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PubMed1988

Computer-controlled positive end-expiratory pressure titration for effective oxygenation without frequent blood gases.

We have previously designed a computerized system to automatically deliver PEEP to maintain functional residual capacity (FRC) at a desired value. The purpose of this study was to compare the computerized PEEP titration system with a standard clinical PEEP titration algorithm in the animal adult respiratory distress syndrome (ARDS) model. Thirty mongrel dogs were anesthetized, paralyzed, intubated, and ventilated. An acute pulmonary injury was produced using 0.09 ml/kg of oleic acid. The animals were then given PEEP for 5 h. Arterial and venous blood gases, BP, thermodilution cardiac output, heart rate, body temperature, total respiratory system compliance (Ctr), and end-tidal CO2 were measured every 30 min. FRC was measured using an automated sulfur hexafluoride washout system every 15 min. The animals were allocated randomly to three ten-animal groups. The first group had PEEP titrated using a standard clinical protocol; the remaining two groups had PEEP updated at 15-min intervals under computer control to maintain FRC at 1.4 times the postanesthetized, postparalyzed, preinjury value. The second group received fixed 3-cm H2O PEEP steps. The third group had variable size PEEP steps depending on the output of a proportional, integral, and derivative (PID) controller. PaCO2 was maintained at 35.8 +/- 3.4 (SD) torr. There was a significant difference in PEEP delivered between the three groups (p = .0006) and in FRC (p = .005). There was no significant difference in PaO2 (p = .80) or venous admixture (Qva/Qt) (p = .84) between the three groups.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1998

Liver as a focus of impaired oxygenation and cytokine production in a porcine model of endotoxicosis.

OBJECTIVES: To determine whether the liver is a focus of insufficient oxygenation and whether liver is a source of tumor necrosis factor (TNF) and interleukin-6 (IL-6) in a porcine model of endotoxicosis. DESIGN: In vivo, prospective, controlled, repeated-measures, experimental study. SETTING: Experimental physiology laboratory in a university. SUBJECTS: Juvenile pigs, weighing 22 to 35 kg. INTERVENTIONS: Catheters for blood sampling were inserted into the carotid artery, portal vein, hepatic vein, and pulmonary artery of anesthetized animals. Ultrasonic flow probes were placed on the portal vein and the hepatic artery. During surgery, normal saline was infused intravenously at 25 mL/kg/hr. Following stabilization, animals were allocated randomly to one of two groups. The endotoxemic group (n = 6) received 50 mg/kg of purified Escherichia coli lipopolysaccharide infused into the external jugular vein over 1 hr. The control group (n = 6) received a sham saline infusion infused over 1 hr. Once the endotoxin or sham infusion was initiated, the rate of the intravenous saline infusion was increased to 48 mL/kg/hr for the remainder of the experiment. Measurements were obtained before the endotoxin or sham infusion, immediately after the infusion, and every 30 mins thereafter for 4 hrs. MEASUREMENTS AND MAIN RESULTS: Blood gases, lactate, and bioactive TNF and IL-6 concentrations were measured from the carotid artery, portal vein, hepatic vein, and pulmonary artery. The porcine model is characterized by systemic hypotension, pulmonary hypertension, and maintenance of cardiac output. Despite decreased hepatic oxygen delivery in endotoxemic animals (p < .02), there was no change in hepatic oxygen consumption compared with controls. Throughout the experiment, there was net hepatic consumption of lactate in both groups. There was no significant hepatic production (or consumption) of TNF or IL-6 in either group. CONCLUSIONS: In this porcine model of endotoxicosis, there is a reduction of hepatic oxygen delivery but dysoxia is not present. The liver is not a source of TNF or IL-6 in this model of endotoxicosis.

Animals↗
PubMed2002

In vitro evaluation of furcal perforation repair using mineral trioxide aggregate or resin modified glass lonomer cement with and without the use of the operating microscope.

This study evaluated in vitro the effect of using the operating microscope on repairing furcation perforations using Vitrebond or mineral trioxide aggregate. Forty-six human molar teeth were mounted into a jig attached to a simulated jaw. The teeth were allocated randomly to four groups (n = 10). Furcal perforations were made in the teeth using an ISO 012 round bur in a slow-speed hand-piece. Each material was used to repair a group of teeth with and without the use of the operating microscope. The remaining six teeth provided positive and negative controls. All groups were stored in 100% humidity, and the repair materials were allowed to set for 72 h at room temperature before being assessed for the quality of placement under x26 magnification. Leakage at the repair was then tested using India ink; the teeth were demineralized, dehydrated in alcohol, and rendered transparent in methyl salicylate. Dye penetration into the furcation repair was evaluated at x26 magnification. There was no difference in the acceptability of the repair with either material whether or not the operating microscope was used. The perforations repaired with mineral trioxide aggregate leaked significantly less to the tracer dye than those repaired with Vitrebond (p < 0.001).

Aluminum Compounds↗
PubMed1997

Combined effects of an angiotensin converting enzyme inhibitor and a calcium antagonist on renal injury.

BACKGROUND: Angiotensin converting enzyme inhibitors have uniformly been shown to prevent the development both of proteinuria and of glomerulosclerosis in rats with a remnant kidney. Conversely, dihydropyridine calcium antagonists (DCA) have failed to demonstrate such a benefit in spite of causing an equivalent reduction in blood pressure. OBJECTIVE: To test the hypothesis that concomitant administration of an angiotensin converting enzyme inhibitor and a DCA would lead to a smaller increase both in proteinuria and in glomerulosclerosis relative to that caused by administration of a DCA alone at similar levels of blood pressure. METHODS: Experiments were carried out using Sprague-Dawley rats that had been subjected to five-sixths renal ablation. Animals were allocated randomly to one of four groups: control (no treatment), amlodipine (A rats), benazepril (B rats), or a combination of benazepril and amlodipine (B + A rats). We implanted intraperitoneal sensors for telemetric monitoring of the animal's blood pressure. Other parameters measured at baseline included proteinuria and inulin clearance. After approximately 7 weeks all of the parameters were remeasured and animals killed for morphologic assessment of the kidney. RESULTS: The B + A rats had lower levels of proteinuria than did the rats in group A (21 +/- 12 mg/day for B + A rats versus 59 +/- 24 mg/day for A rats, P < 0.05). The degree of glomerulosclerosis in the B + A rats was also reduced markedly compared with that in A rats (12 +/- 4% for B + A rats versus 43 +/- 12% for A rats, P < 0.05). Moreover, the results on proteinuria and glomerulosclerosis of B + A rats were similar to those for B rats. These differences could not be explained totally in terms of differences in blood pressure control (144 +/- 12 mmHg in A rats versus 132 +/- 13 mmHg in B + A rats, NS). CONCLUSION: The results were consistent with the observation that a combination of benzepril and amlodipine provides additional protection against renal injury compared with that provided by amlodipine alone. The mechanism for this benefit is not known.

Amlodipine↗
PubMed1996

Reduction of thrombus formation without inhibiting coagulation factors does not inhibit intimal hyperplasia after balloon injury in pig coronary arteries.

BACKGROUND: The proposed mechanisms of restenosis after coronary angioplasty include neointima formation, vessel wall remodeling and mural thrombus. Poloxamer 188 does not inhibit coagulation factors, but was shown to reduce mural thrombus formation in pig coronary arteries after intracoronary stenting in an acute study. This study was performed to examine whether this agent may reduce neointima formation. METHODS: Thirty domestic juvenile pigs of weight 20-30 kg were anesthetized. A left angiogram was performed via a femoral artery. Proximal left anterior descending and circumflex arteries were dilated three times with a 20-30% oversized coronary angioplasty balloon catheter. Fifteen animals were allocated randomly to receive intravenous infusions of poloxamer 188, starting 30 min before angioplasty and continuing for 24 h. The remaining 15 received intravenous 0.45% saline and served as controls. The animals were killed 2 weeks after the angioplasty. Histologic studies of the arteries were performed. The severity of the injury and the amount of thrombus material incorporated in the neointima were assessed by semiquantitative methods. RESULTS: There was no significant difference between injury scores in the two groups. Thrombus material in the neointima in the treatment group was significantly less than that in those of the control group (thrombus areas 0.013 +/- 0.004 compared with 0.029 +/- 0.006 mm2, P < 0.02), but there were no significant differences between the neointimal (0.60 +/- 0.08 and 0.60 +/- 0.13 mm2) and luminal (2.51 +/- 0.21 and 2.44 +/- 0.26 mm2) areas in treatment and control groups. CONCLUSION: Continuous 24 h intravenous infusion of poloxamer 188 after balloon injury in pig coronary arteries may reduce mural thrombus formation significantly, but did not reduce neointima formation.

Angioplasty, Balloon, Coronary↗
PubMed1997

Beneficial effect of nisoldipine in repeated coronary reperfusion.

BACKGROUND: We have demonstrated that when repeated reperfusion is performed after reocclusion, there is a decrease in the amount of myocardial salvage, despite early reperfusion. It is unknown whether this deleterious effect of repeated reperfusion can be antagonized. Therefore, we studied the effect of nisoldipine (a dihydropyridine calcium antagonist) on infarct size, using a repeated-reperfusion model. METHODS: The left anterior descending coronary artery was occluded in anaesthetized dogs. Thirty minutes after occlusion, dogs were allocated randomly to either the treatment group (n = 6; 6 micrograms/kg per min nisoldipine infused intravenously throughout the experiment) or the control group (n = 8; saline). Occlusion was maintained for 2 h, followed by 1 h of reperfusion, then 1 h of reocclusion and 2 h of second reperfusion. An in vivo area at risk was determined by gentian-violet staining, and infarct size was defined and quantitated by triphenyl-tetrazolium-chloride staining. RESULTS: Haemodynamic measurements were similar in both groups. Mass of necrosis/mass at risk was significantly smaller in the nisoldipine group (33.3 +/- 5.8%, mean +/- SEM) compared with controls (46.8 +/- 4.8%; P < 0.05). CONCLUSION: Treatment with nisoldipine induces a beneficial effect by reduction of infarct size in repeated coronary reperfusion.

Animals↗
PubMed1998

Early exercise after experimental myocardial infarction: effect on left ventricular remodeling.

BACKGROUND: The effect of exercise on left ventricular remodeling after myocardial infarction is unclear. The purpose of this investigation was to test whether exercise undertaken during the healing phase of an acute myocardial infarction has an adverse effect on left ventricular remodeling. METHODS: Before surgery, rats (n = 94) were allocated randomly to one of four groups: 1) infarct, swimming exercise; 2) infarct, no exercise; 3) sham operation, swimming exercise; 4) sham operation, no exercise. Beginning 1 week after infarction or sham operation, the rats in the exercise groups swam twice daily for 2 weeks. After a deconditioning period of 5 days, the rats were re-anesthetized, hemodynamic measurements were made, and the hearts were fixed for morphometric analysis. RESULTS: Swimming exercise had no effect on remodeling of infarcted myocardium. Rats with infarcts in the swimming and no exercise groups had similar infarct thicknesses (1.1 +/- 0.2 mm and 0.8 +/- 0.2 mm respectively; NS), and similar degrees of infarct expansion (expansion index 1.2 +/- 0.3 and 1.4 +/- 0.3 respectively; NS). Swimming exercise also had no effect on remodeling of non-infarcted myocardium. Left ventricular volumes and pressure-volume relationships were similar in exercised and non-exercised infarcted rats. CONCLUSION: In rats, 2 weeks of swimming exercise, started 1 week after acute experimental myocardial infarction and followed by 5 days of deconditioning, does not have an adverse effect on left ventricular remodeling.

Analysis of Variance↗
PubMed2000

Beneficial effect of HEPES buffer in repeated coronary reperfusion.

BACKGROUND: We have demonstrated previously that, when repeated reperfusion is performed after reocclusion, there is a decrease in the amount of myocardial salvage, despite early reperfusion. Treatment with nisoldipine induced a beneficial effect by reduction of infarct size in this experimental model. OBJECTIVE: To study the effect of HEPES buffer on infarct size, using a repeated-reperfusion model. METHODS: The left anterior descending coronary artery was occluded in anesthetized dogs. Thirty minutes after the occlusion, dogs were allocated randomly to either the treatment group (n = 7; HEPES 0.64 mmol/l infused intravenously throughout the experiment) or the control group (n = 8; saline). Occlusion was maintained for 2 h, followed by 1 h of reperfusion, then 1 h of reocclusion and 2 h of second reperfusion. An in-vivo area at risk was determined by gentian violet staining, and infarct size was defined and quantitated by triphenyl-tetrazolium chloride staining. RESULTS: Hemodynamic measurements were similar in both groups. Mass of necrosis/mass at risk was significantly smaller in the HEPES group (30.7 +/- 1.6%, mean +/- SEM) compared with controls (50.6 +/- 3.8%, P < 0.001). CONCLUSION: Treatment with HEPES induces a beneficial effect by reduction of infarct size in repeated coronary reperfusion.

Analysis of Variance↗
PubMed1992

Induction of anaesthesia with propofol using a target-controlled infusion system.

Sixty patients premedicated with temazepam were allocated randomly to receive an infusion of propofol designed to achieve and maintain a target blood concentration of 3, 4 or 5 micrograms.ml-1. Induction time was measured from the start of infusion to loss of verbal contact. The success rate of inducing anaesthesia within 3 min of achieving the target concentration was 40% when the predicted target concentration was 3 micrograms.ml-1, 75% when the predicted target was 4 micrograms.ml-1 and 90% when the target was 5 micrograms.ml-1. There were no significant differences between the three groups for time to loss of verbal contact in patients who were induced successfully within 3 min. There were significant reductions in arterial pressure 3 min after achieving the target concentrations within the groups but not between them. The frequency of apnoea and pain on injection was small in all groups. Selecting a target concentration of 5 microgram.ml-1 would successfully induce anaesthesia in the majority of patients premedicated with temazepam without major haemodynamic or respiratory side effects.

Adolescent↗
PubMed2006

Changes in angiopoietin expression in glomeruli involved in glomerulosclerosis in rats with daunorubicin-induced nephrosis.

AIM: To study the potential pathological role of endogenous angiopoietins in daunorubicin-induced progressive glomerulosclerosis in rats. METHODS: Seventy male Wistar rats were allocated randomly into a daunorubicin group (DRB; n=40) or a control group (n=30). The rats in the DRB group were injected with DRB (15 mg/kg), in their tails. Subsequently, at intervals of 1, 2, 4, 6, 8, and 12 weeks, 5 male Wistar rats in each group were chosen randomly for 24 h urinary protein quantitative measurements (24 h UPQM), and determination of plasma tumor necrosis factor alpha (TNF-alpha), angiopoietin-1 (Ang1), and angiopoietin-2 (Ang2) levels. Kidney sections were examined by electron microscopy, Periodic Acid Schiff (PAS) staining, immunohistochemical staining and in situ hybridization histochemistry. RESULTS: As glomerulosclerosis progressed in the DRB group, expression of Ang1 mRNA and protein in glomeruli decreased and expression of TNF-alpha protein, Ang2 mRNA and protein in glomeruli increased. Expression of Ang1 mRNA and protein in glomeruli were negatively correlated with 24 h UPQM, Fn protein expression, and mean area of extracellular matrix (MAECM). In comparison, expression of Ang2 mRNA and protein in glomeruli were positively correlated with 24 h UPQM, Fn protein expression and MAECM; furthermore, there was a positive correlation between plasma Ang2 and 24 h UPQM. Plasma TNF-alpha and expression of TNF-alpha in glomeruli were positively correlated with expression of Ang2 mRNA and protein in glomeruli. There was a negative correlation between Ang1 protein expression and Ang2 protein expression in glomeruli. CONCLUSION: During DRB-induced glomerulosclerosis, podocyte injury led to a shift in the balance of Ang1 and Ang2 in glomeruli. Increased TNF-alpha in plasma and glomeruli may upregulate Ang2 expression in glomeruli. Elevated Ang2 in both plasma and glomeruli may mediate protein permeability through the glomerular filtration barrier. Moreover, local expression of Ang2 may facilitate the progress of glomerulosclerosis by upregulating a component expression of extracellular matrix.

Angiopoietin-1↗
PubMed1996

Efficacy of an ivermectin and pyrantel pamoate combination against adult hookworm, Ancylostoma braziliense, in dogs.

A chewable tablet incorporating ivermectin and pyrantel was tested in 12 Beagle dogs for efficacy against the adult hookworm, Ancylostoma braziliense. The dogs were administered infective larvae of A braziliense orally. Twenty-one days after infection the dogs were weighed and allocated randomly to receive either an oral treatment with ivermectin and pyrantel in a beef-based chewable tablet or no treatment. The chewable tablet was a commercially available product, which was made to deliver ivermectin at 6 micrograms/kg and pyrantel at 5.0 mg/kg to each dog. Seven days after treatment the dogs were euthanased, necropsied, and examined for adult hookworms. At necropsy, no adult A braziliense was observed in any of the 6 treated dogs and all 6 dogs that had been left untreated were infected with adult A braziliense (range, 48 to 161). It was concluded that this combination product is 100% efficacious against adult A braziliense.

Administration, Oral↗
PubMed2001

Growth hormone and fertility in oMt1a-oGH transgenic mice.

Female mice carrying a regulatable growth hormone transgene (oMt1a-oGH) are subfertile when the transgene is actively expressed. This study was designed to characterize subfertility caused by increased concentrations of growth hormone. In particular, this study aimed to: (i) determine the effects of transgene activation and inactivation on mating, conception, maintenance of pregnancy, ovulation rate, litter characteristics and embryonic survival at day 17 of pregnancy, (ii) characterize oestrous cyclicity in transgenic versus wild-type female mice, and (iii) correlate corticosterone concentrations with transgene expression and reproductive performance. Transgenic and wild-type female mice were allocated randomly to one of four treatment groups at weaning: (i) transgenic female mice that always express the transgene, (ii) transgenic female mice that never express the transgene, (iii) transgenic female mice that express the transgene for up to 8 weeks of age and (iv) non-transgenic wild-type female mice receiving the transgene stimulus until 8 weeks of age. Activation followed by inactivation of the transgene resulted in an increased incidence of remating, resulting in an extended interval to establish pregnancy in comparison with all other treatment groups. Transgenic mice that always expressed the transgene and those that expressed the transgene for up to 8 weeks of age had lower pregnancy rates and higher ovulation rates compared with mice from other treatment groups. Both embryonic survival and the duration of the oestrous cycle did not differ among treatment groups. Active expression of the transgene resulted in an increase in the plasma concentration of corticosterone, which was associated with reduced fertility. These data indicate that the presence of a high growth hormone concentration impedes the establishment and maintenance of pregnancy. Increased plasma corticosterone concentrations may interfere with implantation as well as potentiate leptin resistance, which has been reported previously in studies with these mice.

Analysis of Variance↗
PubMed2003

Age at puberty, total fat and conjugated linoleic acid content of carcass, and circulating metabolic hormones in beef heifers fed a diet high in linoleic acid beginning at four months of age.

In the current study, we hypothesized that diets high in linoleic acid would increase conjugated linoleic acid (CLA) tissue content, reduce adiposity and leptin production, and result in an increase in the age at puberty in heifers. Heifers were weaned and blocked by body weight (heavy, n = 10, and light, n = 10) and allocated randomly within block to receive isocaloric and isonitrogenous diets with either added fat (HF, n = 10) or no added fat (C, n = 10) from 4 mo of age until post-pubertal slaughter. Whole sunflower seed (55% oil; 70% linoleic acid) was used as the fat source in HF diets and provided 5% added fat from the start of the study until heifers weighed 250 +/- 8 kg, at which time added fat was increased to 7% of dry matter until slaughter. Body weights were recorded weekly, and blood samples were collected weekly for total cholesterol and hormone analyses. Puberty was confirmed based on serum concentrations of progesterone and ultrasonographic confirmation of corpora lutea. Heifers were slaughtered at 325 +/- 10 d of age, and longissimus muscle between the 9th and 11th rib was collected and analyzed to estimate carcass composition. Subcutaneous and kidney, pelvic, and heart fat were collected at slaughter for fatty acid analyses. The HF heavy group tended (P < 0.10) to reach puberty later than all other groups, and one HF light heifer did not reach puberty during the study. Linoleic acid and cis-9, trans-11 CLA tissue contents were higher (P < 0.03) in HF heifers than controls, but neither total carcass fat nor percentage of dry matter differed by dietary group, although the percentage of protein tended (P < 0.10) to be lower in HF heifers. Mean serum concentrations of leptin did not differ due to diet; however, leptin increased (P < 0.01) linearly as puberty approached. Circulating concentrations of growth hormone and insulin-like growth factor I increased or remained relatively constant between wk 2 to 10 of feeding, and then declined (P < 0.01) until the onset of puberty. Serum IGF-I was lower (P < 0.01) in heifers receiving the HF diet. Mean serum concentrations of insulin and total cholesterol increased (P < 0.01) with time in both groups, but only total cholesterol was increased by the HF diet (P < 0.05). Results indicate that diets high in linoleic acid fed to growing beef heifers beginning early in life have little or no effect on total carcass fat, circulating leptin, or age at puberty despite measurable increases in CLA accumulation.

Adipose Tissue↗
PubMed2003

A mixture model-based cluster analysis of DNA microarray gene expression data on Brahman and Brahman composite steers fed high-, medium-, and low-quality diets.

The objective of this study is to explore aspects of the statistical analysis of gene expression response at the muscle tissue level to varying levels of energy and protein in the diet. Eleven Brahman and Brahman composite steers (weighing 302 +/- 9.8 kg, on average) were allocated randomly into high- (HIGH), medium- (MED), and low- (LOW) quality forage diets for 27 d. After this period, a biopsy of the longissimus dorsi muscle was taken from each animal and total RNA was extracted to generate the labeled target for microarray experimentation. These targets were hybridized to a complementary DNA (cDNA) microarray of 9,274 probes from cattle muscle and subcutaneous fat cDNA libraries. After edits, 151,904 expression intensity levels of 4,747 genes were analyzed. Emphasis was given to the choice of power transformation of the intensity channel readings and to the consistency of readings within each diet quality group. The statistical approach to isolate differentially expressed genes was based on model-based clustering via a mixture of normal distributions estimated through maximal likelihood. The base-2 logarithm was found to be the optimal power transformation to normalize gene intensity levels. A two-sample t-statistic was defined as a measure of possible differential expression. For each of the three diet contrasts, HIGH vs. LOW, HIGH vs. MED, and MED vs. LOW, three clusters were found, two of which contained more than 94% genes with almost no altered gene expression levels, whereas the third cluster contained the remaining genes with a differential expression. Results from the HIGH vs. LOW contrast identified 27 genes with a greater than 95% posterior probability of belonging to the cluster of differentially expressed genes.

Animal Feed↗
PubMed2004

Rapid chilling cannot prevent inferior pork quality caused by high preslaughter stress.

The present experiment investigated whether increasing chilling rate could improve meat quality in pigs exposed to either minimal or high stress immediately preslaughter. Pigs (n = 192) were offspring of halothane-free lines. On various days, four groups of 48 pigs were processed at a commercial plant. Within each group, half the pigs were exposed to either minimal or high preslaughter stress. Before entering the cooler at 45 min postmortem, carcasses of both minimal and high preslaughter stress treatments were allocated randomly to either conventional (+4 degrees C for 22 h) or rapid (three-phase chilling tunnel: -15, -10, and -1 degrees C for 15, 38, and 38 min, respectively, followed by storage at 4 degrees C until 22 h postmortem) chilling. Temperature and pH were measured in the blood at exsanguination and in the longissimus lumborum (LL) and semimembranosus (SM) muscle at 0.5, 2.5, 4.5, 6.5, and 22 h postmortem. Meat quality attributes (water-holding capacity and objective color measurements) were assessed on the LL. Preslaughter stress level affected pH and temperature in both blood and muscle, with lower (P < 0.001) pH values and higher (P < 0.001) temperatures for pigs exposed to high vs. minimal stress. Rapid chilling led to a faster (P < 0.001) temperature decline regardless of preslaughter stress level. Rapid chilling did not (P > 0.05) influence the rate of pH decline in the LL muscle, but reduced (P = 0.061) pH decline in the SM. Rapid chilling, as opposed to conventional chilling, decreased (P < 0.05) electrical conductivity in the LL, regardless of preslaughter stress; however, it could not compensate for the detrimental effect (P < 0.05) of stress on drip loss, filter paper moisture absorption, and meat color (L* value). Results from the present study indicated that increasing chilling rate is not a suitable method to resolve pork quality problems caused by inadequate preslaughter handling.

Animals↗
PubMed2004

Effect of vitamin supplements on some aspects of performance, vitamin status, and semen quality in boars.

The aim of the present study was to determine the effects of dietary supplements of vitamins on vitamin status, libido, and semen characteristics in young boars under normal and intensive semen collection. Sixty Landrace, Yorkshire, and Duroc boars were allocated randomly from 6 to 10 mo of age to one of the following diets: 1) basal diet (industry level) for minerals and vitamins (Control, n = 15); 2) basal diet supplemented with vitamin C (ASC, n = 15); 3) basal diet supplemented with fat-soluble vitamins (FSV, n = 15); and 4) basal diet supplemented with water-soluble vitamins (WSV, n = 15). After puberty (approximately 12 mo of age), semen was collected at a regular frequency (three times every 2 wk) for 5 wk. Thereafter, all boars were intensively collected (daily during 2 wk). A recovery period (semen collection three times every 2 wk) followed and lasted for 10 wk. Sperm quality (percentage of motile cells and percentage of morphologically normal cells) and quantity (sperm concentration, semen volume, and total sperm number) were recorded as well as direct and hormone related measurements of boar libido. Blood and seminal plasma samples were taken to monitor vitamin status. High concentrations of B6 (P < 0.05) and folic acid (P < 0.05) were observed in the blood plasma of WSV boars, whereas greater concentrations of vitamin E (P < 0.01) were obtained in FSV boars. In the seminal plasma, folic acid concentrations tended to be greater in WSV boars (P < 0.08). During the intensive collection period, there was a tendency (P < 0.06) for semen production to be greater in WSV boars, the effect being less pronounced (P < 0.10) in FSV boars. During the recovery period, the percentage of motile sperm cells was greater in WSV boars (P < 0.03) and, to a lesser extent, in FSV boars (P < 0.10) compared with Control boars. Sperm morphology and libido were not affected by treatments. These results indicate that the transfer of vitamins from blood to seminal plasma is limited and the dietary supplements of water-soluble and fat-soluble vitamins may increase semen production during intensive semen collection.

Animals↗
PubMed2005

The physiological and production effects of increased dietary intake of vitamins E and C in feedlot cattle challenged with bovine herpesvirus 1.

The physiological and production effects of feeding additional vitamin E and ruminally protected vitamin C were examined in cattle challenged with bovine herpesvirus 1 (BHV 1). Forty-eight individually penned 6-mo-old Angus and Angus crossbred heifer calves with a mean BW of 151 kg were allocated randomly to four diets in a 2 x 2 factorial arrangement of treatments. Pelleted diets provided either 15 or 185 IU/kg of DM of vitamin E, with or without 3.7 g of ruminally protected vitamin C/kg of DM. Blood samples were taken at start of the experiment and at wk 4, 5, and 6. At the start of wk 5, half of each of the dietary groups was challenged with BHV 1. Feeding additional vitamin E was associated with greater (P < 0.001) mean plasma alpha-tocopherol. In contrast, feeding ruminally protected vitamin C was not associated with greater (P = 0.59) mean plasma ascorbate concentration; however, feeding ruminally protected vitamin C was associated with lower (P = 0.03) mean blood total superoxide dismutase (Cu/Zn SOD and Mn SOD) concentration. Calves fed additional vitamin E had greater (P = 0.05) mean plasma beta-carotene concentrations. There were interactions between dietary intake of vitamins E and C with respect to serum ceruloplasmin concentration (P = 0.01) and G:F (P = 0.05). Bovine herpesvirus 1 challenge was associated with lower white cell count (P = 0.007), lymphocyte count (P < 0.001), and DMI (P = 0.03). Feeding additional vitamin E to calves challenged with BHV 1 was associated with a lower (P = 0.03) serum ceruloplasmin concentration. There was a non-significant trend towards an interaction (P = 0.06) between the feeding of vitamins E and C, with virus-challenged calves fed additional vitamin E alone having greater plasma retinol concentrations. The feeding of vitamins E and/or C in calves challenged with BHV 1 was associated with alterations in the concentrations of other antioxidants. More severe disease may have translated these cellular effects to changes in health and performance.

Animal Feed↗
PubMed1989

The metabolism of 75Se-selenomethionine in sheep given supplementary copper and molybdenum.

Four groups of three ram lambs were fed, in group pens, the following diets from 4 to 19 wk of age: 1) control (6 mg Cu/kg and 1 mg Mo/kg); 2) control plus 10 mg Cu/kg; 3) control plus 10 mg Mo/kg and 4) control plus 10 mg/kg of both Cu and Mo. Copper and Mo were added to the diet as copper sulfate and sodium molybdate. The main ingredients of the diets were alfalfa hay (20%), oats (20%) and corn (59%). At 19 wk, the animals were allocated randomly to individual metabolism cages and received a single oral dose of 75Se-selenomethionine. Liver Cu concentrations at slaughter (22 wk) were 77, 259, 68 and 316 mg/kg fresh weight for treatments 1 through 4. There was clinical evidence of Cu poisoning in lambs on treatment 2. Sheep given Cu supplements without additional Mo had reduced (P less than .05) levels of 75Se activity in muscle compared with control animals. This decrease in muscle 75Se in Cu-supplemented lambs was associated with a nonsignificant increase in 75Se content of other tissues and a nonsignificant increase in fecal excretion of 75Se. Apparent absorption and net retention of 75Se was 80% and 74%, respectively. Long-term ingestion of moderate levels of Cu influenced the metabolism of Se fed as selenomethionine, possibly through effects of chronic Cu toxicity on liver function.

Analysis of Variance↗