Efficacy, persistence and presence of Synergistes jonesii in cattle grazing leucaena in Queensland: on-farm observations pre- and post-inoculation

2013 ◽  
Vol 53 (10) ◽  
pp. 1065 ◽  
Author(s):  
S. R. Graham ◽  
S. A. Dalzell ◽  
Nguyen Trong Ngu ◽  
C. K. Davis ◽  
D. Greenway ◽  
...  

A study of eight commercial cattle herds grazing leucaena (Leucaena leucocephala subsp. glabrata) pastures was undertaken to determine (1) the efficacy of in vitro Synergistes jonesii inoculum (produced in an anaerobic fermenter) in degrading the dihydroxypyridone (DHP) isomers produced during digestion of leucaena forage; and (2) the persistence of the inoculum in the rumen of cattle following a period grazing non-leucaena pastures. Cattle were introduced to the leucaena pastures for an initial period varying from 17 to 71 days. Fourteen to fifteen animals were then sampled for (1) urine and blood plasma to determine toxicity status as indicated by concentration of DHP; (2) faeces for estimation of diet composition; and (3) rumen fluid for detection of S. jonesii by nested polymerase PCR analysis. After a further 42–56 days, animals were resampled as before to confirm toxicity status and inoculated with the in vitro S. jonesii inoculum; the herds were then sampled a third time (42–60 days after inoculation) to test the effectiveness of the inoculum in degrading DHP. Five of the herds were then removed from leucaena pastures for periods ranging from 80 to 120 days and returned to leucaena pastures for 21 days to check persistence of the inoculum as indicated by retention of capacity to degrade DHP. The data indicated (1) a very slow build up of capacity to degrade DHP isomers on some properties before inoculation; (2) frequent occurrence of high levels of 2,3-DHP in urine indicating partial toxin degradation, both before and after inoculation; (3) a low incidence of detection of S. jonesii in rumen fluid after inoculation based on nested PCR analysis; (4) failure of inoculation to degrade DHP on one of two properties tested; and (5) loss of capacity to degrade DHP on some properties after <4 months on alternative non-leucaena pastures. It was concluded that while most herds showed some capability to degrade DHP due to some residual capability from previous exposure, they did not achieve the same rapid and complete DHP degradation reported in the 1980s. Nevertheless, it was concluded that the in vitro inoculum was at least partially effective and should continue to be used by graziers until improved sources of inoculum and/or inoculation methodologies are demonstrated.

2012 ◽  
Vol 52 (5) ◽  
pp. 365 ◽  
Author(s):  
S. A. Dalzell ◽  
D. J. Burnett ◽  
J. E. Dowsett ◽  
V. E. Forbes ◽  
H. M. Shelton

A postal survey of the level of awareness of leucaena toxicity and an on-farm study of the toxicity status of Queensland cattle herds grazing leucaena were conducted to investigate the prevalence of mimosine and dihydroxypyridine (DHP) toxicity in Queensland. In total, 195 of 356 graziers surveyed responded to the postal survey. Sixty-three percent had inoculated their cattle with in vitro Synergistes jonesii inoculum (produced in an anaerobic fermenter) and 30% of these had inoculated more than once. The remainder used inappropriate procedures. Many graziers (43%) had occasionally observed toxicity symptoms of hair loss and poor animal growth rates. In the on-farm study, the toxicity status of 385 animals in 44 individually managed herds on 36 properties was determined by urine analysis of mimosine and DHP concentrations. No animals were experiencing mimosine toxicity, based on low concentrations of this compound found in the urine. Using the criterion that average herd urine concentrations of DHP >100 μg/mL was indicative of subclinical toxicity, 48% of herds were exposed to subclinical toxicity due to dominant 3,4-DHP (21%) or dominant 2,3-DHP (27%) toxicity; many of these herds had been inoculated with S. jonesii and were thought to be protected. The finding that 27% of herds were excreting high concentrations of 2,3-DHP was unexpected. Statistical analysis of herd-management data revealed that the method used by graziers to inoculate their herds was significantly (P < 0.05) but weakly linked to herd protection status. It was concluded that subclinical 3,4-DHP and 2,3-DHP toxicity remains a problem in Queensland and is likely to be limiting animal production in a significant number of cattle grazing leucaena-grass pastures.


2022 ◽  
Vol 8 (1) ◽  
Author(s):  
Manuel Gómez-García ◽  
Héctor Argüello ◽  
Lucía Pérez-Pérez ◽  
Clara Vega ◽  
Héctor Puente ◽  
...  

Abstract Background Swine dysentery (SD) is a severe infectious disease with a relevant impact on pig production usually caused by Brachyspira hyodysenteriae, although B. hampsonii causes an identical clinical picture. SD control relies on antimicrobials, good management practices and strict biosecurity with cleaning and disinfection as crucial tools to avoid the pathogen transmission. This study evaluates the in-vitro efficacy of an array of commercial disinfectants against a collection of B. hyodysenteriae isolates using broth tests. The efficacy of cleaning and disinfection protocols was also evaluated on two farms with endemic SD using surface swabs collected in emptied pens before and after cleaning and disinfection procedures, using both real-time PCR and bacterial microbiological culture. Results Most of the commercial disinfectants evaluated were effective against all B. hyodysenteriae isolates tested, with a reduction of more than 5.00 log10 CFU/mL (bactericidal efficacy of 99.999%). However, some isolates exhibited reduced susceptibility to Virkon-S and Limoseptic disinfectants. The evaluation of cleaning and disinfection protocols on farms with SD outbreaks showed that approximately half the pens tested (n = 25) were positive by real-time PCR after pigs removal (mean B. hyodysenteriae counts 5.72 ± 1.04 log10 CFU/mL) while almost 20% of the pens remained positive after cleaning (n = 7) and disinfection (n = 5) procedures although with significantly lower, mean estimates (4.31 ± 0.43 log10 CFU/mL and 4.01 ± 0.55 log10 CFU/mL, respectively). Conclusions These results show the efficacy of disinfectants against B. hyodysenteriae but also stress the need to implement adequately the cleaning and disinfection protocols on pig farms and review and revise their efficiency periodically.


1993 ◽  
Vol 33 (5) ◽  
pp. 541 ◽  
Author(s):  
JB Moran ◽  
DE Croke

Dairy cows in mid lactation grazed paspalum-dominant perennial pastures and were offered either crushed wheat or maize silage at 0, 25, 50, or 75 MJ metabolisable energy/cow.day. Another herd was offered maize silage ad libitum. Milk yield and composition, liveweight and body condition, and pasture intakes were monitored over 8 weeks during summer. Cow performance was recorded for another 3 weeks when all cows were supplemented with the same feedlot ration. Samples of pastures before and after grazing, supplement, rumen fluid, and faeces were collected for chemical analyses. Linear regressions were used to calculate mean milk responses and rates of pasture substitution for the 2 supplement types. Yields of milk and milk solids increased with level of supplement fed (with 1 exception) and were higher in cows fed wheat at the same level of supplemental energy. However, cows fed maize silage achieved higher body condition scores. On average, cows supplemented with wheat and maize silage, respectively, produced 0.72 and 0.38 kg extra milk/kg supplement (DM), and they substituted pasture at the rate of 0.87 and 1 .O1 kg pasture DM/kg supplement DM. Low pasture quality (117 g crude protein/kg DM and 59.5% in vitro digestibility) was considered the main cause of high levels of pasture substitution and poor milk responses to maize silage feeding. Cows fed 6.8 kg DM/cow.day of maize silage had very low rumen ammonia-N and faecal N concentrations. It was concluded that additional N should be included with maize silage when fed to cows grazing low quality perennial pastures, even with feeding levels as low as 2 or 3 kg DM/cow.day.


1990 ◽  
Vol 63 (1) ◽  
pp. 17-26 ◽  
Author(s):  
A. J. Vince ◽  
N. I. Mcneil ◽  
J. D. Wager ◽  
O. M. Wrong

An in vitro faecal incubation system was used to study the metabolism of complex carbohydrates by intestinal bacteria. Homogenates of human faeces were incubated anaerobically with added lactulose, pectin, the hemicellulose arabinogalactan, and cellulose, both before and after subjects had been pre-fed each carbohydrate. Fermentation of added substrate was assessed by the production of short-chain fatty acids (SCFA) and suppression of net ammonia generation over 48 h of incubation. Control faecal homogenates to which carbohydrate was not added yielded an average increment of SCFA of 43 mmol/l, equivalent to 172 mmol/kg in the original stool. The addition of lactulose, pectin and arabinogalactan each increased the yield of SCFA by a similar amount, averaging 6·5 mmol/g carbohydrate or 1·05 mol/mol hexose equivalent; organic acid yield was not increased by pre-feeding these substances for up to 2 weeks. Acetate was the major SCFA in all samples at all times and, after pre-feeding with extra carbohydrate, butyrate concentrations exceeded propionate in all samples. Faecal homogenates incubated with cellulose showed no greater SCFA production than controls over the first 48 h, but there was a slight increase when samples from two subjects pre-fed cellulose were incubated for 14 d. Net ammonia generation was markedly suppressed by addition of lactulose to faecal incubates with an initial period of net bacterial uptake of ammonia. Pectin and arabinogalactan also decreased ammonia generation, but the reductions were not significant unless subjects were pre-fed these materials; cellulose had no effect on ammonia generation.


2019 ◽  
Vol 59 (4) ◽  
pp. 696
Author(s):  
Michael J. Halliday ◽  
Hayley E. Giles ◽  
Jagadish Padmanabha ◽  
Chris S. McSweeney ◽  
Scott A. Dalzell ◽  
...  

An experiment was conducted to investigate the efficacy of a cultured Synergistes jonesii inoculum in degrading the Leucaena leucocephala (leucaena) toxins: 3-hydroxy-4(1H)-pyridone and 3-hydroxy-2(1H)-pyridone (3,4- and 2,3-DHP). Sixteen stall-housed Bos indicus steers naïve to leucaena were fed varying combinations of forage-harvested leucaena and Chloris gayana (Rhodes grass). Dietary treatments, offered at 25 g dry matter/kg LW.day, were: 25% leucaena; 50% leucaena; 100% leucaena; and 50% leucaena, switched to 50% Medicago sativa (lucerne) after 6 weeks at time of inoculation. The experiment was 10 weeks in duration, consisting of a 6-week pre-inoculation period, followed by inoculation with cultured S. jonesii, and a 4-week post-inoculation period. Mean daily dry matter intake was recorded. Twenty-four-hour urine collections and rumen fluid samples were obtained weekly for estimation of total urinary DHP, and detection of S. jonesii using nested polymerase chain reaction analysis including presence of single nucleotide polymorphisms (SNP), respectively. In the pre-inoculation period, total urinary DHP increased quickly to high levels, then gradually declined after Week 3 with 2,3-DHP the dominant isomer through to Week 6. Indigenous strains of S. jonesii were sporadically detected by PCR analysis, indicating S. jonesii was present before inoculation but at the lower limits of detection. After inoculation there was no change in the rate of total DHP degradation or the frequency of detection of S. jonesii, although there was increased rate of degradation of 2,3-DHP. SNP indicated the presence of different strains of S. jonesii in both indigenous and cultured S. jonesii. DMI was low, especially in the 100% treatment, due in part to the high stem content of the forage-harvested leucaena and probable DHP toxicosis. It was concluded that the cultured S. jonesii inoculum did not fully protect animals against leucaena toxicity.


Reproduction ◽  
2017 ◽  
Vol 154 (4) ◽  
pp. 535-545 ◽  
Author(s):  
Joanna Budna ◽  
Artur Bryja ◽  
Piotr Celichowski ◽  
Rotem Kahan ◽  
Wiesława Kranc ◽  
...  

Proper oocyte maturation in mammals produces an oocyte capable of monospermic fertilization and embryo preimplantation. The cumulus-oocyte complexes (COCs), surrounding an oocyte, play a significant role in oocyte maturation. During this process, when the COCs undergo cumulus expansion wherein tightly compact cumulus cells (CCs) form a dispersed structure, permanent biochemical and molecular modifications occur in the maturing oocytes, indicating that the gene expression between immature and mature oocytes differs significantly. This study focuses on the genes responsible for the cellular components of morphogenesis within the developing oocyte. Brilliant cresyl blue (BCB) was used to determine the developmental capability of porcine oocytes. The immature oocytes (GV stage) were compared with matured oocytes (MII stage), using microarray and qRT-PCR analysis to track changes in the genetic expression profile of transcriptome genes. The data showed substantial upregulation of genes influencing oocyte’s morphology, cellular migration and adhesion, intracellular communication, as well as plasticity of nervous system. Conversely, downregulation involved genes related to microtubule reorganization, regulation of adhesion, proliferation, migration and cell differentiation processes in oocytes. This suggests that most genes recruited in morphogenesis in porcine oocytein vitro,may have cellular maturational capability, since they have a higher level of expression before the oocyte’s matured form. It shows the process of oocyte maturation and developmental capacity is orchestrated by significant cellular modifications during morphogenesis.


Author(s):  
S.K. Aggarwal

The proposed primary mechanism of action of the anticancer drug cisplatin (Cis-DDP) is through its interaction with DNA, mostly through DNA intrastrand cross-links or DNA interstrand cross-links. DNA repair mechanisms can circumvent this arrest thus permitting replication and transcription to proceed. Various membrane transport enzymes have also been demonstrated to be effected by cisplatin. Glycoprotein alkaline phosphatase was looked at in the proximal tubule cells before and after cisplatin both in vivo and in vitro for its inactivation or its removal from the membrane using light and electron microscopy.Outbred male Swiss Webster (Crl: (WI) BR) rats weighing 150-250g were given ip injections of cisplatin (7mg/kg). Animals were killed on day 3 and day 5. Thick slices (20-50.um) of kidney tissue from treated and untreated animals were fixed in 1% buffered glutaraldehyde and 1% formaldehyde (0.05 M cacodylate buffer, pH 7.3) for 30 min at 4°C. Alkaline phosphatase activity and carbohydrates were demonstrated according to methods described earlier.


Author(s):  
Henry H. Eichelberger ◽  
John G. Baust ◽  
Robert G. Van Buskirk

For research in cell differentiation and in vitro toxicology it is essential to provide a natural state of cell structure as a benchmark for interpreting results. Hypothermosol (Cryomedical Sciences, Rockville, MD) has proven useful in insuring the viability of synthetic human epidermis during cold-storage and in maintaining the epidermis’ ability to continue to differentiate following warming.Human epidermal equivalent, EpiDerm (MatTek Corporation, Ashland, MA) consisting of fully differentiated stratified human epidermal cells were grown on a microporous membrane. EpiDerm samples were fixed before and after cold-storage (4°C) for 5 days in Hypothermosol or skin culture media (MatTek Corporation) and allowed to recover for 7 days at 37°C. EpiDerm samples were fixed 1 hour in 2.5% glutaraldehyde in sodium cacodylate buffer (pH 7.2). A secondary fixation with 0.2% ruthenium tetroxide (Polysciences, Inc., Warrington, PA) in sodium cacodylate was carried out for 3 hours at 4°C. Other samples were similarly fixed, but with 1% Osmium tetroxide in place of ruthenium tetroxide. Samples were dehydrated through a graded acetone series, infiltrated with Spurrs resin (Polysciences Inc.) and polymerized at 70°C.


Author(s):  
Pınar Ercan ◽  
Sedef Nehir El

Abstract. The goals of this study were to determine and evaluate the bioaccessibility of total anthocyanin and procyanidin in apple (Amasya, Malus communis), red grape (Papazkarası, Vitis vinifera) and cinnamon (Cassia, Cinnamomum) using an in vitro static digestion system based on human gastrointestinal physiologically relevant conditions. Also, in vitro inhibitory effects of these foods on lipid (lipase) and carbohydrate digestive enzymes (α-amylase and α-glucosidase) were performed with before and after digested samples using acarbose and methylumbelliferyl oleate (4MUO) as the positive control. While the highest total anthocyanin content was found in red grape (164 ± 2.51 mg/100 g), the highest procyanidin content was found in cinnamon (6432 ± 177.31 mg/100 g) (p < 0.05). The anthocyanin bioaccessibilities were found as 10.2 ± 1%, 8.23 ± 0.64%, and 8.73 ± 0.70% in apple, red grape, and cinnamon, respectively. The procyanidin bioaccessibilities of apple, red grape, and cinnamon were found as 17.57 ± 0.71%, 14.08 ± 0.74% and 18.75 ± 1.49%, respectively. The analyzed apple, red grape and cinnamon showed the inhibitory activity against α-glucosidase (IC50 544 ± 21.94, 445 ± 15.67, 1592 ± 17.58 μg/mL, respectively), α-amylase (IC50 38.4 ± 7.26, 56.1 ± 3.60, 3.54 ± 0.86 μg/mL, respectively), and lipase (IC50 52.7 ± 2.05, 581 ± 54.14, 49.6 ± 2.72 μg/mL), respectively. According to our results apple, red grape and cinnamon have potential to inhibit of lipase, α-amylase and α-glucosidase digestive enzymes.


1994 ◽  
Vol 71 (04) ◽  
pp. 499-506 ◽  
Author(s):  
Mark W C Hatton ◽  
Bonnie Ross-Ouellet

SummaryThe behavior of 125I-labeled recombinant hirudin towards the uninjured and de-endothelialized rabbit aorta wall has been studied in vitro and in vivo to determine its usefulness as an indicator of thrombin activity associated with the aorta wall. Thrombin adsorbed to either sulfopropyl-Sephadex or heparin-Sepharose bound >95% of 125I-r-hirudin and the complex remained bound to the matrix. Binding of 125I-r-hirudin to the exposed aorta subendothelium (intima-media) in vitro was increased substantially if the tissue was pre-treated with thrombin; the quantity of l25I-r-hirudin bound to the de-endothelialized intima-media (i.e. balloon-injured in vitro) correlated positively with the quantity of bound 131I-thrombin (p <0.01). Aortas balloon-injured in vivo were measured for thrombin release from, and binding of 125I-r-hirudin to, the de-endothelialized intimal surface in vitro; 125I-r-hirudin binding correlated with the amount of active thrombin released (p <0.001). Uptake of 125I-r-hirudin by the aorta wall in vivo was proportional to the uptake of 131I-fibrinogen (as an indicator of thrombin activity) before and after balloon injury. After 30 min in the circulation, specific 125I-r-hirudin binding to the uninjured and de-endo- thelialized (at 1.5 h after injury) aorta wall was equivalent to 3.4 (± 2.5) and 25.6 (±18.1) fmol of thrombin/cm2 of intima-media, respectively. Possibly, only hirudin-accessible, glycosaminoglycan-bound thrombin is measured in this way.


Sign in / Sign up

Export Citation Format

Share Document