framework for further studies on the functional aspects of buffalo spermatozoa.

AN OVERVIEW OF SEMEN EXTENDERS AND FUTURE CHALLENGES TO DEVELOPMENT OF ARTIFICIAL INSEMINATION IN CAMEL

Artificial insemination is an emerging technique to ensure productivity and rapid genetic improvement in camels. This technique is not well developed due to involving different challenging factors because of semen collection, viscosity, nature of ejaculates, dilution in stabilized semen extenders, processing and cryopreservation, challenging related to artificial insemination and low conception rate. Numerous bovine commercial and non-commercial extenders with slight modification have been utilized for camel semen cryopreservation with little success. The gelatinous nature of the camel semen is one of the major challenges for proper evaluation, dosage calculation and cryopreservation. Various techniques have been used to liquefy the semen within a short spin of time without compromising the quality of sperm cells. This review provides precise data that appears in the peer reviews journals collected most of information to highlight the different semen extenders, addition of different supplementation and essential additives in semen extenders, challenges factors regarding camel bull and camel cow involved in success of artificial insemination.

Comparison of ultrasonographic measures of reproductive tract in Thai swamp buffalo heifers and cows

Although artificial insemination (AI) technology is widely used in buffalo breeding in Thailand, AI in buffaloes has a lower conception rate compared to AI in beef cattle. It is crucial to understand the development of the ovary and reproductive system of buffalo heifers and cows. The objective of the present study was to evaluate the reproductive tract characteristic using ultrasound measurements during the luteal and follicular phases in Thai swamp buffalo heifers and cows. The studies of reproductive tract were conducted in buffalo cows (n=8; BCS=3.38) and heifers (n=8; BCS=3.25). The reproductive tract was evaluated by measuring the size of the ovary, dominant follicle, CL, uterine horn, cervix, and vulva. The buffalo cows had larger diameter of the cervix and vulvar width (P&lt;0.05) compared with those of heifers. In the follicular phase, buffalo cows had a mean ovarian diameter (ipsilateral POF) of 2.35 cm, and heifers had a mean ovarian diameter of 2.24 cm (P&gt;0.05). The average preovulatory follicle diameter was 1.29 cm in buffalo cows and 1.18 cm in heifers (P&gt;0.05). In the luteal phase, the mean ovarian diameter (ipsilateral CL) of buffalo cows was significantly larger than heifers (P&lt;0.05; 2.46 vs. 2.09 cm, respectively). The diameters of the CL in buffalo heifers and cows were 1.27 and 1.47 cm, respectively (P&gt;0.05). Buffalo cows and heifers have no differences in ovarian components in the follicular and luteal phases, but there are differences in the size of the reproductive tract, which reproductive tract of buffalo cows is larger than heifers.

Female Reproductive Organ Monitoring (FROM) as a method of enhancing livestock reproduction

Low conception rate, long calving interval, and poor calf production limits the profitability of livestock production keeping food security a concern. In the ASEAN region, artificial insemination (AI) remains the most common reproductive biotechnology used for livestock breeding to produce up-graded and genetically superior animals that could address the need for food and income to the rural farming communities. Field technicians play a crucial role in carrying out AI to enhance reproduction especially in the remote areas. While ultrasonography emerged as an efficient tool to check the reproductive organ of animals for efficient reproduction, the cost of the machine hinders its availability and access by Field technicians. Skills on palpation per rectum of the ovarian dynamics and tonicity of the uterus are important assets. This paper discusses the importance of Female Reproductive Organ Monitoring or FROM in the economical and efficient application of AI in the field and enhance livestock reproduction. Strategies to develop the skills of AI practitioners are outlined to come out to skilled technicians who could execute an accurately check the reproductive status of the animals and determine the perfect time to carry out an effective and efficient AI. This method is helpful in determining the timing of AI making the resources, time and efforts of the technicians maximized and livestock production more efficient.

Vaginal Cytology as a tool for estrus detection improves the success of artificial insemination in water buffalo

Estrus detection in water buffalo is affected by the high incidence of poor manifestation inherent in this animal species. This affected the success rate of Artificial Insemination (AI) and Embryo Transfer (ET) due to the failure of perfect timing in AI and embryo-recipient synchrony in ET. While various ways of estrus detection were reported, the accuracy was interfered with by other symptoms that signify the health condition rather than the reproductive status of the animal. This results in a low conception rate and long calving intervals in AI and ET programs. Vaginal Cytology is a simple clinical tool of estrus detection that can also detect the pathological status of the reproductive tract and the perfect time for AI. While this is greatly used in canines, application in large animals was limited. The need to collect the swab from animals in the field and bring the smeared sample for analysis to the laboratory hindered its use and application. Our study, however, showed that by adopting this tool in estrus detection, increase in conception rate and calf production were achieved. A >60.0% cornification with the presence of >10 mm Graafian follicle is enough indicators of the perfect time for AI resulting in 80-100% conception. The development of a water buffalo vaginal chart helped determine the time of estrus. Strategies to adopt this tool for improved livestock reproduction are warranted.

The effect of genetic defects on pregnancy loss in Swedish dairy cattle

The effect of carrier status of 10 lethal recessive genetic defects on pregnancy maintenance in Swedish dairy cattle was examined. The genetic defects were Ayrshire Haplotype 1, Ayrshire Haplotype 2, BTA12, BTA23, and Brown Swiss Haplotype 2 in Red Dairy Cattle (RDC), and Holstein Haplotype 1, 3, 4, 6, and 7 (HH1-HH7) in Holstein. Effects of carrier status of BTA12 and HH3 on conception rate (CR), interval from first to last service (FLS), and milk production were also examined. Data were obtained for 1,429 herds in the Swedish milk recording system, while information on carrier status of genetic defects was obtained from the Nordic Cattle Genetic Evaluation. In total, data on 158,795 inseminations in 28,432 RDC and 22,018 Holstein females were available. Data permitted separate analyses of BTA12 and HH3, but carrier frequencies of other defects were too low to enable further analysis. Pregnancy loss was defined as failure to maintain pregnancy, where pregnancy status was confirmed with manual and chemical pregnancy diagnosis, insemination, calving, sales and culling data. Odds ratios (OR) and probabilities of pregnancy loss and CR were estimated using generalized linear mixed models, while pregnancy loss, CR, FLS, milk, protein, and fat yields were analyzed using linear mixed models. Pregnancy losses were reported on average within the first month post-AI. At-risk matings were more prone to suffer pregnancy loss in BTA12 (OR = 1.79) and HH3 carriers (OR = 1.77) than not-at-risk matings. At-risk matings also had lower CR (OR = 0.62 and 0.63 for BTA12 and HH3, respectively) than not-at-risk matings. Carrier females of BTA12 had longer FLS and higher milk production than noncarriers. Conception rate and pregnancy maintenance could be improved by avoiding at-risk matings. This finding could help reduce pregnancy loss due to genetic defects in the breeding program for improved fertility.

PSIII-7 Effect of Time of Estrus on Conception Rate for a Sexed Semen Artificial Insemination Protocol in Multiparous Beef Cows

Abstract Sexed semen artificial insemination is a breeding technique that allows producers to shorten breeding seasons, optimize genetics through use of superior semen, create calves based on sex preference, and increase profitability. Sexed semen is a technology that sorts semen by differences in DNA content between X (female) and Y (male) bearing sperm. However, sexed semen practices have yet to be widely used in beef cows due to reduced sperm numbers, low conception rates, and increased costs. The objective of this study was to determine the effect of time of estrus upon fixed-time artificial insemination (FTAI) of sex-sorted semen on conception rate using two different estrous synchronization protocols. Multiparous commercial beef cows (n = 73) were randomized by age, body condition score (BCS), and days post-partum at the University of Arkansas Livestock and Forestry Research Station in Batesville. Both synchronization treatments (TRT) used a controlled internal drug releasing device (Eazi-breed CIDR; 1.38g progesterone) inserted intravaginally on d -14 of the protocol simultaneous to administration of prostaglandin F2α (PGF; 500µg cloprostenol sodium; Estrumate). In the first treatment (TRT 1; 7&amp;7 Synch), gonadotropin-releasing hormone (GnRH; 86µg gonadorelin; Fertagyl) was administered on d -7. In the second treatment (TRT 2; 8&amp;6 Synch), GnRH was administered on d -6. Both treatments were then administered PGF simultaneous to CIDR removal on d 0, 66 ± 2h before FTAI and administration of GnRH. Standing heat (estrus) was visually detected every 3 h for 30 min intervals between CIDR removal and FTAI. Heat detection patches were used in conjunction with visual detection of estrus. Time of estrus was signified as time of standing immobile when mounted in combination with presenting a patch score of 4 (&amp;gt;75% color removed). Time of estrus (TD) was deviated from time of FTAI and categorized into three equal time groups (Grp 1 = 0 to 11.0 h; Grp 2 = 11.01 to 22.0 h; and Grp 3 = 22.01 to 33.0 h). Conception rate (CR) was determined via ultrasound 37 ± 2 d after FTAI. Data were analyzed using the GLIMMIX procedure of SAS 9.4. CR did not differ by age of dam (P = 0.58), BCS (P = 0.48), or TRT (P = 0.83). However, TD had an effect on CR (P = 0.002); and resulted in CR of 45% (Grp 1), 87% (Grp 2), and 42% (Grp 3). In conclusion, these results indicate artificially inseminating cows with sexed semen between 11.01 and 22.0 h after time of standing estrus will increase pregnancy rates for multiparous commercial beef cattle.