Browsing by Author "Novak, Curtis L."

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    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.
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    Beginning of Life
    Novak, Curtis L.; Troche, Catalina (Virginia Cooperative Extension, 2007)
    This is a reference for leaders and teachers of the 4-H school project, 'Beginning of Life," which is designed to help youth obtain a better understanding of life and embryonic development.
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    Beginning of Life Record Book
    Novak, Curtis L. (Virginia Cooperative Extension, 2019-04-15)
    This document is a student record book for the 4-H project, "Beginning of Life."
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    Beginning of Life Record Book
    Novak, Curtis L. (Virginia Cooperative Extension, 2007)
    This is the student record book for the 4-H project, "Beginning of Life."
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    A Brighter Idea: Eggs
    Novak, Curtis L. (Virginia Cooperative Extension, 2019-04-15)
    Provides information to help with a better understanding of eggs and their uses.
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    A Brighter Idea: Eggs!
    Novak, Curtis L. (Virginia Cooperative Extension, 2009-09-22)
    This booklet is designed to provide a better understanding and use of the Incredible Edible Egg.
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    Broiler Performance and Intestinal Alterations When Fed Drug-Free Diets
    Sun, Xiaolun (Virginia Tech, 2004-08-10)
    A study was carried out to investigate the effects of a drug-free feeding program on broiler performances. A total of 2,496 Cobb 500 chicks were randomly assigned to one of four dietary treatments with each group replicated 13 times. The four diets evaluated were: 1) negative control (NC): basal diet without growth promoter or coccidiostat; 2) positive control (PC): diet 1 + Lincomycin; 3) Program 1 (PG1): diet 1 + Bio-Mos®, Vegpro®, MTB-100®, Acid Pak 4-Way®, and All-Lac XCL®; 4) Program 2 (PG2): diet 1 + Bio-Mos® and All-Lac XCL®. Additives were used at commercially recommended rates. All chicks were vaccinated with a live oocyst coccidia vaccine on d 0 at the hatchery. Four phases of feeding were used during the trial with changes occurring at d 14, 28, and 35. Performance values measured were body weight, feed intake, yield, and mortality, while body weight gain and feed conversation rate (FCR) were calculated. Chicks were challenged with coccidia at d 14 to evaluate the protective effect of the feeding programs and coccidia vaccination. Segments of duodenum, ileum, and ceca were removed to measure intestinal morphology. Final body weight gains of birds on PC (2.736 kg) were greater (P < 0.05) compared to NC (2.650 kg), while birds on PG1 (2.681 kg) and PG2 (2.710 kg) were similar to positive and negative control. Overall, feed intake was similar across the treatments with the exception of period 2 (15 to 28 days) when birds consumed more (P < 0.05) of PC and PG1 compared to NC. Cumulative FCR at d 35 and 49 was improved (P < 0.05) in birds consuming PC and PG2 when compared to NC. Overall, birds consuming NC had greater mortality (P < 0.05; 12%) compared to PC (7.6 %), PG1 (4.6%) and PG2 (6.7 %) with most of the mortality occurring from d 0 to d 28. Mortality for birds consuming PG1 was also lower (P < 0.05) compared to the PC. There were no dietary effects on lesion scores or yields of processed products at d 42 (females) or d 49 (males). Interaction of dietary treatments with age and days of age alone showed effects (P < 0.0001) on the morphology of duodenum, ileum, and ceca. Lamina propria in ceca was thicker (P < 0.008) in birds consuming NC compared to PG1 and PG2. This study indicated that feeding birds without growth promoters resulted in greater mortality and decreased performance compared to using an antibiotic, while Bio-Mos® in combination with All-Lac XCL® helped to reduce the negative effects.
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    Chick-N-Que
    Novak, Curtis L.; Troche, Catalina (Virginia Cooperative Extension, 2009)
    This publication presents various methods for barbequing whole and halved chickens. Discusses equipment, proper preparation, and cooking procedures, and includes sauce recipes.
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    Chicken Barbeque Contest
    Jamison, Kathleen; Novak, Curtis L.; Osborne, Lena (Virginia Cooperative Extension, 2012)
    Presents guidelines for the 4-H chicken barbeque contest
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    Comparison of Prophylactic or Therapeutic Dietary Administration of Capsaicin Oleoresin for Resistance to Salmonella in Broiler Chickens
    Orndorff, Brandy Michelle-Woolsey (Virginia Tech, 2004-06-24)
    Expt. 1 evaluated effects of 0 or 10 ppm CAP in the starter phase (d 1-16) on chicks challenged with SE on d of age. Therapeutic inclusion of 10ppm CAP increased (P < 0.05) L/S and ceca positives. In Expt. 2, capsaicin oleoresin (CO) was included in finisher diets (d 30-37) at 0, 5, or 20 ppm with SE challenge on day 31. Inclusion of 5 ppm CO increased (P < 0.05) ceca SE positives and demonstrated 1.05 and 1.39-log fewer SE cfu at CO concentration of 5 or 20 ppm, respectively. A linear decrease (P < 0.05) in lamina propria thickness of SE challenged birds was observed with increased CO. Expt. 3 evaluated prophylactic CO treatment at 0, 5, or 20 ppm in starter, grower, and finisher diets for resistance to SE or ST challenge on d 14 or 29. With challenge on d 14, 5 ppm CO reduced ceca (P<0.005) SE positives and 1.1-log fewer SE cfu. Likewise, 20 ppm CO reduced (P < 0.05) SE ceca positives. Salmonella typhimurium isolation rate was reduced (P<0.05) with 5 ppm CO, and ST cfu were reduced 1.4-log with 5 ppm CO compared to 20 ppm. Lamina propria thickness increased (P < 0.05) linearly as CO concentration increased. With d 29 challenge birds fed 5 ppm CO exhibited 1.08-log fewer SE cfu, and 20 ppm CO reduced L/S positives (P < 0.025) for SE and resulted in 1.39-log fewer SE cfu. Lamina propria thickness decreased with 5 ppm CO and SE or ST challenge compared to non-challenged birds fed 5 ppm (P < 0.0005). An increase was observed in ST or SE, birds fed 20 ppm CO compared to non-challenged, birds fed 20 ppm CO (P < 0.01). No differences were observed in mast cell number in either Expt. 2 or 3. These data provide evidence that prophylactic or therapeutic dietary CAP differentially affect broiler susceptibility to Salmonella and prophylactic administration may provide non-antibiotic means to reduce Salmonella in broilers.
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    Effect of Corn Quality and Enzyme Supplementation on Broiler Performance, Gastrointestinal Enzyme Activity, Nutrient Retention, Intestinal Mucin, and Jejunal Gene Expression
    Sun, Xiaolun (Virginia Tech, 2007-11-19)
    Three 2à 2 factorial experiments (EXP) were conducted to investigate the underlying mechanism of corn quality and a supplemented cocktail enzyme of amylase, protease, and xylanase on broiler performance from 0 to 49 days of age. In each of the first two EXP, the four diets used consisted of (1) diet AR-/BR-; reduced dietary energy by increasing corn A matrix metabolizable energy (ME) 138 kcal/kg in EXP 1 or 125 kcal/kg ME with corn B in EXP 2; (2) diet AR+/BR+; AR-/BR- plus Avizyme 1502® (AZ); (3) diet AN-/BN-; normal energy diet; (4) diet AN+/BN+; AN-/BN- plus AZ. In EXP 3, four dietary treatments came from EXP 1 and 2 consisted of: AN-, AN+, BN-, and BN+. For each EXP, 1,440 male Ross 708 chicks were randomly assigned to one of the four dietary treatments (trts) with 9 replicates (reps)/trt and 40 chicks/ rep on day (d) 0. Body weight gain (BWG) and feed intake (FI) were determined on feed change days (d 14, 28, and 37) and on d 7 and 49. On d 28, subsets of birds were transferred to Petersime batteries to evaluate feed passage rate and nutrient retention. Digesta samples from gizzard, jejunum, and ileum as well as pancreatic tissue samples were collected for analyses of amylase, protease, and xylanase activities. Intestinal tissue samples were collected for determination of maltase, sucrase, and aminopeptidase N activities. Jejunal tissue on d 28 was also collected for total RNA isolation and a subsequent genome-wide microarray assay. On d 50, 54 birds per trt were processed to evaluate carcass yield. Interactions of ME and AZ were observed in both EXP 1 and 2. In EXP 1, interactions of ME and AZ on BWG were observed with higher values in birds fed AN- while lower in birds fed AN+, while opposite observations in EXP 2 with corn B diets. In both EXP 1 and 2, feed conversion ratio (FCR) in birds fed normal energy diets was better (P <0.05) as compared to birds fed reduced energy diets after d 28. Percent fatpad was increased (P <0.05) with dietary energy levels in EXP 1. Percent pectoral minor was increased (P <0.05) in birds fed AZ diets (4.80 vs. 4.62%). In EXP 3, interaction of dietary corn and AZ (P < 0.05) on BWG was noted during d 14 and 37. Birds fed corn B diets had better (P < 0.05) BWG and feed efficiency as compared to birds fed corn A diets until d 14. Nitrogen retention on d 30 was greater (P < 0.05) in birds fed AN- and BN+ as compared to birds fed AN+ and BN-. A 2.8% more apparent metabolizable energy with nitrogen correction (AMEn) in corn A diets was observed as compared to corn B diets. Corn A had higher amylase and xylanase activities as compared to corn B. Xylanase activity in jejunal and ileal digesta of birds fed corn A diets were higher (P < 0.05) as compared to that of corn B birds on d 7 and 49. Sucrase-isomaltase contributed 63, 80, and 74 % of the total maltase activity in duodenum, jejunum, and ileum. Sucrase activities in duodenum and jejunum were correlated (P < 0.05) with performance, whereas duodenal aminopeptidase N was negatively correlated (P < 0.05) with performance except period BWG. Pancreatic amylase and protease as well as gizzard protease and xylanase activities were correlated (P < 0.05) with performance. Number of jejunal genes regulated (P < 0.05) by corn variety was 77 as compared to those by enzyme supplementation in corn A diets (30 genes) and corn B diets (23 genes). Immune response and metabolism related genes were the most regulated genes in birds fed different corn diets without enzyme addition. In conclusion, enzyme supplementation improved broiler performance. Dietary formulation strategy using either reduced energy or normal energy in associated with enzyme supplementation should base on the feed ingredient quality. Corn quality may come from active components such as protease inhibitor and xylanase, and improved performance in birds fed high quality corn diets might also relate with minimal immune response and metabolic demand.
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    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.
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    The Egg-citing Egg
    Novak, Curtis L. (Virginia Cooperative Extension, 2007)
    A record book for 4-H egg projects.
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    The Egg-citing Egg
    Novak, Curtis L. (Virginia Cooperative Extension, 2019-04-15)
    A record book for 4-H egg projects
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    The Egg-citing Egg - Teacher/Leader Guide
    Novak, Curtis L.; Roche, Catalina; Jamison, Kathleen (Virginia Cooperative Extension, 2019-04-12)
    Leader's guide for the Egg-citing Egg 4-H project.
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    The Egg-citing Egg - Teacher/Leader Guide
    Novak, Curtis L.; Roche, Catalina; Jamison, Kathleen (Virginia Cooperative Extension, 2007)
    Leader's guide for The Egg-citing Egg 4-H project
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    A Forty-Nine Day Evaluation of Bio-Mos® Replacement of Roxarsone in a Commerically Based Broiler Feeding Program
    Herfel, Tina Marie (Virginia Tech, 2007-07-23)
    A study was conducted to investigate the effects of roxarsone and Bio-Mos® on broiler production, gut morphology and bone strength. Three thousand and ten broilers were randomly assigned to 1 of 5 dietary corn-soybean meal based treatments: 1) negative control (NEG), basal diet; 2) positive control (POS; NEG + 27 ppm Bacitracin MD); 3) roxarsone (ROX; POS + 50 ppm of roxarsone); 4) Bio-Mos® (BIO; POS + 0.15 and 0.5% Bio-Mos® added during the starter and grower periods, respectively); 5) Bio-Mos®+All-Lac XCL (BIO+LAC; POS + 0.2, 0.1, and 0.05% Bio-Mos® during the starter, grower and finishing periods, respectively and 0.25g All-Lac XCL/bird sprayed at hatchery). On day 14, 7 of the 14 replicate pens/treatment were challenged with Eimeria maxima (3 x 104 oocysts/bird). Tibias were collected on day 28 and 49 to determine bone-breaking strength. Non-challenged birds had higher body weight gains (BWG) and lower feed conversion (FCR) from day 0 to 49 than challenged birds (P < 0.05). Jejunal crypt depth was increased in challenged broilers compared to non-challenged broilers at 28 days-of-age (P < 0.05). From day 0 to 35, ROX birds had lower BWG and FI than BIO and BIO+LAC birds (P < 0.05), while FCR was similar. Supplementing roxarsone resulted in reduced feed intake and BWG, but no significant differences were noted in FCR compared to feeding Bio-Mos®. ROX fed broilers had decreased ileal crypt depth compared to all other dietary treatments (P < 0.05). Muscle As concentration was lower than FDA allowable limits in broilers fed ROX without a withdrawal period at 28 days-of-age. Including roxarsone or Bio-Mos® did not generally improve production compared to broilers fed the negative diet.
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    Pharmacological Screening of Some Medicinal Plants as Antimicrobial and Feed Additives
    Thakare, Mohan N. (Virginia Tech, 1999-02-10)
    The following study was conducted to investigate the antibacterial and feed additive potential of medicinal plants. Ethanol extracts of different medicinal plants including Curcuma longa (Turmeric), Zingiber officinale (Ginger), Piper nigrum (Black Pepper), Cinnamomum cassia (Cinnamon), Thymus vulgaris (Thyme), Laurus nobilis (Bay leaf), and Syzgium aromaticum (Clove) were tested using the disc diffusion method for their antimicrobial activity against the common poultry pathogens E. coli, S. typhimurium, E. faecium, and E. faecalis. Cinnamon extract (CE), at 130 mg/disk, exhibited antibacterial activity against E. coli, S. typhimurium, and E. faecalis. Thyme extract (TE), at 30 mg/disk, exhibited antibacterial activity against E. coli, E. faecium, and E. faecalis while the remaining medicinal plants extracts showed no activity. The minimum inhibitory concentration (MIC) of the cinnamon and thyme ranged from 31.25 to 250 mg/ml by the dilution method. From this in vitro antibacterial study, cinnamon and thyme were selected for a 21-d feeding trial in broilers to study their influence on feed consumption, body weight gain, and feed conversion. There were 6 dietary treatments groups: 1) negative control (NC) containing no plant extracts or antibiotic, 2) positive control (PC) containing BMD (bacitracin) at 50g/ton of feed, 3) Diet 1 plus low level of cinnamon extract (LCE) at 290 gm/100 kg of feed, 4) Diet 1 plus high level of cinnamon extract (HCE) at 580 gm/ 100 kg of feed, 5) Diet 1 plus low level of thyme extract (LTE) at 290 gm/100kg of feed, and 6) Diet 6 plus high level of thyme extract (HTE) at 580 gm/100 kg of feed. No significant changes in body weight gain were observed with the cinnamon extracts compared to the NC or PC at 7, 14, or 21 d. The HTE reduced body weight gain compare to the NC and PC at 7, 14, and 21 d (P < 0.02). No difference in feed efficiency was observed with any of the treatments except LCE which reduced feed efficiency compared to other treatments. No difference in feed consumption was found among any of the treatments. These results suggest that cinnamon and thyme have antibacterial activity in vitro, and thyme has an activity that reduces body weight. Since cinnamon caused no significant change in body weight gain compared to positive or negative controls, it warrants further study as a substitute for antibiotics in the diet.
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    Poultry yearly plan and record book
    Novak, Curtis L. (Virginia Cooperative Extension, 2007)
    A record book for 4-H Poultry projects.
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    Poultry Yearly Plan and Record Book
    Novak, Curtis L. (Virginia Cooperative Extension, 2019-04-12)
    A record book for 4-H poultry projects.