592 research outputs found
Effect of cleaning /disinfection strategies on helminth infections in finishing pigs
Ascaris suum is the most prevalent helminth on organic pig farms (Carstensen et al., 2002)
and is transmitted mainly via the faeces. The use of anthelmintics does not fit in the organic
principles and preventive measures are promoted. This project focused on assessing the efficacy
of a cleaning protocol for the dunging area of pens on Ascaris s. transmission to pigs. In
4 batches with 8 identical pens for 15 pigs each (n=480 pigs) 6 pigs per pen were orally infected
with Ascaris s. The other pigs can be earliest infected at 10 weeks and half of the pens
were thoroughly cleaned at that time. Affected livers and egg counts in the manure had to
show if this cleaning protocol keeps the non infected animals free of Ascaris s. The results
show no effect of the cleaning protocol on the non infected pigs. These pigs had 57% damaged
livers in both treatment and 50% had positive egg counts in the manure. The conclusion
is that pen hygiene does not contribute to a reduction of Ascaris s. infections
Effect of rooting area and drinker in the outdoor run on behaviour and Ascaris infection of organic pigs
Hygiene is often a problem on the outdoor runs of growing organic pigs. Manure and urine are mainly excreted outside, but spread all over the run. Reduc-ing the dirty surface may improve well being, reduce ammonia emission, improve hygiene and reduce labour and parasite infections. The presence of a rooting area and of a drinker on the outdoor run were tested in a 2x2 factorial design. The pens with the rooting areas had a higher number of pigs on the outdoor run than the pens without a rooting area (1.6 vs 1.2 pigs). This was caused by more pigs in area 2 and 3. At higher temperatures there were more pigs outside, except in the root-ing area: this was popular at all temperatures.
A rooting area resulted in a cleaner outdoor area, however in some cases the root-ing area became a dunging area. An extra outdoor drinker leads to a cleaner area around the drinker, but to a dirtier indoor area. No difference in Ascaris infection was found between the four treatment combinations
Kijk lam vaker in ogen
Aan de kleur van het ooglid kan worden afgelezen of een lam lijdt aan bloedarmoede, als gevolg van haemonchose. Op basis van deze waarneming kunnen alleen de lammeren die lijden aan haemonchose worden ontwormd. Dit minimaliseert de selectie op resistente maagdarmwormen en maximaliseert het behoud van de effectiviteit van het gebruikte middel op het bedrij
Leverbot toenemend probleem
In de specifieke leverbotgebieden (door nattere perioden en peilverhoging nemen die toe) kan ernstige leverbotbesmetting voorkomen. Voor het behandelen van melkvee tegen leverbot zijn in Nederland alleen middelen geregistreerd voor niet-melkgevende koeie
Low Bandwidth Communication for Networked Power Hardware-In-The-Loop Simulation
Power-Hardware-In-the-Loop (PHIL) simulations allow the design and validation of power hardware components in virtual power system schemas with near real-time operation. This technique is increasingly used in the development cycle of many products to reduce design costs and increase design fidelity. The Hardware under Test (HuT) interfaces with a simulation of the user’s choosing through a hardware interface (HI). The digitally simulated system (DSS) runs on the real-time simulator before sending a reference value to the hardware interface to enforce. In this virtual to real interface, closed-loop stability and the simulation accuracy are the two paramount criteria in regards to the operational safety and experimental reliability.
The stability of the PHIL simulation represents the highest challenge in the implementation of this digitally simulated power system. The interface between the HuT and the DSS ideally adds zero distortion and maintains a unity gain. In practice, PHIL methods each have stability and accuracy trade-offs that will be discussed.
Any delay present in the simulation may negatively damp the system into unstable conditions. Careful consideration and compensation of interface delays can alleviate these adverse conditions. By communicating via time-frequency communication and partitioning a Point of Common Coupling (PCC) into the Hardware Interface controller, complex linear and nonlinear circuits may be simulated in a safe, stable and accurate environment.
Analysis and verification of this thesis has been tested using a PHIL testbed at the University of South Carolina. The PHIL testbed is composed of a TI TMS320F28335 digital signal processor, Opal-RT real-time simulator, and Matlab/Simulink
Sturen mestgedrag voorkomt spoelworminfectie niet
Het mestgedrag van biologische vleesvarkens blijkt in een groot hok goed te sturen met de juiste plaatsing van lignest, voerbak, drinkbak en buitenuitloop. Maar ook met het verminderen van het contact met de mest en het schoonspuiten van de uitloop vermindert het aantal spoelworminfecties niet
Effect of some herbs as alternative for conventional treatment of Ascaris suum in pigs
The current study describes the effects of three individual herbs for the prevention and control of a mild infection of Ascaris suum in growing and finishing pigs. In our study, feed (a commercial organic starter diet) was supplemented with 1% of one of the three herbs (Papaya, Boldo leaf and Artemisia). Comparatively, a negative control group (no treatment) was included. Based on the results of the experiment the researchers do not advise to use the tested herbs as appropriate alternatives for conventional treatment of Ascaris suum in pigs. A combination of thoroughly cleaning the pig house and regularly deworming with a conventional drug seems to be the most effective strategy to prevent infections of Ascaris suum in pig
End-of-life care in general practice in the Netherlands
Wal, G. van der [Promotor]Eijk, J.TH.M. van [Promotor]Deliens, L.H.J. [Promotor
In vivo testing of alternatives for conventional treatment of Ascaris suum in pigs
Summary
The percentage of disapproved livers of growing and finishing pigs has been increased significantly during the last years. In organic pig farms, this percentage is often higher than in conventional pig farms. In most cases, disapproved livers are the result of an infection with Ascaris suum. Usually, an infection of Ascaris suum is treated or controlled by using conventional synthetic drugs belonging to the benzimidazoles, levamisole and macrocyclic lactones. Organic farmers, however, prefer a non-pharmaceutical approach of worm control. Therefore, phytotherapy could be an perspective alternative.
The objective of this study was to test herb alternatives for the prevention and control of a mild infection of Ascaris suum in growing and finishing pigs. Two different herb mixtures were tested. Feed was supplemented with 3% of a herb mixture, thereby adding 1% Thymus vulgaris, 1% Melissa officinalis and 1% Echinacea purpurea to the diet, or with 4% of a herb mixture, thereby adding the mentioned herbs plus 1% Camellia sinensis (black tea) to the diet. Pigs were infected by 1000 worm eggs each. Comparatively, a negative control group (no treatment) and a positive control group (treatment with conventional synthetic drug Flubendazole) were included.
An experiment was conducted with 32 young boars (average starter weight was 24 kg) purchased from a SPF-pig farm. The pigs were monitored during 67 days in the period December 2006 until February 2007. In this study, four experimental treatments were compared:
1. negative control: no treatment was applied to prevent or control an infection with Ascaris suum;
2. positive control: pigs were treated with a conventional anthelmintic (Flubendazole) one week before slaughter;
3. herb mixture: pigs were fed a diet supplemented with a herb mixture;
4. herb mixture + tea: pigs were fed a diet supplemented with a herb mixture (as treatment 3) plus black tea.
From this experiment it was concluded that a diet with a herb mixture containing 1% Thymus vulgaris, 1% Melissa officinalis and 1% Echinacea purpurea for growing and finishing pigs did not decrease the number of pigs which are infected with Ascaris suum, but did reduce the average number of worms in the gastro intestinal tract. The addition of 1% black tea to this herb mixture did not result in a lower number of infected pigs and also did not reduce the average number of worms in pigs. Flubendazole appeared to be an effective deworming product.
On organic farms with a low worm infection probably a combination of a conventional synthetic drug and a diet with herb mixture containing 1% Thymus vulgaris, 1% Melissa officinalis and 1% Echinacea purpurea is an option. It depends on the level of worm infection whether it is an opportunity to deworm sows, weaners and/or growing finishing pigs with a diet containing the herb mixture to keep the level of Ascaris suum at an acceptable low level. Examination of faeces of sows, weaners and growing and finishing pigs regularly, and also the percentage of disapproved livers of growing and finishing pigs, can support to monitor the level of worm infection on the farm. Based on this monitoring probably a strategy of varying deworming with a synthetic drug and a diet with herb mixture can be developed for the different categories of pigs. Further research on this method, and also the suitable period to supply this herb mixture to sows related to stage of pregnancy and weaners related to age and feed intake, is desirable
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