Search Results

You are looking at 101 - 110 of 1,083 items for :

  • Refine by Access: All Content x
Clear All

Summary

High plasma cortisol concentration is associated with perception of stress and reduced immune function in pigs. Neonatal pigs (12, 19, or 26 days old) were tested to determine maximal cortisol response to a mild restraint stressor. Pigs were fitted with indwelling jugular cannulas 4 days prior to restraint. One day before restraint, 10 ml of blood was removed for lymphocyte isolation and subsequent in vitro lymphocyte proliferation and interleukin 2 (il-2) assays. On the day of restraint, blood samples were drawn 10 minutes before and 3, 10, and 20 minutes after holding each pig in a supine position for 1 minute. Plasma cortisol concentration was determined by use of radioimmunoassay. Pigs with maximal cortisol response greater than the mean value for that age group were classified in the high-responder (hires) group. Conversely, those with values lower than the mean maximal response were assigned to the low-responder (lores) group. The HIRES pigs had larger relative adrenal gland weights and higher baseline and maximal cortisol responses, compared with lores pigs (P = 0.0170, P = 0.0002, P = 0.0001, respectively). Mitogen-induced lymphocyte proliferative responses (to phytohemagglutinin, concanavalin A, and pokeweed mitogen) were 60% lower (P = 0.0037, P = 0.0432, P = 0.0103, respectively) in hires vs lores pigs. In vitro il-2 production did not differ between hires and lores pigs. Lymphocyte proliferation induced by the B-cell mitogen, pokeweed mitogen, decreased 56% with age (P = 0.0151). Production of il-2 was numerically decreased (P = 0.06) by 50% in 26-day-old pigs, compared with earlier ages. These results indicate that neonatal pigs with low cortisol response to stress may have an advantage, from an immunologic standpoint, over pigs prone to stress.

Free access
in American Journal of Veterinary Research

Abstract

Objective

To quantify glutamine use by viscera drained by the portal vein in neonatal calves and to determine whether uptake could be stimulated by long-term IV infusion or long-term use of oral supplements.

Animals

4 healthy neonatal calves.

Procedure

A femoral artery, jugular vein, and the portal vein were surgically cannulated in each calf. Blood flow in the portal vein was measured, using an ultrasonic transit-time flow probe. Calves were given an IV infusion of glutamine on days 6, 8, and 10 after surgery. Before the first infusion, calves were fed a diet of milk only. The diet was supplemented with glutamine for the second and third infusions. Glutamine was administered via the jugular vein during a 5-hour period. Venous and arterial blood samples were collected every hour for 5 hours.

Results

During glutamine infusion, uptake of glutamine by viscera drained by the portal vein increased in association with increased production of ammonia. Glutamine supplementation of the diet did not alter glutamine uptake. Glutamine infusion did not increase viscera uptake of indispensable amino acids. Longterm use of glutamine supplements or infusion of glutamine for periods of more than 1 hour increased glutamine uptake by viscera. Arterial leucine concentration and uptake of leucine by the viscera decreased during glutamine infusion, indicating that leucine became the limiting factor.

Conclusion

Glutamine administration (supplements or infusions) to calves may require that a mixture of amino acids be provided to improve effectiveness.

Clinical Relevance

Glutamine may be beneficial in treatments designed to promote intestinal healing in diarrheic calves. (Am J Vet Res 1999;60:446-451)

Free access
in American Journal of Veterinary Research

In the report “Expression of interleukin-1β, interleukin-8, and interferon-γ in blood samples obtained from healthy and sick neonatal foals” ( Am J Vet Res 2012;73:1418–1427), the units for plasma lactate concentration in panel F andy-axis unit

Full access
in American Journal of Veterinary Research

Abstract

Objective—To determine effects of the selectin inhibitor TBC1269 on neutrophil-mediated pulmonary damage during acute Mannheimia haemolytica-induced pneumonia in newborn calves.

Animals—Eighteen 1- to 3-day-old colostrumdeprived calves.

ProcedureMannheimia haemolytica or saline (0.9% NaCl) solution was inoculated in both cranial lung lobes of 12 and 6 calves, respectively. Calves were euthanatized 2 (saline, n = 3; M haemolytica, n = 4) or 6 hours (saline, n = 3; M haemolytica, n = 8) after inoculation. Four M haemolytica-inoculated calves euthanatized at 6 hours also received TBC1269 (25 mg/kg, IV) 30 minutes before and 2 hours after inoculation. Conjugated diene (CD) concentrations, inducible nitric oxide synthase (iNOS) expression, and apoptotic cell counts were determined in lung specimens collected during necropsy.

Results—Conjugated diene concentrations were significantly increased in all M haemolytica-inoculated groups, compared with saline-inoculated groups. Calves treated with TBC1269 had decreased concentrations of CD, compared with untreated calves, although the difference was not significant. Number of apoptotic neutrophils and macrophages increased significantly in TBC1269-treated calves, compared with untreated calves. Inducible nitric oxide synthase was expressed by epithelial cells and leukocytes. However, iNOS was less abundant in airway epithelial cells associated with inflammatory exudates. Degree of iNOS expression was similar between TBC1269-treated and untreated calves.

ConclusionsMannheimia haemolytica infection in neonatal calves resulted in pulmonary tissue damage and decreased epithelial cell iNOS expression. The selectin inhibitor TCB1269 altered, but did not completely inhibit, neutrophil-mediated pulmonary damage. ( Am J Vet Res 2001;62:17–22)

Full access
in American Journal of Veterinary Research

Abstract

Objective—To evaluate the effect of 2 oxytocin products administered to sows at the onset of fetal expulsion on the integrity of umbilical cords, meconium staining, and piglet mortality.

Animals—2099 neonatal pigs.

Procedure—180 parturient sows were randomly assigned to 3 stratified groups of 60 sows each. Two groups of sows were injected IM at the onset of fetal expulsion with 1 of 2 oxytocin commercial products (20, 40, or 50 U for sows weighing 120 to 150 kg, 151 to 250 kg, or ≥ 251 kg, respectively). Control sows were treated IM with saline (0.9% NaCl) solution. Farrowing time, expulsion intervals, and numbers of stillborn and liveborn piglets were recorded for each sow. Piglets were evaluated for inspiratory effort, heart rates, and degree of meconium staining of skin (nonstained, and moderately or severely stained). Umbilical cords were classified as normal in appearance, edematous, congested, hemorrhagic, or ruptured.

Results—Oxytocin-treated sows had a significant decrease in farrowing time and expulsion intervals and also had a significantly higher number of stillborn piglets per litter, compared with control sows. The number of piglets per litter with ruptured and hemorrhagic umbilical cords was significantly greater in oxytocin- treated sows, compared with control sows. In near-death stillborn piglets, oxytocin treatment significantly decreased inspiratory efforts at birth and increased the rate and severity of meconium staining, compared with saline treatment.

Conclusions and Clinical Relevance—Oxytocin given to sows at the onset of fetal expulsion significantly increases the rate of fetal distress, anoxia, and intrapartum death in piglets. (Am J Vet Res 2002;63:1571–1574)

Full access
in American Journal of Veterinary Research

Objective

To evaluate alterations in lymphocyte subpopulations, CBC results, and clinical signs in neonatal calves inoculated with 3 commercially available proprietary multiple-antigen vaccines containing known quantities of endotoxin.

Design

Prospective, randomized controlled field trial.

Animals

36 healthy Holstein heifer calves between 3 and 31 days old.

Procedure

Vaccines were administered to 18 calves according to label instructions, except for the recommended age of administration. The 18 other calves served as unvaccinated controls. Two weeks after entry into the study, calves were given secondary doses of the same vaccines. Calves in both groups were examined and blood samples were collected for determination of lymphocyte subpopulations and hematological parameters once daily for 5 days beginning on the day that both the primary and the secondary vaccinations were given. Lymphocyte subpopulations, including BoCD2*, BoCD4+, BoCD8+, B cells, and γ/δ T cells, were determined by use of flow cytometry, using monoclonal antibodies as markers.

Results

Vaccinated calves did not develop clinical signs of illness. There were no significant differences in absolute numbers of lymphocyte subpopulations between vaccinated and unvaccinated calves. Vaccinated calves had significantly higher rectal temperatures, total WBC counts, and absolute neutrophil counts than did control calves. These differences persisted for 3 to 4 days after vaccination.

Clinical Implications

Findings confirm empirical observations that vaccination with multiple products at the same time may induce evidence of an inflammatory response in most calves. Additional research is indicated to further evaluate the safety of using multiple vaccines simultaneously. (J Am Vet Med Assoc 1996;209:638-642)

Free access
in Journal of the American Veterinary Medical Association

Abstract

Objective—To compare experimentally induced concurrent infection with bovine viral diarrhea virus (BVDV) and bovine rotavirus (BRV) with infection of either virus alone in calves.

Animals—Seventeen 1-day-old gnotobiotic calves.

Procedure—Calves were allotted to 8 treatments as follows: group 1, mock-infected control calves (n = 2); group 2, inoculated with BVDV on day 1 (2); groups 3, 5, and 7, inoculated with BRV on days 1 (2), 4 (1), or 7 (2), respectively; and groups 4, 6, and 8, inoculated with BVDV on day 1 and with BRV on days 1 (2), 4 (2), or 7 (4), respectively. Concentrations of BVDV in serum and ileal tissues were measured, and BRV shedding in feces was determined. Histologic examination and immunohistochemical analysis were conducted to detect lesions and viral antigens.

Results—Neonatal calves inoculated with BVDV alone or with BVDV on day 1 and BRV on day 7 developed villus atrophy and submucosal inflammation of the intestines. Concurrent BVDV and BRV infections acted synergistically in the intestinal tract, causing more severe enteric disease than infection with either virus alone. Severe lymphoid depletion was associated with BVDV infection in calves regardlesss of concurrent BRV infection.

Conclusions and Clinical Relevance—Infection with BVDV played direct and indirect roles in enteritis in neonatal calves, causing villus atrophy in the duodenum and submucosal inflammation of the intestines. Also, BVDV potentiated effects of BRV. Concurrent infection with BVDV and BRV resulted in more severe enteric disease in neonatal calves than infection with BRV or BVDV alone. (Am J Vet Res 2002;63:1179–1186)

Full access
in American Journal of Veterinary Research

Summary

We examined the effect of infusion of lipopolysaccharide (lps) on serum tumor necrosis factor alpha (tnfα) concentration and clinical attitude in 2- to 3-day-old colostrum-fed (cf) and colostrum-deprived (cd) foals. Eleven cf and 8 cd neonatal foals were given a bolus IV infusion of Escherichia coli O55:B5 lipopolysaccharide (0.5 µg kg of body weight) in sterile saline (0.9% NaCl) solution. Four cf and 2 cd foals were given saline solution alone. Serum IgG concentration and serum anti-lps IgG(T) antibody titer were determined for each foal prior to infusion. A depression index was used to score clinical abnormalities. Serum tnfα concentration was estimated by use of an in vitro cytotoxicity bioassay that used WEHI 164 clone 13 cells as targets. The cytotoxic serum factor was identified as tnfα by immunoprecipitation with caprine antisera raised against the 15 NH2- terminal amino acids of human tnfα. Tumor necrosis factor alpha was not detected in any preiniusion serum samples nor in any samples from foals given saline solution alone. Serum tnfα concentration increased in all lps-infused foals and peaked between 60 and 90 minutes after infusion. Serum tnfα concentrations, expressed as mean percentage of peak serum tnfα concentration, persisted longer in cd foals given lps than in cf foals given lps. All lps-infused foals displayed clinical signs of endotoxemia, but mean depression index scores of the cf and cd foals given lps were not significantly different at any time. Serum tnfα concentrations were correlated with depression index scores in both lps-infused groups. Mean rectal temperature increased by 1 hour and remained high for 4 hours after infusion in cf foals given lps . Mean rectal temperature in cd foals given lps was significantly less than that for cf foals given lps 1 and 2 hours after infusion and was higher than mean rectal temperature prior to infusion 3 and 4 hours after infusion. Neither preinfusion total serum IgG concentration nor serum anti-lps IgG(T) antibody titer correlated with peak serum tnfα concentration in the 19 lps-infused foals.

Free access
in American Journal of Veterinary Research

Abstract

Objective—To determine the effects of a 24-hour infusion of an isotonic electrolyte replacement fluid (IERF) on weight, serum and urine electrolyte concentrations, and other clinicopathologic variables in healthy neonatal foals.

Animals—4 healthy 4-day-old foals.

Design—Prospective study.

Procedure—An IERF was administered to each foal at an estimated rate of 80 mL/kg/d (36.4 mL/lb/d) for 24 hours. Body weight was measured before and after the infusion period. Urine was collected via catheter during 4-hour periods; blood samples were collected at 4-hour intervals. Variables including urine production; urine and serum osmolalities; sodium, potassium, and chloride concentrations in urine and serum; urine and serum creatinine concentrations; urine osmolality-to-serum osmolality ratio (OsmR); transtubular potassium gradient (TTKG); and percentage creatinine clearance (Crcl) of electrolytes were recorded at 0, 4, 8, 12, 16, 20, and 24 hours during the infusion period. Immediately after the study period, net fluid and whole-body electrolyte changes from baseline values were calculated.

Results—Compared with baseline values, urine and serum sodium and chloride serum concentrations, urine and serum osmolalities, OsmR, and percentage Crcl of sodium and chloride were significantly increased at various time points during the infusion; urine production did not change significantly. After 24 hours, weight, TTKG, serum creatinine concentration, and whole-body potassium had significantly decreased from baseline values.

Conclusions and Clinical Relevance—Results suggest that administration of an IERF containing a physiologic concentration of sodium may not be appropriate for use in neonatal foals that require maintenance fluid therapy. (J Am Vet Med Assoc 2005;227:1123–1129)

Full access
in Journal of the American Veterinary Medical Association

Abstract

Objective

To quantify glutamine use in viscera drained by the portal vein in neonatal calves and to assess the relative nutritional importance of glutamine, glucose, and acetate for enterocytes.

Animals

5 healthy neonatal calves.

Procedure

A femoral artery, jugular vein, and the portal vein were surgically cannulated in each calf. Blood flow in the portal vein was measured by use of an ultrasonographic transit-time flow probe. A series of solutions was infused on 4 days for each calf. On the infusion days, acetate, glucose, glutamine, and saline (0.9% NaCl; control) solutions were administered IV during 1-hour periods via the jugular vein. Venous and arterial blood samples were collected during the last 15 minutes of each 1-hour infusion.

Results

Uptake of glutamine and glucose by viscera drained by the portal vein was 0.3 ± 1.1 and 1.9 ± 3.1 µmol/kg0.75/min, respectively, during saline infusion. During acetate, glucose, and saline infusions, glucose was a greater source of energy for the intestines than was glutamine. However, during glutamine infusion, uptake of glutamine by viscera drained by the portal vein increased significantly (29.9 ± 11.2 µmol/kg0.75/min), which was associated with an increase in ammonia production (7.0 ± 0.5 µmol/kg0.75/min). Toxicosis was not associated with IV administration of glutamine.

Conclusion

Glutamine infusion resulted in an increase in glutamine uptake by viscera drained by the portal vein, which was associated with an increase in ammonia production and a slight increase in oxygen consumption.

Clinical Relevance

These solutions may be used to develop treatments that enhance healing of intestines of diarrheic calves. (Am J Vet Res 1999;60:437-445)

Free access
in American Journal of Veterinary Research