M.S. - Animal Sciences

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https://hdl.handle.net/10125/589

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Now showing 1 - 10 of 53
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    Evaluating the impact of increasing vitamin C and E concentration on primary ovine satellite cells
    (2025) Blad , Taya J N; Reichhardt, Caleb C.; Animal Sciences
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    EVALUATION OF EGGSHELLS USING A SCANNING ELECTRON MICROSCOPE AND ENERGY DISPERSIVE SPECTROMETRY
    (2024) Mahato, Prem Lal; Mishra, Birendra; Animal Sciences
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    THE STRESS RESPONSE OF THE BRASSY CHUB, A LOCAL REEF FISH AND CANDIDATE FOR SUSTAINABLE AQUACULTURE
    (2024) Merlo, Reilly Stanton; Seale, Andre P.; Animal Sciences
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    MITIGATION OF HEAT STRESS IN BROILER CHICKENS USING DIETARY SUPPLEMENTATION OF MICROALGAE
    (2023) Chaudhary, Ajay; Mishra, Birendra BM; Animal Sciences
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    Effects Of Microalgae, With Or Without Xylanase Supplementation, On Growth Performance And Gut Health Parameters Of Broiler Chickens
    (University of Hawaii at Manoa, 2023) Mishra, Pravin; Jha, Rajesh; Animal Sciences
    Modern broilers are selected for a fast growth rate in a shorter period. The rapid increase in body weight leads to the possibility of gut disorders like poor gastrointestinal tract development, poor nutrient utilization, and gut dysbiosis if not managed properly. Nutritional programming using several feedstuffs and co-products has been studied to manage gut health without compromising growth performance. Microalgae are becoming potential sustainable feed ingredients, while terrestrial feedstuffs are becoming scarce and costly. They are rich in nutritional and functional values but have lower digestibility. Therefore, the study evaluated the effects of microalgae with or without xylanase supplementation on growth performance and gut health parameters of broiler chickens. A total of 162-day-old Cobb 500 chicks were raised for 35 days. Birds were fed with three dietary treatments: a) corn-soybean meal-based diet (CON), b) CON + 3% microalgae (MAG), and c) MAG + xylanase (MAG+XYN) in two phases (starter: d0-21 and finisher: d22-35). Weekly body weight (BW) and feed intake were recorded to calculate average daily gain (ADG), average daily feed intake (ADFI), and feed conversion ratio (FCR). On d35, carcass and organ weight were recorded. Tissue samples were collected for histomorphology (duodenum, jejunum, and ileum) and total RNA isolation (ileum) on d3 and d35. In addition, blood was collected for serum immunoglobulin (on d35) and cecal digest for short-chain fatty acids, microbiota characterization, and functional metabolic pathways determination (on d3 and d35). Ileal gene expression related to the gut barrier, immunity, antioxidant, and nutrient transporter was determined using qPCR. Bioinformatics analyses were performed in CLC Genomic Workbench and STAMP. All other data were analyzed in GraphPad Prism or RStudio using one-way ANOVA followed by Tukey’s multiple comparison test. The significance level was set at p<0.05, and the results are expressed as the mean ± SEM. The BW, ADG, and ADFI were significantly higher (p<0.05) in MAG and MAG+XYN compared to the CON group. No significant difference (p>0.05) was found for FCR. Relative carcass and organ weight also showed no significant differences among treatments (p>0.05). The expressions of ZO1, CD56, and SLC7A7 were significantly higher (p<0.05) in the MAG group. Statistically insignificant, however, villi height (VH), crypt depth (CD), VH:CD, and villi surface area (VSA) tended to increase in MAG and MAG+XYN groups both on d3 and d35. Relative microbial abundance at the genus level showed that MAG and MAG+XYN groups had a diverse microbial community on d3 and d35. However, no bacterial genus has a significant difference in their relative abundance on d3, but sixteen genera showed significant differences in their relative abundance among the dietary treatments on d35. Most of these bacteria are short-chain fatty acid-producing bacteria. Moreover, MAG and MAG+XYN-fed broilers had better responses than CON groups for metabolic pathways (D-mannose degradation, Pectin degradation I and II, β-1-4-mannan degradation, tetrahydrofolate biosynthesis, glutathione biosynthesis, glutathione-peroxide redox reactions, lactate fermentation to propanoate, acetate, and hydrogen, etc.) both on d3 and d35. In conclusion, the use of microalgae with or without xylanase in a corn-soybean meal-based broilers diet promotes growth performance, immunity, and gut health of broiler chickens. Improvement in SCFA production, microbial diversity, and metabolic pathways is a sign of improved gut health. Most of the statistically changed pathways are related to fiber utilization and oxidative stress reduction. In addition, using microalgae in feeding programs may help to produce healthy broilers.
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    The Stress Response Of Mozambique Tilapia (Oreochromis Mossambicus) Transferred To Dynamically Changing Salinities
    (University of Hawaii at Manoa, 2022) Chang, Ryan James Akira; Seale, Andre P.; Animal Sciences
    An organism’s survival depends on effectively responding to stressors. One of the many stressors aquatic organisms face is osmotic stress due to differences between their internal and environmental solute concentrations. In estuarine environments, euryhaline fish can maintain a stable internal osmolality despite daily changes in environmental salinity. The capacity of euryhaline fish to maintain homeostasis in a wide range of salinities is largely facilitated by the endocrine system. The hypothalamus-pituitary-interrenal (HPI) axis plays a role in the hypo- and hyperosmotic stress responses by facilitating ion and water transport at the gill while also modifying glucose metabolism to provide energy. I characterized responses of the HPI axis and glycogen metabolism in the gill and liver of the euryhaline Mozambique tilapia (Oreochromis mossambicus) under salinity stress. Specifically, in one study I analyzed fish transferred from freshwater (FW) to seawater (SW) and from SW to FW and, in the other, from steady state salinities to salinities that changed between FW and SW every 6 h to simulate a tidal environment. In both studies, I found that the effects of salinity in the HPI-axis were mainly characterized by changes in branchial corticosteroid receptor expression. Moreover, a robust rise in plasma glucose was observed when fish were transferred to FW, and in the FW phase of the tidal cycle, suggesting that glucose may play an osmotic role in compensating for the fall in plasma osmolality triggered by FW environments. Given the natural changes in salinity that occur in a range of wild and controlled environments, identifying changes in the underlying components of the stress response to perturbations in salinity can help mitigate the maladaptive effects of stress, thereby informing environmental management and aquaculture practices.
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    Transcriptomic Analysis Of Bovine Endometrium With Short Uterine Tract Leading To Infertility
    (University of Hawaii at Manoa, 2022) ADNAN, MAHFUZ RAHMAN; Mishra, Birendra; Animal Sciences
    Background: Beef is one of the most highly consumed meat worldwide. With the increasing human population, the demand for beef will be increased by 43% in 2050. However, the production of beef cattle has declined in recent years. Infertility/subfertility is one of the main reasons causing a decline in beef production. Infertility is the diminished or incapability of females to produce viable offspring, causing a substantial economic loss. Since 1980, infertility has been increasing among the cattle population worldwide. Infertility is triggered by several factors, including developmental defects of the reproductive tract. Recently, Hawaii beef producers reported that heifers selected for breeding had good body condition scores and were bred several times with fertile bulls but failed to conceive. After slaughtering at a local abbatoir, these heifers had small uterine tract with normal ovaries. The uterus provides the biological environment for the embryo’s growth and development. Bovine endometrium consists of caruncular (CAR) and Intercaruncular (ICAR) regions. The caruncular region serves as the implantation and placentation site, whereas the intercaruncular region contains numerous glands for preparing the biological environment for the embryo's growth and development. Studies have suggested that secretions from the ICAR are necessary for the conceptus growth, development, and survival. So far, there is no report on infertility induced by smaller reproductive tract in bovines. Therefore, we hypothesized that the heifers with short uterine tract might have abnormal uterine transcriptomic profiles and developmental defects leading to infertility. The objectives of this study are to 1) analyze the morphological difference between the short and normal uterine heifers, and 2) determine the genes and biological pathways in the intercaruncular endometrium of the heifers with short uterine tract compared to normal heifers.Methods: We examined the reproductive tracts of over 171 cattle from local slaughterhouses; among them, 51 heifers had a smaller uterine tract. Uterine tissues were collected from a subset of infertile heifers (n=6, designated as the short uterine tract). Uterine tissues were also collected from cyclic heifers having normal uterine tract (n=6, cyclic heifers, designated as the normal uterine tract). Samples were selected, matching the heifers' corpus luteum stage (II). For the histological study, uterine tissues were collected and fixed in 10% Neutral buffered formalin. The fixed tissues were sectioned and stained with Hematoxyline and Eosin. For the transcriptomic study, intercaruncular tissues were collected in RNAlater solution. Total RNAs were isolated and were subjected to high-throughput RNA-sequencing (n=5/group). The differentially expressed genes (DEGs) were determined between the short uterine tract compared to normal. To delineate the DEGs and associated biological pathways, Gene Ontology, Kyoto Encyclopedia of Genes and Genomes (KEGG), and Ingenuity Pathway Analysis were done. The most highly upregulated and downregulated genes expression were validated using real-time quantitative PCR (qPCR). Results and conclusion: Total uterine layer length, endometrial layer length, and gland numbers were significantly lower in the short uterine tract than normal. A total of 521 genes were differentially expressed in the short uterine tract compared to normal. The top 20 downregulated genes in the short bovine endometrium were NLRP12, ENSBTAG00000052892, ENSBTAG00000055111, ENSBTAG00000036102, LOC112444733, LOC100847874, OTOG, CLCNKA, NPPC, CYP26A1, LOC788915, VNN2, PRKCG, LOC782061, MYOT, PLA2G3, ANKS1B, GPR183, ST8SIA6, and TMIE. Metabolic pathways, carbon metabolism, and Wnt signaling pathways were the top three enriched pathways by the downregulated DEGs. The qPCR result confirmed the expression of the DEGs in short uteri compared to normal. In conclusion, heifers with short uterine tract had significantly decreased endometrial layers, uterine glands, and altered transcriptomic profiles. The decrease in uterine glands probably resulted in lower uterine secretions necessary to support embryo growth and development. As a result, heifers with short uteri were infertile even when they were bred by fertile bulls.
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    Thermal-induced changes in cell volume and hormone release in prolactin cells of Mozambique tilapia
    (University of Hawaii at Manoa, 2021) Woo, Daniel Wan; Seale, Andre P.; Animal Sciences
    The multifunctional pituitary hormone prolactin (PRL), is critical for survival when fish acclimate to freshwater environments by stimulating ion retention, ion absorption, and water secretion. Due to the important role PRL plays in osmoreception, examining the effect of temperature on this fundamental process can offer insight into how natural, climate-change- driven, or controlled temperatures may alter a process that underlies salinity acclimation in fish. Consistent with their role in fresh water (FW)-acclimation, PRL cells of the euryhaline and eurythermal Mozambique tilapia (Oreochromis mossambicus), respond to a drop in osmolality with a short-term release of PRL. Hyposmotic-induced PRL release is triggered by an increase in cell volume that enables extracellular Ca2+ to enter the cell through the transient receptor potential vanilloid 4 (TRPV4), a stretch gated cation channel shown to be thermosensitive in some vertebrates. While the cell-volume-dependent secretory response of tilapia PRL cells to a hyposmotic stimulus is well established, the effects of temperature on PRL cells have not been characterized. PRL cells were dispersed from the rostral pars distalis (RPD) of Mozambique tilapia and incubated at 26 and 32 °C in isosmotic and hyposmotic media. A delayed rise in PRL release from dispersed PRL cells was observed in response to an increase in temperature while hyposmotic-induced PRL release occurred rapidly. When dispersed PRL cells were subjected to a temperature increase from 26 to 32 oC, ~50% of the total cells gradually increased in volume by ~8%; all cells were responsive to a hyposmotic stimulus (280 mOsm/kg), increasing in volume by ~20%. These findings indicate that thermal-induced PRL release may be mediated, at least in part, through a cell-volume-dependent mechanism, similar to how osmoreception is achieved. Moreover, a possible mechanism through which many of the functions of PRL are affected by temperature is proposed.