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1.
Herbicides may raise, lower, or not affect the concentration of poisonous compounds in plants. Herbicides, 2,4,5-T and silvex controlled Wasatch milkvetch (Astragalus miser var oblongifolius) and markedly reduced the concentration of miserotoxin, a poisonous aliphatic nitro compound. The concentration of phototoxic furocoumarins in the leaves of spring parsley (Cymopterus watsonii) decreased to nontoxic concentrations 4 to 5 weeks after treatment with 2,4-D. The hydrocyanic acid content of wild cherry (Prunus spp) decreased after treatment with 2,4-D and 2,4,5-T, but increased in Sudangrass (Sorghum halapense) after treatment with 2,4-D. The alkaloid concentration in Barbey larkspur (Delphinium barbeyi) increased after treatment with 2,4,5-T or silvex, decreased in horsetail (Equisetum palustre) after treatment with MCPA, and was unaffected in Datura after treatment with several herbicides. The effect of herbicides on nitrate concentration in plants was dependent upon the species of plant and the herbicide used.  相似文献   

2.
The main purpose of the present work was to study the long-term effects of 2,4-dichlorophenoxyacetic acid (2,4-D) in swine, rats and chickens.In preliminary short-term experiments with calves and pigs, definite although reversible toxic effects were seen after single doses of 200 and 100 mg/kg, respectively. Rats and chickens seemed to tolerate 100 and 300 mg/kg, respectively, without ill-effects. On repeated administration daily doses of 50 mg/kg could be toxic to pigs, whereas chickens tolerated 300 mg/kg/day for several weeks without visible effects. Symptoms of acute poisoning in calves were dysphagia, anorexia, tympanites and muscular weakness. Anorexia was apparent also in acutely or subacutely poisoned pigs together with locomotory disturbances, transient diarrhoea and, in severe cases, vomiting, muscular weakness and general depression. In all animals showing symptoms of poisoning a reduced disappearance rate of 2,4-D from plasma was apparent. On autopsy the pigs showed signs of gastro-intestinal irritation and pneumonia and renal degeneration. In the rats and chickens no gross pathological changes were seen.In the long-term studies 5 young pigs were fed 2,4-D (500 p.p.m.) for up to 12 months. Main clinical signs were growth depression, locomotory disturbances, anaemia and albuminuria. Morphological changes included moderate hepatic and renal degeneration. In another experiment 2,4-D was fed to a pregnant sow throughout the gestation period and for 6 further weeks. The sow exhibited no characteristic signs, and on autopsy no changes attributable to 2,4-D were noted. The newborn piglets, however, were underdeveloped and apathetic. Ten out of 15 died within 24 hours. On continued feeding of 2,4-D to the survivors until 7–8 months of age the main effects were a marked growth depression, persistent anaemia and moderate degenerative changes of liver and kidneys.Pregnant rats were given 2,4-D (1000 p.p.m.) in the drinking water during the gestation and further for up to 10 months. The administration of 2,4-D was continued to the second generation rats for up to 2 years. Except for a retarded growth and an increased mortality in the second generation no unequivocal clinical or morphological changes were seen.In chickens continued administration of 2,4-D (500 p.p.m. in the feed or 1000 p.p.m. in the drinking water) caused a reduced eggproduction and pronounced kidney enlargement due to epithelial proliferations, this latter lesion appearing only when very young chicks were used as experimental animals.The experimental results indicate the chronic toxicity of 2,4-D for the species examined to be moderate. Apart from the nephrotoxicity demonstrated in chicks the long-term effects were non-specific. Of particular interest, however, are the high mortality in the newborn piglets and the reduced egg production in the chickens as indications of a possible interference with reproduction.  相似文献   

3.
Two experiments comprising a total of 80 Danish Landrace pigs in the period 20–90 kg live-weight were carried out to study the effect of dietary levels and ratios of Ca and P on serum values of Ca, inorg. P, and alkaline phosphatase and on the development of degenerative arthritis and atrophic rhinitis.In both experiments each kg feed (Table 1) was supplemented with 600 i. u. vitamin D3 and 80 p. p. m. Zn.In the first experiment the Ca:P ratio was 1.2 and the amount of Ca increased from 0.48 % to 1.20 % without influencing daily gain, feed conversion, carcass performance (Table 2) or frequency of atrophic rhinitis (Table 3). The Ca:P ratio in scapula was 2.15. Only when the diet was supplemented with 1.20 % Ga and 1.00 % P the bone quality was histomorphologically adequate (Figs. 1–4).In the second experiment various Ca:P ratios (ranging from 0.1 to 3.0) were compared with the recommended level and ratio of 0.72 % Ga and 0.60 % P. Performance of pigs on the normal level was better than for the other pigs (Table 4). Clinically, various degrees of leg-weakness and -deformation occurred, most pronounced in the high Ca — low P group. Very little lameness and no convulsions were observed. Marked hypocalcemia was not found. Unilateral high Ca intake increased serum Ca significantly, and serum alkaline phosphatase slightly, and decreased serum P (Figs. 5–7). Advanced pericytic osteolysis, poor mineralization and generalized osteodystrophia fibrosa were found in the low Ca groups (Figs. 8–13). The groups showed no differences in frequency of atrophic rhinitis (Table 5), and rickets was not observed.The incidence of degenerative joint lesions was not increased in pigs on the unfavourable Ca:P ratios, and depended apparently more on litters than on diets.  相似文献   

4.
Trees were felled 150 mm above ground level and various mixtures of picloram with 2,4‐D araine, 2,4,5‐T amine in water solution or 2,4,5‐T ester in diesel oil were applied to the freshly‐cut surfaces. Mixtures of picloram/2,4‐D amine and picloram/2,4,5‐T amine, both water soluble, gave the highest kill rates when applied to trees in the growing season (October and May). The oil emulsifiable picloram/2,4,5‐T ester formulation tended to be effective throughout the year and high kill rates were frequently obtained with applications made in June or July. Application rates of picloram/2,4‐D amine or picloram/2,4,5‐T amine (expressed as g a.e. picloram per mm girth) required to kill 80% of the trees were 0,012–0,016 for A. karroo; 0,016–0,037 for T. sericea and 0,037 for J. globiflora. Few of the treatments applied to B. spiciformis trees resulted in kill rates of more than 65%.  相似文献   

5.
The development of circulating antibodies for H. parahaemolyticus was studied in experimentally infected SPF pigs and in-contact SPF pigs. Blood serum titers were determined by a modified complement fixation test with normal SPF swine serum as a source of supplementary complement factor, and by an indirect haemagglutination test.CF and IHA titers became positive within the first 2 weeks following exposure to H. parahaemolyticus, and reached peak values after 2 to 7 weeks (Figs. 1 to 3). The exposed pigs proved immune, in that they showed no clinical symptoms on challenge after resp. 6, 9 and 11 weeks.While distinct titers were thus obtained with both tests in SPF swine experimentally exposed to H. parahaemolyticus, the CF test proved more specific than the IHA test when the 2 tests were compared in a field outbreak of polyserositis (Glässers disease) caused by H. parasuis. The CF test would therefore seem to be preferable to the IHA test in field diagnostic work (Table 1).A noticeable finding was that challenge did not elicit an anamnestic antibody response in any of the immune pigs (Figs. 1 to 3). This fact together with negative bacteriological findings in the animals in question would seem to suggest that the challenge dose was unable to establish a permanent infection in the respiratory tract of the immune pigs.  相似文献   

6.
Groups of each 10 boars, weight range 20-60 kg, were fed ad libitum the following 4 rations of similar protein: energy ratio: Ration I (control), Ration II (+ 2% soyaoil ), Ration III (+ 2% soyaoil + 5% lard), Ration IV (+ 7% lard). When the animals reached 60 kg body weight each group was halved. One half had free access to the above rations, while the other half were fed ad libitum on the control ration. At body weights of 50 and 100 kg the concentrations of urea, insulin, glucose and cholesterol were measured, in addition the fatty acid composition of the backfat. At the end of the experiment (100 kg) the content of fat in the carcass was calculated by determining the specific gravidity of the carcass. There was little difference in the intake of metabolizable energy (ME) of the different groups of animals at both body weight ranges as a result of the reduction in feed intake of the fat supplemented diets on account of the higher ME-content. There were little differences in the glucose and urea concentrations in the blood of the animals fed the different rations. The highest cholesterol and the lowest insulin levels were measured in groups III and IV, when 5 and 7% lard was added, respectively. The animals, continuously fed Rations III and IV over the whole period of experiment, had a significantly higher fat content (p less than 0,05) than the control animals. There was a very marked influence of the fatty acid intake on the fatty acid pattern of the backfat. Following the change of feed to the control ration at 60 kg body weight, the linoleic acid content of the animals in Groups III and IV was significantly reduced (p less than 0,001) from 15.7 to 11.2%. However this was higher than the 7.3% linoleic acid measured on the animals continuously fed the control ration.  相似文献   

7.
The study comprises 136 strains of Corynebacterium pyogenes originating from cattle (105), swine (20), sheep (1), and insects (10). For comparison 2 strains of human origin and 1 strain of Gorynebacterium hemolyticum were examined.One of the bovine strains was atypical, being gelatinase-negative, otherwise the strains of Cb. pyogenes were found to be biochemically identical apart from minor deviations in fermentation patterns (Table 1). Neither were antigenic differences demonstrated (gel diffusion analyses, Figs. 1 and 2).Both of the human strains agreed biochemically with Cb. pyogenes (Table 1). By gel diffusion cross analyses one of them was found to be identical with Cb. pyogenes, the other not, though anti-genically related to it (Fig. 2).Gb. hemolyticum deviated biochemically as well as serologically from Gb. pyogenes, but the 2 organisms shared antigenic determinants (Fig. 3).  相似文献   

8.
Lambs suffering from Acute Respiratory Distress Syndrome (ARDS) showed elevated PCV, neutrophilia, a tendency towards lymphopenia, eosinopenia, hyperphosphatemia, hypoglycemia and extremely low serum Ca values during the first couple of days after the outbreak of symptoms. During the very early phase, plasma potassium values were mostly lowered (Figs. 1-3, Table I). The possible involvement of histamine is shortly discussed: either 1) through an atopic reaction, 2) because of acute ruminal acidosis and sudden histamine formation, or 3) involvement of endotoxins.  相似文献   

9.
Investigations concerning the effect on fur-bearing animals of large doses of vitamin D3 were carried out. The material comprised 62 animals in all--10 silver foxes, 17 blue foxes and 35 mink (Table II). Daily doses of 5 IU vitamin D3/g body weight for two months did not produce clinical symptoms in the foxes. However, a short while after the dose was increased to 10 IU, the animals showed loss of appetite, had difficulty in moving, were apathetic and developed dark coloured faeces. Analysis of blood serum showed markedly raised calcium values (Table III). Calcium deposits were demonstrated in the kidneys and in some cases also in the musculature, gastric mucosa, bronchi and the larger blood vessels. No abnormal signs were shown by 30 mink which received 0.6--0.7 IU vitamin D3/g body weight for five months. PM findings were normal.  相似文献   

10.
Bovine fetal muscle cells were exposed to culture media containing 2 mg and 20 mg per liter of 2,4-dichlorophenoxy acetic acid (2,4-D) for varying intervals to determine the in vitro response of mammalian cells to this compound. The concentrations of 2,4-D used were comparable to those used in spray programmes although the residues normally found in pasture are much lower since 2,4-D is rapidly degraded under field conditions. Untreated and treated cultures were analyzed for total cell count, mitotic index and the percentages of differentiating and degenerating cells. The response of cultures to treatment was similar irrespective of the concentrations of 2,4-D used although in higher concentrations there was an initial drop in mitotic index. Other changes noted in treated cultures included an increase in differentiating and degenerating cells compared to those in control. The mitotic cells in treated cultures exhibited unipolar and tripolar spindles and a variety of other abnormalities including malorientation of the mitotic apparatus in relation to the axis of the cell. Myoblasts in initial stages of myogenesis were noted to be in mitosis in treated cultures suggesting that 2,4-D may have a stimulatory effect on myoblasts which in normal myogenesis are in post mitotic stage.  相似文献   

11.
刘芳  王玉祥  陈爱萍  张博 《草地学报》2012,20(4):741-746
以新疆野生黄花苜蓿(Medicago falcata L.)为材料,通过愈伤组织诱导及分化途径获得再生植株;从种子硬实、外植体、激素(2,4-D和KT)、培养基方面探讨野生黄花苜蓿组织培养的影响因素。结果表明:4℃低温处理与浓硫酸浸种结合是破除黄花苜蓿硬实的较优方法,发芽率达90%;下胚轴为诱导愈伤组织的最佳外植体;MS培养基比改良的SH培养基对愈伤组织的诱导更有效,MS诱导培养基为MS+2,4-D 0.5 mg·L-1+KT 0.8 mg·L-1+蔗糖30 g·L-1+琼脂粉7 g·L-1,出愈率达到80%;浅绿色和浅黄色的愈伤组织在MS+2,4-D 0.2 mg·L-1+KT 0.4 mg·L-1+CH 1 g·L-1+蔗糖20 g·L-1+琼脂粉7 g·L-1的培养基上分化较好,分化率为30%。研究结果将为黄花苜蓿生物技术育种奠定一定的基础。  相似文献   

12.
以草地早熟禾品种——新格莱德成熟种子为供试材料,在含3.0mg/L2,4-二氯苯氧乙酸(2,4-D)、0.5mg/L6-苄氨基嘌呤(6-BA)的MB5培养基中进行胚性愈伤组织诱导的培养。并从生长了7~9个月的胚性愈伤组织中分离出原生质体,将该原生质体置于KM8P培养基(含3.0mg/L2,4-D、0.5mg/L6-BA、100mg/L水解酪蛋白、100mg/L水解乳蛋白、1%蔗糖、0.4mol/L甘露醇)中进行了液体浅层培养。结果表明,新格莱德原生质体在上述KM8P培养基中培养3d后出现第1次细胞分裂,2~3周后形成小细胞团,此时添加低渗培养液2~3次,小细胞团持续分裂并形成愈伤组织。当愈伤组织块长至3~5mm时,转入固体培养基MS+3.0mg/L2,4-D+0.5mg/L6-BA和MS+0.5mg/L萘乙酸(NAA)+5.0mg/L6-BA上进行培养,使其细胞增殖和分化,且逐步形成完整的植株。  相似文献   

13.
In a field study with fattening pigs, effects of feed particle size at the dietary presence of organic acids on Salmonella prevalence were measured. On two farms (f1/f2), each holding ~800 pigs, diets based on finely ground (control) or coarsely ground ingredients (experiment) were fed as crumbs. On f1 both control and experimental grower and finisher diets contained identical concentrations of formic and propionic acid (0.4% and 0.2% respectively). On f2 only finisher diet of the experimental group contained 1.2% potassium diformate. At the start of the fattening period no statistical differences were measured between Salmonella prevalence in animals fed control and experimental diets on both farms. At slaughter Salmonella prevalence in caecal contents was lower (p < 0.05) on f1 in animals fed the experimental diet. Furthermore, the number of seronegative meat juice samples taken from these animals [optical density (OD) <10] was higher (p < 0.001); seropositive as well as distinct seropositive samples (OD ≥20 and ≥40 respectively) were less frequent (p < 0.01) compared to samples from animals fed the control diet. Feeding the experimental diet on f2 resulted in a lower Salmonella detection rate in faeces before slaughter (p < 0.01). Salmonella prevalence was lower in caecal content at slaughter for pigs fed the experimental diet compared to those fed control diet (p < 0.0001). The number of distinct seropositive meat juice samples (OD ≥40) was lower (p < 0.01) for pigs fed the experimental than for those fed the control diet. In comparison to pigs in the control group, starch concentrations in the caecal content from pigs in the experimental groups on both farms were higher (p < 0.05) and the pH values lower (p < 0.05). Propionate (p < 0.0001) and butyrate (p < 0.01) concentrations were higher in the caecal content taken from pigs in the experimental group on f2.  相似文献   

14.
Establishing regeneration systems of Gannong No.4 alfalfa   总被引:2,自引:3,他引:2  
为实现对甘农4号紫花苜蓿Medicago sativa cv.Gannong No.4的遗传改良,研究拟建立一个操作简便、可重复性强、遗传性稳定、培养周期短和再生率高的转基因受体系统,为其遗传改良奠定基础。研究以MS为基本培养基,在不同浓度的2,4 D与6 BA的诱导培养基上,以甘农4号紫花苜蓿下胚轴为外植体,诱导愈伤组织,诱导率为86.85%~99.56%,其中MS+2 mg/L 2,4 D+1 mg/L 6 BA诱导率最高;浅黄色至淡绿色的愈伤组织在MS+0.5 mg/L KT+0.1 mg/L NAA培养基上的分化最好且植株颜色嫩绿。丛生芽在1/2MS+0.5 mg/L NAA的生根培养基上可再生成完整的苜蓿植株。  相似文献   

15.
Picloram‐potassium and various mixtures of picloram with 2,4‐D amine, 2,4,5‐T ester or amine, or 2,4,5‐T ester alone were injected into incisions made in the cambium of standing Brachystegia spiciformis and Julbernardia globiflora trees. Each arboricide was tested at a range of application rates, at different times of the year and at three different sites for each species. Picloram‐potassium and 2,4,5‐T ester were also tested on Terminalia sericea trees. Glyphosate, MCPA, mixtures of mecoprop and 2,4,5‐T amine and different mixtures of 2,4‐D ester with 2,4,5‐T ester, cacodylic acid and Tandex were tested on B. spiciformis and J. globiflora trees at one site and only in January. Aboricides containing picloram, with or without the addition of 2,4‐D or 2,4,5‐T, were the most effective chemicals for the control of trees. Higher application rates were required to kill B. spiciformis and J. globiflora between May and October when they were not actively growing. T. sericea trees were susceptible to arboricide treatment throughout the year. The response of individual trees to treatment with arboricides appears to be related to size.  相似文献   

16.
Two studies were conducted to determine the persistent efficacy of doramectin pour-on against an artificial, trickle challenge of mixed nematodes in calves. In each study, 42, 4-8 months old calves were randomly assigned into four groups of 10 animals each (T1-T4), plus two larval-viability monitor animals. All animals were treated with fenbendazole (10 mg kg(-1)) 14 days prior to the start of the study to clear any existing infection. Doramectin pour-on at 500 microg kg(-1) was used on each animal in Groups T2, T3, and T4 with intervals of 1 week (Day 0, 7, and 14, respectively). Calves in Group T1 were treated with saline solution on Day 0 and at the same volumetric rate (1 ml 10 kg(-1)) as the doramectin treated animals. All treatments were applied in a single passage along the midline of the back, from the withers to the tailhead. Subsequently, trickle inoculations with infective larvae were administered to all calves for 22 consecutive days (Days 14-35). Doramectin pour-on provided > or = 91.9% efficacy against challenge with Dictyocaulus viviparus, Haemonchus spp., and Ostertagia ostertagi for up to 35 days post-treatment and against challenge with Cooperia oncophora, Cooperia punctata, and Oesophagostomum radiatum for up to 28 days post-treatment.  相似文献   

17.
董宽虎  于娜  程钰宏 《草地学报》2009,17(2):141-144
以7日龄白羊草(Bothriochloa ischaemum(L.)Keng)真叶作为外植体,进行愈伤组织诱导和植株再生研究,筛选较合适的激素组合,以建立白羊草再生体系。结果表明:在愈伤诱导阶段KT的作用明显,其与2,4-D的交互作用优于ABA与2,4-D,也高于单独使用2,4-D,在2,4-D1.0 mg/L+KT0.5 mg/L时诱导率最大,达到93.45%;分化阶段6-BA0.1 mg/L与NAA 0.04-0.06 mg/L的激素组合中分化率差异不明显。  相似文献   

18.
The development of drug-metabolizing enzymes in female sheep livers   总被引:1,自引:0,他引:1  
The purpose of this investigation was to determine age-related changes of some hepatic drug-metabolizing activities in Lacaune ewes in the foetal, neonatal (1 and 4 weeks), growing (7 months), pregnant (11 months) and adult (6 years) stages. Although microsomal cytochrome P-450 was not detected in 3-month-old foetuses, it increased regularly from 1-week- to 11-month-old animals. Among mixed-function oxidases, the development of aminopyrine and ethylmorphine N-demethylases, benzo(alpha)pyrene hydroxylase and ethoxycoumarin O-deethylase were correlated to that of total cytochrome P-450. Due to their presence in foetal liver or their more rapid evolution, cytochrome b5, NADPH cytochrome c reductase, aniline hydroxylase, benzphetamine N-demethylase and erythromycin N-demethylase did not parallel the ontogenesis of cytochrome P-450. Hepatic transferases showed different developmental patterns from mono-oxygenases, so UDP glucuronyltransferase was detected in the foetus, reached maximum activity in all young ages up to the pregnant stage and subsequently fell in adult ewes. Concerning glutathione S-transferase accepting 1-chloro-2,4-dinitrobenzene as substrate, similar values were obtained in the foetus and all young animals, whereas five- to tenfold higher values were obtained in both pregnant and adult female sheep. N-acetyltransferase using sulphamethazine did not significantly change from foetuses to adults but there were large differences in the capacity of hepatic acetylation between animals belonging to the same group.  相似文献   

19.
Hydrolysis of phytate in the stomach and the small intestine as influenced by intrinsic plant (wheat) and supplemented microbial phytase (A. niger) were investigated with six minipigs (40-50 kg initial BW) fitted with re-entrant-cannulas in the duodenum, 30 cm posterior to the pylorus (animals 1, 4, 5, and 6) and ileocecal re-entrant cannulas, 5 cm prior the ileocecal junction (animals 1, 2, and 3), respectively. Dietary treatments were as follows: (1) diet 1, a corn-based diet (43 U Phytase/kg DM); (2) diet 2, diet 1 supplemented with microbial phytase (818 U/kg DM) and (3) diet 3, a wheat-based diet (1192 U/kg DM). At 0730 and 1930 per animal 350 g diet mixed with 1050 ml de-ionized water were fed. Digesta were collected continuously and completely during 12 h after feeding. Duodenal recovery of dry matter and total phosphorus were 100% in the period between two feedings, irrespective of dietary treatment. In animals fed the wheat-based diet, dry matter left the stomach faster (p < 0.05) during the first hour after feeding than in animals fed the corn-based diets (41.3 vs. 31.0 and 25.8% of intake, respectively). Supplemented microbial phytase did not affect ileal dry matter digestibility of the corn-based diet. In the first hour after feeding, phosphorus concentration of the duodenal digesta of animals fed corn-based diets with or without supplemented microbial phytase (5.86, 6.19 mg total P/g DM) exceeded the dietary level considerably (4.30 and 4.21 mg total P/g DM) indicating a higher solubility of corn than wheat phosphorus in the stomach. Apparent ileal P absorption was higher (p < 0.05) in the wheat-based diet (37.6%) and corn-based diet supplemented with microbial phytase (34.3%) than in the unsupplemented corn-based diet (17.6%).  相似文献   

20.
A diet providing less than 20 mg of magnesium per 100 kcal that maintains urine pH near 6.0 3 to 5 hours after eating, or a diet providing this amount fo magnesium (see Table 2) with 1 gm of ammonium chloride or 1.5 gm of dl-methionine added daily, should be fed for 1 to 3 months to dissolve struvite uroliths (see Fig. 1). The low-magnesium diet should be fed indefinitely to prevent recurrence, because struvite urolithiasis and all of its effects (hematuria, pollakiuria, and/or complete to partial obstruction to urinary excretion) recurs repeatedly in cats that have previously experienced the condition if they are returned to regular cat food. In contrast, if a diet low in magnesium is fed, recurrence is uncommon. For cats that have never been affected, feeding a low-magnesium ration is unnecessary. For all cats, the following measures are recommended: encourage exercise, allow frequent urination, prevent obesity, decrease confinement, keep the litter box clean, and always have palatable water readily available.  相似文献   

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