Keiji Okada

Keiji Okada
Iwate University · Agriculture

About

61
Publications
5,018
Reads
How we measure 'reads'
A 'read' is counted each time someone views a publication summary (such as the title, abstract, and list of authors), clicks on a figure, or views or downloads the full-text. Learn more
655
Citations
Citations since 2017
8 Research Items
323 Citations
201720182019202020212022202301020304050
201720182019202020212022202301020304050
201720182019202020212022202301020304050
201720182019202020212022202301020304050

Publications

Publications (61)
Article
Full-text available
Nuclear plant accidents can be a risk for thyroid cancer due to iodine radioisotopes. Near the Fukushima Daiichi nuclear power plant, cattle were exposed to radiation after the accident occurred in May 2011. Here we estimated the total radiation exposure to cattle thyroid and its effects on thyroid function. Until October 2016, the estimated extern...
Article
Full-text available
Since the Fukushima nuclear accident in 2011, various abnormalities have been reported in animals living in the contaminated area. In the present study, we examined DNA damage in cattle living in the "difficult-to-return zone" by 8-hydroxy-2′-deoxyguanosine, comet, and micronucleus assays using their peripheral blood. The radiation exposure dose ra...
Article
ESR tooth enamel retrospective doses were obtained for teeth of 16 cattle bred in the two ranches located in the area contaminated by Fukushima Dai-ichi Nuclear Power accidents in 2011. The obtained doses are up to 1.0 Gy for cattle bred in both two ranches. The doses obtained for cattle in Omaru ranch, with higher contamination, are roughly consis...
Article
Full-text available
To study the effect of ionizing radiation on thyroid glands, 66 Japanese Black cattle residing in the restricted area of the Fukushima Daiichi Nuclear Power Plant in 2013–2017 were pathologically examined. There were no clinical symptoms of thyroid disease in these cattle. Three cases of goiter and seven of atrophy were found in two among the four...
Article
Since the Fukushima nuclear accident, radioactive contamination of foods has become a serious concern among the Japanese people. In the present study, the decontamination effects of boiling and water extraction on beef slices containing radioactive cesium were examined, focusing on the effects of beef thickness and treatment time. Boiling effective...
Article
Full-text available
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 unaffect...
Article
In the region contaminated by the Fukushima nuclear accident, radioactive contamination of live cattle should be checked before slaughter. In this study, we establish a precise method for estimating radioactive cesium concentrations in cattle blood using urine samples. Blood and urine samples were collected from a total of 71 cattle on two farms in...
Article
The amount of radioactive cesium in various tissues of cattle which lived in the highly contaminated area designated as the "difficult-to-return zone", was measured in May and December of 2014. The average concentration of radioactive cesium in the skeletal muscles ranged from 3900 to 5500 Bq/kg, and there was no significant difference between May...
Article
Radioactivity inspection of slaughtered cattle is generally conducted using a portion of the neck muscle; however, there is limited information about the distribution of radioactive cesium in cattle. In this study, therefore, we measured not only radioactive cesium but also stable cesium in various tissues of 19 cattle that had been kept in the are...
Article
Full-text available
The present study was undertaken to evaluate 8-hydroxy-2′-deoxyguanosine (8-OHdG) level in peripheral lymphocytes during the transition period in dairy cows. Twenty cows that belong to the Iwate Livestock Breeding Center (Morioka city, Iwate prefecture, Japan) were subjected to study. Whole blood samples were collected from the same animals at two...
Article
Full-text available
We investigated various essential factors for optimum infrared thermography for cattle clinics. The effect of various factors on the detection of surface temperature was investigated in an experimental room with a fixed ambient temperature using a square positioned on a wall as an object. Various factors of animal objects were examined using cattle...
Article
After the disastrous incident of the Fukushima Daiichi Nuclear Power Station, various agricultural, livestock and fishery products have been inspected for radioactive contamination with cesium in Japan. In this study, radioactive cesium was measured in various edible parts of cattle to verify the current inspection method for cattle, in which the n...
Article
Full-text available
The present study was designed to elucidate if ethionine administration could be used to induce hepatic lipoperoxidation in cattle, as indicated by the increase concentrations of the lipid peroxidation products, malondialdehyde (MDA) and 4-hydroxyalkenals (4-HAE) in the hepatic tissues. Five cows were injected intraperitoneally with dl-ethionine (1...
Article
The objective of this study was to determine whether subacute ruminal acidosis (SARA) could be diagnosed by continuous measurements of the reticular pH, as compared with the ruminal pH, using healthy cows fed a control diet and SARA cows fed a rumen acidosis-inducing diet. The reticular and ruminal pH were measured simultaneously by a radio transmi...
Article
Full-text available
To assess the relationship between pH and temperature in the ruminal bottom fluid, circadian changes were monitored using cows fed a control diet (C diet) or a rumen acidosis-inducing diet (RAI diet) by using a wireless radio-transmission pH- measurement system. These two parameters were measured simultaneously at 10-min intervals on day 14 after c...
Article
Full-text available
We developed a novel wireless radio transmission pH measurement system to continuously monitor ruminal bottom pH in cows, and compared these measurements to pH values determined by a spot-sample method. The wireless system consists of a pH sensor, data measurement receiver, relay unit, and personal computer with special software. The bullet-shaped...
Article
Full-text available
Circadian pH changes in the fluid of the rumen (bottom and middle) and reticulum were assessed simultaneously using wireless and wired radio-transmission pH-measurement systems in cows fed a control diet (C diet) or rumen-acidosis-inducing diet (RAI diet). The pH in the three sites decreased following the morning and evening feedings. In cows fed t...
Article
Full-text available
To develop a simple procedure for estimating glomerular filtration rate (GFR) in calves, a three-sample method using iodixanol was first compared to that using the standard agent inulin. Iodixanol and inulin were co-administered intravenously to calves at 40 mg I/kg and 40 mg/kg, respectively, and blood was collected 30, 60, 120, and 180 min later....
Article
An indwelling ruminal pH system has been used for the continuous recording of ruminal pH to evaluate subacute ruminal acidosis (SARA) in dairy cows. However this system does not allow the field application. The objective of this study was to develop a new radio transmission pH measurement system, and to assess its performance and usefulness in a co...
Article
In order to understand the effects of the automatic milk replacer feeding system on calf health, we examined the effect of frequent milk feeding on curd formation in the abomasum using ultrasonographic imaging. Eight male Holstein calves were divided into a milk-replacer group and a fresh milk group. Calves were fed twice a day to 12 days after bir...
Article
Eight Holstein bull calves were divided into two groups; a non-treated control group and a famotidine treated group. Fresh milk was fed twice a day. The experiment was conducted between 7 and 14 days of age. During the experimental period the control group was injected with physiological saline, and the famotidine group was injected with famotidine...
Article
In order to examine the relationship between white scour and fatty acids, we added fatty acids to the milk replacer. Twenty healthy Holstein calves were divided into 4 groups, five calves per group; a control group with no fortified fatty acid, and 3 groups fed either with oleic, stearic, or palmitic acid, respectively. The calves were fed milk rep...
Article
Inadequate milk curd formation in the abomasum of newborn calves causes malnutrition and diarrhea. In order to define the factors of inadequate curd formation, we compared the curd forming ability among 9 kinds of milk replacers, bulk milk (raw milk), and skim milk both in vitro and in vivo. When rennet was added, the raw milk and one milk replacer...
Article
Full-text available
The aim of this study was to ultrasonographically evaluate curd formation in 29 pre-ruminant calves that were fed a clotting milk replacer. Abomasal curd was absent in 8/29 calves at 2 h after feeding. In these eight calves, abomasal contents were observed as an anechoic image with small echogenic spots (five calves), or as an echogenic image with...
Article
The goal of the present study was to measure the total glutathione level and glutathione reductase activity in bovine erythrocytes and liver biopsy. Five cows were injected intraperitoneally with DL-ethionine (12.5 mg/kg B.W.), and two control cows were injected with normal saline (0.9% NaCl). Ultrasonography guided liver biopsy, and blood samples...
Article
The goal of this study was to assess if oxidative stress, as measured by alterations in the concentrations of antioxidant enzymes in the liver and erythrocytes of cattle, could be induced following dl-ethionine administration. Whole blood, serum and liver biopsy samples were collected 0, 4, 7 and 10 days after intra-peritoneal ethionine administrat...
Article
Full-text available
The aim of this study was to determine whether ultrasonography could be used to evaluate curd formation in the abomasum of preruminant calves. Holstein-Friesian calves were fed one of three milk replacers: clotting (five calves), non-clotting (four calves) and pH-dependent clotting (clots form at pH 5.5, but not at pH 6.5; six calves). Ultrasonogra...
Article
Full-text available
This article summarizes the different types of free radicals, antioxidants and the effect of oxidative stress on the activities of glutathione peroxidase and glucose 6-phosphate dehydrogenase in bovine liver diseases. A growing body of evidence suggests that the formation of reactive oxygen species is a common occurrence associated with most if not...
Article
Although not scientifically proven, hoof trimming has been empirically shown to increase milk yields in healthy dairy cows. In this study, we examined the effect of one-time hoof trimming on blood biochemical composition, milk yield, and milk composition in healthy dairy cows. Eleven cows in the mid to late lactation period that were clinically fit...
Article
To evaluate the nutriture of Japanese black cattle with growth retardation, a metabolic profile test was carried out in 8 cattle with growth retardation and in 10 cattle with normal growth. During our observation for 1 month before blood sampling, the cattle with growth retardation ingested their forage completely. They showed lower low-density lip...
Article
Nitroblue tetrazolium (NBT) reductivity of peripheral blood neutrophils and blastogenic activity of peripheral blood lymphocytes were investigated in cows administered with a single oral dose of active egg white product (AEWP; 500mg/kg). NBT reductivity of neutrophils increased and reached a maximum level at one to three days after administration....
Article
Serum alkaline phosphatase (ALP) activities were measured during dry and lactational periods to investigate the influence of lactation on serum ALP activity in cows. Higher levels of serum ALP activity were seen in lactational periods than in dry periods. The serum activities of bone-specific ALP (BALP), liver ALP (LALP), tartrate resistant acid ph...
Article
The present study examined the effects of feeding order of grain and protein supplements on ruminal nitrogen (N) loss through the diurnal variation of ruminal ammonia N and urea N in the blood and milk of dairy cows. Three ruminally fistulated cows were used in a 3 × 3 Latin square arrangement of treatments; that is, grain supplement fed at the fir...
Article
A total of 60 cattle were examined for the presence of pathological liver lesions. The liver lesions were classified as glycogen degeneration, liver abscess, sawdust liver and fatty degeneration. The value of serum adenosine deaminase (ADA) activity was investigated as a pilot study for diagnosing liver diseases in cattle. Serum ADA activity was si...
Article
Full-text available
A total of 46 cattle, including 25 as control, 16 with glycogen degeneration and 5 with severe fatty degeneration were studied. Whole blood and liver tissue specimens were used to measure glutathione peroxidase (GSH-Px) and Glucose-6-Phosphate Dehydrogenase (G6PD) activities. The present study determined the value of these parameters in diagnosing...
Article
A total of 46 cattle, including 25 as control, 16 with glycogen degeneration and 5 with severe fatty degeneration were studied. Whole blood and liver tissue specimens were used to measure glutathione peroxidase (GSH-Px) and Glucose-6-Phosphate Dehydrogenase (G6PD) activities. The present study determined the value of these parameters in diagnosing...
Article
As simplified methods of measuring rumen ammonium nitrogen (R-NI-13-N), we used the reagent for blood ammonia (NH3-kit), the reagent for serum urea nitrogen (BUN-kit), and the reagent for dry-type blood autoanalyzer (Drychem). The compared measurements made with them and those made with the conventional steam-distillation method. Even when operatio...
Article
第一胃フィステルを装着した泌乳牛2頭を供試し、噴門付近の固形物層(上部)と腹嚢の液状層(底部)における第一胃液性状を経時的に比較した。pHは両部位とも飼料給与前と給与後1時間にほぼ同一の値を示し、その後急激に低下した後、底部では数時間にわたりが低値で推移した。総揮発性脂肪酸(VFA)濃度は概ね底部が高値で推移した。pH、総VFA濃度ともに上部の大きな変動により、部位間に有意差の生じる時間帯があり、pHと総VFA濃度との間に有意な負の相関が認められた。VFA構成比率とアンモニア態窒素(NH3N)濃度は両部位とも採取時間を通じてほぼ同一の値で推移し、部位間に有意差はなかった。上部から第一胃液を採取する経口カテーテル法の採取時間は、pHが最低値付近で部位間に差がなく、NH3N濃度が最高値に達する飼...
Article
Eight periparturient Holstein Friesian cows were examined for plasma tartrate-resistant acid phosphatase (TRAP) activity to assess the degree of bone metabolic activity and to evaluate the association between the change in calcium (Ca) concentration and bone metabolism during the periparturient period. Milk fever occurred in 1 of 8 cows just after...
Article
The feed of 5 postpartum Japanese Black cows was changed from a low-starch ration (day 0) by the addition of 3kg per day of dent- corn silage. As a result of the change, calf fecesbegan showing preliminary signs' of scours between day 1 and day 3. Between day 5 and day 7, these calves suffered from watery white scours. Fat percent in the dams' milk...
Article
We investigated the relation between diet starch content and lactic-acid levels in bovine rumen fluid and blood. Three Holstein dairy cows were fed orchard grass abundantly for 3 weeks. They were then fed a diet containing 34% starch (dry weight) for another 3 weeks. Specimens were collected two hours after ingestion of the concentrate. Rumen-fluid...
Article
The correlation between the serum hydroxyproline concentration and serum activity levels of TRAP and BALP was examined in 41 cows. The correlated coefficient (r) was 0.6391 for TRAP and 0.3147 for BALP, respectively. Judging from the significant correlation to the serum hydroxyproline concentration, serum TRAP activity is an index for bone metaboli...
Article
Full-text available
Urinary excretion of N-acetyl-beta-D-glucosaminidase (NAG) was examined in healthy dogs and dogs with urinary diseases, and its clinical usefulness as an indicator of urinary diseases was discussed. Twenty-eight healthy dogs and 20 dogs with urinary diseases were used. Urinary NAG activity was measured using p-nitrophenyl N-acetyl-beta-D-glucosamin...
Article
Urinary excretion of N-acetyl-β-D-glucosaminidase (NAG) was examined in healthy dogs and dogs with urinary diseases, and its clinical usefulness as an indicator of urinary diseases was discussed. Twenty-eight healthy dogs and 20 dogs with urinary diseases were used. Urinary NAG activity was measured using p-nitrophenyl N-acetyl-β-D-glucosaminide as...
Article
A female Japanese Black cow showed hemorrhage under the mucous membrane of the eye conjunctiva and the vagina, and thrombocytopenia in peripheral blood. The clinical manifestations repeated spontaneously during long-term observation. The clinical findings were stable except for severe periodic bleeding. Prothrombin time, activated partial thrombopl...
Article
To observe changes in bone metabolism and associations between it and the development of milk fever, we investigated serum tartrate-resistant acid phosphatase (TRAP) activity at each lactating stage in 83 cows. The animals were from farms A and B, where milk fever occurred rarely, and farms C and D, where it was frequent. On farms A and B, serum TR...
Article
For the sake of examining the relationship between blood concentrations of lactic acid (LA) and ammonia (NH3) and rumen condition, 25 Holstein dairy cows were divided into 3 groups on the basis of diet: normal (N), high starch (S), and high protein (P). In the S group, the number of protozoa and their motility in rumen fluid decreased remarkably af...
Article
Examination of 17 cases of canine pyometra showed high levels of serum alkaline phosphatase (ALP) activities in 13 animals (the high ALP group) and normal levels in 4 animals (the normal group). Results concerning clinical symptoms and blood examinations for the two groups were compared. More clinical abnormalities were observed in the high ALP gro...
Article
Five postpartum Japanese Black cows were first given low-starch feed then 3kg/day of corn silage. As a result of this regimen, all calves showed premonitory signs in the feces 1-3 days following the administration of silage to their dams. The calves contracted aqueous white scours after the dams began eating silage. Total numbers of protozoa in dam...
Article
Quantities and components of milk from 5 Japanese Black cows were examined over a period of 17 postpartum days. During the test period, the dry-matter intake of each cow remained unchanged. From the 2nd to the 16th postpartum day, milk-fat rate was 5.11±1.04%, milk-protein rate 3.80±0.39%, and lactose rate 4.68±0.24%. Average milk quantity from the...
Article
In the first farm trial of our evaluation of the effects of the preparation Sairei-to on scouring calves, we used 61 Japanese black calves divided into an experimental and a control group. Sairei-to was administered to the experimental group and an intestinal protectant to the control group. After3 days of treatment, we checked the calves for the p...
Article
We investigated the diet content and properties of blood and milk in 11 pairs of Japanese Black cows and their calves for the one month following delivery. Four pairs (group A) had been no cases of white diarrhea during the year prior to this study, and 7 pairs (group B) had been a high occurrence of white diarrhea in calves during the same period....
Article
To examine the association between oxidative stress and antioxidants in neonatal calves after birth. Sera from 6 healthy Holstein-Friesian cows and 7 of their newborn calves were obtained at various intervals after birth. Lipid peroxides in serum of cows and their newborn calves were estimated by measuring concentrations of thiobarbituric acid-reac...
Article
The relationship between the incidence of calf white scour and alcohol stability of cow's milk (Utrecht abnormality) was investigated in 16 pairs of Japanese black cows and their calves with white scour within six-weeks after birth as well as 5 pairs of healthy controls. Of 16 cows with diseased calves, 9 (56.3%)(Group A) were positive for alcohol...
Article
A metabolic profile test after parturition was performed on Japanese black dams of 7 farms, from days 8 to 99 (stage I), from days 100 to 199 (stage II) and, from days 200 or later (stage III). In group A (41 dams of 3 farms) given corn silage throughout the year, the calves experienced frequent occurrence of white scour and the dams showed abnorma...
Article
In a diabetic 4-year-old Japanese black cow, the urinary concentration of N-acetyl-β-D-glucosaminidase (NAG) and NAG index were 8.4U/l and 20.2U/g, respectively, being higher than in non-diabetic cows. The form B NAG isozyme was 66.6% in the present case, while 20% in non-diabetic cows. In the diabetic case, the renal function was lowered. Histopat...
Article
Granulosa-cell tumor was found in a Holstein cow showing abnormal parturition. On 8 days prior to delivery, swelling, hyperemia and looseness of the vulva were remarkable. Vaginal examination revealed fully opened cervical canal and bloody mucus discharge, while enlarged udder or labour pains were not observed. No labor pains appeared for 8 days, s...
Article
Clinical signs, changes in blood characteristics, plasma estrogen and progesterone levels were investigated during theperiod of the 7 days before expulsion to the 3 days after expulsion in 5 cows having twins. Values obtained were compared with those of 8 cows with single birth. An average of gestation length of the cows with twins was 8 days short...
Article
In an attempt to synchronize estrus and ovulation, a total of 39 Holstein heifers, 13-to 19-month-old, in a pasture were injected subcutaneously with PGF2-alpha analogue (Fenprostalene, A-75). In Experiment I, 21 heifers in the luteal phase were administered with 2 ml of A-75 (1 mg of Fenprostalene). Nineteen heifers that showed estrus 2-5 days aft...
Article
Storage conditions of blood for plasma progesterone assay were examined using heparinized whole blood from pregnant cows, both with and without addition of sodium azide (NaN3). Concentrations of plasma progesterone in blood without NaN3 decreased from 7.6±3.2 (Mean±SD) ng/ml to 6.1±2.4ng/ml (4°C) and 5.6±2.4ng/ml (20°C) after two hrs storage.Therea...

Network

Cited By

Projects