Pathological findings of Japanese Black Cattle living in the restricted area of the Fukushima Daiichi Nuclear Power Plant accident, 2013–2016

Fifty‐one Japanese black cattle from four farms in the evacuation zone of the Fukushima nuclear accident were examined pathologically during the period, 2013–2016. We found no evidence of a radiation effect on pathological findings in any of these autopsy cases, although nine cases (3.7%) of enzootic bovine leukosis (EBL) and three cases (1.2%) of goiter were diagnosed. Estimated integrating dose of external exposure in EBL cases ranged from a maximum of 1200 mSv to a minimum of 72 mSv. Clinically, five cases showed wobble, dysstasia or paralysis. Exophthalmos was observed in three cases. Macroscopically, enlarged lymph nodes, multiple irregular masses of intra‐abdominal and intrapelvic adipose tissue, diffuse thickening of the abomasal submucosa with ulceration, and numerous white nodules of myocardium were observed. Histologically, neoplastic lymphoid cells were extensively proliferated and infiltrated in the lesions. Lymphoid tumor cells showed mature or large lymphoblastic appearance. Immunohistochemically, tumor cells were positive for BLA‐36, CD20 and CD5, and negative for CD3. Three cases showed diffuse enlargement of the thyroid gland with no mass or nodule lesion. Histologically, diffuse proliferation of follicular epithelium was observed with preservation of normal structures. There were no malignant findings such as cellular atypia or invasion to capsule.     

Decreased blood cell counts were not observed in cattle living in the “difficult‐to‐return zone” of the Fukushima nuclear accident

White blood cells, especially lymphocytes, are susceptible to radiation exposure. In the present study, red blood cell, total white blood cell, and lymphocyte counts were repeatedly measured in cattle living on three farms located in the “difficult‐to‐return zone” of the Fukushima nuclear accident, and compared with two control groups from unaffected areas. Blood cell counts differed significantly between the two control groups, although almost all the values fell within the normal range. The blood cell counts of the cattle in the “difficult‐to‐return zone” varied across sampling times even on the same farms, being sometimes higher or lower than either of the two control groups. However, neither a statistically significant decrease in blood cell counts nor an increase in the rate of cattle with extremely low blood cell counts was observed overall. The estimated cumulative exposure dose for the cattle on the most contaminated farm was within a range of 500–1000 mSv, exceeding the threshold for the lymphopenia. Because of the low dose rate on these farms, potential radiation damages would have been repaired and have not accumulated enough to cause deterministic effects.     

Fetal and neonatal goiter in cynomolgus monkeys following administration of the antithyroid drug thiamazole at high doses to dams during pregnancy

To evaluate morphologic alterations in the thyroid gland in the second generation in cynomolgus monkeys, pregnant dams were exposed to high doses of thiamazole. In Experiment A, dams received thiamazole intragastrically via a nasogastric catheter from gestation day (GD) 50 to GD 150 or on the day before delivery. Initially, the dose level was 20 mg/kg/day (10 mg/kg twice daily); however, the dose level was subsequently decreased to 5 mg/kg/day (2.5 mg/kg twice daily), since deteriorated general conditions were observed in two dams. Six out of seven neonates died on the day of birth. The cause of neonatal death was tracheal compression and suffocation from goiter. The transplacental exposure to thiamazole affected the fetal thyroid glands and induced goiter in all neonates. The surviving neonate was necropsied 767 days after discontinuation of thiamazole exposure and showed reversibility of the induced changes. In Experiment B, dams were intragastrically administered thiamazole at 5 mg/kg/day (2.5 mg/kg twice daily) for treatment periods from GDs 51 to 70, 71 to 90, 91 to 110, 111 to 130 and 131 to 150. All fetuses showed enlarged thyroid glands but were viable. Histopathologically, hypertrophy and/or hyperplastic appearance of the follicular epithelium of the thyroid gland was observed at the end of each treatment period. The most active appearance of the follicular epithelium, consisting of crowded pedunculated structure, was demonstrated at end of the treatment period from GD 131 to 150. This is the first report on the morphology of fetal and neonatal goiter in the cynomolgus monkey.     

Pharmacokinetics of tulathromycin in nonpregnant adult ewes

The objectives of this study were to determine plasma concentrations and pharmacokinetic parameters of tulathromycin after a single subcutaneous administration in the cervical region in sheep using the cattle labeled dose of 2.5 mg/kg. Six adult healthy ewes were administered tulathromycin on day 0. Blood samples were collected just prior to dosing and at selected time points for 360 h. Plasma samples were analyzed to determine tulathromycin concentrations, and noncompartmental analysis was performed for pharmacokinetic parameters. The mean maximum plasma concentration was 3598 ng/mL, the mean time to maximum concentration was 1.6 h, and the apparent elimination half‐life ranged from 68.1 to 233.1 h (mean 118 h). When comparing our results to goats and cattle, it appears sheep are more similar to cattle in regard to the concentrations observed and pharmacokinetic parameters. In summary, the pharmacokinetics of tulathromycin in sheep appear to be similar enough to those in goats and cattle to recommend similar dosing (2.5 mg/kg SC), assuming that the target pathogens have similar inhibitory concentrations.     

Saponin Adjuvants. IV. Evaluation of The Adjuvant Quil a in the Vaccination of Cattle Against Foot-And-Mouth Disease

The saponin adjuvant Quil A has been investigated in the vaccination of cattle against foot-and-mouth disease. Using a Frenkel type vaccine a dose-response relationship has been established between Quil A and neutralizing antibody titres. Ten ml of vaccine was combined with 0, 50, 200, 800, and 3200 µg of Quil A. The combinations were each injected into 4 animals. The local reaction on the site of injection produced by injection of the vaccine alone and in combination with different doses of Quil A has been estimated. On this basis a therapeutical dose at 1 mg of Quil A has been estimated to combine maximum adjuvant effect with a minimum of adverse reactions. This dose has been tested in the vaccination of cattle with FMD vaccines derived from BHK suspension cell virus of type O and A respectively. The vaccines were tested in 10 ml and 5 ml doses with or without Quil A, and each in 4 animals. It is concluded that Quil A is a valuable adjuvant for use in the induction of neutralizing antibodies against foot-and-mouth disease in cattle.     

Weight increase of the thyroid gland as a tentative screening parameter to detect the illegal use of thyreostatic compounds in slaughter cattle

A total of 45 normal or enlarged thyroid glands of adult slaughter cattle were weighed and analyzed by thin-layer chromatography for the presence of residues of the following thyreostatic compounds: thiouracil, methylthiouracil, propylthiouracil, phenylthiouracil, and methimazole. In 21 glands, mostly from imported animals, residues of methylthiouracil or methimazole were detected. These thyroids ranged in weight from 68-245 g (mean value 118 g). Glands in which no residues were found, varied in weight between 20 and 124 g (mean value 42 g). Taking an upper limit of 60 g as normal, 4 out of 22 were false-positive' with respect to the 5 thyreostatic compounds screened for, while no false-negative cases were scored. On the basis of these results the weight increase of the thyroid gland is proposed as a simple indirect parameter in the screening for the illegal use of thyreostatic compounds in slaughter cattle.     

Endocrine Gland and Brain Weights of Market Weight Bulls and Steers Representing the Shorthorn Breed and Several Breed Crosses

Thyroid, adrenal, pituitary and brain weights were first determined in 1971 in 492 market weight cattle representing purebred Shorthorns and crosses of “foreign” breeds, Charolais, Simmental and Limousin with Hereford, Angus and Shorthorn. Thyroid weights were also determined in a similar group of 433 cattle the following year. The data were reported on a per 100 kg body weight basis and analyzed within the subgroups of breed of sire, breed of dam and location.

The average thyroid weight per 100 kg of body weight for males within subgroups over the two years ranged from 3.99 to 8.71 g, while that for steers ranged from 3.81 to 4.41 g. The average thyroid weight for a group of 18 Limousin sired heifers was 3.71 g. The average adrenal weight per 100 kg of slaughter weight ranged from 3.66 to 4.20 g in the males and from 3.66 to 3.86 g in the steers. Pituitary weight per 100 kg body weight at slaughter ranged from 486-511 mg in bulls and from 469-510 mg in steers. Average brain weight ranged from 85.5 to 97.3 g in males and from 92.2 to 94.1 g in steers.

Breed differences existed only for the pituitary gland, with Simmental sired males and steers having heavier glands than Charolais sired males and steers.

Sex differences were significant for the thyroid and the brain. Thyroids of males were generally heavier than those of steers, while brains of steers were heavier than those from males.

Thyroid, adrenal and brain weights were significantly different between two genetically similar purebred herds of Shorthorns.

     

An assessment of the risks to the health of grazing animals from the radioactive contamination of pastures

As a result of the Chernobyl accident sheep and cattle in Wales, Cumbria and Scotland became contaminated with radionuclides of caesium and iodine. In the worst case, the maximum levels of contamination were of the order of 4000 Bq/kg of caesium-137 and 2000 Bq/kg of caesium-134 in muscle and 2,000,000 Bq/kg of iodine-131 in the thyroid gland. Calculations show that the radiation dose rates to the animals from these burdens of the radionuclides of caesium would have been approximately one thousandth of the dose rate needed to cause clinical signs of damage; in the case of iodine-131 approximately 10,000 times higher levels of the nuclide would have been required to cause clinically perceptible damage to the thyroid gland. In any forseeable nuclear accident severe problems of human health would arise before any detrimental effects on livestock could be detected.     

Dual-purpose Guzerá cattle exhibit high dairy performance under heat stress

The present study evaluated the heat stress response pattern of dual-purpose Guzerá cattle for test-day (TD) milk yield records of first lactation and estimated genetic parameters and trends related to heat stress. A total of 31,435 TD records from 4,486 first lactations of Guzerá cows, collected between 1986 and 2012, were analysed. Two random regression models considered days in milk (DIM) and/or temperature × humidity-dependent (THI) covariate. Impacts of −0.037, −0.019 and −0.006 kg/day/THI for initial and intermediate stages of lactation were observed when considering the mean maximum daily temperature and humidity to calculate THI. Heritability estimates ranged from 0.16 to 0.35 throughout lactation and THI values, suggesting the possibility to expect gains from selection for such trait. The variable trajectory of breeding values for dual-purpose Guzerá sires in response to changes in THI values confirms that the genotype × environment interaction due to heat stress can have some effect on TD milk yield. Despite the high dairy performance of Guzerá cattle under heat stress, estimated genetic trends showed a progressive reduction in heat tolerance. Therefore, new strategies should be adopted to prevent negative impacts of heat stress over milk production in Guzerá animals in future.     

Goiter with vascular anomalies in a litter of Polish Lowland sheepdogs

At approximately 4-5 mo of age, three Polish Lowland sheepdog puppies from a single litter of eight puppies presented to their respective primary veterinarians with bilateral subcutaneous masses in their ventral cervical regions. Evaluation, including thyroid function testing, surgical exploration with resection, computed tomography, and angiography, identified the masses as enlarged thyroid glands with severely dilated and abnormal vasculature in the regions of the glands. The dogs were also found to have serum concentrations of thyroid hormones that were below the reference ranges. None of the three dogs showed clinical signs of hypothyroidism, except for the presence of goiter. One dog also had a patent ductus arteriosus that was surgically repaired. All dogs were clinically normal at 2 yr of age. This is the first report of major vascular anomalies associated with goiter in any species. The mechanism is unknown.     

Physiological limit of the daily endogenous cholecalciferol synthesis from UV light in cattle

The link between UV light (sunlight) and endogenous cholecalciferol (vitamin D₃) synthesis in the skin of humans has been known for more than a 100 years, since doctors for the first time successfully used UV light to cure rickets in children. Years later, it was shown that UV light also had a significant effect on the cholecalciferol status in the body of cattle. The cholecalciferol status in the body is measured as the plasma concentration of 25‐hydroxycholecalciferol, which in cattle and humans is the major circulating metabolite of cholecalciferol. Very little is, however, known about the quantitative efficiency of UV light as a source of cholecalciferol in cattle nutrition and physiology. Hence, the aim of this study was to determine the efficiency of using UV light for increasing the plasma 25‐hydroxycholecalciferol concentration in cholecalciferol‐deprived cattle. Twelve cows deprived of cholecalciferol for 6 months were divided into three treatment groups and exposed to UV light for 30, 90 or 120 min/day during 28 days. UV‐light wavelengths ranged from 280 to 415 nm and 30‐min exposure to the UV light was equivalent to 60‐min average summer‐sunlight exposure at 56 °N. Blood samples were collected every 3–4 days and analysed for 25‐hydroxycholecalciferol and cholecalciferol. Results showed that increasing the exposure time from 90–120 min/day did not change the slope of the daily increase in plasma 25‐hydroxycholecalciferol. Hence, it appears that cholecalciferol‐deprived dairy cattle are able to increase their plasma 25‐hydroxycholecalciferol concentration by a maximum of 1 ng/ml/day from UV‐light exposure.     

Nitrate-Induced Goiter in Captive Whitespotted Bamboo Sharks Chiloscyllium plagiosum

Abstract

Elasmobranch susceptibility to goiter formation in captive environments has been well documented. Until recently, most public aquariums operated under the belief that the etiology of goiter in elasmobranchs was nutritional and specifically caused by insufficient dietary iodine. Recent studies have demonstrated that high environmental nitrate (NO₃-N) inhibits the ability of the thyroid gland to utilize available iodide, resulting in thyroid gland overstimulation by thyroid stimulating hormone and ultimately leading to the development of goiter. The objective of this study was to evaluate the effects of high environmental nitrate concentrations on thyroid function in juvenile whitespotted bamboo sharks Chiloscyllium plagiosum. In July 2008, five juveniles (80–150 g) were exposed to a low-nitrate environment (NO₃-N concentration < 1 mg/L of water) and five were exposed to an elevated-nitrate environment (NO₃-N = 70 mg/L) for 29 d in a flow-through natural seawater system. Nitrate exposure did not affect growth rates (e.g., weight, length, and condition factor) and did not alter free plasma thyroxine concentrations during the 29-d experimental period. However, histological examination of thyroid glands from sharks exposed to elevated nitrate revealed the development of diffuse hyperplastic goiter. With increasing restrictions on water use, most modern aquaria operate as recirculating systems, which results in higher and more chronic nitrate exposure for captive animals. Goiter is one of the most common health problems in captive elasmobranchs, and this study suggests that nitrate exposure is an important factor in the etiology of this disease.

Received August 4, 2010; accepted February 22, 2011     

Morphology and Distribution of Lamellar Corpuscles in the Mesentery of the Cat

Mesentery samples obtained from 13 mixed breed cats were stereoscopically and microscopically examined and yielded the following results. In the mesentery, lamellar corpuscles were densely distributed around blood vessels, with a mean number of 182.2 ± 20.9 and mean maximum and minimum diameters of 0.98 ± 0.18 mm and 0.54 ± 0.08 mm, respectively. While most lamellar corpuscles were isolated, some complex lamellar corpuscles were found in the mesentery. Lamellar corpuscles in the mesentery appear to serve more as internal receptors that detect changes in the internal environment than as external receptors. In addition, those found around blood vessels in the mesentery are likely to be involved in blood pressure regulation.     

Epidemiological and pathological studies on congenital diffuse hyperplastic goiter in calves.

Perinatal diseases such as weak calf, stillbirth, or abortion were found in 86 calves from about 600 cows in a farm (A Farm) in 1987 and 1988. Such perinatal diseases were decreased to 36 calves in 1989 and 1990 after an additional supply of seaweed was made to the maternal feeds. From these cases, 23 stillborn and weak calves were pathologically examined. The mean weight with standard deviation of the 18 thyroid glands was 36.3 +/- 28.6 g before feeding of the seaweed supplement, and 12 (67%) of the glands showed moderate to marked degree of diffuse hyperplastic goiter in histological criteria. On the other hand, 5 glands weighed 12.0 +/- 3.4 g and revealed no such histological lesions after the additional supply. These results suggest that the goiter had been associated with birth of weak calves. Further study was performed on 37 newborn calves affected with Akabane disease in 1986 in A Farm and the neighbouring B Farm located. Seven (54%) of 13 thyroid glands from A Farm and 1 (4%) of 24 glands from B Farm showed histologically moderate to marked goitrous lesions. There were dotted "Inugarashi", Rorippa indica, family Cruciferae in both pastures. The mean iodine contents of the orchard grasses were 87 and 121 micrograms/kg on dry basis in A and B Farms. Marginal deficiency or lower limit of iodine and possible thiocyanate content of "Inugarashi" may have been responsible for the goiter in the farms.     

Effects of age on the pharmacokinetics of single dose sulfamethazine after intravenous administration in cattle

Sulphonamides are still being used widely, influenced by the low cost and the efficacy against many common bacterial infections, since they present a broad spectrum of activity. The aim of this study was to determine the effect of age on the pharmacokinetic/pharmacodynamics (PK/PD) integration of intravenous sulfamethazine (60 mg/kgbw) in cattle, and the possible therapeutic outcomes. Six healthy female calves, at the age of one, three, seven and fifteen weeks were used. Normality analysis was assessed with the Shapiro-Wilk test. Non-parametric tests for paired data were used. Plasma concentrations were quantified using HPLC/uv. Differences were found between one-three-weeks-old calves and seven-fifteen-weeks-old calves, in pharmacokinetic parameters (clearance, area under the concentration-time curve and elimination half-life) and in the PK/PD integration. The ratios obtained in PK/PD integration (T>MIC, WAUC) confirm that it is necessary to apply twice the dose of sulfamethazine in ≥ 7 weeks-old cattle to reach a satisfactory dosage regimen (MIC ≥ 32 μg/mL).     

Comparison of urine and blood as a convenient and practical sample for estimating the contamination level of live cattle with radioactive cesium

Blood and urine were compared to clarify which is a better sample for estimating the concentration of radioactive cesium in muscles of live cattle. The most probable concentration of ¹³⁷Cs in muscles was 21.0 times that in blood, and the error of this estimation was 28%. The concentration of ¹³⁷Cs in blood was estimated accurately using urine samples. The estimation error did not increase so much (33%), even when the concentration of ¹³⁷Cs in muscles was estimated using urine samples. On the other hand, the maximum volume of blood that can be collected with one syringe is 50 ml, whereas it is easy to collect 1,000 ml of urine. It took at least 360 min to confirm that a cow meets the legal standard by inspecting 50 ml of blood. However, with 1,000 ml of urine, a 20 min measurement time was sufficient for this purpose. This difference in the required measurement time is critically important for practical use. In addition, urine can be collected by farmers themselves, whereas the blood collection requires a veterinarian. Therefore, urine is a more convenient and practical sample for estimating the contamination level of live cattle with radioactive cesium.     

Implementation of total body photon irradiation as part of an institutional bone marrow transplant program for the treatment of canine lymphoma and leukemias

A total body irradiation (TBI) protocol was developed to support a bone marrow transplant (BMT) program for the treatment of canine hematologic malignancies. The purpose of this prospective study is to describe implementation of the protocol and resultant dosimetry. Nongraphic manual treatment planning using 6 MV photons, isocentric delivery, 40 × 40 cm field size, wall‐mounted lasers to verify positioning, a lucite beam spoiler (without use of bolus material), a dose rate of 8.75 cGy/min at patient isocenter, and a source‐to‐axis distance of 338 cm were used for TBI. A monitor unit calculation formula was derived using ion chamber measurements and a solid water phantom. Five thermoluminescent dosimeters (TLDs) were used at various anatomic locations in each of four cadaver dogs, to verify fidelity of the monitor unit formula prior to clinical implementation. In vivo dosimetric data were then collected with five TLDs at various anatomic locations in six patients treated with TBI. A total dose of 10 Gy divided into two 5 Gy fractions was delivered approximately 16 h apart, immediately followed by autologous stem cell transplant. The mean difference between prescribed and delivered doses ranged from 99% to 109% for various sites in cadavers, and from 83% to 121% in clinical patients. The mean total body dose in cadavers and clinical patients when whole body dose was estimated by averaging doses measured by variably placed TLDs ranged from 98% to 108% and 93% to 102% of the prescribed dose, respectively, which was considered acceptable. This protocol could be used for institutional implementation of TBI.     

Effect of dietary supplemental ascorbic acid and folic acid on the growth performance,redox status,and immune status of broiler chickens under heat stress

This experiment was conducted to investigate the effects of dietary supplemental L-ascorbic acid (AA) and folic acid (FA) on broiler chickens under heat stress (HS) conditions when supplemented either alone or in combination. For this aim, the effect of these supplements on the broilers’ growth performance, some blood parameters, antioxidant, and immune status were evaluated. Hatchling Cobb-500 broilers (total = 240) were fed either corn and soybean meal-based diet (control group) or basal diet supplemented with 200 mg AA/kg diet, 1.5 mg FA/kg diet, or 200 mg AA plus 1.5 mg FA/kg diet, for 35 days during the summer months (n = 6 replicates/group, 10 birds/replicate). The minimum and maximum average temperatures ranged from 84.5 to 96.2 °F, and the relative humidity ranged from 68.5 to 76.5%. Supplemented vitamins either alone and (or) in combination increased (P < 0.01) broilers’ growth performance, thyroid hormones levels, insulin growth factor1, blood hemoglobin, total protein, albumin, globulin, heat shock protein70, total antioxidant capacity, catalase enzyme activity, superoxide dismutase enzyme activity, antibody titer against Newcastle disease virus, and decreased (P < 0.01) heterophil/lymphocytes. The effects (P < 0.01) of the supplemented vitamins on the analyzed parameters were better when they were added in combination. In conclusion, the combination of AA and FA at 200 and 1.5 mg/kg, respectively, increased the broilers’ antioxidant status with coordinated improvement in the growth performance and health status under HS.

     

Stochastic Simulation Model Comparing Distributions of STEC O157 Faecal Shedding Prevalence Between Cattle Vaccinated With Type III Secreted Protein Vaccines and Non‐Vaccinated Cattle

Pens of cattle with high Escherichia coli O157:H7 (STEC O157) prevalence at harvest may present a greater risk to food safety than pens of lower prevalence. Vaccination of live cattle against STEC O157 has been proposed as an approach to reduce STEC O157 prevalence in live cattle. Our objective was to create a stochastic simulation model to evaluate the effectiveness of pre‐harvest interventions. We used the model to compare STEC O157 prevalence distributions for summer‐ and winter‐fed cattle to summer‐fed cattle immunized with a type III secreted protein (TTSP) vaccine. Model inputs were an estimate of vaccine efficacy, observed frequency distributions for number of animals within a pen, and pen‐level faecal shedding prevalence for summer and winter. Uncertainty about vaccine efficacy was simulated using a log‐normal distribution (mean = 58%, SE = 0.14). Model outputs were distributions of STEC O157 faecal pen prevalence of summer‐fed cattle unvaccinated and vaccinated, and winter‐fed cattle unvaccinated. The simulation was performed 5000 times. Summer faecal prevalence ranged from 0% to 80% (average = 30%). Thirty‐six per cent of summer‐fed pens had STEC O157 prevalence >40%. Winter faecal prevalence ranged from 0% to 60% (average = 10%). Seven per cent of winter‐fed pens had STEC O157 prevalence >40%. Faecal prevalence for summer‐fed pens vaccinated with a 58% efficacious vaccine product ranged from 0% to 52% (average = 13%). Less than one per cent of vaccinated pens had STEC O157 prevalence >40%. In this simulation, vaccination mitigated the risk of STEC O157 faecal shedding to levels comparable to winter, with the major effects being reduced average shedding prevalence, reduced variability in prevalence distribution, and a reduction in the occurrence of the highest prevalence pens. Food safety decision‐makers may find this modelling approach useful for evaluating the value of pre‐harvest interventions.