A hematologic and blood chemical study of Swedish purchased calves.

The hemoglobin (Hb), packed cell volume (PCV), erythrocytes (R.G.), serum iron (SI) and unsaturated iron binding capacity (UIBG) were examined in a total of 386 purchased calves for the duration of 1 year. The calves were tested within 3 days of arrival at the buyer’s herd. The average age of the calves was 28 ± 10 days ().The results may be summarized as follows:

1. Approx. 35% of the calves had Hb values ≦ 10.0 g/100 ml.
2. Fifteen% of the calves had ≦ 6.0 × 10⁶ R.C. per µl.
3. Fifty-three calves or about 14% showed SI values ≦ 40 µg/100 ml and 131 calves or 34% ≦ 80 µg/100 ml.
4. Twenty-seven % of the calves had UIBG values > 501 µg/100 ml.
5. Almost half the calves (48%) had a saturation percentage of transferrin with iron below 20% and 138 calves (36%) below 15%.

These figures among others in the study indicate that 13–35% of the purchased calves suffered from iron deficiency anemia.     

A light and electron microscopic study of changes in blood and bone marrow in acute hemorrhagic Trypanosoma vivax infection in calves.

Eleven 6-month-old calves were tsetse fly challenged with a stock of Trypanosoma vivax (IL 2337) that causes hemorrhagic infection. The calves were randomly euthanatized every 4 to 6 days; two other calves served as controls. Peripheral blood changes included anemia, thrombocytopenia, and an initial leukopenia. Later in the course of infection, leukocytosis associated with lymphocytosis and neutropenia developed. Moderate reticulocytosis (highest mean count 3.6 +/- 3.7%, maximum count 9.4%) accompanied the first wave of parasitemia, but poor response (highest mean 0.4 +/- 0.0%) occurred during the second wave, despite the persistence of severe anemia. Light microscopic examination of bone marrow samples showed a drop in the myeloid: erythroid ratio with a decrease in granulocytes, particularly metamyelocytes, bands, and segmenters. Increase in lymphocyte counts corresponded with the appearance of lymphoid nodules within the marrow. Megakaryocytic volume increased significantly in infected animals, and some megakaryocytes showed emperipolesis of red cells, neutrophils, and lymphocytes. Transmission electron microscopic examination of the bone marrow revealed that trypanosomes had crossed the sinusoidal endothelium into the hematopoietic compartment as early as the second day of parasitemia. Macrophages proliferated in the bone marrow; and from the second day of parasitemia until the end of the experimental infection, on day 46, the macrophages had phagocytosed normoblasts, eosinophil and neutrophil myelocytes, metamyelocytes, bands, and segmenters, as well as reticulocytes, erythrocytes, and thrombocytes. Therefore, dyserythropoiesis and dysgranulocytopoiesis were responsible, in part, for the observed anemia and granulocytopenia, respectively.     

Pathological studies on systemic mycoses in calves.

Systemic mycoses were found in 19 (4.7%) of 406 calves less than 6 months old which were autopsied during the past 10 years. Alimentary mycosis occurred in 12 (63.2%) of 19 cases. In alimentary mycosis, mucormycosis showed the highest rate of occurrence (91.7%, 11/12 calves) followed by aspergillosis 41.7% and candidiasis was 9.3%. Mucormycosis and aspergillosis were characterized by focal hemorrhagic necroses with hyphal proliferation and thrombi in the mucosa and muscular layers of the forestomach, abomasum, and small intestine. Candidiasis was characterized by hyperkeratosis with pseudohyphae and microconidia in the mucosa of the omasum. Four of 12 calves (33.3%) had mixed infections of the alimentary tract consisting of Mucorales and Aspergillus species. Pulmonary aspergillosis was found in 10 (52.6%) of 19 calves. There were micro-abscesses with hyphal proliferation or asteroid bodies in the lungs. Infections involving both the alimentary tract and respiratory organs were noted in 3 (10.5%) of 19 calves. Disseminated mycosis was found only in one calf. In alimentary mycosis, administration of antibiotics for the treatment of diarrhea and early weaning were thought to be an important predisposing factor.     

The pathogenesis of Trypanosoma congolense infection in calves. IV. The kinetics of blood coagulation.

Blood coagulation studies showed there was a pronounced thrombocytopenia and hypofibrinogenemia in Holstein calves infected with Trypanosoma congolense TREU 112. There was also ineffective thrombopoiesis characterized by an increased megakaryocytic mass, reduced uptake of 35S-methionine into peripheral blood platelets and a normal platelet lifespan. There was an increased uptake of isotopic label into fibrinogen and a shortened half life indicating a consumptive error with increased peripheral use of fibrinogen. No consistent abnormalities were found in ethanol gelation, partial thromboplastin time, clot retraction and lysis or plasminogen assay. Fibrin split products were rarely detected. These findings suggest that in the chronic form of bovine trypanosomiasis there is a partially compensated consumption coagulopathy.     

The effect of arterial blood sampling sites on blood gases and acid-base balance parameters in calves.

In 21 healthy calves, 1-6 months old, the interrelationship and comparability of acid-base balance variables (pH, HCO3-, BE) and blood gases (pCO2, pO2, and sat-O2) were evaluated in arterial blood collected from a larger, centrally localised (the a. axillaris) and a smaller peripheral artery (the a. auricularis caudalis). Sampling was done by direct puncture of the vessels without local anaesthesia. Except for blood pH, significant differences were observed in the average values of pCO2, pO2, HCO3-, sat-O2 (P < 0.001), and BE (P < 0.05). Analyses of blood from the a. axillaris showed higher pH, pO2, and sat-O2 values, and lower pCO2, HCO3-, and BE values compared with that from the a. auricularis caudalis. Despite statistically significant differences between some variables, in all indices high and significant correlation relationships were recorded (R = 0.928-0.961; P < 0.001). Therefore, from the biological and clinical point of view, these differences are unimportant and the presented method of peripheral arterial blood sampling can be considered suitable for evaluating blood gases and acid-base status.     

The effect of low temperatures on biochemical indicators in the blood of calves]

Twenty calves, heifers of the Holstein-Friesian breed and crossbreds with the Slovak Pied breed, were divided into two groups at the average age of 19 days. The trial group was kept outdoors in wooden hutches and the control group was housed in an insulated building. Blood was sampled at the age of 20, 33, 48 and 60 days at the outdoor temperatures of 3 degrees C, -2 degrees C, -5 degrees C and -8 degrees C. The calves kept in hutches where temperatures were always lower than in the insulated calf-house had the higher level of nonesterified fatty acids in all observations. The largest, highly significant difference was determined at the age of 60 days at the outdoor temperature of -8 degrees C (271 mumol/l vs. 224 mumol/l), and the significance of differences was also observed in the first and third blood samplings at the temperatures of 3 degrees C and -5 degrees C. The differences were highly significant in the first group between the first and fourth, and second and fourth samplings. In the calves kept in the insulated building the difference was significant between the first and fourth observation because the content of free fatty acids was also gradually increasing in this case (Tab. I). Glycaemia values were also higher in the calves kept in hutches (Tab. II). The most noticeable (significant) difference was determined at the age of 48 days at the outdoor temperature of -5 degrees C (4.3 mmol/l vs. 3.9 mmol/l). Significant differences within the group were recorded only in calves from the trial group kept in hutches. Insulin concentrations increased gradually with the older age of animals (Tab. II). At the age of 20 days the values were identical in fact in both groups and the highest concentrations were recorded at the age of 60 days. The differences between the groups were not significant, the largest difference was observed at the end of milk feeding period at the age of 60 days (19 microUI/l in calves from hutches and 15.6 microUI/l in calves from the insulated building). Triiodothyronine concentrations decreased from the starting values of 0.8 nmol/l and 0.76 nmol/l in both groups at the age of 33 days to the values of 0.61 and 0.62 nmol/l.(ABSTRACT TRUNCATED AT 400 WORDS)     

Light and electron microscopic studies on alpha naphthyl acetate esterase activity of peripheral blood T lymphocytes in chicken.

The purpose of this study was to determine the percentage of peripheral blood T lymphocytes and the localization of Alpha Naphthyl Acetate Esterase (ANAE) enzyme at the electron microscopic level in healthy adult chickens by an alpha naphthyl acetate esterase procedure. Peripheral blood samples taken from 30 adult Leghorn breed chickens were used. The percentage of ANAE positive lymphocytes was 56.4 +/- 2.82% (SD). Pseudoeosinophil and eosinophil granulocytes showed a granular positivity. In the electron microscopic examination, ANAE positive reactions were seen in lysosomal granules found in T lymphocytes, pseudoeosinophil, and eosinophil granulocytes.     

Comparative study of blood coagulation tests in the horse and pony

The clotting times obtained with different assay procedures for routine coagulation tests were examined for horse and pony samples. The whole blood clotting time test and the activated coagulation test seemed to give similar results when both tests were done at 22 C. The results obtained for the activated partial thromboplastin time assay varied, depending on the commercial reagent used for the test. Consistent results were obtained for the one-stage prothrombin time assay with each reagent used.     

Anthelmintic activity of paraherquamide in calves.

Paraherquamide, an oxindole alkaloid metabolite of Penicillium paraherquei and Penicillium charlesii, was tested against the adult stages of nine common gastrointestinal and lung nematodes of calves at single, oral dosages of 0.5, 1.0, 2.0 or 4.0 mg kg-1. At dosages 1.0-4.0 mg kg-1 there was 95% or more removal of Haemonchus placei, Ostertagia ostertagi, Trichostrongylus axei, Trichostrongylus colubriformis, Cooperia oncophora, Nematodirus helvetianus, Oesophagostomum radiatum, and Dictyocaulus viviparus. Cooperia punctata, the dosage-limiting species, was virtually unaffected by any dosage except the highest, which produced an efficacy of 89%. The 0.5 mg kg-1 dosage was 95% or more efficacious against H. placei, O. ostertagi, C. oncophora, and D. viviparus, but weaknesses were evident against the other five species. No adverse reaction was observe in any calf.     

Acetylsalicylic acid and blood coagulation in the horse.

Equine blood may contain salicylic acid (SA) taken up as free acid or represents the metabolite of acetylsalicylic acid (ASA). To obtain information of SA in race horses we screened blood samples of trotting-horses routinely drawn to be analyzed for doping substances. The individual values determined followed a Gaussian distribution displaying a geometric mean of 19 ng SA per ml serum. A probit analysis revealed linear relationship (r = 0.995). Additional studies examined the antithrombotic efficacy of ASA in the horse. An oral dose of 300 mg ASA considerably elevated the bleeding time for more than 2 hours with concomitant SA serum levels between 800 and 1000 ng/ml. It is concluded that salicylate levels even below 1 microgram/ml serum bring about considerable pharmacologic effects such as prolongation of bleeding time, decrease in blood viscosity and possibly dilatation of blood vessels. These effects may improve the tissue supply with blood including oxygen.     

A longitudinal study into the effect of grazing on claw disorders in female calves and young dairy cows

To estimate the prevalence of claw disorders in youngstock and first parity heifers and to evaluate the effect of grazing on claw disorders, 10 Dutch dairy herds participated in a 2-year longitudinal study. Five herds were zero-grazed, while in the other five herds cows and youngstock had access to pasture during the summer. Twenty female calves <1year of age and 20 females between 1 and 2years of age were randomly selected on each farm, and were individually monitored at 3 monthly intervals for 2years. Data from 366 animals with at least five observations were analysed using linear mixed models with a binomial error distribution. Independent variables were grazing, age, month of observation and previous occurrence of the disorder, while herd and animal were included as random effects. Of these 366 animals, 287 had calved once and 76 twice at the end of the study. Analytic results were obtained for digital dermatitis (DD), interdigital dermatitis/heel horn erosion (IDHE) and sole haemorrhages (SH), all of which had a prevalence of >15%. The prevalence of DD increased considerably around first calving on both the grazing and the zero-grazing farms. The prevalence of IDHE increased with age while SH prevalence showed a more fluctuating pattern. Digital dermatitis was less frequently observed in pastured animals than in permanently housed animals (OR=0.12-0.64 depending on month of observation; P<0.05), with the strongest effect being seen during the period when the herds which grazed cattle actually had animals at pasture (May to August). Grazing was also associated with lower levels of IDHE and SH, again particularly during the grazing season.     

Activation of bovine peripheral blood monocyte and its suppressive effect on parasitemia in Theileria sergenti infected calves.

Activation of bovine peripheral blood monocytes and its suppressive effect on parasite growth was examined in Theileria sergenti-infected calves by using a rosette assay that detects changes in Fc receptor expression and by luminol-dependent chemiluminescence response. Monocyte activation preceded the peak of parasitemia but was depressed parallelly with the growth of the parasites. When four calves were treated with prednisolone, three showed a good correlation between the suppression of monocyte activity and an increase of parasitemia.