VTechWorks Repository :: Browsing by Author "Smith, Edward J."

Browsing by Author "Smith, Edward J."

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Additional Molecular Evidence that The Royal Palm is Probably a Turkey Breed
Smith, Edward J.; Xu, Jun; Adikari, J. (2019-07-09)
In earlier investigations, we reported the uniqueness of Royal Palm from other commonly raise heritage turkeys. Here, we provide evidence from screening using primers specific for the Melanocortin 1 (MC1R) Receptor gene (located on turkey chromosome 13, accession number NC_015023). Five heritage strains, including Broad Breasted Bronze (48), Blue Slate (40), Midget White (40), Royal Palm (45), and Spanish Black (48) were included in the analyses of approximately 3300 base pairs of the MC1R gene. Seven SNPs were identified and validated. Among the haplotypes identified, only Royal Palm had unique haplotypes. When combined with previous investigations, we believe that the Royal Palm may be a breed and not a strain. It may therefore be the most viable resource for introgression with a goal of genetic improvement.
Advancing livestock genomics education and research in developing countries using strategies from the Virginia Tech PREP and IMSD training programs
Smith, Edward J. (2019-07-11)
Our unique and impactful research and education program plan includes distinct activities that target three overlapping phases of each trainee’s tenure, which we define as the “moving in,” “moving through,” and “moving out” phases. During the “moving in” phase, 8 trainees “who need a PREP” will be recruited and assigned to mentors using our proven strategy that is “scholar-driven” and combines mentor qualities such as prior experience, which has resulted in a 98% retention for each of our 3 funding cycles. $409,537 annually or ~2.1 Million for five years. our successful interdisciplinary Initiative for Maximizing Student Development (IMSD) program for pre-doctoral (graduate) and pre-baccalaureate (undergraduate) students from groups underrepresented in careers in the biomedical and behavioral sciences. Our training program is a partnership with departments and interdisciplinary graduate programs which takes advantage of Virginia Tech’s (VT) history of excellence in Engineering and the Behavioral and Life Sciences. With lessons learned in the last eight years, we will continue to recruit across disciplines and from diverse geographic areas and institutions. From the first cycle, 2007-12, a total of 23 pre-doctoral students participated in the VT IMSD program. A total of 16 (or 69.5%) have completed and received the PhD degree; Total Year 1: $467,489.
An Assessment of the Effects of Oxidative Stress and Dietary Antioxidants on Toxin-Induced Dilated Cardiomyopathy in the Turkey (Meleagris gallopavo)
Gyenai, Kwaku Barima (Virginia Tech, 2009-12-16)
Dilated cardiomyopathy (DCM) or round heart disease is a muscle disease of the heart characterized by left ventricular dilatation and abnormal systolic and diastolic ventricular function. In animals, including turkeys and humans, DCM is a major cause of morbidity and mortality that results in heart failure. In the turkey, DCM can be idiopathic or induced. Since idiopathic or spontaneous DCM occurs in about 2-4 % of normal turkeys, it is of significant concern to the poultry industry. This dissertation was designed to increase our understanding of the pathophysiology of DCM in commercial turkeys. Specific objectives included: evaluating the influence of dietary selenium (Se) and vitamin E on poults fed toxic levels of furazolidone (Fz). Evaluating differences among reciprocal crosses of turkey varieties in susceptibility to a toxic level of Fz that induces DCM were used to assess the role of genetics in DCM. Using glutathione (GSH), glutathione peroxidase (GPx), malondialdehyde (MDA), and plasma uric acid (PUA) as biomarkers, oxidative stress (OS) levels were evaluated. Oxidative stress was also evaluated in poults fed diets containing varying concentration and combinations of vitamin E (0, 50 and 100 IU/kg) and Se (0.0, 0.3 and 0.5 mg/kg). Results from echocardiography measurements at four weeks of age, for poults fed toxic levels of Fz, showed the Narragansett x Bourbon Red reciprocal cross had the lowest internal-diastolic (LVIDd) and systolic dimensions (LVISd), while the Bourbon Red x Narragansett reciprocal cross had the largest LVIDd and LVISd. Left ventricular internal-diastolic and systolic dimension were lower for cross bred than parental poults. In treatment poults, heterosis for ventricular dilation was most significant for Bourbon Red x Narragansett cross. The data suggest that reciprocal crosses respond differently to toxin that induces DCM and genetics may influence a turkey's response to toxic levels of Fz that causes DCM. Results from OS measurements in poults fed normal and those fed normal diets with Fz at two weeks of age, showed no significant differences in MDA and GPx levels. PUA and GSH levels were however significantly increased for poults fed Fz-containing diets. At four weeks of age, no differences were observed for MDA and GPx measurements between poults fed normal and Fz-containing diets. PUA levels increased for poults fed normal diets with Fz, while GSH levels increased only for those fed normal diets. Differences between poults fed normal and Fz-containing diets were significant for GPx measurements. Results of this study showed that, feeding diets with Fz does not increase OS. Measure of the influence of feeding diets supplemented with different concentrations and combinations of Se and vitamin E to poults fed either normal or normal diets with Fz at two and four wks of age, showed higher MDA levels for poults fed Fz-containing diets supplemented with 0.3 mg/kg Se and 100 IU/kg vitamin E. For antioxidant biomarkers, GPx activity were increased for poults fed normal diets with Fz supplemented with 0.5 mg/kg Se and those fed 100 IU/kg vitamin E. Poults fed normal diets supplemented with 100 IU/kg vitamin E had the highest GPx. PUA levels were higher for poults fed normal diets with Fz supplemented with 0.5 mg/kg Se at two wks of age. At four wks of age, PUA concentrations were higher for poults fed Fz-containing diets supplemented with 100 IU/kg vitamin E. Increased PUA were also observed for poults fed diets supplemented with 0.5 mg/kg Se and 50 IU/kg vitamin E and 0.5 mg/kg and 100 IU/kg vitamin E. Poults fed diets supplemented with 50 and 100 IU/kg vitamin E had the highest GSH at two wks of age. Measurements taken at 2 wks of age, for poults fed normal diets supplemented with different concentrations and combinations of Se and vitamin E had increased GSH levels when compared with those fed diets with Fz at four wks of age. In this study, we showed that supplementation of poults fed normal diets with Fz with different concentrations and combinations of Se and vitamin E did not reduce DCM at 2 wks of age. However, at 4 wks of age, though DCM was not decreased by feeding diets supplemented with different concentrations and combinations of Se and vitamin E, reduced oxidant and antioxidant biomarkers were observed.
An Assessment of the Molecular Basis of Toxin-induced Dilated Cardiomyopathy in an Avian Animal Model
Tian, Xi (Virginia Tech, 2008-12-09)
Dilated cardiomyopathy (DCM), a disease of the myocardium, causes morbidity and premature death in humans and other domestic animals including turkeys. Though DCM results from many different factors including those that are unknown or idiopathic, genetic factor is a major cause of idiopathic DCM. In this study, I assessed the molecular basis of toxin-induced DCM in turkeys by evaluating the association and effect of mutations in candidate genes in the nucleus and mitochondria on the incidence and severity of this disease. Echocardiographic measurements at 3 weeks of age showed that birds on furazolidone-containing diet exhibited a significant DCM phenotype (increased left ventricular end diastolic dimension and left ventricular end systolic dimension) with a marked decrease in the left ventricular shortening fraction. Pathological phenotype confirmed the dilated heart with extended cell necrosis. Two mutations, both in NADH dehydrogenase genes, were found to be associated with DCM. Real-time RT-PCR quantification indicated that mRNA expression of alpha cardiac actin gene (ACTC) were significantly different between control and treatment birds. While ACTC expression increased, though moderately, in control birds from week 1 to 3, it decreased significantly in treatment birds. These findings suggest that the mitochondrial DNA variation and ACTC expression may be associated with the turkey's response to toxin. Therefore, further research is needed to investigate the molecular mechanism of toxin-induced DCM in the turkey.
An Assessment of the Relationship among Oxidative Stress, Adaptive Immunity and Genetic Variations in the Chicken, Gallus gallus
Deng, Hui (Virginia Tech, 2010-09-01)
Oxidative stress (OS) has been associated with aging and age-related diseases in humans, as well as with the decline in economic trait performance in poultry and other domesticated animals. However, the potential effects of OS on the poultry immune system are not well understood. In addition, the impact of bird genetic variation on redox balance remains to be elucidated. Thus, the central hypothesis of this dissertation is: The bird's adaptive immunocompetence is impacted by their OS level, which is not only influenced by environmental factors, but also related to genetic phenotype of either mitochondrial DNA (mtDNA) or nuclear DNA (nDNA). In the first phase of this study, White Leghorn chickens were provided ethanol at different concentrations in drinking water to induce OS. Biomarkers including malondialdehyde (MDA), glutathione (GSH), and plasma uric acid (PUA) were measured to assess OS before and after ethanol treatment. The adaptive immune response during an OS event was measured by plasma IgG and IgM levels, major lymphoid organ weights, CD4+/CD8+ cell ratio, and histopathological analysis of the immune organs. Results showed that when OS was induced by 10% ethanol, chicken adaptive immune responses decreased; however, when birds were exposed to 2% ethanol, there was an enhancement in antioxidant defense and immune response; These results would suggest a negative correlation between OS level and chicken adaptive immune response. In the second phase of the study, subsets of chickens were selected based on their high (H)- or low (L)-OS to assess for variations in their genetic phenotypes. Using MDA levels, 36 chickens were chosen to scan a 2734-bp region of mtDNA, but no definitive SNP was detected. In another experiment, 40 chickens were conversely selected according to three biomarkers for OS. Although no variation was found at eight SNP loci tested across the mitochondrial genome, mtDNA damage measured by 8-hydroxy-2′-deoxy-guanosine was shown to increase with time, and at higher levels in the high OS birds (p < 0.05). Thses results suggest that long-term high OS levels in chickens may increase the somatic mutation of their mtDNA. In the final phase of this dissertation, the effect of nDNA on OS, measured via a genome-wide association study was performed with 18 H and 18 L chickens using the latest chicken 60k SNP microarray for genotyping. Among 56,483 SNPs successfully genotyped, 13 SNPs across five independent loci were associated with OS at significance level of p ≤ 0.001, and another 144 SNPs were also associated with OS (p ≤ 0.01). These results indicate new loci and related genes for their genetic influence upon redox balance. In general, experiments carried out on White Leghorn chickens here have shown that adaptive immune response is tightly related to changes of OS. Further, genetic variance in nDNA is associated with the risk of high OS or the ability to better resist it.
Attracting and Retaining Minorities in the Biomedical Sciences Including Genomics: a Community-based Approach
Smith, Edward J. (2014-08-21)
Candidate Gene Expression and SNP Analyses of Toxin-Induced Dilated Cardiomyopathy in the Turkey(Meleagris gallopavo)
Lin, Kuan-chin (Virginia Tech, 2006-03-28)
Dilated cardiomyopathy (DCM), a heart disease, affects many vertebrates including humans and poultry. The disease can be either idiopathic (IDCM) or toxin-induced. Idiopathic DCM often occurs without a consensus cause. Though genetic and other studies of IDCM are extensive, the specific etiology of toxin-induced is still unknown. Here, our objective was to compare the level of mRNA expression of two candidate genes including troponin T (cTnT) and phospholamban (PLN) using quantitative reverse transcription polymerase chain reaction (RT-PCR) in toxin-induced DCM affected and unaffected turkeys. Cardiac TnT and PLN were chosen because their spontaneous expression has been reported to be associated with IDCM. We also scanned these genes for single nucleotide polymorphisms (SNPs) that could be useful in evaluating their functions in the incidence and severity of toxin-induced DCM in turkeys. There were no significant differences between affected and unaffected birds in the expression of both cTnT and PLN. A total of 12 SNPs were detected in cTnT and PLN DNA sequences. One of the seven haplotypes detected in cTnT was the most frequent. Linkage analysis showed that cTnT gene was unlinked on the current turkey genetic map. Resources developed here, including SNPs, haplotypes, cDNA sequences, and the PCR-RFLP genotype procedure will be used for future investigations involving cTnT and PLN and toxin-induced DCM.
Characterization of Expressed Sequence Tags From a Gallus gallus Pineal Gland cDNA Library
Hartman, Stefanie; Touchton, Greg; Wynn, Jessica; Geng, Tuoyu; Chong, Nelson W.; Smith, Edward J. (Hindawi, 2005-01-01)
The pineal gland is the circadian oscillator in the chicken, regulating diversefunctions ranging from egg laying to feeding. Here, we describe the isolation andcharacterization of expressed sequence tags (ESTs) isolated from a chicken pinealgland cDNA library. A total of 192 unique sequences were analysed and submittedto GenBank; 6% of the ESTs matched neither GenBank cDNA sequences nor thenewly assembled chicken genomic DNA sequence, three ESTs aligned with sequencesdesignated to be on the Z_random, while one matched a W chromosome sequence andcould be useful in cataloguing functionally important genes on this sex chromosome.Additionally, single nucleotide polymorphisms (SNPs) were identified and validatedin 10 ESTs that showed 98% or higher sequence similarity to known chicken genes.Here, we have described resources that may be useful in comparative and functionalgenomic analysis of genes expressed in an important organ, the pineal gland, in amodel and agriculturally important organism.
Development and characterization of DNA markers for two avian species
Kamara, Davida F. (Virginia Tech, 2006-05-22)
Central to the application of genomics to animal agriculture are DNA markers, especially microsatellites and single nucleotide polymorphisms. These markers are the resources necessary for constructing genetic maps and for determining how improved and unimproved animal breeds are related. Here, DNA markers were developed for two avian species, the turkey, Meleagris gallopavo, and the budgerigar (budgie), Melopsittacus undulatus. Genomic libraries enriched for simple sequence repeats were used to generate about 70 budgie sequences of a total length of 38 kb. From these sequences, 9 primer pairs were designed and used to screen for informativeness in a panel of DNA samples from unrelated budgie samples. All but one of the nine primers evaluated were polymorphic with the number of alleles ranging from two to four. Comparative analysis involving the use of these budgie primers showed moderate sequence similarity to turkey and chicken. The genomic libraries and the comparative sequences provide useful genomic reagents that could be used to construct a budgie genome map. In the turkey, ten previously described microsatellites and a gene-based single nucleotide polymorphism (SNP) were used to evaluate the relatedness of heritage varieties to a commercial strain. Estimates of Nei's genetic distance (D) and genetic differentiation (Rst) between populations using microsatellite markers showed that the commercial strain is genetically more closely related to the Bourbon Red and Narragansett and least related to the Royal palm and Spanish Black. Gene flow (Nm) level was highest between the commercial and Bourbon Red populations. The SNP analysis by PCR-RFLP revealed that the commercial strain was more closely related to the Spanish black and Narragansett and least related to the Bourbon red and Blue slate. Though results of the two marker systems, microsatellite and SNP, were inconsistent, they provide insights into using heritage turkeys to genetically improve commercial populations by introgression. The present thesis investigation showed that DNA markers provide a strong opportunity to develop genomic reagents needed to test hypotheses in little-studied agriculturally important and model avian species.
The diode array velocimeter
Smith, Edward J. (Virginia Tech, 1992)
A novel, point measurement, proof-of-concept laser velocimeter has been developed and tested. The diode array velocimeter (DAV) uses a single laser beam for its probe. The DAV measures velocity within a seeded, transparent medium by timing the passage of a seed particle’s image across an array of PIN photodiodes. This prototype device can measure one component of mean velocity as well as one component of time-averaged turbulence intensity. The concept for the DAV is rather simple. It also has an advantage over existing laser velocimeters in that it is relatively inexpensive. Measurements made with the prototype DAV are compared to those made by a single hot-wire anemometer in a turbulent wall bounded flow with a freestream velocity of 10 m/s. The prototype DAV was found to be accurate to within 10% of U_e in mean velocity, and within 1.5% of U_e in turbulence intensity. The prototype DAV can measure mean velocities as great as 60 m/s. It has the potential for making measurements in highly turbulent reversing flows.
DNA Sequence and Haplotype Variation Analyses of Circadian Clock Genes and Their Effects on Phenotypes in the Turkey, Meleagris gallopavo
Adikari Mudiyanselage, Jayantha Bandara Adikari (Virginia Tech, 2012-12-04)
Present study was planned to compare the phenotypic variation of performances traits among commercial (CC) and heritage varieties of turkeys. Information about heritage turkey varieties continues to be limited. In addition, the emerging turkey genome sequence provides a unique opportunity to understand the DNA sequence variation and its associations with performance traits. The turClock, turPer3, turCry1 and turCry2 genes were screened and evaluated for its association with their performance traits. As expected, CC turkeys were superior to heritage birds in performance for most of the traits evaluated. However, heritage turkeys showed better reproductive performances compared to CC turkeys. A total of 41 SNPs were identified from the genes that screened. The haplogroups in the turClock gene were significantly associated with body weight (BW) at 309 d of age, feed conversion ratio (FCR) for 34 - 68 d and 69 - 159 d, egg production and average egg weight (P " 0.05). The haplogroups developed from turPeriod-3 gene were significantly associated with BW at 231 d of age, average daily gain (ADG) for 160 - 231 d, FCR for 69 - 159 d and 160 - 231 d, egg production traits, semen quality traits and plasma melatonin concentration (P " 0.05). In the turCry1 gene, haplogroups were significantly associated with ADG for 35 - 68 d, FCR for 160 - 231 d and 34 - 231 d, egg production and ejaculate volume (P " 0.05). The haplogroups identified from turCry2 gene were significantly associated with BW at 34, 68 and 231 d of age, ADG for 160 - 231 d, FCR for 34 - 68 d, average egg weight (P " 0.05). These findings reveal that phenotypic variation observed in growth and reproductive parameters among turkeys could be used for selecting birds for future breeding programs. DNA sequence variations at the nucleotide and haplotype levels are associated with some of growth, reproductive parameters and plasma melatonin of turkeys. Thus DNA sequence variations that identified of the circadian genes may have some regulatory role in the molecular mechanism of the circadian clock which may affect the circadian rhythm of the animal.
DNA Sequence and Haplotype Variation Analysis of Inflammatory Response Genes NLRX1, IL6, and IL8 in the Turkey (Meleagris gallopavo)
Russell, Kadijah Lashunte (Virginia Tech, 2019-02-08)
Genotype-phenotype analyses continue to be the primary goal for genome analyses in livestock and poultry breeding. Essential to accomplish this goal is the need to identify variation at the genomic level. To test the hypothesis that DNA sequence variations in inflammatory response genes are associated with phenotypic differences in the heritage turkey, the primary objective of this project was to search for single nucleotide polymorphisms (SNPs) in candidate inflammatory response genes. A minor objective was to develop a system for inducing inflammatory response in the turkey using a microbe-based lipopolysaccharide (LPS), an approach previously described for the chicken. A total of 18 SNPs was identified in the three genes screened in this project: Interleukin 6 (IL6) and 8 (IL8), and NLRX1. Mortality data from the LPS challenge were not significantly different among the strains. Further gene expression analyses will be part of future work. The SNP data represent the first extensive analyses of candidate inflammatory response genes in the turkey. Combined with the protocols developed for inflammation assessment in the turkey the SNPs described here will be valuable resources for future inflammation:genotype evaluation in the turkey
Effects of Growth Hormone and Insulin-Like Growth Factor-I on Milk Protein Gene Expression and Nutrient Uptake and Cell Proliferation in Clonal Bovine Mammary Epithelial Cells
Zhou, Yinli (Virginia Tech, 2007-08-23)
The overall objective of this research was to further understand the mechanism by which growth hormone (GH) stimulates milk production in cattle. Three studies were conducted toward this objective. In the first study, the effects of GH and insulin-like growth factor-I (IGF-I), a major mediator of GH action in vivo, on cell proliferation, nutrient transport, and milk protein gene expression in bovine mammary epithelial cell line MAC-T cells were determined. GH increased (P < 0.01) expression of four major milk protein genes in MAC-T cells transfected with GHR expression plasmid. Cotransfection analyses indicated that GH also stimulated (P < 0.01) luciferase reporter gene expression from the promoters of the four milk protein genes in MAC-T cells. These findings together with the fact that GHR mRNA and protein are expressed in the epithelial cells of the bovine mammary gland suggest that GH may directly stimulate milk protein gene expression in the mammary gland. This study also showed that IGF-I increased the proliferation (P < 0.01) and amino acid transport (P < 0.05) in MAC-T cells. Because GH is known to stimulate IGF-I production in animals, IGF-I-mediated mammary epithelial cell proliferation and amino acid uptake may be additional mechanisms by which GH increases milk production in cattle. In the second study, the role of connective tissue growth factor (CTGF) on IGF-I-stimulated proliferation of MAC-T cells was investigated. A microarray analysis revealed that IGF-I decreased CTGF mRNA expression in MAC-T cells (P < 0.01). This effect of IGF-I was further found to be mediated through the PI-3 kinase/Akt signaling pathway from the IGF-I receptor (IGF-IR). CTGF alone stimulated MAC-T cell proliferation (P < 0.01). However, together with IGF-I, CTGF attenuated the proliferating effect of IGF-I on MAC-T cells, and this attenuation was reversed by additional IGF-I. Therefore, IGF-I inhibition of CTGF expression may benefit IGF-I stimulation of MAC-T cell proliferation. CTGF had no effect on IGF-I-induced phosphorylation of IGF-IR or total IGF-IR expression in MAC-T cells, suggesting that CTGF may attenuate IGF-I stimulation of MAC-T cell proliferation through a postreceptor inhibition of the IGF-IR signaling pathway. In the third study, whether a milk yield-associated T/A polymorphism in exon 8 of the bovine GHR gene affected GHR signaling was determined. It was found that the two corresponding GHR variants did not differ in mediating GH induction of gene expression, suggesting that the two GHR variants are not functionally different and hence are unlikely to mediate different effects of GH on milk production. In summary, the results of this dissertation research suggest that GH may directly stimulate milk protein gene expression and indirectly stimulate mammary epithelial cell proliferation and amino acid uptake through IGF-I, thereby stimulating milk production in cattle. The results also suggest that IGF-I stimulation of mammary epithelia cell proliferation may involve an inhibition of CTGF expression in the cells.
Effects of Source and Level of Trace Minerals on Performance, Mineral Excretion, Intestine and Bone Development, and Immune Response in Commercial Turkeys
Li, Lihong (Virginia Tech, 2009-01-23)
To compare the effect of a standard commercial trace mineral dietary program to low levels of organic minerals on turkey performance, mineral excretion, bone strength, and carcass yield, day-old Hybrid poults (n=1,224) were randomly distributed to one of four treatments with 9 replicates. Experimental treatments consisted of: standard inorganic (SI) with a commercial supplementation program (Mn, Zn, Cu, Se), reduced inorganic (RI) with 10% level of SI, and two organic regimens of Bioplex®/Sel-Plex® (at the same level of RI during period 1 and 2 and at 2/3 of RI for period 3, 4, 5, and 6, or at the same level of RI for entire trial). Body weight (BW), body weight gain (BWG), feed conversion ratio (FCR), and feed intake (FI) were evaluated and fresh excreta were collected at d 28, 49, 70, 84, 105 and 133. Tibias and femurs were collected at d 49, 84 and 133. Trace mineral concentration in litter and carcass yield were determined at d 133. Overall, there was no significant effect on BW, cumulative BWG, FCR, or FI due to treatments (P < 0.05). The contents of Mn and Zn in excreta and litter were significantly reduced (P < 0.05) in Bioplex®/Sel-Plex® or RI diet compared to SI during the study. Cu excretion was significantly reduced at d 84 and 133. Tibias from the SI treatment had increased bone strength at d 49. Carcass yield at processing was significantly improved (P < 0.05) by feeding Bioplex®/Sel-Plex® treatments compared to the SI diet. To investigate the effect of organic or inorganic Zn combined with other trace minerals on turkey performance, immune response, and intestinal development, a 2 by 4 factorial design was utilized with coccidia vaccinated and non-vaccinated and 4 dietary treatments varying in level and source of Zn with Mn, Cu, and Se. A total of 2,376 day-old Hybrid turkeys were assigned to one of the combinations with 9 replicates of each. Dietary treatments consisted of: 1) standard inorganic (SI), Zn (150 ppm) with Mn (165 ppm), Cu (10 ppm), and Se (0.2 ppm); 2) reduced inorganic (RI), Zn, Mn, and Cu at 10% of SI, and Se at 0.2ppm; 3) organic 1 (O1), at the same level of RI; 4) organic 2 (O2), Zn (30 ppm) with the same level of Mn, Cu, and Se as O1. Body weight, BWG, FI and FCR were determined weekly. Bursa, thymus, and spleen were weighed, and duodenum and jejunum were collected at d 7, 14, 28, and 42. Peripheral blood was collected for T-lymphocyte populations on d 21, 28, and 42. Cumulative FI was influenced by vaccination (P=0.003). Cumulative BWG and BW were significantly decreased by vaccination except on d 14. Cumulative BWG increased in poults fed RI compared with those fed O2 (P=0.03). Poults fed O2 had significantly decreased BW when compared with RI after d 28. Cumulative FCR was not affected by diet and vaccination. Vaccination increased spleen weight on d 7 and thymus weight on d 42 (P < 0.05). The birds fed O2 had increased thymus weight when compared with those fed SI at d 7 (P < 0.05). The vaccinated poults had higher numbers of CD4+ T-cells than non-vaccinated birds on d 28 and d 42 (P < 0.05), and an interaction between diet and vaccination was observed (P < 0.05). Compared to non-vaccinated poults, CD4+/CD8+ ratio was significantly increased in vaccinated poults on d 42 (P = 0.0475). The villus height in vaccinated birds was significantly increased in the jejunum (P = 0.0012), but diets did not affect intestinal morphology. In summary, using low levels of organic or inorganic trace minerals is adequate to maintain turkey performance and immune response and decreased trace minerals excretion.
Family growth response to fishmeal and plant-based diets shows genotype x diet interaction in rainbow trout (Oncorhynchus mykiss)
Pierce, Lindsey Renea (Virginia Tech, 2008-07-02)
The ability of rainbow trout to efficiently utilize plant-based diets for growth and the genetic variation for that trait have not been thoroughly examined. In this study, growth of a pedigreed population from the commercial Kamloop strain was assessed while feeding plant-based or traditional fishmeal-based diets. Both fish oil (5.00%) and soybean oil (8.43%) were included in the plant-based diet, and only fish oil was used in the fishmeal diet (10.10%). Ninety-five full-sib families nested within 47 half-sib families were reared in a common environment. Parentage assignment was performed on approximately 1,000 fish fed each diet using eight microsatellite markers chosen for non-duplication, a minimum of five alleles with no known null alleles, at least 50% heterozygosity, and unambiguous scoring. Progeny were assigned to parental pairs using two allocation programs, PAPA and FAP, to increase accuracy and to test assignment efficiency. The fish fed the fishmeal/oil diet were approximately 8% larger than the fish fed the plant-based diet (P < 0.05). A significant genotype x diet effect accounted for 5% of the random variation. The genetic correlation for growth on the two diets was 73%, with a heritability of 30% across the diets. With this, I conclude that substantial genetic variation for utilizing pant-based diets containing soybean meal and oil exists in this widely used commercial rainbow trout strain. The genetic variation can be explored to detect and select for genes involved in proved utilization of plant-based diets containing soybean meal and oil if growth on plant-based meals becomes a long-term breeding goal in rainbow trout production.
Future Farmers of Virginia Chapter Chats January 1928
W. S. N.; Bladding, Russell; Badger, William B.; Cassell, Stuart K.; Roach, Everett; Farmer, A. B.; Frazier, John; Locke, Turner; Mason, Jr., H. T.; Owen, Gordan; Bridgman, John; Munday, Howard; Haines, Harry; Smith, Aubrey; Smith, Edward J.; Cross, Willard; Russell, Dorsey; Marmaduke, Stanley; Coburn, Robert; Bethel, Ben; Grubb, Sumpter; Chaffin, Joe; Elam, Arthur; Breeden, Ray; Manning, William; Whitfield, Thomas; Poff, Bremen; Crigger, William; Peoples, Frank; Bridgman, Remmie; Hamilton, Hugh; Grecar, W. Sutherland,; Brown, J. H. (The Future Farmers of Virginia, 1928-01)
Future Farmers of Virginia Chapter Chats March 1928
Newman, Walter S.; Berger, D. J.; Parrish, Wesley; Shirey, Robert; Keister, Joe; Locke, Turner; Miller, J. W.; Eason, Elmo; Harris, Jr., George; Buchanan, Chalkley; Trull, Harley; Smith, Robert E.; Head, Jas. E.; Poole, B. C.; Jackson, Graham; Smith, Edward J.; Lawson, Rodney; Buchanan, Robert; Barnes, Sam; Breeden, Ray; Wake, Orville; Stickley, Robert; Meek, Jack; Golay, Henry; Cline, D. A.; Peoples, Frank (The Future Farmers of Virginia, 1928-03)
Future Farmers of Virginia Chapter Chats November 1927
W. S. N.; Wolfe, T. K.; Clements, D. M.; Beard, Joseph E.; Keister, Joe; E. C. M.; Price, Albert; Smith, Kenneth; Wall, William; Hutton, Andrew; Johnson, Duval; Roach, Everett; Wampler, Ernest; Thornton, Perry; Reid, Joe; Stafford, Horace; Harris, Jr., George A.; Semple, Richard; Buchanan, Chalkley; Walker, Jr., W. Benjamin; Yeatts, Howard; Hubbard, John; Morris, L. W.; Poole, Bert; Monday, Howard; Waterfield, Charlie; Smith, Edward J.; Russell, Dorsey; Russell, Edgar; Whitlow, Billie; Coburn, Robert; Myers, Ross; Bethel, Benjamin; Grubb, Sumpter; Chaffin, Joe; Barham, Montgomery; Hockman, Cecil; Meek, Jack; Stephenson, Ernest; Williams, Ryan; Rhinehart, Stanley; Henry, Mertie (The Future Farmers of Virginia, 1927-11)
Genetic Analysis of Toxin-Induced Dilated Cardiomyopathy in the Turkey (Meleagris gallopavo)
Gyenai, Kwaku Barima (Virginia Tech, 2005-07-22)
Dilated cardiomyopathy (DCM) or round heart disease is a muscle disease of the heart which is characterized by ventricular dilatation and abnormal systolic and diastolic left ventricular function. In animals, including turkeys and humans, DCM is the major cause of morbidity and mortality which results from heart failure. In the turkey, DCM can be idiopathic or induced. Since idiopathic or spontaneous DCM occurs in about 1-4% of normal turkeys, it is of significant concern to the poultry industry. In this study, it was proposed that the incidence and severity of DCM in the turkey may have a genetic basis. To test this hypothesis, I investigated differences in the incidence and severity of DCM in five domesticated turkey varieties including Blue Slate (BS), Bourbon Red (BR), Narragansett (N), Royal Palm (RP) and Spanish Black (SB). Preliminary investigations tested the reliability of echocardiography (ECHO) as a non-invasive and non-destructive technique for diagnosing DCM in a large number of birds from hatch to four weeks-of-age. One-day-old poults for both the preliminary and hypothesis testing investigations were obtained from Privett Hatcheries (Portales, New Mexico). The birds were raised under standard management conditions. In the preliminary investigation and to test my hypothesis, DCM was induced by feeding birds ad libitum standard diets containing 700 parts per million furazolidone. Results of the preliminary investigations showed that left ventricular end-diastolic dimension (LVEDD) and left ventricular end-systolic dimension (LVESD) were the most consistent ECHO indicators of DCM from hatch to 4 weeks-of-age. Variety differences in response to furazolidone were evaluated using these parameters as well as percent mortality. At 9 days-of-age, differences between control and treatment birds for percent mortality and LVESD were significant in the RP variety only but significant for LVEDD in RP and SB. At 29 and 33 days-of-age, all the pair-wise comparisons between control and treatment birds were significant for both LVEDD and LVESD. On average, the BR variety had the smallest dilatation of the heart and lowest mortality at 33 days-of-age when compared to other varieties. The results described in this thesis show, for the first time, variety differences in the turkey's response to diets containing furazolidone. They provide strong evidence that, like previous reports for idiopathic DCM, an animal's response to Fz-induced DCM has a strong genetic component.
Genetic Characterization of Zambian Native Cattle Breeds
Zulu, Dackson Nkonje (Virginia Tech, 2008-09-09)
Breed characterization is a primary step in designing appropriate management and conservation programs of livestock in developing countries. Since cattle represent a major food animal species in Zambia, its conservation is a major goal for both the government and non-governmental organizations. To support the conservation effort, the objective of this thesis research was to assess the phenotypic and molecular characteristics of indigenous Zambian cattle breeds including Angoni, Barotse, Tonga, and Baila based on body measurements and randomly amplified polymorphic DNA (RAPD) markers, respectively. A total of 100 animals, 25 from each of the four breeds associated with different tribes and region of Zambia, were used in the molecular analysis research. Additionally, 10 Holstein x Jersey crossbred animals were used as a reference and to test the extent of cross-breeding, if any, of the indigenous stock with exotic breeds. To further compare the Zambian indigenous breeds, morphometric measurements including body length, heart girth, and height at withers on 50 animals of each breed were measured. Blood was collected from animals at randomly selected farms and DNA isolated by standard protocols in Zambia. A total of 10 primers, of the 20 evaluated for informativeness, were used in the RAPD-PCR analyses. Differences among the four breeds for all the three morphometric measurements were significant with the Barotse significantly higher than the other three (P<0.05). The average number of bands per primer was 7.1 and the percentage of polymorphic bands per primer ranged from 40 to 71.4 with an average of 64.8%. Breed divergence was highest between the Tonga and the Barotse and lowest between the Tonga and Baila breeds. Both the morphometric measurements and RAPD-based distance estimates suggest that the Barotse may be different from the other indigenous breeds while the Tonga and Baila were more closely related. In addition, the genetic distance estimates imply that the Holstein x Jersey crosses are different from the four Zambian indigenous cattle breeds evaluated. This thesis research provides, for the first time, the basic genetic information necessary for conservation of Zambian cattle breeds and the use of these populations for effective crossbreeding. The data suggest that though there is isolated by geographic distance and cultural differences among the tribes, two of the breeds are significantly related.

Browsing by Author "Smith, Edward J."

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