Scholarly Works, School of Animal Sciences

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  • Age-related dysregulation of proteasome-independent K63 polyubiquitination in the hippocampus and amygdala
    Bae, Yeeun; Venkat, Harshini; Preveza, Natalie; Ray, W. Keith; Helm, Richard F.; Jarome, Timothy J. (Pergamon-Elsevier, 2025-08-06)
    Cognitive decline with aging is a complex process involving multiple brain regions and molecular mechanisms. While the role of the canonical protein degradation function of the ubiquitin–proteasome system (UPS) has been well studied in the context of aging and age-associated memory loss, the non-proteolytic functions of ubiquitin activity remain poorly understood. Here, we investigated the role of lysine-63 (K63) polyubiquitination, the most abundant form of proteasome-independent ubiquitination, in aged rats, focusing on the hippocampus and amygdala, two brain regions reported to have cellular and molecular alterations with age that are associated with age-related memory loss. Using an unbiased proteomic approach, we observed a significant increase of K63 polyubiquitination in the hippocampus across the lifespan. Reducing K63 polyubiquitination in the hippocampus of aged male rats using the CRISPR-dCas13 RNA editing system enhanced contextual fear memory, while similar manipulations in middle-aged rats, which typically have normal memory, had no effect, emphasizing the age-dependent role of K63 polyubiquitination in memory formation. Conversely, the amygdala showed a consistent reduction of K63 polyubiquitination protein targets across the lifespan, and further reductions of K63 polyubiquitination improved memory retention in aged, but not middle-aged, male rats. Together, our findings reveal the dynamic and region-specific functions of K63 polyubiquitination in the brain aging process, providing novel insights into its contribution to age-associated memory decline.
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    Increased DNA methylation of Igf2 in the male hippocampus regulates age-related deficits in synaptic plasticity and memory
    Kincaid, Shannon; Stickling, Courtney P.; Farrell, Kayla; Bae, Yeeun; Patrick, Morgan B.; Bhanot, Gitali; Cummings, Adam; Abraham, Jennifer; Alisesky, Abby; Ferrara, Nicole; Rosenkranz, J. Amiel; Jarome, Timothy J. (Elsevier, 2025-10-01)
    The aging process is characterized by a general decline in cognitive abilities, which affects nearly 33 % of U.S. adults over the age of 70 and is a risk factor for the development of dementia and Alzheimer's disease. Numerous studies have reported increased neuroinflammation and impaired synaptic plasticity and memory with age in the hippocampus, a major brain region involved in the formation and storage of most memories. However, much remains unknown about the mechanisms that contribute to age-related deficits in synaptic plasticity and memory. The Insulin-like growth factor 2 (Igf2) is a genomic imprinted gene that is expressed from a single allele in all species. Though IGF2 has been shown to be important in development, synaptic plasticity, and memory formation in the hippocampus and administration of IGF2 can improve memory late in life, whether changes in regulation of this gene contribute to age-related memory decline have yet to be explored. Here, we show that aged (24 months) male rats have increased CpG-site specific promoter methylation and reduced expression of Igf2 in the hippocampus relative to young adult (3 months) and middle-aged (12 months) rats. Importantly, CRISPR-dCas9 mediated increase of DNA 5-hydroxymethylation, an active transcriptional mark, of the Igf2 promoter in the hippocampus improved memory and long-term potentiation in aged, but not middle-aged, rats. These data indicate that increased DNA methylation of Igf2 in the hippocampus contributes to age-related deficits in synaptic plasticity and memory.
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    Adding gastrointestinal parasite resistance to the breeding objective in hair sheep: initial steps
    Forbes, Robert M.; Murphy, Thomas W.; Burke, Joan M.; Notter, David R.; Spangler, Matthew L.; MacNeil, Michael D.; Lewis, Ronald M. (Oxford University Press, 2024-11-19)
    Gastrointestinal parasite resistance is a heritable trait important to breeders of hair sheep. However, the U.S. Maternal Hair Index, provided by the National Sheep Improvement Program, omits parasite resistance. Selection indexes were designed in this study to continue improving total weight of lamb weaned per ewe lambing (TW), the current goal, and reduce postweaning fecal egg count (PFEC), an indicator of parasite resistance. These indexes placed varying emphasis on PFEC relative to TW. Annual genetic gains in TW and PFEC were predicted. Measurements for the traits used to construct the indexes were simulated to compare selection decisions-the number of rams and ewes chosen in common-between the current and the alternative indexes. Placing 79% of the selection emphasis on TW, and thereby 21% on PFEC, appeared preferable. With this balance, genetic gains in TW were reduced by only 2% relative to the current index, while PFEC was reduced favorably by as much as 8%. Additionally, over 60% of the males and 80% of the females were chosen in common between the current index and the proposed index including PFEC. Parasite resistance, therefore, can be incorporated as another selection criterion, with a positive impact on the productivity and fitness of hair sheep.
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    Estimates of optimal supplies of animal-sourced foods differ by food system goal and socioeconomic context
    White, Robin R.; Hall, Mary Beth (National Academy of Sciences, 2024-12-10)
    Reduced consumption of animal- sourced food (ASF) has been recommended for environmental and human health objectives; however, ASF can be important for food security and diet affordability. We explored country- level relationships among various metrics of food supply, socioeconomic context, food security, diet affordability, and agricultural greenhouse gas emissions (GHGe) to characterize how optimal inclusion ranges for ASF vary with socioeconomic factors and food system goals. Data from 2015 to 2022 for 153 countries were sourced to generate Bayesian Networks representing relationships among the studied food system metrics. Networks were used in simulations to characterize optimal ASF inclusion to achieve environmental, food security, or diet affordability goals based on individual country data. Results are most appropriately interpreted in aggregate rather than as representations of specific countries due in large part to data limitations. Across countries simulated, median total ASF inclusion in the food supply to support food security, GHGe, or affordability objectives was 18.2% +/- 12.1%, 11.9% +/- 6.8%, and 17.6% +/- 8.5%, respectively. Joint optimization for these goals resulted in median ASF inclusion of 15.1% +/- 7.2%, with notable regional differences. Although ASF increases were supported in most developing regions, decreases were supported in developed countries. The reported SD in optimal ASF inclusion were considerable, and represented between- country variation. Empirical relationships of food categories to goals consistently favored dairy and egg products over meats. These results support previous literature highlighting the environmental intensity of ASF, but also indicate that moderate ASF supplies contribute to multiple food system goals simultaneously.
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    Effect of Supplemental Trace Mineral Source on Haircoat and Hair Loss in Adult Cats
    Amundson, Laura A.; Millican, Allison A.; Cornelison, Alyssa S.; McGilliard, Michael L.; Matti, Taryn (MDPI, 2025-09-11)
    Trace minerals (TMs) are pivotal for skin health and haircoat quality. The objective of this study was to evaluate effects of organic TMs, in the form of lysine and glutamic acid-complexed TMs (Zn, Mn, Cu, and Fe), on feline hair growth and haircoat characteristics. Cats (mean 8.4 yr) were fed a Control diet (inorganic TM, sulfates) for 15 days before being assigned to treatment diets for 90 days. Treatments were Control (n = 20) or lysine and glutamic acid-complexed TM (Zinpro Corp. Eden Prairie, MN, USA) sources (TMC-LG; n = 20), formulated at iso-levels (100 ppm Zn, 15 ppm Mn, 12 ppm Cu, 80 ppm Fe). At the beginning of the test period (day 0), an area was shaved to evaluate hair growth on days 45 and 90, in addition to haircoat characteristics and hair loss. At day 45 (diet × day, p = 0.02), cats fed TMC-LG tended to have 0.023 g less shed hair compared to Control cats (p = 0.08). Similarly, dander scores differed at day 45 (diet × day, p = 0.02), with TMC-LG (0.66) cats having more favorable scores compared to Control (1.05; p = 0.03). There were no significant differences between treatments at day 90. Cats fed TMC-LG had a transient improvement in hair loss and dander scores at day 45 compared to the Control over the 90-day trial.
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    The Effects of Endophyte-Infected Tall Fescue on the Production and Reproductive Performance Parameters of Beef Cattle and Calves
    Taylor, Amber A.; Fike, John H.; Mercadante, Vitor R. G.; Pent, Gabriel J. (MDPI, 2025-07-15)
    Records from 2012 to 2019 for two herds were analyzed to determine how tall fescue (Schedonorus arundinaceus (Schreb.) Dumont) endophyte (Epichloë coenophialum) status affected the productivity of spring-calving cows and calves. Pastures either contained tall fescue with wildtype endophyte (high levels of ergot alkaloids) or novel- or endophyte-free tall fescue (largely ergot alkaloid free). The experimental design was a randomized complete block with year as the replication unit. Forage samples from the farm with toxic endophyte-infected tall fescue contained 1136 ± 413 ppb total ergot alkaloids, while forage from the non-toxic pastures on the second farm contained 118 ± 83 ppb total ergot alkaloids. Artificial insemination pregnancy rates and calving rates were greater (p < 0.05) for cows that grazed non-toxic tall fescue (51.2 ± 2.8% and 93.5 ± 1.4%, respectively) than for cows on toxic endophyte-infected tall fescue (43.3 ± 2.8% and 88.8 ± 1.4%, respectively). Birth weights and weaning weights were greater (p < 0.05) for calves from the non-toxic tall fescue system (37 ± 1 kg and 278 ± 8 kg, respectively) than for calves from the toxic endophyte-infected tall fescue system (33 ± 1 kg and 254 ± 8 kg, respectively). Raising cattle on tall fescue without the toxic endophyte improved cow and calf productivity.
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    Productivity, Fermentation Parameters, and Chemical Composition of Silages from Biomass Sorghum Hybrids in Ratoon Crop
    Silva, Yara América da; Orrico Junior, Marco Antonio Previdelli; Retore, Marciana; Ceccon, Gessí; Amaral, Isabele Paola de Oliveira; Orrico, Ana Carolina Amorim; Muglia, Giuliano Reis Pereira; Fernandes, Tatiane (MDPI, 2025-09-18)
    Biomass sorghum stands out for its high dry matter yield and ratooning ability, enabling additional harvests and silage production. This study evaluated the productive potential and fermentation quality of silages from ratoon biomass sorghum hybrids. A 5 × 2 factorial randomized block design was used, with five hybrids (CMSXS5039, CMSXS5044, CMSXS7102, CMSXS7103, and BRS 716) grown in two municipalities of Mato Grosso do Sul, Brazil (Dourados and Jateí). Dry matter production (DMP) did not differ (p > 0.05) among the hybrids within each municipality; however, overall yield was higher in Jateí, averaging 12 t DM/ha. In Dourados, CMSXS5039 and CMSXS5044 showed the highest lactic acid concentrations (46.71 and 59.73 g/kg DM), whereas in Jateí, CMSXS7102, CMSXS7103, and BRS 716 stood out (45.70, 44.78, and 40.77 g/kg DM, respectively), among the sites, Jateí had the greater lactic acid production (49.95 g/kg DM). Aerobic stability (AS) averaged 28.5 h, with higher values in Dourados (p < 0.05), about 16 h longer than in Jateí. BRS 716 and CMSXS5044 presented the highest crude protein contents (115.17 and 118.33 g/kg DM). CMSXS5039 grown in Jateí had the lowest neutral detergent fiber and the highest starch and non-fiber carbohydrate values. Biomass sorghum hybrids exhibited good yield potential and good silage quality even under low rainfall conditions, with CMSXS5039 best suited for more energetic diets and BRS 716 and CMSXS5044 for more proteic diets.
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    Principal components-based selection criteria for genetic improvement of growth in sheep breeding programs
    Mandal, Ajoy; Gayari, Indrajit; Lalhmingmawii, Sylvia; Notter, David R.; Baneh, Hasan (2025-09-25)
    Background: The objective of this study was to investigate the use of principal components (PC) as potential selection criteria to improve growth in sheep. The PC were derived from body weights of 2223 Muzaffarnagari lambs at birth, 90, 180, 270 and 360 days of age. Univariate animal models including various combinations of direct and maternal effects were fitted to the PC. Genetic correlations among PC and with body weights and estimated growth curve parameters for the Brody and Richards functions were estimated using bivariate animal models. Results: The first three PC explained 94% of multivariate variation in body weights. PC1 contrasted lambs with larger versus smaller body weights at all postnatal ages. PC2 contrasted lambs with heavier versus lighter birth weights, with little emphasis on postnatal weights. PC3 placed positive emphasis on weights at birth and after 6 months of age but negative emphasis on weight at 3 through 9 months of age. Direct heritabilities for PC1, PC2, and PC3 were 0.19, 0.12 and 0.08, respectively. Maternal genetic and permanent environmental effects affected PC1 (0.04 and 0.08, respectively). PC2 was influenced by maternal genetic effects (0.10). Direct genetic correlations of PC1 with PC2 and PC3 were 0.48 and 0.72. The maternal genetic correlation between PC1 and PC2 was 0.97. Genetic relationships of PC1 with yearling weight and with estimates of final body weight from both growth functions exceeded 0.65. PC2 was genetically correlated with birth weight (≥ 0.64) and degree of maturity for body weight at birth (u0; ≥ 0.83). PC3 had negative genetic correlations with measures of maturing rate (~ -0.86) and with u0 ( -0.52 and -0.49), but positive correlations with final body weight (0.85 and 0.90) and time required to reach 50% of mature weight (0.83). Maternal genetic correlations of PC1 and PC2 with birth weight and u0 exceeded 0.83. Conclusions: We conclude that PC could be used as selection criteria in genetic improvement programs in sheep. Also, selection on PC1 and PC2 would likely be adequate to describe and improve direct and maternal genetic potentials for postnatal growth and birth weight, respectively, in Muzaffarnagari lambs.
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    Prepartal liver glutathione and its association with lactation performance, metabolism, and health outcomes in transition dairy cows [Supplemental materials]
    Souza Lima, Ana Flavia; de Oliveira, Maria Helena; Begalli, Gustavo; Grazziotin, Rodrigo; Halfen, Jessica; Trevisi, Erminio; Osorio, Johan (2025-09)
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    Modulating Fermentation in Total Mixed Ration Silages Using Lasalocid Sodium and Essential Oils
    Amaral, Isabele Paola de Oliveira; de Oliveira, Mariany Felex; Junior, Marco Antonio Previdelli Orrico; Retore, Marciana; Fernandes, Tatiane; da Silva, Yara América; Orrico, Ana Carolina Amorim; de Andrade, Ronnie Coêlho; Muglia, Giuliano Reis Pereira (MDPI, 2025-08-15)
    This study evaluated the effects of lasalocid sodium (LASA) and essential oils on the fermentation and nutritional quality of total mixed ration (TMR) silages. A 4 × 2 factorial design tested four additives—a control (distilled water), LASA (375 mg/kg DM), limonene essential oil (LEO), and a blend of cinnamaldehyde and carvacrol (EOB), both at 400 mg/kg DM—during summer and autumn. The TMRs were formulated to meet the nutritional requirements of lactating cows producing 20 kg of milk per day. After 110 days of ensiling, silages were analyzed for fermentation losses, pH, short-chain fatty acids, ammoniacal nitrogen (NH3-N), aerobic stability (AS), and chemical composition. The additives significantly improved dry matter recovery (DMR), especially LASA and EOB in autumn. EOB showed the lowest effluent losses and highest AS, with higher acetic acid and lower NH3-N contents. LEO and EOB increased lactic acid, while LASA reduced ethanol and butyric acid levels in summer. Crude protein increased with LEO in autumn, and LASA and LEO improved total digestible nutrients (TDNs) in summer. EOB-treated silages had higher fiber fractions in autumn, without compromising feed value. Therefore, LASA, LEO, and particularly EOB enhanced silage fermentation and nutrient preservation, with EOB showing the most consistent results across seasons.
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    Transcriptome analysis unveils multiple reasons behind delayed and slower deposition of intramuscular fat compared to subcutaneous fat in cattle
    Tan, Zhendong; Pokhrel, Binod; Zhou, Ziqi; Jiang, Honglin (2025-07-31)
    Background: Intramuscular fat refers to the white adipose tissue deposited between muscle fibers, and its quantity and distribution directly impact the quality and value of beef. Compared to subcutaneous fat, intramuscular fat develops later and accumulates more slowly in cattle. The reasons for the delayed development and slower growth of intramuscular fat in cattle remain unclear. Results: Histological analysis showed that adipocytes in intramuscular fat were smaller than those in subcutaneous fat from the same mature cattle, indicating a delayed development or slower growth of intramuscular fat compared to subcutaneous fat. Intramuscular fat had a lower capacity for retaining or incorporating long-chain fatty acids into triglycerides than subcutaneous fat. Comparing the transcriptomes of intramuscular and subcutaneous fat by RNA sequencing identified more than 1,000 genes differentially expressed (DEGs) between the two adipose depots. Genes upregulated in intramuscular fat included FOXO6, SLC27A1, HDAC9, WWTR1, and PIK3C2A, which are known to inhibit adipose tissue development and growth. Genes downregulated in intramuscular fat included FABP4, AGPAT2, ADIG, ADIRF, and PLIN2, which are known to promote adipose tissue development and growth. Functional enrichment analyses of these DEGs suggested that intramuscular fat may have a lower capacity for fatty acid binding and adipogenesis compared to subcutaneous fat. Furthermore, genes downregulated in intramuscular fat were enriched in signaling pathways such as the PPAR signaling pathway, whereas genes upregulated in intramuscular fat were enriched in pathways including the Wnt signaling pathway. Stromal vascular fraction (SVF) cells from intramuscular fat exhibited a lower adipogenic potential than those from subcutaneous fat. Conclusions: Multiple factors may contribute to the delayed and slower deposition of intramuscular fat compared to subcutaneous fat in cattle, including reduced fatty acid binding capacity, lower triglyceride synthesis, and decreased adipogenesis in intramuscular fat. These differences are possibly driven by lower expressions of genes such as AGPAT2, FABP4, and ADIG, higher expression of genes such as FOXO6, HDAC9, and SLC27A1, reduced activation of the PPAR signaling pathway, and increased activation of the Wnt signaling pathway in intramuscular fat.
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    The Fermentative and Nutritional Effects of Limonene and a Cinnamaldehyde–Carvacrol Blend on Total Mixed Ration Silages
    Amaral, Isabele Paola de Oliveira; Orrico Junior, Marco Antonio Previdelli; Retore, Marciana; Fernandes, Tatiane; da Silva, Yara América; de Oliveira, Mariany Felex; Orrico, Ana Carolina Amorim; de Andrade, Ronnie Coêlho; Muglia, Giuliano Reis Pereira (MDPI, 2025-07-18)
    This study evaluated the effects of different doses of limonene essential oil (LEO) and a blend of cinnamaldehyde and carvacrol (BCC) on the fermentative quality and chemical–bromatological composition of total mixed ration (TMR) silages. Two independent trials were conducted, each focused on one additive, using a completely randomized design with four treatments (0, 200, 400, and 600 mg/kg of dry matter), replicated across two seasons (summer and autumn), with five replicates per treatment per season. The silages were assessed for their chemical composition, fermentation profile, aerobic stability (AS), and storage losses. In the LEO trial, the dry matter (DM) content increased significantly by 0.047% for each mg/kg added. Dry matter recovery (DMR) peaked at 97.9% at 473 mg/kg (p < 0.01), while lactic acid (LA) production reached 5.87% DM at 456 mg/kg. Ethanol concentrations decreased to 0.13% DM at 392 mg/kg (p = 0.04). The highest AS value (114 h) was observed at 203.7 mg/kg, but AS declined slightly at the highest LEO dose (600 mg/kg). No significant effects were observed for the pH, neutral detergent fiber (NDF), acid detergent fiber (ADF), crude protein (CP), or non-fiber carbohydrates (NFCs). In the BCC trial, DMR reached 98.2% at 548 mg/kg (p < 0.001), and effluent losses decreased by approximately 20 kg/ton DM. LA production peaked at 6.41% DM at 412 mg/kg (p < 0.001), and AS reached 131 h at 359 mg/kg. BCC increased NDF (from 23.27% to 27.73%) and ADF (from 35.13% to 41.20%) linearly, while NFCs and the total digestible nutrients (TDN) decreased by 0.0007% and 0.039% per mg of BCC, respectively. In conclusion, both additives improved the fermentation efficiency by increasing LA and reducing losses. LEO was more effective for DM retention and ethanol reduction, while BCC improved DMR and AS, with distinct effects on fiber and energy fractions.
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    Evaluating the effectiveness of participatory science dog teams to detect devitalized Spotted Lanternfly (Lycorma delicatula) egg masses
    Dickinson, Sally; Nita, Mizuho; Aviles-Rosa, Edgar O.; Hall, Nathan; Feuerbacher, Erica N. (PeerJ, 2025-07-16)
    The spotted lanternfly (Lycorma delicatula, SLF) is an invasive planthopper first detected in the United States in 2014, with initial sightings in Pennsylvania. SLF poses a serious threat to agriculture, particularly targeting grapevines, hops, and ornamental plants, resulting in substantial annual economic losses. Due to its life cycle, the early detection and removal of egg masses are the most effective strategies for preventing long-distance dispersal. However, visual detection by humans is time-consuming and inefficient. Detection dogs have demonstrated high accuracy in locating SLF egg masses and differentiating them from environmental distractors. Despite their effectiveness, the number of dogs available through governmental channels is insufficient to meet demand. This study evaluated whether community scientist dog-handler teams could meet standardized detection criteria using SLF egg masses. Teams from across the U.S. were recruited and trained using devitalized egg masses, with oversight provided by local trainers. Following a 3- to 6-month independent training period, team performance was assessed through an odor recognition test and a field trial. Dogs demonstrated a sensitivity of 82% in controlled testing and 58% in field conditions. These results provide proof of concept; community scientist dog teams could play a significant role in protecting their local environments and agriculture from invasive species.
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    Narasin Supplementation Enhances Growth Performance in Grazing Cattle
    Polizel, Daniel M.; Marques, Rodrigo S.; Limede, Arnaldo C.; Cidrini, Fernando A. A.; Gonçalves, José Renato S.; Carvalho, Pedro H. V.; Pires, Alexandre V. (MDPI, 2025-07-01)
    Three experiments were conducted to evaluate the effects of narasin inclusion on the growth performance of grazing beef cattle under similar forage availability and quality. All three experiments were arranged in a randomized complete block design according to the initial BW. Exp 1: 200 Nellore calves (initial BW = 177 ± 15 kg) were randomly allocated in three treatments for 84 d during the rainy season: (1) CONT: mineral supplement; (2) 1400 N: 1400 mg of narasin/kg of supplement; and (3) 2100 N: 2100 mg of narasin/kg of supplement. Narasin inclusion increased (p ≤ 0.01) ADG by 0.077 kg/d and final BW by 6.7 kg, with no differences (p ≥ 0.50) between narasin doses. Exp 2: 240 Nellore calves (initial BW = 195 ± 19 kg) were allocated to CONT or N1400 for 112 d during the rainy season. Narasin inclusion increased (p ≤ 0.01) ADG by 0.082 kg/d and final BW by 9.1 kg. Exp 3: 150 Nellore yearlings (initial BW = 332 ± 22 kg) were allocated for 112 d during the dry season: (1) PROT: protein supplement and (2) PROT250: inclusion of 250 mg of narasin/kg of supplement. Narasin inclusion increased (p ≤ 0.04) ADG by 0.048 kg and final BW by 5.3 kg. For all experiments, narasin inclusion did not impact (p ≥ 0.25) supplement intake. Hence, inclusion of narasin in mineral and protein supplements consistently enhances growth performance of grazing beef cattle across different seasons and production stages, without impacting supplement intake, providing an effective nutritional strategy to enhance productivity on tropical pastures.
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    Embryonic Thermal Manipulation Affects Body Performance Parameters and Cecum Microbiome in Broiler Chickens in Response to Post-Hatch Chronic Heat Stress Challenge
    Dahadha, Rahmeh; Hundam, Seif; Al-Zghoul, Mohammad Borhan; Alanagreh, Lo’ai; Ababneh, Mustafa; Mayyas, Mohammad; Alghizzawi, Daoud; Mustafa, Minas A.; Gerrard, David E.; Dalloul, Rami A. (MDPI, 2025-06-06)
    Rising global temperatures challenge poultry production by disrupting the cecal microbiota, which is essential for chicken health. Thermal manipulation (TM) during embryogenesis is a potential strategy to enhance thermotolerance in broilers. This study examined TM’s effects on the cecal microbiome, body weight (BW), and body temperature (BT) under chronic heat stress (CHS). Fertile Indian River eggs (n = 800) were incubated under control (37.8 °C, 56% RH) or TM conditions (39 °C, 65% RH for 18 h per day from embryonic day 10 to 18). On post-hatch day 18, male chicks were assigned to either CHS (35 ± 0.5 °C for five days) or thermoneutral conditions (24 ± 0.5 °C). The CHS-TM group showed a significantly higher BW than the CHS-CON group (p < 0.05). Under thermoneutral conditions, TM chicks had a lower BT on day 1 (p < 0.05), while the CHS-TM group exhibited a non-significant BT reduction compared to the CHS-CON group under heat stress (p > 0.05). An analysis of the gut microbiome showed that the beta diversity analysis (PERMANOVA, p < 0.05) indicated distinct microbial shifts. Firmicutes and Bacteroidota dominated the phylum level, with CHS increased Bacilli and Lactobacillus while reducing Lachnospirales in the CHS-TM group. These findings suggest that TM modulates gut microbiota and mitigates BW loss, offering a potential strategy to enhance broilers’ resilience to heat stress.
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    Impact of Thermal Manipulation of Broiler Eggs on Growth Performance, Splenic Inflammatory Cytokine Levels, and Heat Shock Protein Responses to Post-Hatch Lipopolysaccharide (LPS) Challenge
    Al-Zghoul, Mohammad Borhan; Hundam, Seif; Mayyas, Mohammad; Gerrard, David E.; Dalloul, Rami A. (MDPI, 2025-06-12)
    Thermal manipulation (TM) during embryogenesis is a promising non-pharmacological strategy to enhance physiological resilience in broiler chickens. This study evaluated the impact of thermal conditioning of fertile eggs on growth performance, inflammatory responses, and molecular stress markers following a post-hatch lipopolysaccharide (LPS) challenge. Fertilized eggs (average weight 62 ± 3 g) were obtained from 35-week-old Indian River broiler breeder hens. A total of 720 eggs were randomly assigned to either the control group (n = 360) or the TM group (n = 360), with each group consisting of two replicates of 180 eggs. Control eggs were maintained under standard incubation conditions (37.8 °C, 56% RH), while TM eggs were subjected to elevated temperature (38.8 °C, 65% RH) for 18 h daily from embryonic day 10 to 18. On post-hatch day 15, control and TM groups were administered either saline or LPS via intraperitoneal (IP) injection. Body weight and temperature, internal organ weights, and splenic mRNA expression levels of inflammatory cytokines, toll-like receptors, transcription factors, and heat shock proteins were assessed. TM did not alter hatchability (p = 0.633), but significantly shortened hatch time (p < 0.05) and improved feed efficiency (p < 0.05). While LPS induced marked inflammatory responses in all birds, those subjected to TM exhibited attenuated proinflammatory cytokine expression, enhanced anti-inflammatory signaling, and differential regulation of stress-associated genes, including nuclear factor kappa B (NF-κB), heat shock protein 70 (HSP70), and heat shock factors (HSFs). These findings suggest that TM during incubation promotes a more regulated immune response and improved stress adaptation post-hatch. This approach offers a potential antibiotic-free intervention to enhance broiler health, performance, and resilience under immunological stress.
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    Follicular Fluid from Cows That Express Estrus During a Fixed-Time Artificial Insemination Protocol Promotes Blastocyst Development
    Harl, Audra W.; Negrón-Pérez, Verónica M.; Stewart, Jacob W.; Perry, George A.; Ealy, Alan D.; Rhoads, Michelle L. (MDPI, 2025-04-25)
    It is not yet understood why cows that exhibit estrus and ovulate are more likely to become pregnant than those that ovulate but do not exhibit estrus during a fixed-time artificial insemination (FTAI) protocol. The objective of this work was to determine whether the follicular fluid from cows that exhibit estrus contributes to the increased likelihood of pregnancy. Lactating crossbred cows were subjected to an FTAI estrous synchronization protocol. Estrous behavior was observed and recorded prior to transvaginal follicle aspiration from cows that did (estrus, n = 7) or did not exhibit estrus (non-estrus, n = 6). Follicular fluid (25%) was then added to in vitro maturation media for the maturation of oocytes (n = 1489) from slaughterhouse ovaries. Cleavage rates were not affected by the estrous status of the cows from which the follicular fluid was collected. Blastocyst rates, however, were greater following maturation in the presence of follicular fluid from estrus cows compared to non-estrus cows (p ≤ 0.01). This difference in blastocyst rates was not related to blastocyst cell numbers (inner cell mass, trophoblast, and total), as they did not differ between estrus and non-estrus animals. This study demonstrates that the follicular fluid, and thus, the follicular environment just prior to ovulation does indeed contribute to improved pregnancy rates following FTAI.
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    Development of a Selective Agar for the Detection of Probiotic Strain Ligilactobacillus animalis NP51 and Other Lactic Acid Bacteria in Cattle Feed
    Thompson, Kasey; Akter, Shamima; Ferguson-Noel, Naola; Maurer, John J.; Lee, Margie D. (MDPI, 2025-06-13)
    The enormous potential of bacteriotherapy in disease treatment and prevention has created a large probiotic market. Significant challenges exist in assessing probiotic quality, efficacy and viability. Lactic acid bacteria (LAB) are commonly used probiotics and the most abundant of the vertebrate microbiota. The goal of this study was to make MRS agar specific for probiotic Ligilactobacillus animalis NP51, since the current formulation is not sufficiently selective. Here, 53 chemicals were screened to identify compound(s) that reduced the growth of non-LAB and fungi on de Mann, Rogosa, and Sharpe (MRS) agar, and which were selective for LAB and specifically the probiotic strain NP51. Cattle feed was selected as the sample type, as it is commonly amended with Lactobacillus or yeast probiotics and often includes silage, a diverse microbial consortium of fungi and LAB. Modified MRS was evaluated for its effectiveness in determining probiotic viability and the detection of L. animalis NP51 in cattle feed, amended with this probiotic. qPCR was used to specifically detect and enumerate NP51 in commercial and experimental feed samples. For four selective agents, nystatin, guanidine hydrochloride, CuSO4, and ZnCl, it was identified that when used together, they reduced the growth of bacteria and fungi, but did not inhibit the Lactobacillus probiotic NP51 and other LAB. Metagenomic analysis revealed LAB as the major group cultivated on modified MRS agar from the plating of cattle feed amended with silage. As an enrichment, modified MRS broth improved the qPCR detection of probiotic strain NP51. This study illustrated that improvements can be made to existing bacteriological media for enumerating probiotic NP51 and determining the product’s viability.
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    Mare Milk and Foal Plasma Fatty Acid Composition in Foals Born to Mares Fed Either Flax or Fish Oil During Late Gestation
    Snyder-Peterson, Erica A.; Shost, Nichola; Thomson-Parker, Timber; Mowry, Kayla C.; Fikes, Kalley K.; Smith, Rachelle; Corl, Benjamin; Wagner, Ashley; Girard, Ivan; Suagee-Bedore, Jessica K. (MDPI, 2025-05-30)
    Maternal supplementation with omega-3 fatty acids during late gestation has been shown to have a variety of benefits for neonates. The current study utilized 13 mares and their foals, assigned to one of three dietary treatments: an unsupplemented control diet (CON; n = 5), or the addition of either fish oil-derived omega-3 (FO; n = 5) or a flaxseed (FLAX; n = 3) supplement. The mares received treatments beginning on day 310 of gestation through day 5 post-parturition. Samples of plasma were collected from the mares prior to beginning supplementation, on days 0, 5, and 30 post-partum. Milk samples were collected from the mares 12 h post-partum. Plasma samples were collected from the foals at birth and at 5 and 30 d post-partum. The fatty acid compositions of the mare plasma, mare milk, and foal plasma were determined using gas chromatography. The data were analyzed using repeated-measures ANOVA. Foals born to FO mares exhibited increased plasma docosahexaenoic acid (DHA) levels at birth compared with those born to CON mares. Across the treatments, the plasma from foals at birth prior to nursing had the highest DHA content compared with on d 5 and 30. No treatment differences were observed in the mare plasma or milk fatty acid composition for DHA levels. FLAX mares had higher 20:3 n6 plasma proportions than FO or CON mares. Beginning supplementation with fish oil on day 310 of gestation may be sufficient to elevate neonatal foal DHA concentrations.
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    Valine and nonessential amino acids affect bidirectional transport rates of leucine and isoleucine in bovine mammary epithelial cells
    Weston, A. Hruby; Teixeira, I. A. M. A.; Yoder, P. S.; Pilonero, T.; Hanigan, Mark D. (Elsevier, 2024-04)
    A more complete understanding of the mechanisms controlling AA transport in mammary glands of dairy cattle will help identify solutions to increase nitrogen feeding efficiency on farms. It was hypothesized that Ala, Gln, and Gly (NEAAG), which are actively transported into cells and exchanged for all branched-chain AA (BCAA), may stimulate transport of BCAA, and that Val may antagonize transport of the other BCAA due to transporter competition. Thus, we evaluated the effects of varying concentrations of NEAAG and Val on transport and metabolism of the BCAA Ala, Met, Phe, and Thr by bovine mammary epithelial cells. Primary cultures of bovine mammary epithelial cells were assigned to treatments of low (70% of mean in vivo plasma concentrations of lactating dairy cows) and high (200%) concentrations of Val and NEAAG (LVal and LNEAAG, HVal and HNEAAG, respectively) in a 2 × 2 factorial design. Cells were preloaded with treatment media containing [15N]-labeled AA for 24 h. The [15N]-labeled media were replaced with treatment media containing [13C]-labeled AA. Media and cells were harvested from plates at 0, 0.5, 1, 5, 15, 30, 60, and 240 min after application of the [13C]-labeled AA and assessed for [15N]- and [13C]-AA label concentrations. The data were used to derive transport, transamination, irreversible loss, and protein-synthesis fluxes. All Val fluxes, except synthesis of rapidly exchanging tissue protein, increased with the HVal treatment. Interestingly, the rapidly exchanging tissue protein, transamination, and irreversible-loss rate constants decreased with HVal, indicating that the significant flux increases were primarily driven by mass action with the cells resisting the flux increases by downregulating activity. However, the decreases could also reflect saturation of processes that would drive down the mass-action rate constants. This is supported by decreases in the same rate constants for Ile and Leu with HVal. This could be due to either competition for shared transamination and oxidation reactions or a reduction in enzymatic activity. Also, NEAAG did not affect Val fluxes, but influx and efflux rate constants increased for both Val and Leu with HNEAAG, indicating an activating substrate effect. Overall, AA transport rates generally responded concordantly with extracellular concentrations, indicating the transporters are not substrate-saturated within the in vivo range. However, BCAA transamination and oxidation enzymes may be approaching saturation within in vivo ranges. In addition, System L transport activity appeared to be stimulated by as much as 75% with high intracellular concentrations of Ala, Gln, and Gly. High concentrations of Val antagonized transport activity of Ile and Leu by 68% and 15%, respectively, indicating competitive inhibition, but this was only observable at HNEAAG concentrations. The exchange transporters of System L transport 8 of the essential AA that make up approximately 40% of milk protein, so better understanding this transporter is an important step for increased efficiency.