Current Organizations / Institutes

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Oluteru E. Orimaye has a total of 31 co-authors. Here are the top co-authors by number of shared publications:


Latest Publications

  • Open Access

    Spleen Metabolome Reveals Immune-Mediated Responses Modulated by Onion Peel Extract in Salmonella-Infected Broiler Chicks

    by Odinaka C. Iwuozo, Paul C. Omaliko, Oluteru E. Orimaye, Safiu A. Suberu, Hye Won Kang, Yewande O. Fasina

    Onion peel extract (OPE) is rich in polyphenolic compounds with antimicrobial potential. Salmonella Enteritidis (SE) infection in young broiler chicks causes morbidity, reduced growth, and contributes to human gastroenteritis through contaminated poultry products. The spleen is a key secondary lymphoid organ coordinating systemic responses to pathogens in chicken. This study evaluated how dietary OPE influences spleen metabolic profiles during SE infection. Day-old Ross 708 male chicks (n = 128) were assigned to four treatments: CON, CON-SE, OPE (6 g/kg), and OPE-SE. Chicks in CON and OPE received sterile broth, whereas CON-SE and OPE-SE received 2.25 × 108 CFU/mL SE at 2 d of age. At 5 and 12 dpi, spleens from six chicks per treatment were collected for untargeted HPLC-MS metabolomics. A total of 857 metabolites were identified and analyzed using MetaboAnalyst 6.0 (p < 0.05; fold change ≥ 2.0; VIP score > 1.0). In CON-SE chicks, energy generating metabolites (6-phosphogluconic acid, methylmalonic acid, propionic acid) increased, while 13,14-dihydro-15-keto-prostaglandin D2 and kynurenic acid decreased. Dietary OPE elevated several dipeptides (L-Val-Gly, L-Leu-Gly, Gly-Gly-Leu, L-Val-L-Met) and reduced ATP linked metabolites (3,6-di-O-methyl-beta-D-glucose and 3-O-beta-D-galactosyl-sn-glycerol). Enrichment analysis showed that SE infection altered valine, leucine, and isoleucine degradation and aromatic amino acid biosynthesis, whereas OPE enriched galactose and biotin metabolism in uninfected chicks, but enriched tryptophan, taurine and hypotaurine metabolism in SE-infected chicks. Overall, dietary OPE optimized response of metabolic pathways associated with immune activation, unlike corresponding pathways in CON-SE birds.

  • Open Access

    Comparative Analysis of Two Dietary Saturated Fat Types on Metabolite Profiles Crossing the Blood–Brain Barrier of Poultry Chicks

    by Oluteru E. Orimaye, Paul C. Omaliko, Nathanael I. Lichti, Bruce R. Cooper, Yewande O. Fasina

    Background: The dorsal raphe nucleus (DRN) produces and distributes serotonin, while the hypothalamus (HYP) uses serotonergic signals to regulate physiological processes in chickens. Coconut oil (COCO), rich in medium-chain fatty acids, is rapidly absorbed without re-esterification. Methods: Day-old broilers (Ross 708 male, n = 160) were distributed into two dietary treatments with five replicates of 16 birds each. The birds were fed a corn–soybean meal (SBM) basal diet supplemented with 3% of poultry fat (CON) or coconut oil (COCO). The body-weight gain (BWG), feed intake (FI), and feed conversion ratio (FCR) were recorded over a 3-week period, and the data were subjected to a t-test. Untargeted metabolomic analysis by high-performance liquid chromatography (HPLC-MS) was used to evaluate the influence of the type of dietary fat on metabolite profiles in the DRN, HYP, and plasma of broiler chickens. Principal component analysis (PCA) was used to identify unique metabolites, and ANOVA was used to identify the metabolites that were significantly abundant (p < 0.05). The metabolites were then annotated using the KEGG and HMDB databases. Results: Birds in the COCO treatment gained more weight on average (0.8446 kg/bird) than birds in the CON group (0.8132 kg/bird; p = 0.0496). Five metabolites associated with multiple significant cellular processes, such as brain function, energy metabolism, and neurotransmission, showed similar differential expression patterns, while two metabolic pathways (butanoate metabolism and alanine, aspartate and glutamate metabolism) were identified. Conclusions: The dietary inclusion of COCO improves BWG in poultry and enhances their overall well-being by modulating metabolite profiles, supporting neurotransmission, and enriching the metabolic pathways essential for growth and brain function.

  • Open Access

    Effects of Onion Peel Inclusion on In Vitro Fermentation, Methane and Carbon Dioxide Emissions, and Nutrient Degradability in Dairy Cow Diets

    by Lydia K. Olagunju, Oludotun O. Adelusi, Peter A. Dele, Yasmine Shaw, Rosetta M. Brice, Oluteru E. Orimaye, Jorge A. Villarreal-González, Hye Won Kang, Ahmed E. Kholif, Uchenna Y. Anele

    Enteric greenhouse gas (GHG) emissions represent a major challenge in livestock production, contributing significantly to global methane output. Various strategies have been explored to mitigate these emissions, including dietary modifications, feed additives, and genetic improvements. In the present study, the focus was on onion peel (OP), a byproduct of the onion processing industry that has shown promise as a natural feed supplement with potential methane-reducing properties. We evaluated the effect of different inclusion levels of OP at 2.5% (OP2.5), 5% (OP5), 7.5% (OP7.5), and 10% (OP10) on the in vitro fermentation of two diets: a total mixed ration referred to as high concentrate (HC), and corn silage referred to as high forage (HF). A 48 h batch culture experiment using a 2 × 3 × 5 factorial arrangement was conducted to assess total gas production (GP), methane (CH4), carbon dioxide (CO2), ammonia (NH3), and hydrogen sulfide (H2S) concentrations, and nutrient degradability. Measurements were taken at 6 h, 24 h, and 48 h of incubation. Significant additive × diet interactions were observed for most of the parameters. The HC diet produced more gas but less CH4, CO2, NH3, and H2S compared to the HF diet (p < 0.05). At 24 h of incubation, the OP at all levels increased CH4, CO2, NH3, and H2S concentrations in the HF diet (p < 0.05). The OP2.5 treatment had the lowest (quadratic effect, p < 0.05) degradable dry matter (dDM) in the HC diet, while the OP linearly (p < 0.001) increased degradable acid detergent fiber (dADF) in both diets. The lowest total volatile fatty acids (VFA) and acetate (quadratic effect, p = 0.027) were observed with the OP5 treatment in the HC diet, while OP5, OP7.5, and OP10 had lower total VFA concentration in the HC diet. At 48 h of incubation, the OP7.5 treatment increased (p < 0.05) GP and CH4 and CO2 production in the HC diet. However, the OP5 treatment had the lowest CH4 production (quadratic effect, p = 0.027) in the HF diet. The highest dDM was observed with OP7.5 treatment (quadratic effect, p = 0.038) in the HC diet with lower values noted at different inclusion levels in the HF diet. Inclusion of OP had no effect on total VFA, and individual VFA in both diets. In conclusion, OP supplementation is more suitable for HF diets than HC diets. A 5% inclusion level is recommended to decrease ruminal CH4production and improve nutrient degradability.


  • Open Access

    Effect of Green Tea (Camellia sinensis) Extract on Growth Performance, Intestinal Health, and Immune Response of Broiler Chickens During Subclinical Necrotic Enteritis

    by Tunde E. Ogundare, Raveendra R. Kulkarni, Paul C. Omaliko, Odinaka C. Iwuozo, Ikenna G. Enenya, Oluteru E. Orimaye, Safiu A. Suberu, Olusola Jeje, Yewande O. Fasina

    This study evaluated the effects of varying levels of dietary green tea extract (GTE) on growth performance, Clostridium perfringens (CP) colonization, and inflammatory responses in broiler chickens during experimental subclinical necrotic enteritis (SNE). In a 21-day experiment, 480 one-day-old male broiler (Ross 708) chicks were equally allotted into four dietary treatment groups. From days 1 to 10, all groups received a corn–soy basal diet, switching to a wheat-fish diet on day 11. Treatments included CON (no GTE), GTX, GTY, and GTZ (250, 500, and 1000 mg/kg GTE, respectively). On day 11, each group split into ACON, AGTX, AGTY, and AGTZ, totaling eight treatments. From days 17 to 20, ACON, AGTX, AGTY, and AGTZ chicks were orally challenged twice daily with 3 mL CP26 (2.5 × 108 CFU/mL). On d 16 (pre-challenge) and d 1 post-challenge, ileo-jejunal contents were collected for CP enumeration, and jejunum tissue was analyzed via qRT-PCR to determine the expression levels of IL-1β, IFNγ, TNF-α, TGFβ, IL-10, and MUC2 genes. Challenged chicks showed poorer (p ≤ 0.05) growth and higher intestinal CP, with a potential improvement in GTE-supplemented diets. Findings suggests that dietary GTE supplementation mitigated the characteristic growth depression during SNE, reduced intestinal CP infection, and modulated inflammatory response in broiler chicks.


  • Open Access

    Synergistic Effects of Mannan Oligosaccharides and Onion Peels on In Vitro Batch Culture Fermentation of High Concentrate and Forage Diets

    by Lydia K. Olagunju, Oludotun O. Adelusi, Peter A. Dele, Yasmine Shaw, Rosetta M. Brice, Oluteru E. Orimaye, Jorge A. Villarreal-González, Hye Won Kang, Ahmed E. Kholif, Uchenna Y. Anele

    The current study evaluated the effect of combining mannan oligosaccharide (MOS) and onion peel (OP) on ruminal in vitro total gas (GP), greenhouse gas emissions, dry matter and fiber fraction digestibility, partitioning factor (PF24; mg degradable DM per mL gas), microbial mass, and volatile fatty acids using two dietary substrates: high forage (HF) and high concentrate (HC) diets. The study was arranged as a 2 × 2 × 6 factorial design with two dietary substrates, two time points (6 and 24 h), and six treatments. The treatments included a control group with no MOS or OP administration and groups administered with 2% of a mixture containing MOS and OP in the following ratios: 1:0 (MOS), 0:1 (OP), 1:1 (MOS:OP), 1:2 (MOS:2OP), and 1:3 (MOS:3OP). No significant diet × treatment interactions were observed for any of the measured parameters. However, treatments decreased (p < 0.05) the undegraded portion of HC, and treatment × substrate interactions were significant (p < 0.05) for PF24 and microbial mass. The treatments in the HC diet produced higher GP (p < 0.001) at 6 h compared to the treatments in the HF diet. Administration of MOS:2OP to the HC diet increased GP at 24 h of incubation, while the lowest GP was observed with the OP in the HF diet. The administration of MOS, OP, and MOS:2OP to the HC diet decreased methane production at 24 h of incubation. Additionally, MOS:2OP and MOS:3OP increased (p < 0.001) degradable acid detergent fiber (dADF) in the HC diet at 6 h of incubation. Both OP and MOS:3OP decreased the degradability of acid detergent lignin in the HC diet (p < 0.001). The OP also resulted in the lowest DM disappearance (p < 0.001) at 24 h of incubation in the HF diet, while the MOS:3OP had the highest dADF. At the end of incubation, the highest productions of total volatile fatty acids and acetate were observed (p = 0.002) with the MOS:OP administration in the HC diet, whereas the lowest values were observed with MOS and OP administration to the HF diet. The inclusion of mannan oligosaccharide and onion peel combinations as additives improved substrate (HC and HF) fermentation, leading to higher GP and volatile fatty production, and modulated fiber degradability by improving the breakdown of acid detergent fiber and acid detergent lignin.


  • Open Access

    The Impact of Three White-Rot Fungi on Nutrient Availability, Greenhouse Gas Emissions, and Volatile Fatty Acid Production in Myceliated Sorghum

    by Lydia K. Olagunju, Omoanghe S. Isikhuemhen, Peter A. Dele, Felicia N. Anike, Joel O. Alabi, Kelechi A. Ike, Yasmine Shaw, Rosetta M. Brice, Oluteru E. Orimaye, Michael Wuaku, et al.

    Our study employed Pleurotus ostreatus, P. djamor, and Trametes versicolor (white rot fungi = WRF) in the process of solid-state fermentation (SSF) to convert sorghum grains into myceliated sorghum (MS). The MS was then used for in vitro studies to assess changes in nutrient content compared to untreated sorghum (control). The results demonstrated a significant (p < 0.001) increase in dry matter (DM), crude protein (CP), ash, neutral detergent fiber (NDF), and acid detergent fiber (ADF) contents of MS. Specifically, CP and ash values saw a remarkable increase from 68 to 330% and 40 to 190% in MS, respectively. Additionally, NDF and ADF degradability values increased significantly (p < 0.001) by 81.5% and 56.2% in P. djamor-treated MS at 24 h post-incubation. The treatment × time interaction was also significant (p < 0.001) for greenhouse gas (GHG) emissions. T. versicolor MS exhibited the highest total volatile fatty acid (TVFA) and propionate production. The use of WRF in the SSF process led to a significant improvement in the nutritional value of sorghum. Despite the varying effects of different WRF on the nutritional parameters in MS, they show potential for enhancing the feed value of sorghum in animal feed.


  • Open Access

    Mitigation Potential of Herbal Extracts and Constituent Bioactive Compounds on Salmonella in Meat-Type Poultry

    by Oluteru E. Orimaye, Deji A. Ekunseitan, Paul C. Omaliko, Yewande O. Fasina

    Herbal extracts have been widely evaluated in poultry production for their beneficial effects and potential substitute for antibiotics, which contribute to AMR and risks to human health through the consumption of infected meat. Salmonellosis is a systemic infection caused by Salmonella, an intracellular bacterium with the ability to cause systemic infections with significant implications for both the health and safety of farmers and consumers. The excessive use of antibiotics has escalated the incidence of antibiotic resistance bacteria in the poultry and livestock industry, highlighting the urgent need for alternatives especially in meat-type poultry. Both in vivo usage and in vitro studies of bioactive compounds from herbal extracts have demonstrated the effective antimicrobial activities against pathogenic bacteria, showing promise in managing Salmonella infections and enhancing poultry performance. Phytobiotic feed additives have shown promising results in improving poultry output due to their pharmacological properties, such as stimulating consumption, and enhancing antioxidant properties and preventing the increasing antimicrobial resistance threats. Despite potential for synergistic effects from plant-derived compounds, a further investigation into is essential to fully understand their role and mechanisms of action, for developing effective delivery systems, and for assessing environmental sustainability in controlling Salmonella in poultry production.


  • Open Access

    Correction: Olagunju et al. Pleurotus ostreatus Can Significantly Improve the Nutritive Value of Lignocellulosic Crop Residues. Agriculture 2023, 13, 1161

    by Lydia K. Olagunju, Omoanghe S. Isikhuemhen, Peter A. Dele, Felicia N. Anike, Brandon G. Essick, Nathan Holt, Nkese S. Udombang, Kelechi A. Ike, Yasmine Shaw, Rosetta M. Brice, et al.

    Authors would like to correct an error in the GC conditions for VFA analysis


  • Open Access

    Effects of the Incubation Period of Pleurotus ostreatus on the Chemical Composition and Nutrient Availability of Solid-State-Fermented Corn Stover

    by Lydia K. Olagunju, Omoanghe S. Isikhuemhen, Peter A. Dele, Felicia N. Anike, Kelechi A. Ike, Yasmine Shaw, Rosetta M. Brice, Oluteru E. Orimaye, Michael Wuaku, Brandon G. Essick, et al.

    The current study aimed to optimize and improve the feeding value of Pleurotus ostreatus-fermented corn stover by evaluating the effects of five solid-state fermentation times and three in vitro fermentation periods on the chemical composition, dry matter disappearance (DMD), microbial mass and volatile fatty acid (VFA) production of treated and untreated corn stover. The study utilized a 3 × 5 factorial design, with eight replicates per treatment. Dry matter, crude protein (CP), ash and non-fiber carbohydrate (NFC) contents increased quadratically (p < 0.05) with increases in the solid-state fermentation time. Increases of 44.4–59.1%, 20.6–78.6% and 40.5–121% were noted for the CP, ash and NFC contents, respectively. Organic matter, ether extract, neutral detergent fiber and hemicellulose contents decreased quadratically (p < 0.05) across the treatments. Similar trends were noted for DM and fiber disappearance in the treatments. The total gas production and in vitro true dry matter digestibility (IVTDMD) increased quadratically, while microbial mass and in vitro apparent DMD increased in a linear manner. The total VFA, propionate and butyrate contents increased linearly. Both the acetate content and the A:P ratio decreased in a linear manner. The results show that the rumen fermentation pathway favors the production of propionate, with increases in propionate production of 7.46 and 8.30% after 2 and 4 wk, respectively. The study showed that a 2 wk period of solid-state fermentation is sufficient to provide a bio-transformed cow–calf feed resource from P. ostreatus-treated corn stover.


  • Open Access

    Pleurotus ostreatus Can Significantly Improve the Nutritive Value of Lignocellulosic Crop Residues

    by Lydia K. Olagunju, Omoanghe S. Isikhuemhen, Peter A. Dele, Felicia N. Anike, Brandon G. Essick, Nathan Holt, Nkese S. Udombang, Kelechi A. Ike, Yasmine Shaw, Rosetta M. Brice, et al.

    Improvement in the nutritive value of corn stover after solid-state fermentation with Pleurotus ostreatus is reported. Two ruminally cannulated dairy cows were used in an in vitro study arranged in a 2 × 3 factorial design with four replicates using P. ostreatus-treated corn stover. The increase in crude protein (58.5%) and ash (25.8%) contents of the treated stover were significantly higher (p < 0.001) than the control. Results suggest a potential increase in in vitro microbial protein synthesis due to a consistent increase (p < 0.001) in microbial mass yield (106–681%), irrespective of the incubation time. The fiber components of the corn stover, except lignin, were significantly reduced (p < 0.05), and the non-fiber carbohydrates were increased by 118% in the treated samples. There was a significant (p < 0.001) increase in both in vitro dry matter disappearance (40.9–240%) and total VFA (5.85–11.2%). Treatment and time interaction was significant (p < 0.001) for propionate production (9.37–14.0%), indicating that the propionate rumen fermentation pathway was preferred. Acetate concentration was reduced (1.76–4.01%), which also resulted in a 7.09–11.42% decrease in the A:P ratio. Overall, results showed that P. ostreatus improved the nutritive value of corn stover by increasing its energetic values, crude protein, microbial mass, and total volatile fatty acid concentrations.