Bovine Blood Samples Research Articles

Determination of lead in blood — An interlaboratory study

An international co-operative blood-Pb interlaboratory study and a Canadian co-operative blood-Pb interlaboratory study were conducted using freeze-dried bovine blood samples with different endogenous Pb levels. The samples were prepared from whole blood of a nonexposed cow and another fed with a single dose of lead acetate. The mean values computed for the two samples analyzed by 25 international participants from 13 countries were 55 and 250 μg Pbl −1, respectively. These results showed a positive bias of 10% for the low level and 9% for the high Pb level with respect to the reference values obtained by isotope dilution mass spectrometry. In the case of the Canadian interlaboratory survey the mean values computed for the two samples analyzed by the 12 participants were 40 and 229 μg Pbl −1, respectively. These results showed a negative bias of 20 and 0.4% in relation to the target values of 50 and 230 μg Pbl −1, respectively. Despite such a bias, the data, on the whole, were of acceptable precision and accuracy when compared with previous interlaboratory blood-Pb surveys.

Interlaboratory Study of Blood Selenium Determinations

Fifty-one laboratories from 14 countries participated in a survey on the determination of selenium (Se) in 8 bovine blood samples with Se concentrations ranging from 0.2 mumol/L (0.016 microgram/mL) to 14 mumol/L (1.1 micrograms/mL). The methods used (and the percentage of participants using each method) were fluorometry (61), hydride-generation atomic absorption spectrophotometry (AAS) (23), graphite-furnace AAS (6), gas chromatography (4), neutron activation analysis (4), and X-ray fluorometry (2). There was little difference in the mean Se results obtained by fluorometry or hydride-generation AAS (P greater than 0.05). Mean intralaboratory coefficients of variation (CVs) from known replicates ranged from 4 to 14% for all samples. Interlaboratory CVs were related to blood Se concentration and increased to 55% at Se levels below 0.4 mumol/L (0.032 microgram/mL). Laboratories that used quality control (QC) schemes had lower interlaboratory CVs than those that did not, but the advantage began to diminish at blood Se concentration below 0.4 mumol/L (0.032 microgram/mL). The high interlaboratory CVs, coupled with the false assurance from the low intralaboratory CVs and the ineffectiveness of the QC schemes at blood Se concentrations below 0.4 mumol/L (0.032 microgram/mL), are of concern in diagnosis of marginal Se deficiency in livestock where the concentrations of interest are in the range 0.15-0.5 mumol/L (0.012-0.039 microgram/mL).

Canadian interlaboratory survey of lead in lyophilized bovine whole blood

A Canadian co-operative blood-Pb interlaboratory survey was conducted based on lyophilized bovine blood samples with different endogenous lead contents. The samples were prepared from whole blood of a non-exposed cow and another fed with a single dose of lead acetate trihydrate. The mean values computed for the three samples analyzed by 12 participants were 40, 229, and 91 μg Pb/l, respectively. These results showed a negative bias of 20%, 0.4% and 14% with respect to the target values of 50, 230 and 106 μg Pb/l, respectively.

Blood glutathione peroxidase

Manual and automated assays for the determination of glutathione peroxidase activity in bovine, sheep, pig, and human blood samples are described. The reactivation of the enzyme in blood samples after storage at -20°C was examined. Cyanide and Drabkin's reagent, as used to prepare hemolysates in other assays, have been shown to inhibit enzyme activity, particularly in stored blood samples, and is omitted from this assay.

Co-operative interlaboratory survey of lead in lyophilised bovine whole blood

An international co-operative blood-lead interlaboratory survey was conducted based on lyophilised bovine blood samples with different endogenous lead contents. The samples were prepared from whole blood of a non-exposed cow and another fed with a single dose of lead acetate trihydrate. The mean values computed for the two samples analyzed by 25 participants from 13 countries were 55 and 250 μg Pb/l, respectively. These results showed a positive bias of 10% for the low lead level and 9% for the high lead level in relation to the reference values obtained by mass spectrometric isotope dilution analysis. Despite such a bias, the data, on the whole, are of acceptable precision and accuracy, especially when compared to previous interlaboratory blood-lead surveys.

Selenium concentration in the blood of ruminants grazing in Northern New South Wales. 1. Analysis of samples collected in the National Brucellosis Eradication Scheme

Bovine blood samples collected for the Brucellosis Eradication Scheme were analysed for selenium as a means of surveying the selenium status of grazing cattle in 10 Pastures Protection Board areas of northern New South Wales. Sources of error were also examined. The average standard deviation of repeat samplings from the same farm was �0.019�g selenium ml-1 and the seasonal variation in blood selenium concentration appeared to be relatively small. Relationships were calculated for predicting the selenium concentration in bovine plasma and liver, and in ovine whole blood, plasma and liver, from the selenium concentration of bovine blood; they were used to extend the survey results to grazing sheep. Samples were collected from 794 farms, and there were significant differences between Pastures Protection Board areas. Cattle in the Glen Innes and Armidale areas had the lowest selenium status with 26 and 14% respectively of herds having blood selenium concentrations = 0.02 �g selenium ml-1.

An evaluation of five commonly used anticoagulants, in relation to the accuracy of haematological tests for bovine, ovine, equine and canine blood

Summary Haematological tests were performed at intervals over a 102-hour period on bovine, ovine, equine and canine blood samples collected into five commonly used anticoagulants — EDTA(K3) at two different concentrations, EDTA(Na2), oxalates and heparin. Haemoglobin estimations on blood from all animals in all anticoagulants gave acceptable results for the period studied. PCV values were acceptable for the entire period with all samples from the bull and ram. All PCV values for the horse and dog proved unacceptable beyond 54 hours. The values from the horse were most consistent from anticoagulants, EDTA(Na_) and heparin, while the sample in heparin gave the most stable results for the dog. Total and differential leucocyte counts were found to be most consistent with EDTA(K3)-2 at 1.02 mg/ml and EDTA(Na2) at 1.5mg/ml. Samples were generally acceptable for 24–102 hours for the total counts and 3–12 hours for the differential counts with these anticoagulants. Heparin-treated blood from the bull and dog showed an initial increase in lymphocytes compared to counts from all other anticoagulants and on the basis of this trial cannot be recommended for this test in cattle and dogs. Because of the rapid degeneration and autolysis of leucocytes it is emphasized that, for valid differential counts, the practitioner should submit well-made blood films prepared at the time of sample collection. Of those anticoagulants studied, EDTA(K3)-2, and EDTA(Na2), can be recommended as the most suitable for general haematological use by veterinarians for cattle, sheep, dogs and horses as they had the least deleterious effect on the accuracy of haematological tests over the longest period of time.

Techniques and results of immunodiffusion test in field trials

The paper deals with the specificity of the hematological diagnosis of bovine leukosis in comparison with the demonstration of either antigen or antibodies by the immunodiffusion test. 75 bovine blood-samples from “high incidence herds” were tested hematologically as well as for the presence of leukosis-specific antigen and antibodies. In 87 % of the infected animals antigen was detected, in 60 % antibodies; 49 % were classified as hematologically positive. 274 blood-samples from herds with an acute leukosis infection were also tested for demonstration of antibodies and lymphocytosis. 37 of these contained antibodies, from which 22 (59, 5 %) also showed a lymphocytosis. 482 samples from herds with a long history of leukosis were tested for the presence of antibodies and lymphocytosis. 19 were found with antibodies, 3 of those (15, 8 %) showed a lymphocytosis. Possible reasons for the different safety of the hematological test in herds with acute or chronic leukosis infection are discussed.

Effect of an interaction between haematocrit and cryoprotectant concentration on freeze-thaw haemolysis of bovine erythrocytes.

Abstract The effect of the haematocrit and cryoprotectant concentration on freeze-thaw haemolysis of bovine red cells was studied. Two-milliliter samples of bovine blood with an haematocrit of either 20 or 60% were diluted with 2 ml of either 5, 4, 3, 2, or 1 m glycerol or DMSO in PBS or with PBS alone. The degree of haemolysis after freezing to −79 °C and thawing was least in blood diluted with 4 m cryoprotectant. At the lower concentrations of cryoprotectant, haemolysis was greater in blood with the higher haematocrit, but this effect decreased as the cryoprotectant concentration was increased and was negligible at the optimal concentration.

A rapid analytical method for persistent pesticides in proteinaceous samples

A recent investigation (1,2) of the relationship between dietary intake of pesticides and subsequent tissue levels required development of a very rapid, simple, and highly sensitive method for the detection and estimation of chlorinated hydrocarbon insecticides in proteinaceous materials. The following procedure has been applied successfully to about 3000 samples of this type in our laboratory and has been particularly useful for analysis of DDT and its relatives in small samples of bovine milk and blood.