Bovine Reproduction Research Articles

Proteomics and metabolomics analyses of mechanism underlying bovine sperm cryoinjury

BackgroundThe cryoinjury of semen during cryopreservation reduces sperm motility, constraining the application of artificial insemination (AI) in bovine reproduction. Some fertility markers, related to sperm motility before and after freezing have been identified. However, little is known about the biological mechanism through which freezing reduces sperm motility. This study investigated the selective effects of cryoinjury on high-motility sperm (HMS) and low-motility sperm (LMS) in frozen-thawed from the perspectives of reactive oxygen species (ROS), mitochondrial membrane potential (MMP), and ATP levels. The molecular mechanism of decreased sperm motility caused by cryoinjury was explored through a joint analysis of 4D-label free quantitative proteomics and non-targeted metabolomics.ResultsThe results indicate that low levels of ROS and high degrees of MMP and ATP play a critical role in the survival of HMS during the freezing process. The sperm samples from the frozen-thawed HMS and LMS were analysed for proteomics and metabolomics, 2,465 proteins and 4,135 metabolites were detected in bovine sperm samples. In contrast to LMS, HMS have 106 proteins and 106 metabolites with high abundance expression, and 79 proteins and 223 metabolites with low abundance expression. Proteomics and metabolomics data exhibit that highly expressed antioxidant enzymes and metabolites in HMS can maintain sperm motility by regulating the ROS produced during freezing to prevent sperm from oxidative stress and apoptosis. Furthermore, the KEGG analysis of differential proteins and metabolites during the freezing process implies that the significant enrichment of glycolysis and cAMP in HMS can guarantee energy supply.ConclusionsThe results provided that during the process of bovine sperm freezing, highly expressed antioxidant enzymes can regulate the reactive oxygen species levels to avoid oxidative stress and the glycolysis signalling pathway ensures ATP production can sustain frozen-thawed sperm motility.

Enhancing Bovine Reproduction: The Progress of Artificial Insemination in Ethiopia

ABSTRACTArtificial insemination (AI) has emerged as a transformative technology in bovine reproduction, revolutionising the agricultural sector globally. In countries like Ethiopia, where livestock is a vital component of the economy and plays a crucial role in ensuring food security and supporting rural livelihoods, advancements in AI hold immense promise and potential. AI has been instrumental in improving the genetic quality of bovine populations, increasing milk and meat production, and facilitating the dissemination of superior genetic traits across diverse breeds. In Ethiopia, traditional breeding practices often face challenges related to limited access to superior breeding stock and inadequate breeding management. The adoption of AI techniques can address these constraints and pave the way for sustainable livestock development. The importance of bovine AI in Ethiopia is underscored by the country's large bovine population, which primarily consists of indigenous zebu cattle breeds known for their adaptability to local environmental conditions. However, challenges persist regarding its widespread adoption and implementation in Ethiopia. Key obstacles include limited access to quality semen from superior sires, inadequate infrastructure and facilities for AI services, insufficient training and capacity building among veterinary professionals and inseminators, and socioeconomic barriers faced by smallholder farmers in accessing AI services. This review aims to critically examine the progress made in bovine AI in Ethiopia, identify the obstacles and constraints hindering its full‐scale adoption, and explore prospects and strategies for overcoming these challenges. By delving into the latest research findings, policy frameworks and practical experiences in bovine AI, this review seeks to provide valuable insights and recommendations for leveraging AI technology to enhance livestock productivity, genetic diversity and sustainable agricultural development in Ethiopia.

Role of trace minerals in cow’s reproductive function and performance: a clinical theriogenology perspective*

Trace minerals (TM) have a crucial role in cattle reproduction. Although microelements are required in small amounts, their bioavailability is essential for the cow reproductive physiology, and for adequate fertility and productivity. They are particularly important for antioxidant protection against cellular damage (e.g. gametes and embryonic cells), hormone synthesis, and pregnancy maintenance. Oral TM supplementation is a common and highly recommended management practice in cattle operations. However, there is substantial variability in TM bioavailability in animals receiving oral TM supplementation. The strategic use of injectable TM supplementation (without replacing traditional oral TM supplements) before episodes of marked stress (e.g. parturition), higher metabolic demand with TM depletion (e.g. last trimester of pregnancy), active immune response (e.g. uterine involution or vaccination), and before breeding helps to maintain adequate TM and oxidative status during critical points of the reproductive program. This manuscript reviews the research-based evidence regarding the effects of TM supplementation on bovine reproduction and its impact on beef and dairy cattle reproductive performance.

Applications of ultrasonography imaging techniques in different aspects of bovine reproduction

Applications of ultrasonography imaging techniques in different aspects of bovine reproduction

Relationship between bull signalment and testicular attributes in a Kenyan bull station.

Male fertility is essential to bovine reproduction, particularly when bulls are used for artificial insemination or single-sire breeding. Bull breeding and soundness examinations (BBSE) are routinely undertaken to identify potentially unfit bulls for breeding. Multiple criteria, including physical examination and determination of testicular and semen parameters, characterize BBSE. Knowledge interstices within this realm, especially in tropical African settings, necessitate pragmatic approaches to address the same. This study aimed to investigate the potential effects of bull parameters on testicular attributes in a tropical setting. The present study recruited healthy bulls (n = 96) aged >16 months with active semen collection used for artificial insemination at the Kenya Animal Genetic Resources Center. The breed breakdown was as follows: Ayrshire (n = 40), Boran (n = 3), Friesian (n = 36), Guernsey (n = 5), Jersey (n = 7), and Sahiwal (n = 5). Age, breed, body weight, scrotal circumference (SC), and testicular echotexture were collected, and the findings were analyzed using R statistical software. SC increased with age and body weight (p < 0.0001). SC varied from one breed to the others (p < 0.0001). Furthermore, as determined using trans-scrotal ultrasonography, hyperechoic testicular lesions were present in 30.21% of the bulls imaged, and the incidence was significantly related to age (p < 0.001). SC is significantly affected by age and body weight. The mean SC was higher in the Bos indicus, but this finding is only indicative because the Sahiwal and Boran sample sizes were small. Notably, the prevalence of hyperechoic testicular foci following trans-scrotal ultrasonography was common in older bulls. However, there is a need to further elucidate this phenomenon's pathophysiology with age as the etiology and possible sequelae of semen quality.

Enhancing early identification of high-fertile cattle females using infrared blood serum spectra and machine learning

Artificial insemination (AI) success in bovine reproduction is vital for the cattle industry’s economic sustainability and for advancing the understanding of reproductive physiology. Identify high-fertile animals’ fertility is a complex task due to multifactorial traits, including hormonal, age-related, and body condition factors. Early high-fertility identification is crucial for timely interventions and enhancing AI success. In this study, we present the potential use of Fourier-transform infrared (FTIR) spectroscopy on blood serum for early identification of high-fertile Nellore female cows for AI protocols. Blood serum FTIR spectra were obtained from Nellore female cows before AI. FTIR spectra underwent data analysis and the results demonstrated successful discrimination between animals that exhibit pregnant and non-pregnant diagnoses 30 days after AI. FTIR spectra revealed consistent vibrational modes, emphasizing Amide I and II bands. Principal Component Analysis (PCA) effectively segregated groups based on molecular information. Linear SVM with C = 10 and 4 PCs achieved 100% accuracy in the group classification. This innovative approach using FTIR spectroscopy and ML algorithms offers a promising means of high-fertile cow identification, potentially improving AI outcomes in Nellore cattle. The study presents valuable insights into advancements in reproductive management practices for this economically significant breed.

Impact of fluazuron on oocyte maturation: May the antiparasitic affect bovine reproduction?

Fluazuron is a novel veterinary pour-on antitick formulation which can be applied simultaneously with bovine reproduction management strategies. Considering the economic importance of the livestock industry in many countries, it is important to know whether antiparasitics such as fluazuron may cause embryonic loss. The aim of this study was to evaluate the toxicological effect of fluazuron on bovine oocytes during in vitro maturation. The best fluazuron concentrations were determined in a preliminary experiment on Chinese hamster ovary (CHO)-K1 cells and further used to compare fluazuron toxicity in both study models. Results of the annexin V and alkaline single cell gel electrophoresis assays demonstrated that fluazuron caused cytotoxicity and genotoxicity in bovine cumulus cells at all the concentrations tested (50, 75 and 100 μg fluazuron/mL). The evaluation of cortical granules and mitochondria distribution showed that cytoplasmic maturation was not affected by fluazuron treatment. However, a decrease in metaphase II + polar body, degenerate oocytes as well as disorganized chromatin in polar body were observed at all concentrations tested. Whereas the fertilization process was not altered by 50 μg/mL fluazuron, the embryo development rate decreased significantly. No significant differences were observed in any of the oxidative stress parameters assessed. This study contributes to a better understanding of fluazuron in bovines, suggesting that the antiparasitic may affect bovine reproduction and might cause embryo loss.

Evaluating impact of season and corpus luteum cavitation on serum progesterone concentration and pregnancy in a Holstein dairy herd

The corpus luteum (CL) is vital to bovine reproduction and can present in 2 forms on ultrasound examination: homoge­neous or cavitary. Impact of CL cavitation on fertility in cattle has been debated. Many variables influence fertility includ­ing heat stress, but little is known regarding the impact of season and risk of association with a cavitary CL. The objec­tives of this study were to evaluate: (1) effect of CL form on serum progesterone, and (2) effect of reproductive status and season on the likelihood of diagnosing a cavitary CL. Blood from Holstein cows (n = 787) on a commercial dairy farm was collected (n = 1,062) at 39-45 days post-insemination. Some cows were sampled more than once. Corpora lutea were categorized as homogeneous or cavitary, and cows were diagnosed as either pregnant or non-pregnant via transrectal ultrasonography at time of blood collection. When adjusted for season and CL status, pregnant cows produced higher serum progesterone (6.880 ng/mL; 95% CI [6.606, 7.153]) than non-pregnant cows (4.664 ng/mL; 95% CI [4.398, 4.931], P &lt; 0.001). When adjusted for progesterone levels and season, pregnant cows were 94.7% less likely (OR = 0.053, P &lt; 0.001) to be diagnosed with a cavitary CL com­pared to non-pregnant cows. No difference was observed in serum progesterone by CL form (P = 0.393). Serum progester­one was significantly lower in summer than fall (P &lt; 0.001), winter (P &lt; 0.001) and spring (P = 0.005). Season did not impact likelihood of diagnosing a cavitary CL.

Gonadotropin-Releasing Hormone (GnRH) and Its Agonists in Bovine Reproduction II: Diverse Applications during Insemination, Post-Insemination, Pregnancy, and Postpartum Periods.

The administration of GnRH and its agonists benefits various aspects of bovine reproductive programs, encompassing physiological stages such as estrous synchronization, post-insemination, pregnancy, and the postpartum period. The positive impact of GnRH administration in overcoming challenges like repeat breeder cows, early embryonic loss prevention, and the management of cystic ovarian disease (COD) is thoroughly surveyed. Furthermore, this review focuses on the significance of GnRH administration during the postpartum period, its role in ovulation induction, and how it enhances the productivity of embryo transfer (ET) programs. An emerging feature of this field is introduced, focusing on nano-drug delivery systems for GnRH agonists, and the potential benefits that may arise from such advancements are highlighted. While this review offers valuable insights into various applications of GnRH in bovine reproduction, it emphasizes the crucial need for further research and development in this field to advance reproductive efficiency and health management in dairy cattle.

Gonadotropin-Releasing Hormone (GnRH) and Its Agonists in Bovine Reproduction I: Structure, Biosynthesis, Physiological Effects, and Its Role in Estrous Synchronization.

GnRH is essential for the regulation of mammalian reproductive processes. It regulates the production and release of pituitary gonadotropins, thereby influencing steroidogenesis and gametogenesis. While primarily produced in the hypothalamus, GnRH is also produced in peripheral organs, such as the gonads and placenta. GnRH analogs, including agonists and antagonists, have been synthesized for the reproductive management of animals and humans. This review focuses on the functions of hypothalamic GnRH in the reproductive processes of cattle. In addition to inducing the surge release of LH, the pulsatile secretion of GnRH stimulates the pituitary gland to release FSH and LH, thereby regulating gonadal function. Various GnRH-based products have been synthesized to increase their potency and efficacy in regulating reproductive functions. This review article describes the chemical structures of GnRH and its agonists. This discussion extends to the gene expression of GnRH in the hypothalamus, highlighting its pivotal role in regulating the reproductive process. Furthermore, GnRH is involved in regulating ovarian follicular development and luteal phase support, and estrus synchronization is involved. A comprehensive understanding of the role of GnRH and its analogs in the modulation of reproductive processes is essential for optimizing animal reproduction.

Bovine Pluripotent Stem Cells: Current Status and Prospects.

Pluripotent stem cells (PSCs) can differentiate into three germ layers and diverse autologous cell lines. Since cattle are the most commonly used large domesticated animals, an important food source, and bioreactors, great efforts have been made to establish bovine PSCs (bPSCs). bPSCs have great potential in bovine breeding and reproduction, modeling in vitro differentiation, imitating cancer development, and modeling diseases. Currently, bPSCs mainly include bovine embryonic stem cells (bESCs), bovine induced pluripotent stem cells (biPSCs), and bovine expanded potential stem cells (bEPSCs). Establishing stable bPSCs in vitro is a critical scientific challenge, and researchers have made numerous efforts to this end. In this review, the category of PSC pluripotency; the establishment of bESCs, biPSCs, and bEPSCs and its challenges; and the application outlook of bPSCs are discussed, aiming to provide references for future research.

Social appropriation of knowledge applying the knowledge management methodology. Case study: San Miguel de Sema, Boyacá

The development of human and technical capacities in rural territories intrinsically promotes the progress and evolution of the rural sector. To achieve this, it is vital to analyze the processes that are currently carried out, to adopt or appropriate the new knowledge that allows rural producers to perceive, interpret and demonstrate the new learning. In the study of the form of appropriation of new knowledge, two epistemological perspectives were used: tacit and explicit knowledge to be applied by the participants of a course oriented towards bovine reproduction in the municipality of San Miguel de Sema, Boyacá, Colombia. After apprehending elements such as reproduction indicators, the participants agreed that the factors that have the most relevance and impact on their production systems and that directly affect reproduction correspond to the management of reproductive indicators, climatic conditions and technical training

Effect of feeding corn silage on semen quality and spermatogenesis of bulls.

Bovine reproduction, including male fertility traits like semen quality, are influenced by a variety of different factors like breed, nutrition, environment, and feeding management. Diet in a crucial determinant, and in this regard although corn silage is generally considered to be a favorable roughage for fattening meat type breeds, it tends to have a negative impact on semen quality. In the current study, alfalfa hay was substituted by corn silage as a roughage source in the diet of bulls to investigate its effects on the fertility of breeding bulls. A feeding trail spanning 140 days was conducted, with semen collection occurring twice a week commencing 60 days after the start of trial. Semen quality parameters, serum antioxidant indexes, sex hormone content in semen, rumen microflora, and sperm transcriptome were characterized. Feeding corn silage enhanced host antioxidant capacity, significantly decreased spermatozoal motility and increased sperm deformity rate in bulls. Furthermore, follicle-stimulating hormone (FSH) and luteinizing hormone (LH) content in semen were significantly decreased (P < 0.05), and the inhibin B (INHB) content was significantly increased (P < 0.01). Feeding corn silage led to significant changes in the diversity of rumen microbiota of cattle at the phylum and genus levels, some of which were significantly correlated with semen quality. Subsequent RNA sequencing indicated that DHH and PITHD1, two genes related to sperm and reproductive development, were differentially expressed, and enrichment analysis also identified several pathways and biological functions relevant to sperm development and reproduction. These results indicate that feeding corn silage modulates semen quality via different pathways. Firstly, corn silage metabolites likely affect the secretion of INHB through the testicular capillaries, which affects semen quality by regulating genes involved in spermatogenesis. Secondly, low lignin content in silage corn appears to reduce abundance of rumen flora that are positively correlated with semen quality. Overall, results indicate that feeding bulls corn silage as the primary source of forage could negatively impact semen quality and may not be appropriate as the primary roughage of forage for breeding bulls.

Alpha-lipoic acid improves bovine preimplantation blastocyst quality and cryotolerance

In vitro embryo production has grown in recent decades due to its great potential for cattle production. However, the quality of in vitro-produced embryos is lower compared with those produced in vivo. The postfertilization culture environment has a major influence on bovine embryo quality. We hypothesize that the inclusion of the inclusion of alpha-lipoic acid (ALA) in the in vitro culture (IVC) medium during the first 24 h would have positive effects on embryo development in vitro and cryotolerance. The aims of this study were to evaluate the antioxidant effect of ALA in IVC medium for 24 h on bovine zygotes (21 h post in vitro fertilization, IVF), day 2 cleaved embryos (46 h post-IVF), and to assess embryo quality, developmental competence, and cryotolerance after vitrification. In all experiments, IVC medium was the Control, and 2.5 μM ALA was the treatment implemented. Viability and reactive oxygen species (ROS) levels in zygotes and day 2 embryos did not differ from the Control (P > 0.05). Supplementation with ALA increased total blastocyst and hatching rates (P < 0.05). It also improved embryo quality, evidenced by the increased blastocyst total cell number and the percentage of excellent-quality embryos observed (P < 0.05). In embryos cultured with ALA and then vitrified, ALA reduced intracellular ROS levels in warmed blastocysts (P < 0.05). In conclusion, ALA supplementation to IVC medium during 24 h is a new advantage in improving embryo quality for assisted bovine reproduction.

Deviations from Mendelian Inheritance on Bovine X-Chromosome Revealing Recombination, Sex-of-Offspring Effects and Fertility-Related Candidate Genes.

Transmission ratio distortion (TRD), or significant deviations from Mendelian inheritance, is a well-studied phenomenon on autosomal chromosomes, but has not yet received attention on sex chromosomes. TRD was analyzed on 3832 heterosomal single nucleotide polymorphisms (SNPs) and 400 pseudoautosomal SNPs spanning the length of the X-chromosome using 436,651 genotyped Holstein cattle. On the pseudoautosomal region, an opposite sire-TRD pattern between male and female offspring was identified for 149 SNPs. This finding revealed unique SNPs linked to a specific-sex (Y- or X-) chromosome and describes the accumulation of recombination events across the pseudoautosomal region. On the heterosomal region, 13 SNPs and 69 haplotype windows were identified with dam-TRD. Functional analyses for TRD regions highlighted relevant biological functions responsible to regulate spermatogenesis, development of Sertoli cells, homeostasis of endometrium tissue and embryonic development. This study uncovered the prevalence of different TRD patterns across both heterosomal and pseudoautosomal regions of the X-chromosome and revealed functional candidate genes for bovine reproduction.

Genetic Study to Establish the Relationship between Sire Fertility and Daughter Performance Traits among Murrah Buffaloes

Background: Bull fertility assumes a vital part in bovine reproduction. Since selection intensity of bulls picked for breeding programs in dairy industry is high as they can sire extensively larger counts of offspring as compared to their female counterparts. Therefore the present study was designed to establish the relationship between the sire fertility and performance traits of the Murrah buffaloes. Methods: A total of 12898 observations were recorded with respect to routine seminal parameters from 130 Murrah breeding bulls spanning between 1995 and 2019 (25 years). Data consisted of 2161 records of 305 days milk yield (305 MY) and lactation length (LL), 2160 records of lactation milk yield (LMY), 2155 records of peak milk yield (PMY), 1905 records of average fat percentage (FP), 1542 records of service period (SP) and 1914 records of conception rate (CR) have been utilized for the current study. Breeding values with respect to 33 Murrah buffalo bulls were taken for the correlation studied and for further ranking of the sires. Result: Average mean values of seminal parameter viz. ejaculated volume (EV), colour (Col), consistency (Con), log sperm concentration (LSC), mass activity (MA), initial motility (IM) and Post-Thaw Motility (PTM) were as 3.25±0.01 (ml), 3.50±0.01 (0-5 scale), 2.52±0.04 (0-5 scale), 3.11±0.01, 2.25±0.01 (0-5 scale), 64.22±0.15 and 38.62±0.19 (%) respectively. The arithmetic means of LMY, 305 MY, PY, LL, FP, CR and SP were calculated to be 2343.33±17.77, 2142.13±13.77, 12.57±0.06, 328.41±2.11, 7.39±0.01, 0.52±0.09 and 166.36±2.75, respectively. The sire rank correlation between the seminal attributes and performance traits was ranged between -0.57±0.15 (ejaculate volume and lactation milk yield) and 0.49±0.16 (semen consistency and lactation milk yield). Association between the fertility using routine semen quality parameters would be helpful to assess the bull fertility which lead to the improvement in the herd fertility.

FISIOLOGÍA RELACIONADA AL USO DE LA ECG EN GANADO DE CARNE Y LECHE

Equine chorionic gonatrophin (eCG) is a high molecular weight glycoprotein produced by endometrial cups in the mare. ECG has primarily LH activity in the mare, but has FSH or LH activity in the cow, depending on the recipient populations in the ovary. Although eCG has been used to induce superovulation in a variety of species, several studies have demonstrated the beneficial effects of eCG on fixed-time AI (IATF) programs in beef and dairy cattle, and embryo recipients. Under these circumstances, eCG has stimulated the development of the ovulatory dominant follicle and produced ovulation of a larger follicle, resulting in a larger and more functional LC and longer embryo survival. In suckling beef cows, 400 IU of eCG at the time of removal of a progesterone device resulted in increased conception rates after IATF,and in dairy cattle managed in pastoral systems, the eCG administration resulted in a significant increase in pregnancy rates, especially in cows in anestrus. In embryo recipients, treatment with eCG has resulted in increased pregnancy rates after embryo transfer. This presentation will review some of this data and explore strategies to use the potential benefits of eCG to improve bovine reproduction.

Applications of transabdominal ultrasonography in bovine reproduction: A review

The non-invasive nature of ultrasonography makes it an important clinical and research tool in bovine reproduction and obstetrics. Ultrasound techniques are becoming increasingly important in animal reproduction and obstetrics and these techniques are helpful in evaluation of various disease conditions of uterus during advance pregnancy in bovines. Accordingly, understanding the use of ultrasound technology is of utmost importance in animal sciences, since ultrasound examinations are now a routine part of diagnostic workups in reproduction and obstetrics. Up to now, most of studies were conducted to assess the status of fetal and uterine structures by trans-rectal ultrasonography, but sometimes it was found to be inefficient in judging the complete status of fetal and uterine structures during mid and advance pregnancy when the fetus is located deep into the abdominal cavity. So, in modern times transabdominal ultrasonography is getting popularity over trans-rectal ultrasonography in bovines during mid and advance gestation to determine the complete status of pregnant animals. The new information that has been generated by use of transabdominal ultrasonography has thrown light on diagnostic and research aspects and created new areas for research. Transabdominal ultrasonographic examination of the reproductive tract can provide useful information related to fetal viability, diagnosis of mid to late term pregnancies, gestational age, assessment of fetus and fetal organs, placentomes, fetal fluids, uterine wall, umbilicus, and identification of developmental abnormalities. To best of my knowledge this is the first review of applications of transabdominal ultrasonography in bovine reproduction because literature related to transabdominal ultrasonography in bovine reproduction and obstetrics is very scanty.

Zearalenone interferes with the sperm-triggered inflammation in the bovine uterus in vitro: Negative impact on sperm motility and survival

Zearalenone (ZEN)-contaminated diets induce detrimental effects on the bovine reproduction. Recently, we reported that active sperm induce pro-inflammatory responses in bovine endometrial epithelial cells (BEECs) in vitro. This study aimed to investigate the impact of presence of ZEN on the sperm-uterine crosstalk in vitro. BEECs monolayers were stimulated by ZEN (10, 100, and 1000 ng/mL) for 0, 3, 6, 12, or 24 h and gene expressions were analyzed by real-time PCR. Moreover, BEECs were pre-exposed to ZEN (10, 100, and 1000 ng/mL) for 24 h then, co-incubated with sperm for 6 h. Conditioned media (CM) from a sperm-BEECs co-culture, after pre-exposure to ZEN, were harvested and exploited to challenge either polymorphonuclear cells (PMNs) or sperm. Both PMNs phagocytic activity toward sperm and sperm motility parameters were then assessed. Results showed that ZEN alone induced pro-inflammatory responses in BEECs through the induction of mRNA expressions of pro-inflammatory cytokines (TNFA and IL1B) and PGES1 at different time points. Pre-exposure of BEECs to ZEN, amplified the sperm-triggered upregulation of pro-inflammatory cytokines (TNFA and IL1B) and chemokine IL8 mRNA abundance in BEECs. Sperm-BEECs conditioned media, primed by ZEN, stimulated the PMNs phagocytosis for sperm whereas suppressed sperm motility parameters. Taken together, these findings indicate that the presence of ZEN augments the pro-inflammatory cascade triggered by sperm in BEECs, provokes PMNs phagocytosis for sperm, and reduces sperm motility parameters. Such immunological reactions may create a hostile environment for sperm competence and survival in the bovine uterus, thus impair fertility.

PSI-15 Embryo viability based upon energy

Abstract The objective of this study was to analyze embryo energy release and whether or not it is indicative of survivability upon successful implantation. In both bovine and equine reproduction, fertility is a lowly heritable trait that has an exceedingly large financial impact on the ability to grow genetic lines. In order to increase pregnancy rates, producers must have access to accurate decision-making tools. Nineteen (n = 19) fertilized bovine embryos collected via flushing by licensed veterinarian, Dr. Russell Killingsworth, DVM, in Shamrock, TX, were assessed for energy release using amplification of video with a Nikon Camera and Iolight Microscope. Once embryos were flushed, they were filmed for a thirty-five (35) second observation period. Embryo dimensions were then taken using Image J software. Embryo release of energy was humanly perceptible and measurable by changes in their morphological dimensions. Measurements of significance were taken on the embryo intercellular mass area (ICM), total embryo area, and on the vertical, diagonal, and horizontal axis of the sub-zonal distance, or the distance between the zona pellucida and outer edge of the ICM. All measurements were taken in microns. Once embryos were successfully measured, all were transferred into recipients. Significant findings presented that embryos with a greater ICM, total embryo area, and sub-zonal vertical, diagonal, and horizontal distance established pregnancies more frequently than embryos with less momentous differences in distance (P &amp;lt; 0.05). This research has shown the relationship between embryo energy and pregnancy had a significance of determining pregnancy viability. This has therefore resulted in enhanced prediction of embryo transfer techniques based on embryo quality making pregnancy rates for producers more predictable and consistent.