Contribution of the seminal microbiome to paternal programming.

The field of Developmental Origins of Health and Disease (DOHaD) has primarily focused on maternal programming of offspring health. However, emerging evidence suggests that paternal factors, including the seminal microbiome, could potentially play important roles in shaping the developmental trajectory and long-term offspring health outcomes. Historically, the microbes present in the semen were regarded as inherently pathogenic agents. However, this dogma has recently been challenged by the discovery of a diverse commensal microbial community within the semen of healthy males. In addition, recent studies suggest that the transmission of semen-associated microbes into the female reproductive tract during mating has potentials to not only influence female fertility and embryo development but could also contribute to paternal programming in the offspring. In this review, we summarize the current knowledge on the seminal microbiota in both humans and animals followed by discussing their potential involvement in paternal programming of offspring health. We also propose and discuss potential mechanisms through which paternal influences are transmitted to offspring via the seminal microbiome. Overall, this review provides insights into the seminal microbiome-based paternal programing, which will expand our understanding of the potential paternal programming mechanisms that currently are focused on the epigenetic modifications, oxidative stresses, and cytokines.

Vitamin and mineral supplementation to beef heifers during gestation: impacts on morphometric measurements of the neonatal calf, vitamin and trace mineral status, blood metabolite and endocrine profiles, and calf organ characteristics at 30 h after birth.

To examine the effects of feeding a vitamin and mineral supplement to beef heifers throughout gestation on mineral status and hormone/endocrine profiles in the dam and calf, and morphometric characteristics and organ mass of the calf at 30 h after birth, Angus-based heifers (n = 72, 14 to 15 months of age, initial body weight [BW] = 380.4 ± 50.56 kg) were estrus synchronized and artificially inseminated (AI) with female-sexed semen. Heifers were blocked by BW and randomly assigned to receive either a basal diet (CON; n = 36) or a basal diet plus a vitamin and mineral supplement (VTM; n = 36) via an individual feeding system beginning at breeding, with both diets targeting BW gains of 0.45 kg heifer-1•d-1. Heifers not pregnant after first AI (CON, n = 19; VTM, n = 18) were re-bred via AI 60 d after treatment initiation, and heifers gestating female fetuses (CON, n = 7; VTM, n = 7) received treatments throughout gestation and were experimental units for this study. Calves were separated from their dams and fed colostrum replacer within 2 h of birth and euthanized 30 h after the first feeding. Calf morphometrics were recorded, and tissues were weighed and sampled. Serum from the dam at calving and serum, liver, and muscle from the calf at 30 h were analyzed for concentrations of minerals. Serum from the dam and calf were analyzed for concentrations of leptin, vitamins A, D, and E, cortisol, growth hormone, and insulin-like growth factor 1. All response variables were analyzed using the MIXED procedure of SAS. Calf body morphometrics and BW of the dam at calving (P ≥ 0.32), calf organ weights (P ≥ 0.21), and calf ovarian follicle counts (P ≥ 0.13) were not affected by maternal treatment. Concentrations of Se and Co in calf serum and Se in calf liver were increased (P ≤ 0.02) in VTM. Serum concentrations of Co and vitamin A in the dam were greater (P ≤ 0.01) in supplemented compared with non-supplemented dams, and serum concentrations of vitamin D were greater (P ≤ 0.0003) in supplemented dams and calves compared with the non-supplemented cohort. Maternal supplementation supported vitamin and mineral status in the neonate, yet had no discernable impact on BW, organ mass, or circulating hormones/metabolites in the calf. Evaluating offspring at later postnatal time points is warranted to determine if prenatal vitamin and mineral supplementation affects performance, health, metabolism, and efficiency of energy utilization in key metabolic tissues in the calf.

Screening and selection of essential oils for an intranasal spray against bovine respiratory pathogens based on antimicrobial, antiviral, immunomodulatory, and antibiofilm activities.

Introduction: The rise in antibiotic resistant pathogens associated with bovine respiratory disease (BRD) poses a serious challenge, particularly to the beef feedlot industry, as they currently depend on antibiotics to prevent BRD to mitigate the financial burden (approx. $1 billion annual loss) inflicted by BRD-associated high mortality and morbidity in feedlot cattle. Thus, there is an impetus need for the development of antimicrobial alternative strategies against BRD. This study aimed to screen and select candidate essential oils (EOs) for the development of an intranasal EO spray that can inhibit BRD pathogens and promote microbiota-mediated respiratory health. Methods: The effects of selected EOs (ajowan, cinnamon leaf, citronella, grapefruit, fennel, and thyme) on a bovine nasopharyngeal microbiota culture were evaluated using 16S rRNA gene sequencing. The microbiota culture was enriched by incubating nasopharyngeal swabs obtained from finishing beef heifers in brain heart infusion broth with and without EOs (0.025%, v/v). These EOs were then also evaluated for their immunomodulatory effects on bovine turbinate (BT) cells by analyzing the concentrations of 15 cytokines and chemokines in cell culture after 24 h incubation. The crystal violet assay was done to assess the antibiofilm activity of EOs against Escherichia coli UMN026 strain. Finally, 15 EOs were screened for their antiviral activity against the bovine viral diarrhea virus 1 (BVDV-1) using BT cells and a fluorescence-based method. Results: Ajowan, fennel, and thyme resulted in a moderate reduction of overall nasopharyngeal microbiota growth with significant alterations of both alpha and beta diversity, and the relative abundance of predominant bacterial families (e.g., increasing Enterobacteriaceae and decreasing Moraxellaceae) compared to the control (p < 0.05). Co-incubation of BT cells with selected EOs resulted in minimal alterations in cytokine and chemokine levels (p > 0.05). Ajowan, thyme, fennel, and cinnamon leaf exhibited antibiofilm activity at concentrations of 0.025 and 0.05%. Reduction of BVDV-1 replication in BT cells was observed with thyme (strong), and ajowan and citronella (moderate) at 0.0125% concentration. Discussion: Accordingly, ajowan, thyme, fennel, cinnamon leaf, and citronella EOs were selected for further development as an intranasal EO spray to prevent and control of BRD pathogens in feedlot cattle.

A single intranasal dose of essential oil spray confers modulation of the nasopharyngeal microbiota and short-term inhibition of Mannheimia in feedlot cattle: a pilot study.

Five essential oils (EOs) were previously characterized in vitro and identified as candidate EOs for the development of an intranasal EO spray to mitigate bovine respiratory disease (BRD) pathogens. In the present study, these EOs were evaluated for their potential to (i) reduce BRD pathogens, (ii) modulate nasopharyngeal microbiota, and (iii) influence animal performance, feeding behavior and immune response when a single dose administered intranasally to feedlot cattle. Forty beef steer calves (7-8 months old, Initial body weight = 284 ± 5 kg [SE]) received either an intranasal EO spray (ajowan, thyme, fennel, cinnamon leaf, and citronella) or PBS (Control; n = 20/group) on day 0. Deep nasopharyngeal swabs were collected on days (d) -1, 1, 2, 7, 14, 28, and 42 and processed for 16S rRNA gene sequencing, qPCR, and culturing. Significant effects of EO on community structure (d1), microbial richness and diversity, relative abundance of some dominant phyla (d1, d2, and d14), and the overall interaction network structure of the nasopharyngeal microbiota were detected. The relative abundance of Mannheimia was lower in the EO calves (4.34%) than in Control calves (10.4%) on d2, and M. haemolytica prevalence on d7 as compared to control calves. Feed intake, average daily gain, feeding behavior, and blood cell counts were not affected by EO treatment. Overall, a single intranasal dose of EO spray resulted in moderate modulation of nasopharyngeal microbiota and short-term inhibition of Mannheimia while not influencing animal performance, feeding behavior or immune response. Our study, for the first time, shows the potential use of intranasal EO to mitigate BRD in feedlot cattle.

Holistic View and Novel Perspective on Ruminal and Extra-Gastrointestinal Methanogens in Cattle.

Despite the extensive research conducted on ruminal methanogens and anti-methanogenic intervention strategies over the last 50 years, most of the currently researched enteric methane (CH4) abatement approaches have shown limited efficacy. This is largely because of the complex nature of animal production and the ruminal environment, host genetic variability of CH4 production, and an incomplete understanding of the role of the ruminal microbiome in enteric CH4 emissions. Recent sequencing-based studies suggest the presence of methanogenic archaea in extra-gastrointestinal tract tissues, including respiratory and reproductive tracts of cattle. While these sequencing data require further verification via culture-dependent methods, the consistent identification of methanogens with relatively greater frequency in the airway and urogenital tract of cattle, as well as increasing appreciation of the microbiome-gut-organ axis together highlight the potential interactions between ruminal and extra-gastrointestinal methanogenic communities. Thus, a traditional singular focus on ruminal methanogens may not be sufficient, and a holistic approach which takes into consideration of the transfer of methanogens between ruminal, extra-gastrointestinal, and environmental microbial communities is of necessity to develop more efficient and long-term ruminal CH4 mitigation strategies. In the present review, we provide a holistic survey of the methanogenic archaea present in different anatomical sites of cattle and discuss potential seeding sources of the ruminal methanogens.

Sequencing and culture-based characterization of the vaginal and uterine microbiota in beef cattle that became pregnant or remained open following artificial insemination.

IMPORTANCE: Emerging evidence suggests that microbiome-targeted approaches may provide a novel opportunity to reduce the incidence of reproductive failures in cattle. To develop such microbiome-based strategies, one of the first logical steps is to identify reproductive microbiome features related to fertility and to isolate the fertility-associated microbial species for developing a future bacterial consortium that could be administered before breeding to enhance pregnancy outcomes. Here, we characterized the vaginal and uterine microbiota in beef cattle that became pregnant or remained open via artificial insemination and identified microbiota features associated with fertility. We compared similarities between vaginal and uterine microbiota and between heifers and cows. Using culturing, we provided new insights into the culturable fraction of the vaginal and uterine microbiota and their antimicrobial resistance. Overall, our findings will serve as an important basis for future research aimed at harnessing the vaginal and uterine microbiome for improved cattle fertility.

Paternal effects on fetal programming.

Paternal programming is the concept that the environmental signals from the sire's experiences leading up to mating can alter semen and ultimately affect the phenotype of resulting offspring. Potential mechanisms carrying the paternal effects to offspring can be associated with epigenetic signatures (DNA methylation, histone modification and non-coding RNAs), oxidative stress, cytokines, and the seminal microbiome. Several opportunities exist for sperm/semen to be influenced during development; these opportunities are within the testicle, the epididymis, or accessory sex glands. Epigenetic signatures of sperm can be impacted during the pre-natal and pre-pubertal periods, during sexual maturity and with advancing sire age. Sperm are susceptible to alterations as dictated by their developmental stage at the time of the perturbation, and sperm and seminal plasma likely have both dependent and independent effects on offspring. Research using rodent models has revealed that many factors including over/under nutrition, dietary fat, protein, and ingredient composition (e.g., macro- or micronutrients), stress, exercise, and exposure to drugs, alcohol, and endocrine disruptors all elicit paternal programming responses that are evident in offspring phenotype. Research using livestock species has also revealed that sire age, fertility level, plane of nutrition, and heat stress can induce alterations in the epigenetic, oxidative stress, cytokine, and microbiome profiles of sperm and/or seminal plasma. In addition, recent findings in pigs, sheep, and cattle have indicated programming effects in blastocysts post-fertilization with some continuing into post-natal life of the offspring. Our research group is focused on understanding the effects of common management scenarios of plane of nutrition and growth rates in bulls and rams on mechanisms resulting in paternal programming and subsequent offspring outcomes. Understanding the implication of paternal programming is imperative as short-term feeding and management decisions have the potential to impact productivity and profitability of our herds for generations to come.

Genome sequences of 11 Alkalihalobacillus clausii, Bacillus safensis, and Escherichia coli bacteriophages isolated from bovine rumen and vagina.

Here, we present the coding-complete genomes of 11 lytic bacteriophages isolated from bovine ruminal fluid and vaginal swabs that can infect the bacterial hosts Alkalihalobacillus clausii, Bacillus safensis, and Escherichia coli.

Whole-body microbiota of newborn calves and their response to prenatal vitamin and mineral supplementation.

Early life microbial colonization and factors affecting colonization patterns are gaining interest due to recent developments suggesting that early life microbiome may play a role in Developmental Origins of Health and Disease. In cattle, limited information exists on the early microbial colonization of anatomical sites involved in bovine health beyond the gastrointestinal tract. Here, we investigated 1) the initial microbial colonization of seven different anatomical locations in newborn calves and 2) whether these early life microbial communities and 3) serum cytokine profiles are influenced by prenatal vitamin and mineral (VTM) supplementation. Samples were collected from the hoof, liver, lung, nasal cavity, eye, rumen (tissue and fluid), and vagina of beef calves that were born from dams that either received or did not receive VTM supplementation throughout gestation (n = 7/group). Calves were separated from dams immediately after birth and fed commercial colostrum and milk replacer until euthanasia at 30 h post-initial colostrum feeding. The microbiota of all samples was assessed using 16S rRNA gene sequencing and qPCR. Calf serum was subjected to multiplex quantification of 15 bovine cytokines and chemokines. Our results indicated that the hoof, eye, liver, lung, nasal cavity, and vagina of newborn calves were colonized by site-specific microbiota, whose community structure differed from the ruminal-associated communities (0.64 ≥ R2 ≥ 0.12, p ≤ 0.003). The ruminal fluid microbial community was the only one that differed by treatment (p < 0.01). However, differences (p < 0.05) by treatment were detected in microbial richness (vagina); diversity (ruminal tissue, fluid, and eye); composition at the phylum and genus level (ruminal tissue, fluid, and vagina); and in total bacterial abundance (eye and vagina). From serum cytokines evaluated, concentration of chemokine IP-10 was greater (p = 0.02) in VTM calves compared to control calves. Overall, our results suggest that upon birth, the whole-body of newborn calves are colonized by relatively rich, diverse, and site-specific bacterial communities. Noticeable differences were observed in ruminal, vaginal, and ocular microbiota of newborn calves in response to prenatal VTM supplementation. These findings can derive future hypotheses regarding the initial microbial colonization of different body sites, and on maternal micronutrient consumption as a factor that may influence early life microbial colonization.

Feeding hempseed cake alters the bovine gut, respiratory and reproductive microbiota.

A growing number of studies have investigated the feasibility of utilizing hemp by-products as livestock feedstuffs; however, their impact on livestock microbiomes remains unexplored. Here, we evaluated the effects of feeding hempseed cake on the gastrointestinal, respiratory, and reproductive microbiota in beef heifers. Angus-crossbred heifers (19-months old, initial body weight = 494 ± 10 kg [SE]) were fed a corn-based finishing diet containing 20% hempseed cake as a substitute for 20% corn dried distillers' grains with solubles (DM basis; Control; n = 16/group) for 111 days until slaughter. Ruminal fluid and deep nasopharyngeal swabs (days 0, 7, 42, 70 and 98), and vaginal and uterine swabs (at slaughter) were collected, and the microbiota assessed using 16S rRNA gene sequencing. Diet affected the community structure of the ruminal (d 7-98; 0.06 ≤ R2 ≤ 0.12; P < 0.05), nasopharyngeal (d 98; R2 = 0.18; P < 0.001), and vaginal (R2 = 0.06; P < 0.01) microbiota. Heifers fed hempseed cake had increased microbial diversity in the rumen, reduced microbial richness in the vagina, and greater microbial diversity and richness in the uterus. In addition to the distinct microbial communities in the rumen, nasopharynx, vagina and uterus, we identified 28 core taxa that were shared (≥ 60% of all samples) across these sampling locations. Feeding hempseed cake appeared to alter the bovine gut, respiratory and reproductive microbiota. Our results suggest that future research aiming to evaluate the use of hemp by-products in livestock diet should consider their impact on animal microbiome and microbiome mediated animal health and reproductive efficiency. Our findings also highlight the need for research evaluating the impact of hemp-associated food and personal care products on the human microbiome.

A Single Intranasal Dose of Bacterial Therapeutics to Calves Confers Longitudinal Modulation of the Nasopharyngeal Microbiota: a Pilot Study.

To address the emergence of antimicrobial-resistant pathogens in livestock, microbiome-based strategies are increasingly being sought to reduce antimicrobial use. Here, we describe the effects of intranasal application of bacterial therapeutics (BTs) on the bovine respiratory microbiota and used structural equation modeling to investigate the causal networks after BT application. Beef cattle received (i) an intranasal cocktail of previously characterized BT strains, (ii) an injection of metaphylactic antimicrobial (tulathromycin), or (iii) intranasal saline. Despite being transient colonizers, inoculated BT strains induced longitudinal modulation of the nasopharyngeal bacterial microbiota while showing no adverse effect on animal health. The BT-mediated changes in bacteria included reduced diversity and richness and strengthened cooperative and competitive interactions. In contrast, tulathromycin increased bacterial diversity and antibiotic resistance and disrupted bacterial interactions. Overall, a single intranasal dose of BTs can modulate the bovine respiratory microbiota, highlighting that microbiome-based strategies have potential in being utilized to mitigate bovine respiratory disease in feedlot cattle. IMPORTANCE Bovine respiratory disease (BRD) remains the most significant health challenge affecting the North American beef cattle industry and results in $3 billion in economic losses yearly. Current BRD control strategies mainly rely on antibiotics, with metaphylaxis commonly employed to mitigate BRD incidence in commercial feedlots. However, the emergence of multidrug-resistant BRD pathogens threatens to reduce the efficacy of antimicrobials. Here, we investigated the potential use of novel bacterial therapeutics (BTs) to modulate the nasopharyngeal microbiota in beef calves, which are commonly administered metaphylactic antibiotics to mitigate BRD when sourced from auction markets. By direct comparison of the BTs with an antibiotic commonly used for BRD metaphylaxis in feedlots, this study conveyed the potential use of the BTs to modulate respiratory microbiome and thereby improve resistance against BRD in feedlot cattle.

A Longitudinal Characterization of the Seminal Microbiota and Antibiotic Resistance in Yearling Beef Bulls Subjected to Different Rates of Gain.

In this study, we evaluated the seminal and fecal microbiota in yearling beef bulls fed a common diet to achieve moderate (1.13 kg/day) or high (1.80 kg/day) rates of weight gain. Semen samples were collected on days 0 and 112 of dietary intervention (n = 19/group) as well as postbreeding (n = 6/group) using electroejaculation, and the microbiota was assessed using 16S rRNA gene sequencing, quantitative PCR (qPCR), and culturing. The fecal microbiota was also evaluated, and its similarity with seminal microbiota was assessed. A subset of seminal bacterial isolates (n = 33) was screened for resistance against 28 antibiotics. A complex and dynamic microbiota was detected in bovine semen, and the community structure was affected by sampling time (R2 = 0.16, P < 0.001). Microbial richness increased significantly from day 0 to day 112, and diversity increased after breeding (P > 0.05). Seminal microbiota remained unaffected by the differential rates of gain, and its overall composition was distinct from fecal microbiota, with only 6% of the taxa shared between them. A total of 364 isolates from 49 different genera were recovered under aerobic and anaerobic culturing. Among these seminal isolates were pathogenic species and those resistant to several antibiotics. Overall, our results suggest that bovine semen harbors a rich and complex microbiota which changes over time and during the breeding season but appears to be resilient to differential gains achieved via a common diet. Seminal microbiota is distinct from the fecal microbiota and harbors potentially pathogenic and antibiotic-resistant bacterial species. IMPORTANCE Increasing evidence from human and other animal species supports the existence of a commensal microbiota in semen and that this seminal microbiota may influence not only sperm quality and fertility but also female reproduction. Seminal microbiota in bulls and its evolution and factors shaping this community, however, remain largely underexplored. In this study, we characterized the seminal microbiota of yearling beef bulls and its response to the bull age, different weight gains, and mating activity. We compared bacterial composition between seminal and fecal microbiota and evaluated the diversity of culturable seminal bacteria and their antimicrobial resistance. Our results obtained from sequencing, culturing, and antibiotic susceptibility testing provide novel information on the taxonomic composition, evolution, and factors shaping the seminal microbiota of yearling beef bulls. This information will serve as an important basis for further understanding of the seminal microbiome and its involvement in reproductive health and fertility in cattle.

Genome Sequences of Alkalihalobacillus clausii, Bacillus safensis, Escherichia coli, and Pasteurella multocida Isolates from the Rumen, Nasopharynx, Vagina, and Uterus of Healthy Beef Cattle.

Here, we present the first draft genome sequences of 10 bacterial strains that were isolated from the rumen, nasopharynx, vagina, or uterus of healthy beef cattle. These genomes are from one Alkalihalobacillus clausii isolate, three Bacillus safensis isolates, five Escherichia coli isolates, and one Pasteurella multocida isolate.

Seminal and vagino-uterine microbiome and their individual and interactive effects on cattle fertility.

Reproductive failure is a major economical drain on cow-calf operations across the globe. It can occur in both males and females and stem from prenatal and postnatal influences. Therefore, the cattle industry has been making efforts to improve fertility and the pregnancy rate in cattle herds as an attempt to maintain sustainability and profitability of cattle production. Despite the advancements made in genetic selection, nutrition, and the implementation of various reproductive technologies, fertility rates have not significantly improved in the past 50 years. This signifies a missing factor or factors in current reproductive management practices that influence successful fertilization and pregnancy. Emerging lines of evidence derived from human and other animals including cattle suggest that the microbial continuum along the male and female reproductive tracts are associated with male and female fertility-that is, fertilization, implantation, and pregnancy success-highlighting the potential for harnessing the male and female reproductive microbiome to improve fertility in cattle. The objective of this narrative review is to provide an overview of the recent studies on the bovine seminal and vagino-uterine microbiome and discuss individual and interactive roles of these microbial communities in defining cattle fertility.

Influence of hempseed cake inclusion on growth performance, carcass characteristics, feeding behavior, and blood parameters in finishing heifers.

As the hemp industry continues to develop in the United States, there is an increasing interest in feeding byproducts of industrial hemp production to livestock. A completely randomized design experiment using crossbred finishing heifers (initial body weight [BW] ±â€…SE = 494 ±â€…10 kg) was conducted to determine the effects of feeding hempseed cake in a corn-based finishing diet (10% forage) formulated to meet or exceed ruminally degradable and metabolizable protein requirements on growth performance, carcass characteristics, feeding behavior, and plasma parameters. Dietary treatments were the inclusion of 20% (dry matter [DM] basis) of dried corn distillers grains plus solubles (DDGS, n = 16) or hempseed cake (HEMP, n = 15). Cattle were housed in two pens, had ad libitum access to feed and water, and individual intakes and feeding behavior were monitored using the Insentec feeding system. Cattle were fed treatment diets for 111 d, and every 14 d BW were measured and blood samples were collected. Blood plasma was analyzed for glucose, urea nitrogen, and individual amino acids, and results were analyzed using repeated-measures analysis in SAS. Final BW, average daily gain, gain:feed, and hot carcass weight decreased (P ≤ 0.05) by 2.3%, 7.7%, 7.7%, and 2.6%, respectively, in heifers fed the HEMP diet than in heifers fed the DDGS diet. Net energy for maintenance and gain (Mcal/kg of feed, DM basis), estimated based on heifer intake and performance, were greater (P = 0.02) for the DDGS diet than for the HEMP diet. All other performance and carcass characteristics were not different (P ≥ 0.20) between treatments. Heifers fed the HEMP diet had greater (P < 0.05) plasma urea nitrogen concentration in samples from each collection day compared with heifers fed the DDGS diet, although there was a treatment-by-day interaction (P < 0.01) because of variability in the magnitude of treatment differences over time. Plasma glucose concentration was not influenced (P = 0.17) by dietary treatment. Plasma concentrations of total amino acids, nonessential amino acids, and essential amino acids were not different between treatments (P ≥ 0.09), although there were several interactions between treatment and day (P ≤ 0.04) for individual amino acids. These data suggest that hempseed cake has a lower net energy for maintenance and gain relative to DDGS when adequate metabolizable protein is supplied, while still providing adequate nutrition to support the acceptable performance of finishing cattle.

This experiment evaluated the effects of dietary inclusion of hempseed cake in comparison with dried corn distillers grains plus solubles (DDGS) on growth performance, feeding behavior, carcass characteristics, and blood parameters in finishing heifers. Angus-crossbred heifers were assigned randomly to one of two treatments (20% hempseed cake [HEMP] or 20% DDGS; dry matter basis) and were fed for 111 d until slaughter. Heifers receiving the DDGS treatment had greater final body weights, average daily gain, gain efficiency, dietary concentration of net energy for maintenance and gain, and carcass weight than heifers fed the HEMP treatment. All other carcass characteristics, as well as feeding behavior, were not influenced by treatment. Plasma urea nitrogen was greater in heifers fed the HEMP diet compared with the DDGS diet, while glucose was not influenced by treatment. Several plasma amino acid concentrations were influenced by treatment. Although the inclusion of hempseed cake decreased growth performance, it could be a viable alternative feed source for cattle.

Bovine Animal Model for Studying the Maternal Microbiome, in utero Microbial Colonization and Their Role in Offspring Development and Fetal Programming.

Recent developments call for further research on the timing and mechanisms involved in the initial colonization of the fetal/infant gut by the maternal microbiome and its role in Developmental Origins of Health and Disease (DOHaD). Although progress has been made using primarily preterm infants, ethical and legal constraints hinder research progress in embryo/fetal-related research and understanding the developmental and mechanistic roles of the maternal microbiome in fetal microbial imprinting and its long-term role in early-life microbiome development. Rodent models have proven very good for studying the role of the maternal microbiome in fetal programming. However, some inherent limitations in these animal models make it challenging to study perinatal microbial colonization from a biomedical standpoint. In this review, we discuss the potential use of bovine animals as a biomedical model to study the maternal microbiome, in utero microbial colonization of the fetal gut, and their impact on offspring development and DOHaD.

The Nasopharyngeal, Ruminal, and Vaginal Microbiota and the Core Taxa Shared across These Microbiomes in Virgin Yearling Heifers Exposed to Divergent In Utero Nutrition during Their First Trimester of Gestation and in Pregnant Beef Heifers in Response to Mineral Supplementation.

In the present study, we evaluated whether the nasopharyngeal, ruminal, and vaginal microbiota would diverge (1) in virgin yearling beef heifers (9 months old) due to the maternal restricted gain during the first trimester of gestation; and (2) in pregnant beef heifers in response to the vitamin and mineral (VTM) supplementation during the first 6 months of pregnancy. As a secondary objective, using the microbiota data obtained from these two cohorts of beef heifers managed at the same location and sampled at the same time, we performed a holistic assessment of the microbial ecology residing within the respiratory, gastrointestinal, and reproductive tract of cattle. Our 16S rRNA gene sequencing results revealed that both α and ß-diversity of the nasopharyngeal, ruminal and vaginal microbiota did not differ between virgin heifers raised from dams exposed to either a low gain (targeted average daily gain of 0.28 kg/d, n = 22) or a moderate gain treatment (0.79 kg/d, n = 23) during the first 84 days of gestation. Only in the vaginal microbiota were there relatively abundant genera that were affected by maternal rate of gain during early gestation. Whilst there was no significant difference in community structure and diversity in any of the three microbiota between pregnant heifers received no VTM (n = 15) and VTM supplemented (n = 17) diets, the VTM supplementation resulted in subtle compositional alterations in the nasopharyngeal and ruminal microbiota. Although the nasopharyngeal, ruminal, and vaginal microbiota were clearly distinct, a total of 41 OTUs, including methanogenic archaea, were identified as core taxa shared across the respiratory, gastrointestinal, and reproductive tracts of both virgin and pregnant heifers.

Characterization of the Microbiota Associated With 12-Week-Old Bovine Fetuses Exposed to Divergent in utero Nutrition.

A recent study reported the existence of a diverse microbiota in 5-to-7-month-old calf fetuses, suggesting that colonization of the bovine gut with so-called "pioneer" microbiota may begin during mid-gestation. In the present study, we investigated 1) the presence of microbiota in bovine fetuses at early gestation (12 weeks), and 2) whether the fetal microbiota is influenced by the maternal rate of gain or dietary supplementation with vitamins and minerals (VTM) during early gestation. Amniotic and allantoic fluids, and intestinal and placental (cotyledon) tissue samples obtained from fetuses (n = 33) on day 83 of gestation were processed for the assessment of fetal microbiota using 16S rRNA gene sequencing. The sequencing results revealed that a diverse and complex microbial community was present in each of these fetal compartments evaluated. Allantoic and amniotic fluids, and fetal intestinal and placenta microbiota each had distinctly different (0.047 ≥ R 2 ≥ 0.019, P ≤ 0.031) microbial community structures. Allantoic fluid had a greater (P < 0.05) microbial richness (number of OTUs) (Mean 122) compared to amniotic fluid (84), intestine (63), and placenta (66). Microbial diversity (Shannon index) was similar for the intestinal and placental samples, and both were less diverse compared with fetal fluid microbiota (P < 0.05). Thirty-nine different archaeal and bacterial phyla were detected across all fetal samples, with Proteobacteria (55%), Firmicutes (16.2%), Acidobacteriota (13.6%), and Bacteroidota (5%) predominating. Among the 20 most relatively abundant bacterial genera, Acidovorax, Acinetobacter, Brucella, Corynebacterium, Enterococcus, Exiguobacterium, and Stenotrophomonas differed by fetal sample type (P < 0.05). A total of 55 taxa were shared among the four different microbial communities. qPCR of bacteria in the intestine and placenta samples as well as scanning electron microscopy imaging of fetal fluids provided additional evidence for the presence of a microbiota in these samples. Minor effects of maternal rate of gain and VTM supplementation, and their interactions on microbial richness and composition were detected. Overall, the results of this study indicate that colonization with pioneer microbiota may occur during early gestation in bovine fetuses, and that the maternal nutritional regime during gestation may influence the early fetal microbiota.

Identification and Mechanistic Characterization of a Peptide Inhibitor of Glycogen Synthase Kinase (GSK3ß) Derived from the Disrupted in Schizophrenia 1 (DISC1) Protein.

Glycogen synthase kinase 3-beta (GSK3ß) is a critical regulator of several cellular pathways involved in neurodevelopment and neuroplasticity and as such is a potential focus for the discovery of new neurotherapeutics toward the treatment of neuropsychiatric and neurodegenerative diseases. The majority of efforts to develop inhibitors of GSK3ß have been focused on developing small molecule inhibitors that compete with adenosine triphosphate (ATP) through direct interaction with the ATP binding site. This strategy has presented selectivity challenges due to the evolutionary conservation of this domain within the kinome. The disrupted in schizophrenia 1 (DISC1) protein has previously been shown to bind and inhibit GSK3ß activity. Here, we report the characterization of a 44-mer peptide derived from human DISC1 (hDISCtide) that is sufficient to both bind and inhibit GSK3ß in a noncompetitive mode distinct from classical ATP competitive inhibitors. Based on multiple independent biochemical and biophysical assays, we propose that hDISCtide interacts at two distinct regions of GSK3ß: an inhibitory region that partially overlaps with the binding site of FRATide, a well-known GSK3ß binding peptide, and a specific binding region that is unique to hDISCtide. Taken together, our findings present a novel avenue for developing a peptide-based selective inhibitor of GSK3ß.