This query was posed by a prospect who was doing his homework prior to making the commitment to investing in an Electric Fencing system. This is the best way to go about it so that you may be absolutely sure that what you are paying for is going to do what you want.
There is a lot of anecdotal evidence that an electric fence is very effective, mainly from satisfied users and that is very welcoming but is not at all scientific and not something that may be quoted. There is very little - or no - tests done in a scientific manner in the UK so we have to rely on outside sources. Even then they are pretty slim.
A very good source of an experiment is this one carried out by the Central Science Laboratory, Surrey on the protection of a field crop of Cauliflowers from Rabbits. It shows that both types of Electric Fencing are over 95% effective and far superior to the existing fence. The outlay was shown to pay for itself in one crop.
We did install a trial specific to electric poultry netting and the results were as expected. The netting gave complete protection from the attentions of feeding foxes for an extended period during a high pressure time of the year.
Hull University have completed a study on the new 125m (410ft) turbine at the Croda Europe plant in Hull assessing the effect they have on the wild life. The fear is that birds are flying into the spinning blades. Initial assessments were not considered successful even if no dead or injured birds were found below the turbines as fox spoor was prevalent. The assumption was that these foxes were picking up any birds struck by the blades. An Electric fence was subsequently erected using a Hotshock energiser and Livestok Sheep nets in an effort to eliminate the infuence of fox scavenging any birds that may hav been struck by the wind turbine blades.
"No evidence of fox prints at all were found whilst the fence was up and operational, the ground was soft for the majority of the study (sometimes frozen however), and so I would assume that tracks would have been easily visible. Before the erection of the fence, the site was covered in fox spoor and so the fence has appeared to certainly deter if not eliminate the foxes entirely from the area within the fence." Anna Phelps.B.Sc (hons), M.Sc. Researcher
That is not to say however that a fox will not find its way through a netting system and wreck havoc in a poultry flock.