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1.
Ergot alkaloids produced by the endophyte (Neotyphodium coenophialum) associated with tall fescue (Lolium arundinaceum) are implicated in the clinical signs of fescue toxicosis. These compounds were hypothesized to correspondingly affect foregut vasculature. The objective of this study was to determine vasoconstrictive potentials of ergovaline, ergotamine, ergocryptine, ergocristine, ergonovine, ergocornine, and lysergic acid on right ruminal artery and vein. Segments of right ruminal artery and vein were collected from the ventral coronary groove of predominantly Angus heifers (n = 10) shortly after slaughter and placed in a modified Krebs-Henseleit buffer on ice. Vessels were cleaned of excess connective tissue and fat, sliced into 2- to 3-mm segments, and suspended in a multi-myograph chamber with 5 mL of continuously oxygenated Krebs-Henseleit buffer (95%O(2)/5% CO(2); pH 7.4; 37°C). Arteries and veins were equilibrated to 1.0 and 0.5 g, respectively, for 90 min followed by the reference addition of 120 mM KCl. Increasing concentrations of each alkaloid were added to the respective chamber every 15 min after buffer replacement. Data were normalized as a percentage of the contractile response induced by KCl. Alkaloid (P < 0.0001), concentration (P < 0.0001), and vessel type (artery or vein; P = 0.004) affected contractility. No arterial response was observed until 10(-6) M for ergovaline and ergotamine; 10(-5) M for ergocryptine, ergocornine, and ergonovine; and 10(-4) M for ergocristine. Lysergic acid did not induce a contractile response in the ruminal artery. No venous contractile response was observed until concentrations of 10(-6) M for ergovaline, 10(-5) M for ergotamine, and 10(-4) M for ergocryptine and ergocristine were achieved. Lysergic acid, ergonovine, and ergocornine did not induce a contractile response in the ruminal vein. A greater arterial maximal response was observed for ergovaline (P < 0.0001), whereas the arterial and venous responses were not different for ergotamine (P = 0.16), ergocryptine (P = 0.218), and ergocristine (P = 0.425). These results indicate that ergot alkaloids associated with toxic endophyte-infected tall fescue are vasoactive and can potentially alter arterial blood supply and venous drainage from the bovine foregut.  相似文献   

2.
Five to six month-old lambs of two different Norwegian breeds (Dala and Rygja) were dosed with 3-methyl indole (3MI) and DL-tryptophan (DL-T), and examined clinically, hematologically and post mortem. Results were compared with the findings in Acute Respiratory Distress Syndrome (ARDS), a condition of acute dyspnea occurring in 5-6 month-old lambs (of Dala and Spael breeds) after they have been moved from mountain pastures onto lush aftermath in September. The results show that such young Norwegian lambs are susceptible to 3MI-dosing, and that the symptoms and lesions were similar to those described earlier in connection with 3MI-dosing in cattle and adult sheep. The results clearly demonstrate that 3-MI-induced pulmonary injury in lambs differs from ARDS as far as both symptoms, hematology and pathology are concerned.  相似文献   

3.
During a 2 year study of diseases in lambs in three early lambing (housed) flocks a total of 428 of 4413 (9.7%) lambs died. All these lambs were examined at post mortem by one investigator who used a routine procedure. Results were stored on a database (dBase III Plus) and analysed using Epiinfo. The peak rate of death occured in lambs less than 1 week old. Over 50% of deaths took place in this period. A small proportion of lambs (approximately 10 out of 1000) died during the prenatal period. Fatalities included chlamydial and mycotic abortions, but in the majority of cases there was no specific abortive agent, lambs were either freshly dead or mummified. Partum deaths (23.3–45.1 per 1000) were categorised into those due to the lambing process, lambs born dead and congenital defects. The most frequent abnormality observed was subcapsular liver rupture (9.3–20.9 per 1000) with up to 60% of affected lambs also having signs of malpresentation (subcutaneous oedema of the neck). Early postpartum deaths (12.9–31.5 per 1000) were primarily associated with starvation.  相似文献   

4.
Abstract

AIM: To determine the effect of oral dosing of sheep with loline alkaloids on their excretion in urine and faeces, and to monitor for any toxic effects.

METHODS: In Experiment 1, six 9-month-old ewe lambs were given a single oral dose of loline alkaloids (52 mg/kg bodyweight (BW); acute exposure) as a suspension of ground meadow fescue (Festuca pratensis) seed in water. In Experiment 2, on six consecutive days, six ewe lambs were given three doses of loline (68 mg/kg BW/day; chronic exposure). Blood was collected at variable intervals up to 72 h in Experiment 1, and up to 8 days in Experiment 2, for haematology and measurement of alkaline phosphatase, aspartate aminotransaminase, creatine kinase and γ-glutamyl transferase in plasma. Urine and faecal samples were collected at similar times for measurement of creatinine in urine and loline alkaloid analysis. A post mortem with histopathology was carried out on two animals at the end of each experiment.

RESULTS: The loline alkaloids, N-acetyl norloline, N-formyl loline, N-acetyl loline, N-methyl loline and loline base were detected in urine within 15 minutes after the single dosing. N-formyl loline and loline base were the predominant metabolites in urine in both experiments. The total quantity of lolines excreted in both urine and faeces was 10% and 4% of the amount dosed in Experiments 1 and 2, respectively. In both experiments, the clinical chemistry parameters in blood and urine were within normal ranges. Post-mortem and histopathological examination did not show any abnormalities.

CONCLUSIONS: This is the first report of loline alkaloid profiles in both urine and faeces of sheep. The appearance of loline alkaloids and the loline base in urine within 15 minutes suggests rapid uptake, metabolism and excretion. Loline alkaloids were non-toxic to sheep at the concentrations they are exposed to under New Zealand grazing conditions. The low recovery of loline alkaloids in urine and faeces in the absence of toxicity signs suggests lolines are extensively metabolised; probably to forms other than N-formyl loline, N-methyl loline, N-acetyl loline, N-acetyl norloline, and loline base in the digestive tract of sheep prior to absorption, and/or in the liver or other tissues following absorption.  相似文献   

5.
Samples of organs from 50 lambs, 3-45 days old, brought to this laboratory from 44 different flocks for post mortem examination, were examined for Listeria monocytogenes. Various diseases were found as cause of the death. The bacterium was isolated from 3 lambs (6%) which had died from E. coli-septicaemia. Two of these lambs were 3 days old whereas the third was 23 days.  相似文献   

6.
High dietary levels of magnesium (greater than 2 g/kg drymatter [DM]) have been implicated as the main causal factor of urinary calculi in concentrate-fed lambs. Experiments were performed to try to reproduce this effect of high magnesium (from added calcined magnesite) on the incidence of urolithiasis in lambs. In the first, store lambs were given diets containing magnesium in the following concentrations: A,2.9; B,8.6 g/km DM. Twenty-four blackface lambs were each allocated to A and B and the control group of 160 lambs was fed a combined dried grass/sugar beet pulp pellet and hay ad libitum (diet C). The animals were housed and fed ad libitum until they were killed at an average liveweight of 35 kg. No animals showed clinical signs of urolithiasis and post mortem only a trace of calculous material was recovered from one lamb fed diet A. In the second experiment housed Suffolk and Suffolk cross lambs were fed a starter beginning at three to four weeks old and changed to a finisher at a liveweight of 23 kg. The feeds were either high magnesium starter (5.7) and finisher (6.0) or low magnesium starter (2.3) and finisher (2.8 g/kg DM). Twenty-two single lambs and 32 twins were assigned to both high and low magnesium diets. Lambs fed additional magnesium drank more water/kg DM intake and one of the single lambs showed clinical signs of urolithiasis and was killed. No others showed clinical signs and from the 62 killed there was no post mortem recovery of calculous material.  相似文献   

7.
The deaths on nine farms of lambs which had been fed cow colostrum as a substitute for ewe colostrum were investigated. Of 105 lambs which received cow colostrum, 65 (61.9 per cent) showed clinical signs of anaemia and 42 (40 per cent) died. The signs of anaemia usually appeared when the lambs were between eight and 12 days old. The most significant post mortem finding was the appearance of the bone marrow which was cream or grey rather than the normal bright red. The types of treatment which were given are summarised. Whey from samples of the colostrum fed to the lambs was tested for its effect on sheep red blood cells. Haemolysis or agglutination of the red cells occurred with some, though not all, of the samples which caused anaemia.  相似文献   

8.
Eighteen helminth-free lambs were randomly allocated to six groups of three. Each lamb was dosed with 3300 infective larvae pooled from two isolates of Nematodirus spathiger known to be benzimidazole resistant. One lamb from each group was treated with oral ivermectin, one with oral oxfendazole and one left untreated 21 days after infection. All lambs were humanely killed 14 days later and small intestine worm counts performed. No Nematodirus were found in the ivermectin-treated lambs. Nematodirus numbers were reduced by 13% in oxfendazole-treated lambs relative to the control lambs.  相似文献   

9.
During 6 years, altogether 458 twin lambs of the Dala and Rygia breeds with their dams were put on ovine white-liver disease (OWLD) pastures which were moderately, heavily or not cobalt fertilized, or on control pastures 15 km apart. Groups of lambs were untreated, regularly dosed with Co sulphate or vitamin B12, dosed with Co pellets, copper oxide needles (CuO), selenium pellets or Co-Se-Cu glass boli, or had access to Co enriched salt lick. Clinical symptoms in untreated lambs included varying degree of reduced weight gain or loss of weight appearing after 6-12 weeks on pasture, at an age of 10-15 weeks. Additional symptoms were seen 2-4 weeks later, including inappetence, listlessness, and often serous eye discharge and crusty ears. Of the untreated lambs on OWLD pastures 18% died or were eutanized because of OWLD. The condition was preventable by Co or B12 administration, which yielded an average increase of mid Sept. live weights of between 8 and 17 kg. Co fertilization of pastures, use of Co enriched salt lick, or dosing with Co pellets are recommended under practical circumstances. The lambs grazing control pastures were on average 17 kg heavier by mid Sept. than the OWLD lambs. They showed some weight increase on extra Co supply.  相似文献   

10.
The relationship between egg elimination and parasitic burden was studied in two groups of 12 lambs experimentally infected with 1000 and 3000 Dicrocoelium dendriticum metacercariae, respectively. Half the animals in each group were slaughtered 2 months post-infection (p.i.) and the other half 6 months p.i. In order to detect and follow elimination of D. dendriticum eggs by the lambs, faeces samples collection started one and a half months p.i. and continued fortnightly until the end of the experiment. Egg elimination was first detected between days 49 and 79 p.i. (mean = 59 +/- 1.6 SE). Mean eggs per gram (epg) was higher in the lambs infected with 3000 metacercariae (347.2 +/- 42.4 epg) than in those infected with 1000 (194.8 +/- 14.4), although no significant differences were detected between both groups using the Student 't' test. Egg elimination was higher in the faeces samples taken in the afternoon (mean = 357.8 +/- 47.6 epg) than in those from the morning (mean = 215.7 +/- 21.3). The percentage of metacercariae which became established as worms was higher in the animals dosed with 1000 metacercariae (21.6%) than in those infected with 3000 (16.3%). The number of worms recovered on necropsy of each animal varied between 30 and 2063 (mean = 346.6 +/- 80.5) and their length between 2.6 and 7.1 mm (mean = 5.2 +/- 0.1). The mean number of parasites for lambs infected with 3000 metacercariae (489.3 +/- 163.1) was higher than that obtained from those dosed with 1000 (215.7 +/- 41.4), although more worms were collected in some cases from the lambs infected with the latter dose than the former. In general there was an increase in the number of epg eliminated as days p.i. and parasitic burden increased. A positive relationship was observed via the correlation coefficient between the number of epg eliminated by each of the lambs throughout the experiment and that of worms recovered. This relationship was more intense on considering only the number of epg eliminated between days 120 and 180 p.i.  相似文献   

11.
No liver damage occurred in a group of 21 lambs dosed intraruminally with up to 9 g of sarsasapogenin or diosgenin daily for 10 consecutive days. In contrast, seven out of 15 lambs dosed with 0.1 mg of sporidesmin/kg liveweight in combination with sarsasapogenin and three out of six lambs dosed with sporidesmin in combination with diosgenin developed liver lesions. These were typical of those induced by sporidesmin. One lamb dosed with sporidesmin in combination with 9 g of diosgenin developed a crystal-associated cholangitis typical of Panicurn intoxication and alveld. No sapogenins were detected in urine by gas chromatography-mass spectrometry. The results suggest that orally administered sarsasapogenin and diosgenin are either not hepatotoxic per se or are too poorly absorbed to elicit a toxic response. The results provide only weak evidence that sporidesmin may be involved in the aetiology of Panicurn intoxication.  相似文献   

12.
A new form of bilateral renal dysplasia in lambs appeared in a commercial sheep flock in 1982. The nature of the problem, the field investigations and the laboratory examinations carried out over three lambing seasons are described. It was concluded that the condition was vertically transmitted and genetic in origin. During the two years that accurate records were kept approximately 30 per cent of the suspected ram's progeny died with lesions of renal dysplasia. The condition recurred during a breeding trial in progeny from one of the two commercial rams originally used on the farm. An autosomal dominant mode of inheritance is suggested. The incidence illustrates the importance of keeping breeding records, especially when several rams are maintained in a flock, and the value of examining a large number of lambs post mortem.  相似文献   

13.
Three groups of eight-four-month-old worm-free lambs were used to investigate the effect of Trichostrongylus colubriformis infection on growth rate, food intake, and concentration of plasma constituents. Groups ALC and ALI were fed ad libitum, the latter being dosed daily with 2500 infective larvae for 14 weeks. Lambs in group PF were paired to individuals in group ALI and offered the same quantity of food as the infected pair consumed. Hypophosphataemia and hypoalbuminaemia developed in ALI at week 3 and hyperglobulinaemia was present from week 6. There was no significant difference in plasma calcium, protein, urea or glucose concentration between the three groups at any stage. No clinical signs of parasitism were seen in seven of eight ALI lambs and egg counts were generally less than 2000 epg. Worm burdens of 1500-82,900 were found at slaughter. Group weight gain was only 50 per cent of PF lambs which received the same digestible energy intake. Group ALI consumed 15-5 kg dry matter per kg gain in bodyweight compared with 8-6 kg/kg and 9-8 kg/kg for ALC and PF respectively. The infections resulted in extensive villous atrophy and flattening of the intestinal mucosa. Bone growth was arrested and osteoporosis present in five group ALI lambs. The possible use of plasma constituents, particularly phosphorus, as aids for the diagnosis of the early stages of trichostrongylosis in the field is assessed.  相似文献   

14.
Growing pigs were fed freshly milled ergot sclerotia (Claviceps purpurea Fr (Tul)) from North American wheat containing 0-31 per cent of total alkaloids of which 30 per cent was ergotoxine, 30 per cent ergosine, 20 per cent ergotamine and 20 per cent other ergot alkaloids. Pigs were induced to ingest a diet heavily contaminated with ergot (10 per cent w/w). The presence of ergot reduced feed intake and growth of the pigs, but there was no evidence of peripheral necrosis, of internal or external haemorrhage, or of changes in haemotological characteristics. Balance experiments in which the diet was contaminated with 4 per cent (w/w) of ergot showed that 90 per cent of the alkaloids were absorbed by the pigs, but none could be detected in tissues or urine. The ingestion of ergot did not affect the digestibility of the diet, but the urinary excretion of nitrogen was increased and the retention of nitrogen reduced. The presence of ricinoleic acid was shown to be a useful diagnostic feature of ergot contamination of diets, digesta and faeces; it was not found in body tissues.  相似文献   

15.
In three multicentered field trials run during 1995 to 1997, involving a total of 12,928 lambs, the preventive effects on blowfly strike of a ready-to-use 5 per cent dicyclanil pour-on formulation and of a ready-to-use 6 per cent cyromazine pour-on formulation were compared with untreated controls for periods of up to 22 weeks. Their efficacy was assessed by calculating the consolidated cumulative strike rate for each treatment group and the consolidated percentage reduction of flystrike achieved by the two formulations. The consolidated cumulative strike rate for all three years together reached 29.2 per cent for the untreated control lambs at week 22, 2.8 per cent for the dicyclanil-treated lambs at week 22, and 6.9 per cent for the cyromazine-treated lambs at week 20. The consolidated cumulative percentage reduction of blowfly strike remained above 89 per cent for the dicyclanil-treated lambs. For the cyromazine-treated lambs the consolidated cumulative percentage reduction of blowfly strike reached 90 per cent during weeks 9 to 10, and 80 per cent during weeks 11 to 12.  相似文献   

16.
Ergot alkaloids present in endophyte-infected (E+) tall fescue cause fescue toxicosis and other toxic effects in livestock that consume infected plant tissue, leading to significant financial losses in livestock production each year. The predominant method currently in use for quantifying ergot alkaloid content in plant tissue is through high-performance liquid chromatography (HPLC), which quantifies the amount of ergovaline, one of many ergot alkaloids in E+ plant tissue. The enzyme-linked immunosorbent assay (ELISA) method used in this study detects quantities of nonspecific ergot alkaloids and therefore accounts for greater amounts of the total ergot alkaloid content in E+ tissue than does HPLC. The ELISA can also be used to more expediently analyze a larger number of forage samples without sophisticated and costly analytical equipment and therefore could be more desirable in a diagnostic setting. The purpose of this study was to evaluate the between-day and within-run variability of the ELISA and to determine the binding efficiency of 6 ergot alkaloids to the 15F3.E5 antibody used in the competitive ELISA to ascertain its feasibility as a quick analysis tool for ergot alkaloids. Straw samples had an average coefficient of variation (CV) for concentration of 10.2% within runs and 18.4% between runs, and the seed samples had an average CV for concentration of 13.3% within runs and 24.5% between runs. The grass tissue-based lysergic acid standard curve calculated from the ELISA had an average r2 of 0.99, with a CV of 2.1%. Ergocryptine, ergocristine, ergocornine, and ergotamine tartrate did not bind strongly to the 15F3.E5 antibody because of the presence of large side groups on these molecules, which block their binding to the antibody, whereas ergonovine and ergonovine maleate were bound much more efficiently because of their structural similarity to lysergic acid. Clarified rumen fluid was tested as an additional matrix for use in the ergot alkaloid competitive ELISA to determine whether future livestock metabolism experiments on the postingestion fate of ergot alkaloids in ruminants could utilize this assay as a quick screening tool for the presence of nonspecific ergot alkaloids in rumen fluid. HPLC and ELISA procedures were compared for their ability in determining ergot alkaloid toxicity based on the repeatability of the procedures and on the specific compounds they measure. The ratio of ELISA concentration to HPLC concentration (ergovaline) varied from 2.00 to 2.81 in seed samples and from 0.62 to 8.66 in straw samples, showing no consistent pattern between the 2 methods. Based on the lack of data at present for the identity of the toxin causing endophyte toxicosis and the lack of agreement between the ergovaline HPLC and ELISA analyses for ergot alkaloids, each method is equally valid as an indicator of toxicityand is the best means for determining the quantity of the specific toxin(s) they measure.  相似文献   

17.
Density gradient centrifugation using a performed self generated gradient of colloidal silica enabled the isolation of microscopic sheep sarcocystis cystozoites, free from heart muscle contamination. The efficiency of separation of cystozoites from residual heart muscle after digestion in pepsin and hydrochloric acid was 63 to 92 per cent. Antigens from cystozoites were used on enzyme-linked immunosorbent assays (ELISA) of plasma from six coccidia-free lambs infected once orally with 70,000 microcystic sheep sarcocystis sporocysts and for raising antisera in rabbits. Use of an anti-sheep IgM conjugate in the ELISA showed that anti-sarcocystis IgM production was transitory, appearing five to 10 days after infection, peaking in concentration at 42 days and following the peak of the acute phase of infection (32 and 33 days) in the lambs. In contrast, total anti-sarcocystis immunoglobulins, detected by ELISA, increased from five to 21 days after infection and continued to increase until the lambs were killed (the last at 81 days) and was more useful in diagnosing chronic infection. No cross reactions between microcystic sheep sarcocystis and Toxoplasma gondii or Eimeria species of sheep were observed. A peroxidase anti-peroxidase test, using rabbit anti-sarcocystis sera, detected second generation meronts and sarcocysts in fixed tissues from infected lambs making it useful for the diagnosis of acute or chronic disease post mortem.  相似文献   

18.
The objective of this study was to evaluate the therapeutic efficacy of paromomycin against cryptosporidiosis in naturally infected lambs under field conditions. The 36 cross-bred neonatal lambs, 3-10 days old, were used. On the first day that lambs showed diarrhea (Day 1) they were randomly divided into three groups. The infected control group (14 lambs) remained unmedicated whereas the two other groups were orally medicated with paromomycin solution (Humatin((R)), Parke Davis, France): 12 lambs (Group A) at 100mg/kg per day for three consecutive days (Days 1-3) and 10 lambs (Group B) at 200mg/kg per day for two days (Days 1 and 2). Drug efficacy was assessed by evaluating the presence of diarrhea, oocyst shedding and weight gains from Days 1 to 23. The results show the efficacy of paromomycin in reducing both cryptosporidial oocyst output and severity of clinical signs. On Day 4, all unmedicated lambs remained infected and excreted large numbers of cryptosporidial oocysts (mean score: 2.5) whereas oocyst output had stopped in most medicated lambs (>60%) and low numbers of oocysts were excreted in the remaining lambs (mean score: 0.45 in Group A and 1 in Group B). Mean oocyst excretion was significantly reduced in medicated lambs from Days 2 to 5 (P<0.05). Treatment also reduced, but not completely prevented, clinical symptoms although diarrhea stopped in most medicated lambs just after drug withdrawal. The mean weight gains of Group A lambs were higher than that of unmedicated lambs throughout the study and statistically significant differences were found from Days 1 to 11 (1.99+/-0.81 versus 1.47+/-0.53) (P<0.05). By contrast, the growth rate of Group B lambs from Days 11 to 23 was impaired when compared with the two other groups (P<0.05) although no significant differences were found at the end of the study (Days 1-23).  相似文献   

19.
Kochia foliage that had tested positive to Dragendorff's reagent (presumptive alkaloids) and had elicited chronic toxicosis when fed to rats was fed to sheep to characterize early stages of kochia toxicosis and evaluate treatments that might improve tolerance. Twelve fine-wool lambs (46 +/- 9 kg BW) were fed chopped kochia hay (35%) mixed with chopped alfalfa hay (65%) for 4 wk. The kochia diet had 14.3% CP and 39.9% ADF. Dry matter intake averaged 3.4% of BW/d. Body weight did not change during 4 wk and blood serum components were not changed from values at the onset. Thereafter, kochia was increased to 50% of diet for five more weeks, during which four treatments were imposed randomly (three lambs/treatment): 1) none; 2) N-acetyl-L-cysteine plus trans-stilbene oxide, 21 and 52 mg/kg of BW, respectively, given i.p. twice weekly; 3) retinyl palmitate, 275 mg, plus alpha-tocopherol, 300 mg/lamb dosed i.m. twice weekly; and 4) zinc sulfate mixed in the feed to provide 500 mg daily. Kochia contained 4.8% oxalate. The diet with 50% kochia had 16% CP and 36% ADF, and digestibility coefficients were 59% for DM, 72% for CP, and 59% for ADF. After 5 wk, blood glucose was elevated slightly, total bilirubin was increased about 1.5-fold (P less than .05), alanine aminotransferase was elevated slightly (P less than .05), and inorganic phosphorus and urea (blood urea N) were diminished (P less than .05); other serum components, including calcium, were unchanged from initial levels (P greater than .10). Treatments had negligible effects for modifying serum signs of mild chronic toxicosis associated with kochia hay fed as 50% of diet.  相似文献   

20.
Four-week-old lambs at pasture were dosed with dog-derived Sarcocystis sporocysts. No difference in growth rates was apparent at a dose of 1 X 10(3) sporocysts per lamb. The minimum dose required to depress growth rate was 2.5 X 10(3) sporocysts per lamb: at 4 weeks post-inoculation (w.p.i.) the weight gain of lambs infected with this dose was 0.6 kg less than the non-infected controls (P less than 0.05). At 11 w.p.i. the difference was 0.7 kg, but this was not significant because of the greater average body weights of both groups. Lambs given 5 X 10(3) sporocysts showed significant depression of weight gain at both 4 and 11 w.p.i. Haematocrit levels at 4-5 weeks post-inoculation were depressed by doses as low as 1 X 10(3) sporocysts.  相似文献   

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