Delineation of maternal versus direct effects heat stress in reducing development at the germinal vesicle (GV) stage is challenging, because oocytes spontaneously resume meiosis after removal from antral follicles. The use S-roscovitine (inhibitor p34cdc2/cyclin B kinase) to hold bovine GV without compromising early embryo was previously validated our laboratory. objective present study assess an elevated temperature commonly seen heat-stressed dairy cows on cumulus-oocyte complexes (COCs)...

Blood‐borne extracellular vesicles (i.e., exosomes and microvesicles) carrying microRNAs (miRNAs) could make excellent biomarkers of disease different physiologic states, including pregnancy status. We tested the hypothesis that circulating vesicle‐derived miRNAs might differentiate status cows had maintained to Day 30 from non‐pregnant or those exhibited embryonic mortality between Days 17 gestation. Cows were randomly assigned for artificial insemination with fertile semen ( n = 36) dead...

To determine if reductions in developmental competence related to heat stress exposure were correlated with perturbations certain RNA populations, poly(A) RNA, total size distribution, and the abundance of transcripts (cyclin B1, GDF9, BMP15, polymerase, HSP70, 18S & 28S rRNA) examined oocytes matured at 38.5 or 41 C. Performing vitro fertilization resulted embryos for examining RNA. Relative germinal vesicle-stage oocytes, amount decreased similarly Total did not change during meiotic...

When the effects of heat stress are detrimental during maturation, cumulus cells intimately associated with oocyte. To determine extent to which affects these cells, in this study, transcriptome profiles that surrounded control and heat-stressed oocytes (41 °C first 12 h only then shifted back 38.5 °C) vitro maturation (IVM) were compared using Affymetrix bovine microarrays. The comparison cumulus-derived revealed a number transcripts whose levels increased ( n =11) or decreased =13) ≥...

Hyperthermia during estrus has direct consequences on the maturing oocyte that carries over to resultant embryo compromise its ability continue in development. Because early embryonic development is reliant upon maternal transcripts and other ooplasmic components, we examined impact of heat stress bovine using microarray. Oocytes were matured at 38.5ºC for 24 h or 41.0ºC first 12 vitro maturation; thereafter. Transcriptome profile was performed total (adenylated + deadenylated) RNA...

Abstract Improved oocyte competence for embryo development and pregnancy was observed following ovulation of preovulatory follicles with greater physiological maturity, as indicated by estradiol production, prior to the gonadotropin-releasing hormone (GnRH)-induced luteinizing (LH) surge. It hypothesized that follicular fluid from maturity better supports maturing oocyte's metabolic requirements improves development. The objective determine if differences in due follicle influence metabolism...

Introduction: Preovulatory follicle response to the luteinizing hormone (LH) surge leads metabolic, molecular, and functional changes in oocyte somatic follicular cells from onset of estrus ovulation. Follicular fluid contains metabolites, miRNAs, proteins, hormones that are byproducts metabolism support cellular processes oocyte, cumulus, granulosa constituents. Numerous studies have highlighted importance composition fertility, but critical gaps exist toward understanding dynamic...

Elevated body temperature (HEAT) in sexually receptive females is a normal part of the periovulatory microenvironment. The objective was to identify direct (first 6 h) and delayed (4 h or 18 recovery) effects at 41 °C exposure during vitro maturation (IVM) on transcripts involved steroidogenesis, oocyte maturation, previously impacted by elevated using targeted RNA-sequencing. Most (72.3%) were first 2 4 hIVM. Twelve fifteen hIVM had higher abundance three lower abundance. Direct related...

Consequences of heat stress exposure during the first 12 h meiotic maturation differed depending on how and when bovine oocytes were activated. If heat-stressed underwent IVF at ~24 h, blastocyst development was less than for respective controls similar to that obtained nonheat-stressed undergoing 30 (i.e. slightly aged). In contrast, if chemical activation with ionomycin/6-dimethylaminopurine 24 not only higher controls, but also equivalent after h. Developmental differences in chemically...

The intimate association of cumulus cells with one another and the oocyte is important for regulating meiotic arrest resumption. objective this study was to determine effects heat stress on cell communication functions that may be related accelerated meiosis during early maturation. Bovine cumulus-oocyte complexes underwent in vitro maturation up 6 h at thermoneutral control (38.5°C) or elevated (40.0, 41.0 42.0°C) temperatures. Gap junction between assessed using fluorescent dye calcein...

Induced ovulation of small pre-ovulatory follicles reduced pregnancy rates, embryo survival, day seven quality, and successful cleavage in beef cows undergoing fixed-time artificial insemination. RNA-sequencing oocytes associated cumulus cells collected from 23 h after gonadotropin-releasing hormone (GnRH) administration to induce the gonadotropin surge suggested capacity for glucose metabolism ≤11.7 mm. We hypothesized that follicular fluid metabolome influences metabolic cumulus-oocyte...

Higher estrus-associated temperatures (HEAT) are a hallmark feature in sexually active females. The overarching aim of this study was to characterize the variability, magnitude, and persistence HEAT heifers suckled beef cows as well identify associated factors when occurring during thermoneutral conditions at onset spring breeding season. In both cows, estrus induced using 7-d controlled internal drug release (CIDR)-PGF2α protocol. Vaginal temperature after prostaglandin F2α administration...

The overall objective was to evaluate the effectiveness of S-enantiomer roscovitine (inhibitor p34cdc2/cyclin B kinase) maintain bovine cumulus-oocyte complexes at germinal vesicle (GV) stage for extended times after removal from antral follicles without compromising subsequent maturation, fertilization and embryo development. Oocytes were cultured in 0, 12.5, 25 or 50 micromol/l S-roscovitine 24 h. Hoechst staining showed that maintained >90% oocytes GV inhibited gonadotropin-induced...

Two studies were conducted with the overarching goal of determining extent to which lipolytic changes relate germinal vesicle breakdown (GVBD) in bovine oocytes matured under thermoneutral or hyperthermic conditions. To this end, cumulus-oocyte complexes underwent vitro maturation for 0, 2, 4, 6 24 h at 38.5 (first study) and 41.0 C (second study; heat stress applied up through first 12 only, then shifted C). Independent temperature, triglyceride phospholipid content decreased markedly by 2...

Extremes in body condition reduce fertility and overall productivity beef cattle herds, due part to altered systemic metabolic conditions that influence the intrafollicular uterine environment. Follicular fluid serum metabolome profiles are influenced by composition women dairy cattle; however, such information is lacking cattle. We hypothesized score (BCS)-related alterations of preovulatory follicular may oocyte maturation while impacting oviductal or Therefore, we performed a study with...

We hypothesized that heat-induced perturbations in cumulus cells surrounding the maturing oocyte may extend to mural granulosa of periovulatory follicle heat-stressed cow subsequently follicular fluid proteome. Lactating Holsteins were pharmacologically stimulated have a dominant was capable responding gonadotropin releasing hormone-induced luteinizing hormone surge. Following administration, cows maintained at ~67 temperature humidity index (THI; thermoneutral conditions) or exposed...

Cows acutely heat stressed after a pharmacologically induced luteinizing hormone (LH) surge had periovulatory changes in the follicular fluid proteome that may potentiate ovulation and impact oocyte developmental competence. Because cellular origins of differentially abundant proteins were not known, we have examined cumulus granulosa cell transcriptomes from follicle cows exhibiting varying levels hyperthermia when occurring LH surge. After pharmacological induction dominant follicle,...

Summary Fescue toxicosis is a common syndrome of poor growth and reproductive performance beef cattle grazing endophyte‐infected tall fescue infected with Lolium arundinaceum Schreb . Together decreased feed intake, rates tissue necrosis due to vasoconstriction, depressed circulating serum prolactin concentrations are typically observed in afflicted toxicosis. Polymorphisms within the XK , Kell blood group complex subunit‐related family, member 4 ( XKR ) gene located on BTA 14 have been...

The objective of this experiment was to evaluate the impact complexed trace mineral supplementation on ovum pick-up (OPU) and in vitro embryo production lactating beef cows. Thirty days prior fixed-time artificial insemination (FTAI; day −30), 68 postpartum cows were stratified by BW, BCS, parity before being randomly assigned 10 pens either a treatment (TRT; n = 5) or control (CNT; group. Each group received weekly supplement allotment 1.16 kg × week−1 cow–calf pair−1 for 14 wk. Cows TRT...

Abstract Cattle induced to ovulate a small, physiologically immature preovulatory follicle had reduced oocyte developmental competence that resulted in decreased embryo cleavage and day 7 quality compared with animals more advanced follicle. RNA-sequencing was performed on oocytes their corresponding cumulus cells approximately 23 h after gonadotropin-releasing hormone (GnRH) administration induce the gonadotropin surge suggested capacity for glucose metabolism oxidative phosphorylation from...

Abstract The overarching aim was to examine the relationship of rectal temperature at fixed time artificial insemination (FTAI) on pregnancy outcomes in a typical breeding season with expected rates approaching 50% using Bos indicus and taurus cattle. This represents continuum steps test hypothesis that elevated body or around is functionally important maximize outcomes. Rectal cattle FTAI ranged from 37.0 40.9 °C; 60.6% were hyperthermic. Positive factors impacting FTAI, condition, estrus...

The activity of the immune system in reproductive tract has been proven to be crucial response uterine diseases, normal functions, and tolerance allogeneic fetus during pregnancy. objectives current study were (1) evaluate vaginal cytokine concentrations postpartum cows undergoing estrus synchronization followed by timed artificial insemination (TAI) (2) correlate bacterial communities with concentrations. Postpartum Angus ( n = 20) subjected a 7-Day Co-Synch protocol pre-synchronization...