Field studies on the biological control of nematode parasites of sheep in the tropics, using the microfungus Duddingtonia flagrans     

Chandrawathani P  Jamnah O  Adnan M  Waller PJ  Larsen M  Gillespie AT 《Veterinary parasitology》2004,120(3):177-187

Long-term field studies were conducted on two government managed small ruminant research farms, located in different geo-climatic regions and approximately 300 km separate from each other, on Peninsula Malaysia. The Infoternak trial (48 weeks) and the Chalok trial (43 weeks) each compared nematode parasite control in separately managed groups of young sheep, either short-term rotationally grazed around a suite of 10 paddocks in addition to receiving a daily supplement of Duddingtonia flagrans spores (Fungus Group); or similar groups of sheep being rotationally grazed alone (Control Group). The prevailing weather conditions at Infoternak farm were of below average rainfall conditions for the most of the trial. As a consequence, only very low worm infections (almost exclusively Haemonchus contortus) were acquired by the 17 sets of tracer lambs that grazed sequentially with the experimental lambs. However on all except 2 occasions in the early part of the trial, the mean tracer worm burdens were significantly lower (P < 0.05) and the experimental lambs grew significantly better (P = 0.054) in the Fungus Group. Rainfall at Chalok farm during the course of the trial was also below average. As a consequence infectivity of pastures was assumed to be relatively low based on faecal egg counts (epg) of the experimental sheep, which following an anthelmintic treatment prior to allocation, remained very low in both treatment groups. Faecal egg counts of undosed replacement lambs in the latter half of the Chalok study, showed a progressive increase in the Control Group to levels exceeding 3000 epg, whereas the Fungus Group remained static at approximately 500 epg. These results show that the deployment of the nematophagous fungus, D. flagrans, can improve the level of parasite control of sheep in the tropics above that which can be achieved by the short-term rotational grazing strategy alone.  相似文献   

Evaluation of biological control of sheep parasites using Duddingtonia flagrans under commercial farming conditions on the island of Gotland, Sweden     

Waller PJ  Schwan O  Ljungström BL  Rydzik A  Yeates GW 《Veterinary parasitology》2004,126(3):299-315

Field trials, conducted over 3 consecutive years, were aimed at assessing farmer opinions of the practicality and effectiveness of using Duddingtonia flagrans to control nematode parasites in their flocks on the Swedish island of Gotland. These trials were also monitored by intensive parasitological investigation. On Gotland, lambing occurs in spring, and around mid-summer (late June), ewes and lambs are moved to saved pastures due to pasture deterioration caused by dry conditions. Weaned lambs are then returned to original lambing pastures in early autumn for finishing. One farm (B) was used for 2001-2003 and a second farm (N) was also used in 2002 and 2003. On each farm, two flocks (each of 20 ewes + twin lambs) were managed separately, namely: fungus group which received a daily supplement + fungal spores from lambing until the summer move (6 weeks) and: control group which received supplement only. For Farm B, the numbers of lambs that were marketed prior to the end of the grazing season, were 13, 18, 19 for the fungus treatment whereas corresponding numbers for the control treatment were 8, 16 and 11 for years 2001, 2002 and 2003, respectively. Final weights of the remaining lambs at the end of each year were also consistently heavier, and the numbers of lambs retained for finishing during winter were less, on the fungus treatment compared with the control treatment. On Farm N, similar results were recorded, with more lambs marketed earlier in the fungus group (25 and 19) compared with the control (19 and 15) in 2002 and 2003, respectively. The weights of the remaining lambs at the end of the trial in 2003 showed a 4.5 kg weight gain advantage of the fungus group compared to the controls. Tracer tests during autumn 2001 on Farm B, showed that Teladorsagia circumcincta plus Trichostrongylus spp. levels were significantly less on the fungus treatment (P=0.018). The summer/autumn of 2002 was one of the driest on record for Gotland. This resulted in very low levels of infective larval availability. But on both farms, T. circumcincta numbers were less on the fungus than on the control paddocks (P=0.048 on Farm B). In 2003 very low numbers of infective larvae were recorded in the autumn tracers for both treatments on both farms. Both farmer co-operators were encouraged with these results and consider that biological control of nematode parasites in their flocks, using D. flagrans, is of practical value.  相似文献   

Metabolic parameters and blood leukocyte profiles in cows from herds with high or low mastitis incidence     

Holtenius K  Persson Waller K  Essén-Gustavsson B  Holtenius P  Hallén Sandgren C 《Veterinary journal (London, England : 1997)》2004,168(1):65-73

The objective of this study was to determine whether there were differences in metabolic parameters and blood leukocyte profiles between cows in herds with high or low yearly mastitis incidence. In this study, 271 cows from 20 high yielding dairy herds were examined. According to the selection criteria, all herds had low somatic cell counts. Ten of the selected herds represented low mastitis treatment incidence (LMI) and ten herds had high mastitis treatment incidence (HMI). The farms were visited once and blood samples were taken from each cow that was in the interval from three weeks before to 15 weeks after parturition. The eosinophil count was significantly lower among cows from the HMI herds in the period from four weeks to 15 weeks after parturition. The plasma concentrations of beta-hydroxybutyrate, glucose, insulin and urea did not differ between groups, but the concentration of nonesterified fatty acids was significantly higher among HMI cows during the period three weeks after parturition. The concentration of the amino acid tryptophan in plasma was significantly lower among the HMI cows prior to parturition. Glutamine was significantly lower in cows from HMI herds during the first three weeks after parturition. Arginine was consistently lower in HMI cows, although the decrease was only significant during the period from four to fifteen weeks after parturition. The results suggest that there were differences in the metabolism and immune status between herds with high or low yearly mastitis treatment incidence indicating an increased metabolic stress in HMI cows.  相似文献   

The effect of birdsfoot trefoil (Lotus corniculatus) and white clover (Trifolium repens) in mixed pasture swards on incoming and established nematode infections in young lambs     

Bernes G  Waller PJ  Christensson D 《Acta veterinaria Scandinavica》2000,41(4):351-361

Lotus corniculatus L., a leguminous plant containing condensed tannins, is now being evaluated in Sweden as a component of mixed pastures. This is because of its high nutritive value, palatability, modest requirement for water, calcium and phosphorous and particularly because it has the ability to survive harsh weather conditions that typify northern Scandinavia. This trial was undertaken to assess the possible parasitological benefits of using L. corniculatus when fed as a minor component in a mixed pasture sward to young sheep. This was compared with similar sheep that were fed pasture with a comparable legume content consisting of Trifolium repens L. Separate groups of lambs, maintained in pens and provided with fresh pasture cuts containing either L. corniculatus or T. repens each day, were trickle-dosed with infective larvae of mixed parasite species. For each pasture type, groups of 6 lambs had either established worm burdens only, received incoming infections only, or had the combination of both adult and incoming infections. Worm burdens were monitored by serial faecal egg counts and at the termination of the study, all animals were slaughtered for worm recovery, identification and enumeration. The results showed that there were no differential effects between L. corniculatus and T. repens on the different stages of development for a range of nematode parasite species recovered from these lambs. Several reasons may account for this: such as the low level of condensed tannins in the L. corniculatus variety tested, the minor proportion of this plant in the diet and/or the variety of L. corniculatus used in this trial which do not provide any benefits to controlling parasites of sheep.  相似文献   

Determining optimal primary sawing and ripping machine settings in the wood manufacturing chain     

Berndt G Lindner  PJ Vlok  C Brand Wessels 《Southern Forests》2015,77(3):191-201

for wood manufacturers around the world, the single biggest cost factor is known to be its raw material. Maximum volume recovery of this raw material is, therefore, of key importance for the industry. The wood products industry consists of several interrelated manufacturing steps for converting trees into logs and logs into finished lumber. Each operation usually optimises its functionality in isolation from the preceding and following operations. It is a well documented fact that the optimisation of decisions through the whole chain of operations is considerably more profitable than the optimisation of individual operations. The objective of this study was to determine the optimal machine settings for two interrelated operations, namely the sawing and ripping operations which have tradition? ally been optimised individually. A model, having two decision variables, was developed which aims to satisfy market demand at a minimal cost. The first decision was how to saw the log supply into different thicknesses by choosing specific sawing patterns. The second was to decide on a rip saw's priority value settings, which determines how the products from the primary sawing operation are ripped into products of a certain thickness and width. The techniques used to determine the machine settings included static simulation with the SIMSAW software to represent the sawing operation and mixed integer programming to model the ripping operation. A metaheuristic, namely the Population Based Incremental Learning algorithm, was used to link the simulation and mixed integer models and to determine the optimal settings for the combined process. The model's objective function was to minimise the cost of production. This cost included the raw material waste cost and the over or under production cost. The over production cost included the stock keeping costs and the under production cost was estimated as the buy?in cost of under supplied products from another wood supplier. The model performed well against current decision software available, namely the Sawmill Production Planning System package, which combines simulation and mixed integer programming techniques to maximise profit. The model added further value by modelling and determining the ripping priority settings in addition to the primary sawing patterns.  相似文献   

Streptomyces cyaneus dermatitis in a dog     

PK Nicholls  G Allen  PJ Irwin 《Australian veterinary journal》2014,92(1-2):38-40

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ON THE Rh AND OTHER BLOOD FACTORS IN JAPANESE     

Waller RK  Levine P 《Science (New York, N.Y.)》1944,100(2603):453-454

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The role of procaine in adverse reactions to procaine penicillin in horses     

CB CHAPMAN  P COURAGE  IL NIELSEN†  BR SITARAM  PJ HUNTINGTON‡ 《Australian veterinary journal》1992,69(6):129-133

Procaine penicillin is a commonly used antibiotic in equine medicine but its use is associated with a substantial incidence of adverse reactions. Soluble procaine concentrations were determined by HPLC in several commercially available procaine penicillin preparations, including some that were involved in adverse reactions. The mean (+/- SEM) soluble procaine concentrations in the veterinary preparations was 20.18 +/- 5.07 mg/ml, which was higher than the concentration in the only procaine penicillin preparation for use in humans in Australia of 7.3 mg/ml. Heating the veterinary procaine penicillin preparations to 50 degrees C for 1 day led to a significant (P less than 0.01) increase in the amount of soluble procaine. Heating to 50 degrees C for 7 days also produced a significant (P less than 0.02) increase. Soluble procaine tended to return to baseline concentrations when veterinary procaine penicillin preparations were heated to 50 degrees C for 2 days then stored for 7 days at room temperature. Administration of procaine HCl intravenously (IV) at 2, 5, and 10 mg/kg produced behavioural, locomotor and vascular reactions, which were clinically similar to those reported in adverse reactions to procaine penicillin. The more severe reactions occurred at higher doses, although different horses responded variably at the same dose. Some adverse reactions lead to recumbency but none were fatal. The blood procaine concentrations 1 min after IV administration averaged 19.0 +/- 12.6 and 25.3 +/- 16 micrograms/ml at 2.5 mg/kg and 5 mg/kg, respectively. Ten min after administration, blood procaine concentrations were significantly higher (P less than 0.001) in the 5 mg/kg group than in the 2.5 mg/kg group. Intramuscular (IM) procaine HCl at 5 mg/kg produced significantly lower (P less than 0.001) blood concentrations than similar IV doses, and, in contrast to the IV doses, the amount of procaine in the blood was significantly higher 5 and 10 min after administration than it was after 1 min. Mild excitatory reactions in 4/5 horses were noted 5 to 10 min after IM administration. Administration of diazepam 20 s before procaine HCl prevented the excitatory adverse reaction in 2/2 horses, but administration after the procaine did not influence the outcome.  相似文献   

A comparison of sites for implanting identification transponders in cattle     

PJS HASKER  J. BASSINGTHWAIGHTE  PJ ROUND 《Australian veterinary journal》1992,69(4):91-91

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Use of hair root as a source of DNA for the detection of heterozygotes for recessive defects in cattle     

PJ HEALY  JA DENNIS  JF MOULE 《Australian veterinary journal》1995,72(10):392-392

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