Comparative toxicity responses of goats fed on Leucaena leucocephala in Australia and Hawaii

1983 ◽  
Vol 34 (6) ◽  
pp. 781 ◽  
Author(s):  
RJ Jones ◽  
RG Megarrity

To examine the apparent absence of toxicity in ruminants fed on Leucaena leucocephala in Hawaii, U.S.A., goats were offered comparable diets of Leucaena and lucerne chaff (control) in both Australia and Hawaii over a 7-week period. Intake of mimosine, excretion of the ruminal metabolite 3-hydroxy- 4(1H)-pyridone (DHP), and serum concentrations of thyroxine (T4) were measured in both studies. Mean mimosine intakes on the highest Leucaena diets in Australia and Hawaii were similar at about 20 g day-1. In Australia, goats on the all-Leucaena diets became hypothyroid after only 3 weeks of feeding, thyroid glands were enlarged and erosion of the oesophageal mucosa and reticulo-rumen occurred. Excretion of DHP in the urine was related to the daily mirnosine intakes, with recoveries of about 86%. In marked contrast, goats fed on Leucaena in Hawaii exhibited no clinical signs of toxicity and excreted less than 1% of the mirnosine intake as DHP in the urine. No degradation of DHP occurred in vitro with rumen fluid from Australian goats, whereas 71% of the added DHP was degraded after 5 h with rumen fluid from goats in Hawaii. The results support the hypothesis that the differences observed are attributable to a different microbial metabolism of mimosine and DHP in ruminants in Hawaii.

2009 ◽  
Vol 49 (8) ◽  
pp. 643 ◽  
Author(s):  
R. J. Jones ◽  
D. B. Coates ◽  
B. Palmer

Droughtmaster steers from the CSIRO Research Station at Lansdown, 50 km south of Townsville, Queensland, were assessed at slaughter for indications of leucaena toxicity and the presence of the 3,4 dihydroxypyridine (DHP)-degrading bacterium Synergistes jonesii. This bacterium had been introduced to the herd 25 years earlier. Absence of clinical signs of ulceration of the oesophagus, absence of DHP in the urine, the presence of normal thyroid glands and the ability of rumen fluid to degrade high levels of mimosine from leucaena shoot tips in vitro all confirmed that these steers had an active bacterial culture capable of degrading mimosine and its degradation products 3,4 and 2,3 DHP. Steers had been away from the Research Station and away from leucaena pastures for long periods but had clearly not lost the bacteria or if they had, they had regained them on return to leucaena pastures on Lansdown. It is postulated that the bacteria may spread via the faeces in cattle yards and remain in the rumen for long periods, even at low levels, in the absence of leucaena in the diet. Reasons other than the effectiveness of the bacterium should be explored to explain the failure of cattle in some Queensland herds to fully degrade 3,4 and 2,3 DHP.


1999 ◽  
Vol 50 (7) ◽  
pp. 1147 ◽  
Author(s):  
A. A. Odenyo ◽  
C. S. McSweeney ◽  
B. Palmer ◽  
D. Negassa ◽  
P. O. Osuji

The capabilities of rumen fluid sources from indigenous African ruminants and hindgut fluid from zebra to ferment leaves of Acacia angustissima, Calliandra calothyrsus, Leucaena diversifolia, Leucaena leucocephala, Leucaena pallida, and Tephrosia bracteolata were evaluated to determine the presence of tannin tolerant or degrading microbes. In vitro gas and ammonia production and loss of neutral detergent fibre were estimated as indices for fermentation. The effect of polyethylene glycol (PEG) on fermentation was tested. The ability of microorganisms in rumen fluid sources to grow in the presence of tannin extracts or tannic acid was also tested and their disappearance was determined by HPLC. There was a significant (P < 0.001) rumen fluid source × fodder type interaction with all variables studied. The highest gas and ammonia production was from samples incubated with rumen fluid from dik-dik and goat. Addition of PEG enhanced fermentation with various rumen fluid sources and from some plant leaves but its effect was greatest (P < 0.001) in A. angustissima. HPLC results showed that tannin and phenolic monomers were hydrolysed by all rumen fluid sources. The conclusion from this work was that rumen fluid from goat, gazelle, Gunther™s dik-dik, and impala effectively fermented tannin-rich fodders and therefore may harbour tannin tolerant or degrading microorganisms.


2012 ◽  
Vol 48 (4) ◽  
pp. 278-283 ◽  
Author(s):  
Leslie Anne Kuczynski ◽  
Paul Schwartz ◽  
Gordon Peddle ◽  
Steven Huang ◽  
Wilfried Mai ◽  
...  

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.


1984 ◽  
Vol 64 (4) ◽  
pp. 937-942 ◽  
Author(s):  
H. KUDO ◽  
K.-J. CHENG ◽  
W. MAJAK ◽  
J. W. HALL ◽  
J. W. COSTERTON

The microbial detoxification of mimosine was detected during in vitro studies with rumen fluid from cattle and sheep in Canada. The toxic amino acid, a component of Leucaena leucocephala (Leguminosae), was degraded rapidly (average rate 2.17 μg∙mL−1∙h−1) by rumen inocula from sheep on a concentrate diet but inocula from sheep on cubed hay showed much less activity (0.44 μg∙mL−1∙h−1). Mimosine was also metabolized by rumen microorganisms from steers on concentrate rations (2.88 μg∙mL−1∙h−1) but rates were lower when inocula originated from cattle fed hay, pasture or silage diets (< 1.87 μg∙mL−1∙h−1). Our results show that in Canada, rumen fluid contains microorganisms capable of mimosine degradation and that the rates of detoxification are enhanced by rumen microbiota from sheep and cattle on concentrate diets. Key words: Detoxification, rumen microorganisms, mimosine, sheep, cattle


1974 ◽  
Vol 77 (1) ◽  
pp. 64-70 ◽  
Author(s):  
Gustav Wägar

ABSTRACT Whether the short-term regulation of thyroidal protein synthesis by TSH occurs at the transcriptional or the translational level was tested by measuring the effect of actinomycin D (act D) on the TSH-induced stimulation of L-14C-leucine incorporation into the thyroidal proteins of rats. TSH was injected 6 h before the rats were killed. The thyroid glands were then removed and incubated in vitro in the presence of L-14C-leucine for 2 h. The pronounced stimulation of leucine incorporation in the TSH-treated animals was depressed as compared with controls but still significant even when the animals had been pre-treated with 100 μg act D 24 and 7 h before sacrifice. On the other hand, act D strongly decreased incorporation of 3H-uridine into RNA. Short-term regulation of thyroidal protein synthesis by TSH appears to be partly but not wholly dependent on neosynthesis of RNA. Hence regulation may partly occur at the translation level of protein synthesis.


1976 ◽  
Vol 81 (2) ◽  
pp. 495-506 ◽  
Author(s):  
A. Radvila ◽  
R. Roost ◽  
H. Bürgi ◽  
H. Kohler ◽  
H. Studer

ABSTRACT Lithium and excess iodide inhibit the release of thyroid hormone from preformed stores. We thus tested the hypothesis that this was due to an inhibition of thyroglobulin breakdown. Rats were pre-treated with propylthiouracil (PTU) for 3 weeks in order to deplete their thyroids of thyroglobulin. While the PTU was continued, lithium chloride (0.25 mEq./100 g weight) or potassium iodide (3 mg per rat) were injected every 12 h for 3 days. Thereafter the thyroglobulin content in thyroid gland homogenates was measured. PTU pre-treatment lowered the thyroglobulin content from 4.21 to 0.22 mg/100 mg gland. Lithium caused a marked re-accumulation of thyroglobulin to 0.60 mg/100 mg within 3 days. While iodide alone had only a borderline effect, it markedly potentiated the action of lithium and a combination of the two drugs increased the thyroglobulin content to 1.04 mg/100 mg. Thyroxine was injected into similarly pre-treated animals to suppress secretion of thyrotrophic hormone. This markedly inhibited the proteolysis of thyroglobulin and 1.3 mg/100 mg gland accumulated after 3 days. Excess iodide, given in addition to thyroxine, decreased the amount of thyroglobulin accumulated to 0.75 mg/100 mg gland. To study whether this could be explained by an inhibitory action of iodide on thyroglobulin biosynthesis, thyroid glands from animals treated with excess iodide were incubated in vitro in the presence of 0.2 mm iodide for 3 h. Iodide decreased the incorporation of radioactive leucine into total thyroidal protein and into thyroglobulin by 25 and 35 % respectively. Iodide did not inhibit protein synthesis in the kidney, liver or muscle tissue. Thus, large doses of iodide selectively inhibit thyroglobulin biosynthesis.


Author(s):  
P. R. Chavelikar ◽  
G. and Neha Rao C. Mandali ◽  
Neha Rao

Ruminal acidosis is an important clinical emergency in small ruminants. In this study, eight healthy farm goats and 24 goats presented at TVCC of the college of Veterinary Sciences and A.H., Anand with clinical signs of ruminal acidosis and having rumen liquor pH below 6 were examined for alterations in the ruminal fluid and serum biochemical parameters. Among various rumen fluid parameters evaluated, the mean values of rumen fluid pH decreased significantly (4.71±0.11 vs. 6.90±0.10), while sediment activity time (46.67±1.20 vs. 24.50±0.78 min) and methylene blue reduction time (29.50±0.73 vs. 10.03±0.27 min) increased significantly in acidotic goats. The normal greenish, aromatic viscous color, odour and consistency of rumen fluid of healthy goats also changed to milky grey/creamy, sour/pungent watery in acidotic goats. The rumen protozoal activity decreased to nil in acidotic goats as compared to the healthy goats. Among various serum biochemical constituents, the mean values of glucose (92.43±1.37 vs. 74.13±1.83 mg/dl), BUN (26.49±0.47 vs. 22.63±1.19 mg/dl), serum creatinine (01.01±0.02 vs. 00.83±0.02 mg/dl) and albumin (03.22±0.03 vs. 03.05±0.05 g/dl), ALT (56.75±1.55 vs. 27.88±1.14 IU/L) and AST (93.25±1.82 vs. 54.00±1.75 IU/L), increased significantly, while there was significant decrease in serum calcium (09.09±0.14 vs. 10.29±0.08 mg/dl) in acidotic goats. The mean values of alkaline phosphatase (IU/L) in acidotic goats increased non-significantly from the base values of healthy goats.


Author(s):  
Sridevi Chigurupati ◽  
Shantini Vijayabalan ◽  
Kesavanarayanan Krishnan Selvarajan ◽  
Ahmad Alhowail ◽  
Fatema Kauser

AbstractObjectivesResearch on endosymbionts is emerging globally and is considered as a potential source of bioactive phytochemicals. The present study examines the antioxidant and antidiabetic of the endophytic crude extract isolated from Leucaena leucocephala leaves.MethodsEndophytic bacteria were isolated from the leaves of L. leucocephala and 16S rRNA gene sequencing was used to establish their identity. The in vitro antioxidant effect of endophytic crude extract (LL) was evaluated using 2-diphenyl-1-picrylhydrazyl (DPPH) and 2, 2′-azino-bis-3-ethylbenzthiazoline-6-sulphonic acid (ABTS) free radical scavenging methods. The in vitro antidiabetic properties of LL were evaluated using α-amylase and α-glucosidase enzyme inhibition assay.ResultsThe isolated endophytic bacteria were identified as Cronobacter sakazakii. LL displayed potent free radical scavenging effect against ABTS and DPPH radicals with an inhibitory concentration 50% (IC50) value of 17.49 ± 0.06 and 11.3 ± 0.1 μg/mL respectively. LL exhibited α-amylase and α-glucosidase inhibition with an IC50 value of 23.3 ± 0.08 and 23.4 ± 0.1 μg/mL respectively compared to the standard drug (acarbose). Both glucose loaded normoglycemic rats and STZ induced diabetic rats treated with LL (200 mg/kg) exhibited a considerable reduction in blood glucose levels p<0.01 after 8 h of treatment when compared to normal and diabetic control rats respectively.ConclusionsThus, the study shows that LL has a wellspring of natural source of antioxidants, and antidiabetic agents and phytoconstituents present in endophytes could be the rich source for bioactive compounds.


Author(s):  
B N Harsh ◽  
B J Klatt ◽  
M J Volk ◽  
A R Green-Miller ◽  
J C McCann

Abstract The objective was to quantify the effects of the beta-adrenergic agonist (β-AA) ractopamine hydrochloride (Actogain, Zoetis, Parsippany, NJ) on nitrogen excretion and nutrient digestibility in feedlot cattle. In experiment 1, twelve Simmental × Angus steers were blocked by bodyweight (531 ± 16 kg) and used in a randomized complete block design. Dietary treatments included: 1) a control without β-AA (CON) or 2) 400 mg/steer/d ractopamine hydrochloride (RAC) for 35 d before slaughter. Diets contained (DM basis) 55% dry rolled corn, 20% corn silage, 15% modified wet distillers grains with solubles, and 10% supplement. For each block, total collection of feed, orts, feces and urine were conducted for two 5 d sampling periods during week 2 and 4 of RAC supplementation. No interaction (P &gt; 0.21) between treatment and collection period was observed for any parameter evaluated. Dietary treatment had no effect (P = 0.51) on DMI, but RAC had decreased fecal DM output (P = 0.04) compared with CON. Thus, RAC had greater apparent total tract DM digestibility (77.2 vs. 73.5%; P &lt; 0.01), N digestibility (72.4 vs. 69.4%; P = 0.01), and NDF digestibility (65.6 vs. 60.2%; P &lt; 0.01) than CON. Although treatment did not affect nitrogen intake (P = 0.52), RAC tended to reduce total nitrogen excretion (113.3 vs. 126.7 g/d; P = 0.10) compared with CON due to a tendency for decreased fecal nitrogen output (53.9 vs. 61.3 g/d; P = 0.10). However, dietary treatment had no effect (P = 0.53) on urinary nitrogen output or percentage of urinary nitrogen excreted as urea (P = 0.28). Experiment 2 was an in vitro experiment conducted to validate the effects of RAC on nutrient digestibility using Simmental × Angus heifers (451 ± 50 kg). Rumen fluid was collected individually by stomach tube from CON- (n = 9) and RAC-fed (n = 10) heifers to inoculate bottles containing a CON or RAC-containing substrate in a split-plot design. No interaction between rumen fluid source and in vitro substrate was observed. Greater IVDMD (P = 0.01) was observed in rumen fluid from RAC-fed heifers compared with rumen fluid from CON-fed heifers. Inclusion of RAC in the in vitro substrate increased IVDMD (P &lt; 0.01). Overall, feeding RAC increased microbial digestion of the dry-rolled corn-based finishing diet to increase total tract dry mater digestion by 5% and reduce nitrogen excretion by 10.6% in the 35 d period prior to slaughter.


Author(s):  
Anne Hege Aamodt ◽  
Einar August Høgestøl ◽  
Trine Haug Popperud ◽  
Jan Cato Holter ◽  
Anne Ma Dyrhol-Riise ◽  
...  

Abstract Objective To test the hypotheses that blood biomarkers for nervous system injury, serum concentrations of neurofilament light chain protein (NfL) and glial fibrillary acidic protein (GFAp) can serve as biomarkers for disease severity in COVID-19 patients. Methods Forty-seven inpatients with confirmed COVID-19 had blood samples drawn on admission for assessing serum biomarkers of CNS injury by Single molecule array (Simoa), NfL and GFAp. Concentrations of NfL and GFAp were analyzed in relation to symptoms, clinical signs, inflammatory biomarkers and clinical outcomes. We used multivariate linear models to test for differences in biomarker concentrations in the subgroups, accounting for confounding effects. Results In total, 21% (n = 10) of the patients were admitted to an intensive care unit, and the overall mortality rate was 13% (n = 6). Non-survivors had higher serum concentrations of NfL (p < 0.001) upon admission than patients who were discharged alive both in adjusted analyses (p = 2.6 × 10–7) and unadjusted analyses (p = 0.001). The concentrations of NfL in non-survivors increased over repeated measurements; whereas, the concentrations in survivors were stable. The GFAp concentration was also significantly higher in non-survivors than survivors (p = 0.02). Conclusion Increased concentrations of NfL and GFAp in COVID-19 patients on admission may indicate increased mortality risk. Measurement of blood biomarkers for nervous system injury can be useful to detect and monitor CNS injury in COVID-19.


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