Search PubMed⌕ Search

Biomedical subjects

D P Olson

Publications and source records attributed to D P Olson.

At least 37 records · Page 2Linked to original sources
PubMed1986

Estimation of repeatability of blood constituents in gestating beef cattle on protein- and energy-restricted diets.

Repeatabilities of blood constituents were calculated for 104 Angus heifers on two separate experiments fed adequate, protein-deficient, energy-deficient, or both protein- and energy-deficient diets. Four statistical methodologies were compared including analysis of variance, principal component (structural) analysis based on the sample covariance and sample correlation matrix, and maximum likelihood. Of 12 blood constituents tested only seven were considered sufficiently important to be included in the analysis. These blood constituents included blood urea nitrogen (BUN), creatinine (Creat), alkaline phosphatase (Alk Phos), total protein (T Prot), total bilirubin (T Bil), cholesterol (Chol) and Iron (Fe). If the standard linear model assumptions were met for heifers on the adequate diet, the estimators appeared to be quite similar for both years except when the correlation coefficient was relatively small. If the assumption of homogeneity of the variance-covariance matrix (compound symmetry) was relaxed, the structural analysis method based on the sample correlation matrix appeared preferable. However, when combining all diets, the maximum likelihood methodology was preferred. Among the specific blood constituents, Alk Phos had the highest repeatability, not only for the heifers on the adequate diet, but also for heifers on other treatments in both years. Repeatabilities for T Prot appeared to be the most consistent over all rations in both years. Repeatability estimates for Fe were high and relative rankings were consistent for both years, while repeatabilities for the other variables were either low and(or) inconsistent.

Animals↗
PubMed1986

Antibody responses in protein-energy restricted beef cows and their cold stressed progeny.

Antibody titers were measured in serum and colostral whey of pregnant beef cows immunized with tetanus toxoid and chicken red blood cells while being fed diets either restricted or nonrestricted in protein and/or metabolizable energy during the last 150 days of gestation. Serum antibody titers were also measured in the colostrum-fed, cold and noncold stressed progeny that were actively immunized with dinitrophenol conjugated to keyhole limpet hemocyanin. In general, there were no major or sustained differences in humoral immune responses to injection of tetanus toxoid or chicken red blood cells between cows fed diets that were adequate or restricted in protein or metabolizable energy. In the few cases where serum antibody titers to tetanus toxoid or chicken red blood cells differed (P less than 0.05) between adequately fed or restricted cows, the differences were no greater than twofold. Anti-chicken red blood cell titers were uniformly low (P less than 0.05) by a magnitude of two to threefold in colostral whey of cows restricted in protein and/or metabolizable energy when compared to titers in cows fed adequate amounts of protein and metabolizable energy. With one exception, neither maternal dietary restriction nor cold exposure had a major effect on the ability of the calves to absorb antitetanus toxoid and chicken red blood cell antibodies from colostrum. The humoral immune responses of all calves to injection of keyhole limpet hemocyanin and dinitrophenol were similar in magnitude.

Animals↗
PubMed1983

Serum chemical values in hypothermic and rewarmed young calves.

Serum chemical values were determined in cold-stressed Holstein bull calves ranging from 1 to 7 days of age. The animals were anesthetized and cold-stressed until their core body temperature (colonic) was lowered 10 C. Animals were then rewarmed in warm water, with heat pads or heat lamps, or were allowed to recover naturally (unassisted) at room temperature. Blood samples were collected at selected intervals during cooling and recovery. Increases (P less than 0.05) were observed in the concentrations of glucose, calcium, phosphorus, iron, alkaline phosphatase, aspartate aminotransferase, lactate dehydrogenase, total protein, albumin, total globulin, serum urea nitrogen, uric acid, total bilirubin, indirect bilirubin, and cholesterol in the cold-stressed calves during cooling. Concentrations of chloride and insulin decreased (P less than 0.05) during the same period. Changes observed in many of the serum chemical values during rewarming were generally the reverse of the respective changes that occurred during cooling, although insulin values became exceedingly high in some cases midway or near the end of recovery. Serum enzyme values also remained high during most of recovery. Data did not indicate a clear advantage of one method of rewarming over the other methods used in terms of return of the serum chemical values to normal.

Animals↗
PubMed1983

Regional differences in body temperature in hypothermic and rewarmed young calves.

One- to 7-day-old Holstein bull calves were anesthetized and cold-stressed until their core body temperature (CBT; colonic) was lowered by 10 C. The calves were then rewarmed in warm water, by heat pads or heat lamps, or allowed to recover naturally (unassisted). Temperatures of peripheral tissues, muscles, and the body core were recorded. The time required to lower the CBT of the cold-stressed calves was 168 +/- 11.7 minutes (mean +/- SE). Cold exposure caused a linear decrease in blood, colonic, rectal, and oral temperatures, whereas temperature decreases in the thigh and pectoral muscles, dorsal and ventral thoracic regions, and the hock joint region were generally of greater magnitude and were curvilinear in pattern. By the time the CBT had decreased 1 C, tissue temperatures during cooling were less than (P less than 0.01) the respective temperatures obtained before cooling. The mean time required to rewarm the calves in warm water (47.1 +/- 3.5 minutes) was less than (P less than 0.05) that for the other rewarming methods. The mean rewarming times for the heat pad (128 +/- 12.8) and heat lamp (125.4 +/- 10.9) methods were greater than (P less than 0.05) that for the warm water method, but less than (P less than 0.05) that for the unassisted calves (190.7 +/- 23.1). In general, there was a linear increase in most of the tissue temperatures during recovery although temperatures in the hock joint region were variable. Temperature differences were observed between the thigh and pectoral muscles and between subcutaneous tissues during cooling and recovery. There was poor correlation between the ages of the calves and the time required to decrease their CBT during cooling and also the time required to increase their CBT, regardless of the rewarming method used.

Animals↗
PubMed1983

Hematologic values in hypothermic and rewarmed young calves.

Hematologic values were determined in cold-stressed and rewarmed 1- to 7-day-old Holstein bull calves. The animals were anesthetized and then cold-stressed by immersion in water until their core body temperature (colonic) had decreased by 10 C. They were kept at the hypothermic state for an additional 1 hour and then were rewarmed by 1 of 3 external rewarming methods or by natural (unassisted) recovery. Changes observed in the hematologic values of the cold-stressed calves during cooling represented a trend, rather than a direct effect of cold exposure because the values did not differ (P greater than 0.05) from those obtained from the noncold-stressed animals. Nevertheless, a linear decrease (P less than 0.05) in the total number of leukocytes was observed in the cold-stressed calves during cooling when compared with preimmersion values. The leukopenia resulted primarily from a neutropenia (P less than 0.05) and secondarily from decreases in the number of other leukocytes. Minor increases were noticed in the total number of erythrocytes, hemoglobin concentration, and PCV, whereas mean corpuscular values generally remained unchanged during cooling. A rapid and linear increase in the total number of leukocytes was noticed in all cold-stressed calves during recovery. The increase in total leukocytes occurred in all types of leukocytes and particularly in segmented and nonsegmented neutrophils.

Animals↗
PubMed1983

Cardiovascular and shivering responses in hypothermic and rewarmed young calves.

Aortic blood pressure, ECG, electromyogram, and heart rate were recorded in cold-stressed and rewarmed young Holstein bull calves. The calves were anesthetized and then cold-stressed by immersion in cold water until their core body temperature (colonic) was lowered 10 C. Hypothermia was continued for 1 additional hour and then the calves were rewarmed by 3 external rewarming methods or were allowed to recover naturally (unassisted). Aortic blood pressure began to decrease in cold-stressed calves by the time their core body temperature had decreased 2 C and continued to decrease during cooling. Heart rate initially increased then decreased with cooling. Blunting of the systolic blood pressure peaks and appearance of extraneous waveforms that obscured the normal component waveforms of the ECG complex were also observed during cooling. Aortic blood pressure and heart rate of cold-stressed calves increased soon after the start of recovery and eventually returned to base line even though the rate of recovery varied depending on the method of rewarming. The component waveforms of the ECG complex became more discernible as rewarming of the cold-stressed calves progressed.

Animals↗
PubMed1981

Effects of prepartum protein restriction in the beef cow on immunoglobin content in blood and colostral whey and subsequent immunoglobin absorption by the neonatal calf.

Protein intake of first-calf beef heifers was restricted during the last 100 days of gestation, and the effects on passive transfer of colostral immunoglobins from the cow to the neonatal calf were examined. There were no significant correlations between concentration of immunoglobins (IgM, IgG1 and IgG2) in the sera or colostrum of the cow and prenatal crude protein consumption (.52 to .98 kg crude protein/day). Absorption of certain colostral immunoglobins (IgG1, and IgG2) by the calf were positively correlated (P less than .01) at 12, 18, 24 and 36 hr after birth to the maternal crude protein consumption. Colostrum was collected from the first milkings of pluriparous dairy cows, and then freeze-dried, mixed and reconstituted to be equivalent to 1 liter of colostrum. Mean IgG1 concentrations for the high and low protein groups were 6.02 +/- .90 and .78 +/- .15 mg . ml-1 (P less than .01), respectively. No relationship (P greater than .05) was found between the concentration of IgM in calf sera and daily crude protein intake of the dam. These data indicate that there was a selective decrease in absorption of IgG1 and IgG2 in calves from heifers fed low protein prenatal diets.

Animals↗
PubMed1981

Total complement hemolytic activity of colostral whey and sera from dairy cows.

Two methods were used to clarify bovine colostrum for quantitation of total complement (C') hemolytic activity in the whey. The renin precipitation method produced whey which tended to have higher C' hemolytic activity (5.0 +/- 3.4 CH50 units) than did whey prepared by ultracentrifugation (2.5 +/- 2.6 CH50 units) although this difference was not significant. No correlation was found between levels of complement in the sera of cows at parturition and in the colostral whey from the same animal. Total complement activity was not detected in milk taken a 96 hours or one month after parturition. This is apparently the first report of quantitation of total C' hemolytic activity in bovine colostrum.

Animals↗
PubMed1981

Immunoglobulin levels in serum and colostral whey or protein-metabolisable energy restricted beef cows.

Aberdeen Angus cows were fed adequate diets or diets restricted in protein and, or metabolisable energy for the last 156 days of gestation to determine effects of nutritional restriction on concentrations of immunoglobulins in serum and colostral whey. There were no significant interactions between the effects of low protein and metabolisable energy on immunoglobulin concentrations. Thus, observed differences in immunoglobulin concentrations between the restricted and adequate dietary groups were attributed to the main effects of treatment. Low protein or metabolisable energy had little overall effect on serum IgM concentrations although levels began to decrease sooner in gestation in restricted animals than in those fed adequate diets. Concentrations of IgG1 in serum of all animals were similar and a precipitous decrease in concentration was noted at about 240 days of gestation and this decrease continued until parturition. Serum IgG2 concentrations increased in all animals as parturition approached. Immunoglobulin concentrations in colostral whey were either similar to or tended to be slightly higher in dietary restricted animals than in animals fed adequate diets although the differences were not significant.

Animals↗
PubMed1981

Antibody and delayed hypersensitivity responses of neonatal calves delivered from protein-restricted dams.

The effects of moderate maternal protein restriction on in vivo humoral and cell-mediated immune responses of bovine neonates were studied. Hereford heifers were fed protein-adequate or protein-restricted rations for the last 150 days of gestation and for 6 months after parturition. At birth, all calves from these heifers were allowed to remain with their dams and were inoculated with tetanus toxoid (TT) and an emulsion of tuberculoproteins and trehalose dimycolate (cord factor) of Mycobacterium bovis. One month later, blood samples were collected from all calves, and sera were examined for antibodies to TT. The calves were given a 2nd inoculation of TT, and anamnestic antibody responses were measured 7 days later. Differences in primary or secondary antibody responses were not observed between principal and control groups of calves. Also, differences in tuberculin reactivity were not observed in calves from cows fed protein-adequate or protein-restricted diets.

Animals↗
PubMed1981

Effects of maternal nutritional restriction and cold stress on young calves: absorption of colostral immunoglobulins.

Fifty-seven newborn calves delivered from heifers fed rations either adequate or restricted in protein or metabolizable energy were housed in cold (1 C) or normothermic (21 C) environmental chambers for 3 days to determine the effects of maternal nutritional stress and cold exposure on ability of the animals to absorb colostral immunoglobulins (Ig). In general, the serum Ig concentrations in the newborn calves from dams fed rations restricted in protein or metabolizable energy and the concentrations in sera of the respective calves from dams fed adequate protein or metabolizable energy were similar throughout the 3-day period of observation. Likewise, the serum Ig concentrations in the cold-exposed calves were similar to those in the calves kept at normothermic temperature. An exponential increase in mean serum concentrations of IgM, IgG1, and IgG2 occurred between 3 and 6 hours of age; the values continued to increase, but at a slower rate after 6 hours and reached a peak by 12 hours of age. Then, IgM and IgG2 decreased until 48 hours, after which time they increased, but IgG1 varied only slightly from the peak at 12 hours and then increased. With one exception, data indicated that neither the maternal dietary restrictions or the cold exposure imposed on the calves caused significant (P greater than 0.05) differences in absorption of colostral Ig when compared with that of the respective calves from dams fed adequate diet or the calves kept at normothermic temperature.

Animal Nutritional Physiological Phenomena↗
PubMed1981

Sympathoadrenal and adrenal hormonal responses of newborn calves to hypothermia.

Seventeen newborn Holstein-Friesian bull calves were cold-stressed by total body immersion in water at 15 to 17 degrees C until the core body temperature was lowered by 10 degrees C. Nine additional calves (noncold-stressed) were immersed in water at 35 to 37 degrees C. Eight of the cold-stressed calves were euthanatized soon after removal from the water while the others (n=9) were allowed to recover in a cold room at 4 degrees C for 72 hours. Noncold-stressed calves were kept at 25 degrees C for 72 hours. Sympathoadrenal an adrenal hormonal responses of calves were determined by analysis of plasma for glucose, corticosteroids, and catecholamines. Plasma concentration of glucose and corticosteroids rapidly increased in cold-stressed calves soon after immersion and remained higher (P less than of equal to 0.05) than concentrations in noncold-stressed calves during immersion and most of recovery. There was a threefold increase (P less than or equal to 0.05) in concentration of catecholamines in plasma of cold-stressed calves and only a slight increase in noncold-stressed calves during immersion. Catecholamine concentrations remained elevated in cold-stressed calves during most of recovery. Results provide direct evidence that sympathoadrenal and adrenal hormonal responses to cold are well developed in newborn calves and that changes in concentrations of glucose, corticosteroids, and catecholamines in plasma of these animals are sensitive indicators of their ability to respond to cold stress.

Adrenal Cortex Hormones↗
PubMed1980

Hemolytic complement levels of neonatal calves delivered from protein-energy malnourished dams and subjected to cold stress.

Beef cows were placed on protein-deficient and/or energy deficient rations for the last 150 days of pregnancy. After birth their calves were placed on 1 or 21 C environmental chambers for 3 days, and sera were collected for determination of complement (C) levels. At birth, the mean complement hemolytic (CH50) titer of all calves was 46.0 +/- 1.7 units, but the titer rapidly dropped (P < 0.01) to 31.6 +/- 1.2 by 12 hours after birth. Levels of C activity then began to rise and reached a mean titer of 76.3 +/- 3.0 by 3 days of age. A quadratic curve of predicted CH50 values was constructed from the data. Differences between principal and control groups of calves were not detected. These results suggest that maternal protein-calorie deprivation and limited cold stresses have little effect on levels of C activity in the bovine neonate. Possible explanations for the decrease in CH50 levels after birth are discussed.

Animals↗
PubMed1980

Effects of maternal protein-energy malnutrition and cold stress on neutrophil function of bovine neonates.

The effects of maternal protein or calorie deprivation (or both) on the bactericidal activity of neutrophils and sera from newborn calves subjected to cold stress were studied. Nutritional deficiencies in the dam had little effect on in vitro bactericidal activity of neutrophils and base-line sera taken at birth. Neutrophils obtained at birth destroyed Staphylococcus aureus but not Escherichia coli when incubated with either unheated or heated autologous base-line sera. Heat treatment of base-line sera to inactivate complement did not alter bacterial growth. When incubated in the presence of autologous base-line sera, neutrophils from 3-day-old calves were no more active in the destruction of either bacterium than were neutrophils from newborn calves. However, addition of day 3 (immunoglobulin-containing) sera enabled day 3 neutrophils to destroy E coli (P < 0.0001). The increased destruction of E coli by day 3 neutrophils and day 3 sera was not affected by heat treatment of the sera. Maternal protein deficiency significantly increased (P < 0.05) destruction of E coli by day 3 neutrophils and sera. This effect was independent of energy levels. There were no differences observed in the bactericidal activity of neutrophils and sera taken from calves exposed to 1 C or 21 C environmental chambers for 3 days. Also, cold stress-nutritional stress interactions were not detected.

Animals↗