VTechWorks Repository :: Browsing by Author "Thye, Forrest W."

Browsing by Author "Thye, Forrest W."

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Abscisic acid ameliorates glucose tolerance and obesity-induced inflammation
Guri, Amir Joseph (Virginia Tech, 2007-10-19)
Obesity is a disease characterized by chronic inflammation and the progressive loss in systemic insulin sensitivity. One of the more effective medications in the treatment of insulin resistance have been the thiazolidinediones (TZDs), which act through the nuclear receptor peroxisome proliferator-activated receptor gamma (PPARgamma ). Due to the many side-effects of TZDs, our laboratory sought out a natural phytochemical, abscisic acid (ABA), with chemical similarities to TZDs. Our first study demonstrated that ABA activates PPARgamma in vitro and significantly ameliorates white adipose tissue (WAT) inflammation and glucose tolerance in db/db mice. We next further examined the effect of ABA on the phenotype of adipose tissue macrophages (ATMs). In doing so, we discovered two separate ATM populations which differed in their expression of the macrophage surface glycoprotein and maturation marker F4/80 (F4/80hi vs F4/80lo). Dietary ABA-supplementation significantly reduced F4/80hiCCR2+ ATMs and had no effect on the F4/80lo population. Utilizing a tissue-specific knockout generated through Cre-lox recombination, we were able to determine that this effect was dependent on PPARgamma in immune cells. To further characterize the differences between the ATM subsets that were affected by ABA, we performed a multi-organ assessment (i.e., WAT, skeletal muscle and liver) of the effect of diet-induced obesity on the phenotype of infiltrating macrophages and T cells into metabolic organs. Based on our new data, we formulated a model by which F4/80hiCCR2hi ATMs infiltrate WAT and ultimately induce a CD11c+ pro-inflammatory phenotype in the resident F4/80loCCR2lo subset. Ultimately, our findings provide evidence that ABA has potential as an alternative preventive intervention, expound the role of PPARgamma in immune cells and, in general, expand our knowledge concerning the immunopathogenesis of obesity-induced insulin resistance.
Concentrations of Conjugated Linoleic Acid Isomers in Human Plasma Reflect Intake of Dairy Products with Enhanced cis-9, trans-11 or tran-10, cis-12 Isomer Content
Shafer, Brian David (Virginia Tech, 2006-06-20)
Dairy products are a primary source of c9, t11-CLA, an anti-carcinogenic agent, in the diet of humans. The t10, c12-CLA isomer, typically in trace amounts in bovine milk fat, also may benefit human health. Four cows received abomasal infusions of c9, t11-CLA or t10, c12-CLA to obtain milk fat used to prepare butter and yogurt with enhanced c9, t11-CLA or t10, c12-CLA content. Human subjects (3 males, 3 females, ages 22 to 29) received CLA-enhanced butter and yogurt (14% of total kcal) in a crossover study with 2-wk periods. Prior to the study (2 wk) and during a 2-wk washout period between the experimental periods, subjects received butter and yogurt without enhanced CLA content. Blood samples were obtained at 0, 2, 4, 6, and 8 wk relative to the start of the first experimental period. The t10, c12- CLA isomer was detected in plasma (1.32 ug/mL) only when dairy products with enhanced t10, c12-CLA was consumed. Baseline c9, t11-CLA was 6.94 ug/mL plasma during control periods, but increased to 8.95 ug/mL when dairy products with enhanced c9, t11-CLA content were consumed. Results indicated concentrations of CLA isomers in human plasma respond to small changes in daily intake of the isomers in dietary sources.
Copper status in multiple trauma patients: measurement of copper balance, serum copper and ceruloplasmin
Clark, Susan F. (Virginia Tech, 1990-10-17)
Changes in copper metabolism have been reported in both thermal injury and skeletal trauma; data regarding copper status in multiple trauma patients (MTP) are nonexistent. Hypercatabolism following multiple trauma may increase copper utilization, deplete copper stores and compromise cuproenzyme synthesis and function. The purpose of this study was to provide information on copper status in MTP and determine whether age, injury severity, clinical outcome or nutritional intake influenced copper status. Twenty-four hour copper losses, serum copper and ceruloplasmin were measured in 11 MTP with Injury Severity Scores (ISS) >12 at 24-48 hours post admission. Collections of biological fluids (urine, nasogastric, chest tube, drains, stools) were analyzed for copper using atomic absorption spectrophotometry (AAS) and quantified over 5 days. Serial serum copper and ceruloplasmin were determined on days 1,3,5,10,15 and patient discharge by ASS and rate nephelometry inmunoprecipition, respectively. Eight patients received parenteral nutrition (PN). Three received intravenous glucose/electrolyte infusions (IV). urine (n=11) and nasogastric losses (n=8) were statistically greater than normal (p<.001). The mean ± SEM cumulative copper losses of urine, chest tube drainage, nasogastric secretions and other drains were 790 ± 116 (n=11), 833 ± 130 (n=7), 261 ± 46 (n+8), and 150 ± 58 μg/5 d (n=8), respectively. Urinary losses represented 10 to 12 times the normal copper excretion. Serum copper on day 1 and ceruloplasmin day 3 were significantly higher than normal (p<.025). Cumulative copper balance in the IV group was - 2266 μg and -440 μg in the PN group. No relationship was found between copper loss and ISS. Patients in their twenties demonstrated the greatest urinary copper loss. The physiological and biochemical effects of extensive copper loss in the MTP require further evaluation. These patients may have a predisposition to copper deficiency due to excessive copper losses and may require increased copper supplementation.
The effect of a comprehensive weight reduction program on blood variables, body composition, and nutrient intake in obese black women
Peccatiello, Kathy Louise (Virginia Tech, 1987-08-05)
The effect of comprehensive weight reduction program on selected blood parameters, body composition, and nutrient intake was investigated in 56 obese black women, 22 to 51 years old. Subjects attended nutrition and behavior modification classes once per week for 3 months. Twenty subjects participated in a low impact aerobics programs 3 times per week for 3 months. A 3.8 kg average weight loss was observed. A 2.6% significant reduction in body fat (BF) was observed in the exercise group. Total cholesterol (TC) and low-density lipoprotein-cholesterol (LDL-C) fell significantly from 198 to 175 mg/dL, and 130 to 109 mg/dL, respectively, in the exercise group. High density lipo-protein2-cholesterol (HDL2-C) was lowered significantly from 24 to 17 mg/dL in the non-exercise group. Triglycerides, HDL-C, TC/HDL-C ration, glucose, thyroxin, and insulin values were not significantly altered. Significant reductions in protein, fat, and cholesterol intake were reported. A comprehensive weight loss treatment promoted gradual weight loss, changes in body composition and food intake patterns, and significantly altered some blood lipid levels in obese black females.
Effect of a Low-Carbohydrate, High-Protein Diet on Bone Mineral Density, Biomarkers of Bone Turnover, and Calcium Metabolism in Healthy Pre-Menopausal Females
Coleman, Mary Dean (Virginia Tech, 2004-07-15)
Low-carbohydrate, high-protein (LCHP) diets have been shown to induce weight loss and beneficial changes in blood lipids that suggest cardiovascular disease risk reduction; however, LCHP diets have not been adequately investigated for health effects on the skeleton. A randomized trial to determine the effects of a LCHP diet on bone mineral status, biomarkers of bone turnover, indicators of acid-base balance, calcium homeostasis and fasting lipids in healthy pre-menopausal women was conducted. Women, aged 32 - 45 y, with a body mass index between 25-41 kg/m2 were randomized into one of two diet groups: LCHP (n = 13) or high-carbohydrate, low-fat (HCLF) (n = 12). Anthropometric (body weight, lean mass, fat mass) and bone mineral density (BMD) and content (BMC) measures and markers of lipid metabolism were taken at weeks 0, 6, and 12. Measures of acid-base balance, protein metabolism, and calcium homeostasis were conducted at weeks 0, 1-4, 6, and 12. Serum osteocalcin was analyzed at weeks 0, 1, 2, 6, and 12, while urinary NTx was analyzed at weeks 0, 1 and 2. Weight loss was significant at the end of 12 weeks in both diet groups (P < 0.05) but there was no Diet x Time interaction. Total proximal femur BMD was lower in the LCHP group (P < 0.05) compared to the HCLF group by week 12. Femoral neck BMC decreased in the LCHP diet group (P < 0.05), whereas total forearm BMC increased (P < 0.05) in the HCLF diet group by week 12 of the study. Serum osteocalcin showed significant main effects of diet (P < 0.05) and time (P < 0.0001), but a Diet x Time interaction was not observed. Urinary NTx exhibited no main diet effect, time effect or Diet x Time interaction at weeks 1 or 2. Urinary pH was lower in the LCHP group compared to the HCLF group throughout the study (P < 0.0001). Urinary calcium excretion was higher in the LCHP group and lower in the HCLF group (P < 0.0001) compared to baseline values at all intervals of the study. Urinary phosphorus excretion exhibited a significant diet effect (P < 0.001) and time effect (P < 0.002), while no Diet x Time interaction was observed. Total cholesterol, high-density and low-density lipoprotein cholesterol, and triacylglycerol concentrations did not differ between diets during the study. In conclusion, a LCHP diet appears to stimulate bone loss, while a HCLF diet appears to attenuate bone loss in healthy pre-menopausal women undergoing 12 weeks of weight loss.
The effect of a zinc deficiency and alcohol intake during gestation in the rat
Reynolds, Kathryn A. (Virginia Polytechnic Institute and State University, 1987)
The effect of alcohol and/or zinc deficiency was evaluated in seven groups of pregnant rats and their pups. Females which had been acclimated to alcohol before breeding were fed liquid alcohol diets with either 14 or 0.1 ppm Zn. Comparisons were made with animals pair fed isocaloric liquid carbohydrate diets with the same Zn levels. Other comparisons were made by pair feeding a high zinc diet to a low zinc diet, and by feeding a high zinc diet ad lib. A reduced food intake and Zn deficiency affected maternal status by decreasing weight gain, liver Zn and plasma Zn concentration. Litter size, litter weight, and fetal liver and brain weight were decreased only in the alcohol zinc deficient group compared to adequately fed controls. The concentration and total quantity of fetal liver Zn were decreased due to a Zn deficiency. The combination of Zn deficiency and alcohol decreased only total Zn in fetal brain. The concentrations of protein, DNA, and RNA in fetal liver and brain were similar regardless of dietary treatment. The quantities of protein, DNA, and RNA were decreased in fetal liver due to Zn deficiency. ln fetal brain, only the combination of alcohol and Zn deficiency decreased total protein and RNA, while DNA was not affected. Although alcohol by itself had no effect on the above variables, its combination with a Zn deficiency did. In addition, there were 58 resorptions and 15 malformations seen in Zn deficient alcoholic dams compared with no more than 15 and 2, respectively, in any of the other groups. Teratogenesis caused by a Zn deficiency was increased with alcohol consumption.
The effect of boron supplementation on bone mineral density and hormonal status in college female athletes
Volpe, Stella L. (Virginia Tech, 1991)
Twenty-eight college female volunteers, 18 to 24 years of age, were studied to determine their bone mineral density and hormonal status following 10 months of supplementation with boron. Seventeen of the subjects were college athletes (A) who participated in either varsity basketball, tennis, track, triathlons, or volleyball. Eleven eumenorrheic subjects were placed in the sedentary group (S). All athletes were eumenorrheic, except for two, who were amenorrheic. The subjects were randomly assigned to either a placebo (cornstarch) or 3 mg of Tri-Boron (TWin Labs, Ronkonkoma, NY) per day. The study was single blind; the placebo and boron supplements were identical in appearance. The subjects' maximal oxygen consumption (V02max ) was assessed at month 0 only, in order to compare the athletes' aerobic capacity to that of the sedentary group. Subjects were measured at time 0 and 10 months for the following: average daily food intake, bone mineral density, plasma 1,2 5-dihydroxyvi tamin D3 , and plasma alkaline phosphatase. The following parameters were determined at 0, 6, and 10 months: serum 17-Beta estradiol progesterone, and testosterone, and percent body fat, and body weight. The athletes had a significantly greater V02MX (p < 0.05) than the sedentary group. There were no differences between the A and the S groups' food intake as measured in kcals, protein, fat, carbohydrate and fiber content. Although average body weight did not differ between activity groups, the athletes had a significantly lower (p < 0.05) percent body fat than the sedentary group. The athletes showed a slight increase in bone mineral density, whereas the sedentary group showed a slight decrease. The difference between these changes was significant (p < 0.05) between the activity groups. Furthermore, the athletes showed a slight increase in plasma 1,25-dihydroxyvitamin D3 , while the sedentary group showed a decrease in this measure; the difference between these changes also proved to be significant (p < 0.05) between activity groups. There were no significant differences in plasma alkaline phosphatase values. Serum 17-B estradiol and testosterone values exhibited a significant (p < 0.05) increase for all groups combined at 6 months. There were no significant changes observed in serum progesterone. Although significant changes were observed in some of the variables measured, none of the changes were a result of the boron supplementation.
Effect of Carbohydrate-Protein Beverage on Glycogen Resynthesis and Muscle Damage Induced By Eccentric Resistance Exercise
Wojcik, Janet Regina (Virginia Tech, 1998-04-17)
This study examined effects of carbohydrate (C), carbohydrate-protein (CP), or placebo (P) beverages following eccentric resistance exercise on muscle damage by serum creatine kinase (CK), muscle protein breakdown by urinary 3-methylhistidine (3MH), muscle soreness, isokinetic muscle strength, muscle glycogen resynthesis, and serum hormones. Untrained males (N=26) underwent a 9-day controlled meat-free diet and 24 hr urine collections. To reduce glycogen, subjects cycled for 40 min at 70% of VO_2peakfollowed by 5 cycling sprints on day 4 evening. On day 5, fasted subjects performed 100 eccentric leg flexions at 120% of 1-RM and drank C (n=8, 1.25 g C/kg), CP (n=9, 0.875 g C/kg, 0.375 g protein/kg), or P (n=9) beverages immediate post-exercise (IPE) and 2 hr later. Muscle biopsies were taken IPE on day 5, and days 6 and 8 mornings. Blood was obtained days 4-10 fasted plus IPE, 3 hr, and 6 hr post-exercise on day 5. At 3 hr on day 5, insulin was higher for CP (24.6 ( 15.5 µIU/ml) and C (17.2 +/- 10.9 µIU/ml) than P (5.3 +/- 0.4 µIU/ml, p<.05). Glycogen was low on day 5, partially recovered on day 6, and normal by day 8 (p<.01) with no difference among groups. Isokinetic quadriceps peak torque at 60^o/s decreased 24% on day 6 and remained depressed by 21% on d 8 (p<.01) for all groups. Soreness peaked on day 7 and CK on day 8 (p<.01) with no differences by group. CK increased (p<.01) over day 5 (delta CP 24.6 +/- 19.1, delta P 39.2 +/- 71.6, delta C 70.8 +/- 60.4 U/L) and was highest for C (p<.05). On day 5, CP had lowest 3MH (193.0 +/- 13.8 µmol/d) versus C (251.1 +/- 22.5 µmol/d, p<.05). Testosterone at 3 hr on day 5 was lower for C (4.2 +/- 0.3 ng/ml) and CP (4.3 +/- 0.3 ng/ml) versus P (5.1 +/- 0.2 ng/ml, p<.05). In summary, glycogen, muscle strength and soreness were unaffected by beverage. However, a CP beverage may be beneficial for reducing muscle damage and protein breakdown on the day of eccentric resistance exercise.
Effect of dietary zinc and copper on plasma zinc, copper, total cholesterol in young adult males
Brocavich-Nielsen, Juliann M. (Virginia Tech, 1990-07-06)
An eight week controlled feeding study was conducted to determine the effects of dietary zinc and copper on plasma zinc, copper, total cholesterol (TC), and high density lipoprotein cholesterol (HDL-C) levels in young adult males receiving two levels of zinc. Source of dietary calcium was also varied, however possible interactions or effects of calcium were not determined in this study. Subjects consumed zinc supplements of 10 mg/day, in combination with 1 of 3 diets, resulting in zinc:copper ratios of 30: 1 (Dairy Calcium, or DC group), 20:1 (Control or CO group), and 20:1 (Calcium Carbonate or CC group). Copper content of all diets was approximately 1 mg/day. Plasma levels of zinc, copper, TC, and HDL-C did not differ significantly between the groups. However, plasma levels of copper, zinc, and HDL-C, were found to be significantly affected by the specific week of controlled feeding across all 3 groups (p<.05). Plasma copper at baseline was significantly lower than at weeks 2,4,6, 8, and post treatment. Plasma zinc at baseline, and weeks 2 and 4, was found to be significantly lower than at weeks 6, 8, and post treatment. At week 6, plasma HDL-C was noted to be significantly higher than at baseline, weeks 2, 4, 8, and post treatment. Spearman correlation coefficients determined negative correlations between plasma copper and TC (r=-0.39, p<0.04), and plasma copper and zinc (r=-0.43, p<0.02) in the DC group. A positive correlation was also noted between plasma zinc and TC (r=0.32, p<0.10) in the DC group. Plasma copper and HDL-C were determined to be negatively correlated in the CO group (r=-0.48, p<0.005). Plasma zinc and HDL-C were found to be negatively correlated in the CC group (r=-0.58, p<0.001).
The effect of different sources of dietary fiber on the plasma total and lipoprotein cholesterol, liver cholesterol, fecal neutral steroid excretion and histology of major organ tissues in hamsters
Jonnalagadda, Satya Srivathsa (Virginia Tech, 1992-05-05)
The effect of diets with various dietary fiber sources on the plasma lipids, liver cholesterol, the histology of the gastrointestinal tract, heart, liver and kidney and the fecal neutral steroid excretion was investigated in hamsters. 155, 9-11 wk old, male Golden-syrian hamsters were fed a purified basal hypercholesterolemic diet (0.1% cholesterol, 10% fat, 4% dietary fiber) for 5 wk to elevate plasma lipid levels. Based on wk 4 plasma total cholesterol (TC) levels hamsters with elevated levels were randomly assigned, 16 animals/group, into six groups for another 4 wk: control, oat bran, guar gum, cellulose, xylan and sacrifice. After 4 wk of the fiber diets (10% dietary fiber), the plasma TC levels were significantly lowered in the oat bran, guar gum and xylan groups (16%, 12% and 15%, respectively) (p<.05). They were also significantly lower than the control and cellulose groups. Plasma HDL-C concentrations tended to be lower in all the treatment groups, but was significantly decreased only in the guar gum group (12%) (p<.05). The combined plasma VLDL-C + LDL-C was significantly lowered by the oat bran, cellulose and xylan diets (38%, 40% and 34%, respectively) (p<.05). The liver cholesterol concentration increased significantly from 1 mg cholesterol/g liver to 4.1 mg cholesterol/g liver (p<.05) after 4 wk of the control diet; this was further increased significantly only in the cellulose group (5.6 mg cholesterol/g liver), while the other treatment groups showed no significant changes or differences compared to the control diet group (wk 4). The total fecal neutral steroid excretion was significantly (p<.05) higher in the oat bran group compared to the other treatment groups. No major differences were observed in the tissue histology of the animals in the different treatment groups. In the present study, it appeared that oat bran, guar gum and xylan were effective hypocholesterolemic agents; however, their mechanism of action is still not clear.
The effect of early nutrition and activity levels on the development of obesity in rats
Bazzarre, Terry Lee (Virginia Tech, 1973-11-06)
This investigation was undertaken to study the effects of feeding two levels of caloric density factorially with two levels of activity on the growth rate and body composition of male weanling pups from 25 to 67 days of age. The effects of ad libitum feeding the dams of these pups the same two diets during gestation and lactation on the growth rates and activity levels of these pups were also examined. Following weaning, the pups in both Studies A and B, were placed by weight in outcome groups of four each. The pups in each outcome group were then randomly assigned to one of the following four treatments: I - high-fat diet, spontaneous exercise; II - high-fat diet, restricted exercise; III - chow diet, spontaneous exercise; IV - chow diet, restricted exercise. The pups whose dams were given the 60% fat ration during gestation and lactation (B) attained a higher weaning weight (73 g) than the pups of the dams fed a 4.5% fat ration (Purina Chow) during gestation and lactation - A (55 g). The final body dimensions (length and width) did not appear to be different (Tables IV and V). Pups in Study B tended to run considerably more meters per day than the pups in Study A although the differences were uncertain because of the wide variation. The final body weights attained were greater for the pups in Study B than the pups in Study A except for treatment I. Except for treatment I, the Except for treatment I, the order of the weight gains within treatments among experiments was comparable. It appeared that the differences in final body weight attained could be attributed to the initial differences present at weaning which reflected the dietary treatments of the dams during gestation and lactation. The difference of treatment I in Study B from the trends exhibited by the other three treatments, was manifest by the lower final body weight attained (246.25 ± 9 g) and the lower total weight gain (170.77 ± 8 g) of Study A. The animals in Study B all consumed a greater number of kcal per day than the animals in the corresponding treatments in Study A. The differences in feed consumption between the two experiments appeared to be significant only for those animals receiving the 60%-fat diet.
The effect of exercise and fish oil supplements on the blood lipid levels of the hamster
Kennel, Phyllis D. (Virginia Tech, 1989-07-05)
The effect of aerobic exercise and fish oil supplements on plasma lipid parameters was investigated in the hamster. The hamsters were fed a basal hypercholesterolemic purified diet (0.1% cholesterol, 15% fat) to elicit an elevated lipid response. Fifty-six hypercholesterolemic hamsters were divided into four groups: control, swimming (trained up to one hour every other day), daily fish oil supplementation (.35g/kg/day omega-3), and a swimming/fish oil combination. The effect of these treatments on plasma TC, TG and pooled samples of plasma HDL-C, HDL2â C, LDL-C and VLDL-C was studied over 12 weeks. All hamsters had a significant increase in body weight. Feed intakes increased at 6 weeks and then declined over the second 6 weeks, but remained above the beginning levels.
The effects of a walking program on aerobic fitness, riboflavin and thiamin status, and birth outcome in pregnant women taking vitamin-mineral supplements
Lewis, Richard D. (Virginia Polytechnic Institute and State University, 1986)
The effects of an aerobic walking program, from 22 to 30 wk gestation, on aerobic fitness, riboflavin and thiamin status, and birth outcome were studied in 28 healthy, pregnant women, 24-36 yr of age, receiving vitamin-mineral supplements. Aerobic capacity was evaluated by measurements of heart rate (HR) and relative oxygen consumption (VO₂, ml/kg/min) during two submaximal treadmill walking tests (22 and 30 wk). HR responses were significantly lower for walking subjects (W; n=l8) compared to nonwalking (NW; n=l0) at two (~2.9 METS) and four (~3.8 METS) min, and near significant at six (~4.6 METS) min of the 30 wk tests. HR at two min of exercise for NW subjects increased significantly from 22 to 30 wk. Oxygen consumption for W decreased significantly from 22 to 30 wk at two, four, and six min of exercise. Comparison of VO₂ changes (22 to 30 wk) between W and NW indicated a significant difference at six min and near significance at four min. Riboflavin and thiamin status, as determined by erythrocyte glutathione and transketolase activity coefficients, was adequate for 86% of the subjects with respect to riboflavin and 96% for thiamin. There was a significant correlation (r = 0.58) between aerobic activity scores and ETKAC values (W group). Participation in a walking program slightly improved aerobic capacity without affecting birth outcome or riboflavin and thiamin status in pregnant women taking vitamin-mineral supplements.
Effects of added dietary fat and protein on the growth and carcass characteristics of turkeys
Blair, M. E. (Virginia Polytechnic Institute and State University, 1986)
Two experiments were conducted to quantitate the effects of several parameters on the growth, carcass characteristics and fat deposition of the turkey. In the first experiment, 0, 5, 10 or 15% fat from three sources (Fat 1, Fat 2 or Fat 3) was added to low (18%), standard (21%) or high (24%) protein diets fed to Nicholas Large White male turkeys from 8 to 22 weeks of age. Carcass quality as measured by fat deposition, carcass yield and breast meat yield was determined. The addition of each 1% added fat up to 10% increased body weight gain .72%. Feed consumption decreased 1.3% and feed efficiency increased 2.3% for each 1% added fat up to 15%. Addition of Fat 2 to the diet resulted in significantly better feed efficiencies as compared with Fat 1 or Fat 3. The feeding of low protein diets as compared with standard protein diets decreased body weight gain, feed consumption and feed efficiency 13.2, 5.7 and 8.1%, respectively. Addition of fat to the diet increased 22-week body weight and the amount of breast meat produced per kg feed consumed. For each 1% added fat to low and standard protein diets, leaf and gizzard fat deposition increased 10.2 and 8.0%, respectively. Feeding low protein diets resulted in a 10.4% decrease in body weight and a 19.5% decrease in breast meat yield. The increase in leaf and gizzard fat deposition from each 5% increment of added fat up to 10% was counteracted by a 3% increase in dietary protein. In the second experiment, both sexes of the Nicholas Large White, Jaindl Large White and Jaindl Medium White strains were fed standard (21%) or high (24%) protein diets containing 0, 5 or 10% added dietary fat from 8 to 28 weeks of age. Carcass quality as measured by yield of carcass parts, fat deposition and the composition of breast meat was determined at 16, 20, 24 and 28 weeks of age. The Nicholas strain of turkey had a greater growth rate and consumed less feed to reach heavier weights than the Jaindl Large strain. Addition of 10% fat to the diet decreased feed consumption 12% and increased feed efficiency 17%. Fresh carcass and breast meat yield increased with age of the turkey, indicating that marketing at younger ages does not take full advantage of the meat producing capability of the turkey. The Jaindl Large and Medium White strains averaged 6.8 and 6.9% more breast meat yield than the Nicholas strain. The Nicholas strain deposited 4.36 times more leaf fat and 1.84 times more lipid within the breast meat as compared to the Jaindl Large strain. Added dietary fat decreased fresh carcass yield .41% and breast meat yield .65%. Feeding high protein diets increased fresh carcass yield and breast meat yield .25 and .47%, respectively.
The effects of broccoli on the excretion of urinary conjugates
Kim, Yuni T. (Virginia Tech, 1992-09-05)
The effects of dietary broccoli on the body's ability to detoxify were studied in 18 male subjects between the ages of 22-40 years. The biological parameters used for measuring detoxification were the four major urinary conjugates, namely, mercapturates, sulfoconjugates, glucuronides, and amino acid conjugates. Dietary broccoli increased the urinary excretion of mercapturates and sulfoconjugates, but did not influence the excretion of glucuronides and amino acid conjugates. A significant linear trend was observed over the six-day broccoli diet treatment for both urinary mercapturate (P<0.005) and sulfoconjugate (P<0.0001) excretion. The linear trend for the mercapturate excretion was in a dose-dependent manner, resulting in a 1.3 and 2.1 fold increase by the third and sixth days, respectively, of the broccoli diet, compared to the control. For sulfoconjugates, an unexpected decrease was observed on the first day of the broccoli diet. However, within the six-day broccoli dietary treatment, a continuous increase in conjugate excretion was observed, resulting in a 2.5 fold increase by the sixth day compared to the first day. The excretion of sulfoconjugates was not necessarily dose-dependent, and increased excretion at the highest level of broccoli (500 g) could be due to a time effect. Overall, sulfoconjugate excretion was the highest (3.98-8.91 mmole/24 h) followed by the amino acid conjugates (3.06-5.99 mmole/24 h) and glucuronides (2.85-3.54 mmole/24 h). Mercapturate excretion was the lowest (0.16-0.34 mmole/24 h). In spite of its low excretion level, the level of urinary mercapturates appeared to be the most responsive urinary conjugate to the different levels of broccoli diet.
The Effects of Interval Training and Modest Calorie Restriction in the Treatment of Obesity
Stockunas, Michelle Marie (Virginia Tech, 2000-08-29)
Moderate intensity exercise (MIT) was compared to high intensity interval exercise (HIIT) as part of a nine week treatment strategy for 13 obese men. Both groups exercised three days per week beginning at 45% VO2max. The MIT protocol progressed to 65% VO2max by week eight. The HIIT protocol consisting of 16 short (30 s), 8 medium (90 s), and 4 long (180 s) intervals progressed to 110% VO2max, 100% VO2max, and 90% VO2max, respectively, by week nine with low intensity intervals at 40% VO2max. Exercise duration of the MIT group was adjusted to allow for energy expenditure equal to that of the HIIT group. Modest dietary restriction and weekly group nutrition education sessions were part of the treatment. Weight decreased similarly by 2.4% in the MIT group and 2.8% in the HIIT group (p<0.05). For the groups combined, exercise resulted in a 7% decrease in body fat percent (%BF) and a 9% decrease in fat mass (FM) (p<0.05). There was no difference in the change in %BF or FM for either group. There were no changes in fat free mass (FFM) over the treatment or between groups. Waist circumference decreased 2.8% overall with no differences between the two groups (p<0.05). There were no differences in waist-to-hip ratio (WHR) or waist-to-thigh ratio (WTR) due to the intervention. The activity of vastus lateralis b 3-hydroxyacyl CoA dehydrogenase (HADH) increased 37% and 97% (p<0.05) for the MIT and HIIT groups respectively with a trend for differences between the two groups (p=0.055). The results show that an exercise program of moderate or high intensity is effective to cause weight reduction. The data suggest that HIIT may be more effective over a longer treatment period if the observed trend for greater capacity for muscle fat oxidation translates into improved body fat loss.
Energy intake and expenditure in individual female collegiate distance runners
Braddick, Jeanne Ann (Virginia Tech, 1986-03-05)
In recent studies, caloric intakes among female distance runners were reported to be insufficient to support training intensities. To study energy intake and expenditure in female collegiate distance runners, ten members of the Virginia Tech cross-country team were utilized as subjects.
Free and peptide amino acid fluxes across the mesenteric and non-mesenteric viscera of sheep and calves
DiRienzo, Douglas B. (Virginia Tech, 1992-09-05)
The flux of free and peptide amino acids across the stomach and intestinal tissues was quantified using sheep and calves maintained in "steady state” conditions by feeding at hourly intervals. Crossbred wethers and Holstein steers were surgically cannulated in the abdominal aorta, mesenteric vein and portal vein. All animals were fed an orchardgrass, corn, SBM-based diet. The steers received three abomasal infusions; a control solution, and an amino acid mixture simulating casein and casein each at a rate equivalent to 25% of daily crude protein intake. Nutrient fluxes from the mesenteric and portal-drained viscera were measured; non-mesenteric flux was calculated as the difference between portal flux and mesenteric flux. Results of this study support the concept that free amino acids are absorbed by the small intestine and not by the stomach. The flux of peptide amino acids across the portal-drained-viscera indicate that a major portion of the amino acids which are absorbed by cattle and sheep are absorbed in the form of peptides from the stomach. The observation that large quantities of peptide amino acids are absorbed from the stomach is unique and it is expected that this most important discovery will revolutionize the feeding of ruminants.
Gastrointestinal acidity, protein and starch digestibility and amino acid absorption in ruminants fed a high-concentrate diet with limestone, magnesium oxide or defluorinated phosphate
Christiansen, Michael Lee (Virginia Polytechnic Institute and State University, 1988)
Twelve wether lambs (32kg) with abomasal and ileal cannula were fed a 90% concentrate basal diet (800 g/d), basal + 1.5% magnesium oxide (MgO)(812 g/d), basal + 1.5% limestone (812 g/d) or basal + 3.0% limestone (824 g/d) to study the effect of·these minerals on intestinal pH, rumen fermentation, N balance, dry matter and crude protein digestibility (DMD, CPD), and small intestinal disappearance of amino acids (AAD). Limestone (3%) increased (P < .03) rumen pH. Magnesium oxide increased (P < .10) ileal and fecal pH. Limestone significantly increased N absorption and pre-abomasal DMD, but decreased (P < .03) AAD. N retention was not improved by the treatments. An 82-d feeding trial was conducted with 72 wether lambs (avg initial wt: 28 kg) to study the effect of 1 or 3% fine (70% < 53 µ) or coarse (85% > 425 µ) limestone on rumen environment, weight gain and feed efficiency of lambs fed an all-concentrate diet. Rumen pH and VFA molar proportions were not affected by the treatments. Limestone (3.0%) decreased (P < .10) total rumen VFA concentrations and increased (P < .10) fecal pH. Weight gain was not different (P > .10) among the treatments. Coarse limestone increased (P < .10) feed efficiency. Five Angus heifers (285 kg) with duodenal and ileal cannulae were fed a 90% concentrate control diet (7.5 kg/d) or the same diet containing 1.60% defluorinated phosphate-regular (5.5%, 19.0% and 33.0% on 1400, 1180 and 850 µ sieves, respectively, DRP-R), 1.60% defluorinated phosphate-coarse (85% evenly among large sieves, DRP-C), 1.28% limestone or .5% MgO to study the effect of limestone or MgO on intestinal pH, DMD, starch digestibility (SD), CPD and AAD in beef cattle fed a high-concentrate diet. Ileal pH was increased by MgO. Fecal pH was increased (P < .05) as follows: MgO > DRP > limestone and control. Minerals increased (P < .05) duodenal liquid flow. Limestone and DRP-C increased (P < .05) acid flow to the duodenum. Total tract DMD, SD and CPD were similar among treatments. Limestone and DRP-R increased (P < .10) AAD. DRP-C tended to increase AAD, but differences were not statistically significant.
Gluconeogenesis in the liver of growing and lactating ruminants: the influence of ration composition and stage of lactation
Kenna, Twila M. (Virginia Polytechnic Institute and State University, 1991)
Thirty six: Holstein bull calves were assigned to a 3X3 factorial design with ration physical forms of chopped hay (CH), ground hay (GR) and all concentrate (CONC) and rumen degradable nitrogen (RDN) of 30, 45 and 60%. Metabolic body weight, liver weight and blood glucose were greatest in CONC-fed calves. Neither dry matter nor ash content of liver tissue was affected by either physical form or RDN. Within physical form, protein content was highest and fat lowest in livers of CH-fed caIves. Within RDN, livers of calves feel 30% RDN rations had lowest protein and highest fat content. RDN percent had no effect on carbon dioxide production. Livers from CONC-fed calves produced significantly· (P<.05) more carbon dioxide from [1⁻¹⁴C}propionate and [U⁻¹⁴C}lactate.Glucose production from propionate and lactate was greatest for CONC-fed and 60% RDN-fed calves, although significant only from lactate within physical form. Interaction between ration physical form and RDN makes interpretation of propionate data difficult. In 30% RDN-fed calves both lactate and propionate metabolism was similar for GR- and CONC-fed animals. At 45 and 60% RDN rations, CONC- and CH-fed calves had similar gluconeogenic rates from propionate but glucose from lactate was significantly greater in livers of CONC-fed calves compared to GR- and CH-feet animals. Ten lactating and five dry Holstein cows were liver biopsied at various stages of lactation (30,60,90,120,180 days postpartum and dry) and when fed two rations, control ( 18% CF) or high concentrate (HI CONC, 10.5% CF). Lactating cows at 30 and 60 days and dry cows were fed the control ration. After 60 days half the cows remained on the control ration and half the lactating cows were changed to the HI CONC ration. Milk fat percent was depressed in cows fed HI CONC ration. Milk fat percent was depressed in cows fed HI COCC ration. HI CONC cows consumed more dry matter and due to the higher energy content reached a positive energy balance before control cows. Rumen fluid volatile fatty acid production was not affected by stage of Lactation or ration fed. Both plasma glucose and plasma insulin nonsignificantly increased as lactation progressed. Liver tissue protein did not change over lactation but increased when HI CONC ration was fed. Stage of lactation affected (P<.0002) propionate metabolism to carbon dioxide with higher production at 120 days compared to 180 days. By ration, HI CONC cows' livers produced more carbon dioxide than control cows’ livers. Feeding the HI CONC ration significantly increased labelled glucose production. Increased production of both labeled carbon dioxide and glucose by liver from cows fed HI CONC ration was nonsignificant when based on liver protein content. Carbon dioxide/glucose ratio was similar for lactating (>60 days) and dry cows. Cows early in lactation (30 days) had significantly lower carbon dioxide/glucose ratios, indicating a higher glucose production. Ration and stage of lactation are important factors in ruminant metabolism.. Gluconeogenesis, a pathway especially important in ruminants, is affected by both factors. In calves and cows, concentrate rations increased glucose production. Ration RDN, studied in calves, affected lactate metabolism to glucose. The liver of lactating cows showed a greater response (increase in glucose production) to stage of lactation than ration fed demonstrating the importance of energy balance on ruminant metabolism.

Browsing by Author "Thye, Forrest W."

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