Rules and Guidelines
Want to participate in the discussions? Please read our Community Rules and Guidelines. Need some help? Visit Support and Answers.

  • State Not Answered
  • Locked Locked
  • Replies 45 replies
  • Subscribers 32 subscribers
  • Views 4030 views
  • Users 0 members are here
Options
You may also be interested in
This discussion has been locked.
You can no longer post new replies to this discussion. If you have a question you can start a new discussion

Cattle deaths

lyledunn
Some 10 prize bullocks died in quick succession whilst housed over winter in a cattle shed. The government vet was unable to reach a conclusion on cause but apparently does not discount electric shock as an indirect cause. 

The shed comprises steel columns and trusses with corrugated iron sheeting over. The floor comprises re-Inforced concrete slats over the slurry tank. The pens have steel barriers supported by steel posts all of which are heavily corroded but still making contact with other albeit fortuitously.

The earthing system is TT with the shed steelwork on its own providing a substantially low impedance of 5 ohms using a loop tester. A 100mA RCD protects the rather ropey lighting circuits.defccf32df3c757507a0db6ad0a35f87-huge-a5af3537-8eae-4a3c-9126-68fa60b61ac7.jpg

whilst the floor could be wet, I can’t conceive how a voltage difference could be established even if the steelwork was at 230v

  • 0

    R.Davies BSc(UMIST) AMIMechE CIEH:

    Before Mr Betteridge gets too excited, electrocution amongst cattle is rare especially those numbers, the most common cause of cattle deaths is one of the Clostridial diseases, most of them tend to be rapid and fatal, Clostridia is part of a family of anaerobic bacteria found in the soil and farm environments, grass, hay and water, it does take a while to spot as cultures have to be developed to identify the particular strain, just an observation.




    Interesting! I might add that there might have been a small outbreak, which by coincidence stopped at the same time as the leccy was cut off.


    We can get clostridium infections too - tetanus, botulism, and a nasty gut rot - and I just thought that you might like to know that botox is also produced by them.

  • 0

    R.Davies BSc(UMIST) AMIMechE CIEH:

    Before Mr Betteridge gets too excited, electrocution amongst cattle is rare especially those numbers, the most common cause of cattle deaths is one of the Clostridial diseases, most of them tend to be rapid and fatal, Clostridia is part of a family of anaerobic bacteria found in the soil and farm environments, grass, hay and water, it does take a while to spot as cultures have to be developed to identify the particular strain, just an observation.


    Rob.


     




    Presumably that would show up in the post mortem examination of the cattle and the death of ten bullocks would not remain unexplained for long. 


    However I only have a passing knowledge of cattle diseases from being an occasional driver of a knacker wagon back in the days when BSE first appeared in this country and from working around farms. So I'll leave the medical examinations to the vets and just check the electrical installation out as I have far more experience of locating vermin damage to electrical installations.


    Andy Betteridge 

  • 0

    John Peckham:

    I wonder if the DNO are sure there is no underground cable fault present ?


    I think a long lead and a voltmeter testing between the supply earth and and exposed and extraneous parts would be a useful exercise kitted out with rubber boots for PPE. The and between exposed and extraneous  parts. Followed by the Capon test between a long screwdriver stuck in the ground and exposed and extraneous conductive parts.




    With ten dead bodies on the floor I think I might go for some dead testing first, rather than live testing. 


    Andy Betteridge 

  • 0
    Dead testing as in with the electrical supply disconnected, rather than testing the bodies on the floor.
  • 0
    Andy, yes I did say that I found it difficult to conceive that a voltage gradient of a detrimental order for cattle would appear for long durations but I was factoring in the proper function of the upfront 100mA RCD. There are no downstream RCDs. If the fault current was just below the tripping current of the RCD, with a Ra of approximately  5ohms we are looking at voltage of no concern. However, if we assume that the RCD failed to operate (although it responded immediately to test and the farmer reported that it operated occasionally), then we are left with the fuse to provide fault protection. Whilst there was nothing other than minimal lighting in the shed in question, an adjoining shed did have higher rated circuits. By the way, the general installation could only be described as dangerously sub-standard.
  • 0
    A typical “healthy” 100mA RCD could be letting 70 mA of current flow through the building without tripping.


    The last farm I went to do work in the farm house did not have any RCD protection to the farm building supplies at all. The buildings installation originally had its own meter, to save money the meter had been removed and the tails dogged into the house meter tails before the old VOELCB for the house installation without a RCD being installed, all TT.


    I have learnt to be very careful when testing installations like that, I went to a house where I had already told them to get an earth rod and RCDs installed several years prior. They said they had a problem with the lights, when I tested at the main switch, double checking with a test lamp I found:


    L-N 240 volts + lamp lit.


    L-E Zero volts + lamp did not light up.


    N-E 240 volts + lamp lit.


    When you discount reversed polarity on the incoming supply the only option left is that every bit of earthed metalwork in the house is sitting at 240 volts including all the appliances and decorative metal electrical accessories, 


    There follows a quick Oh **** ! moment. Then you start dead testing to find the cables the rats have chewed and wee’d on.


    Going back to the post it seems logical to me if the lights are mounted on the steel frame of the building or the cables cross it, then the stanchions are more likely to be a source of concern than the floor and I would start testing around them.


     Andy Betteridge 


  • 0
    I am presuming that the cattle all died on the steel slatted floor and the flooring is a common denominator.


    Andy Betteridge.
  • Former Community Member
    0 Former Community Member

    weirdbeard:




    lyledunn:

    Some 10 prize bullocks died in quick succession whilst housed over winter in a cattle shed




    Hi Lyle, how quick do you mean by quick? Within minutes, hours or days etc, and were they randomly fallen in the shed or in a particular spot?


     


     




    Additionally @lyledunn, when you say they were housed over winter, was it last winter or was it recent that they died?

  • 0
    Many thanks for your input WB, it was over a short time period of a few weeks in winter 2017/2018. The common factor as far as the farmer was concerned was that the deaths followed a night of rain. You can see why he is then tying this to a possible electrical fault. Random positions in shed. Interestingly, most of the deaths occurred in the part of the shed that has a rubber covering over the floor slats but others occurred where there is no rubber covering. The shed roof is deliberately not continuous and with relatively open sides to both gable ends it must be a dreadful place in the middle of a cold wet winter!

  • 0
    Given the value of the stock logic would dictate replacing the lighting with some new LED floods and its circuit, whilst ripping out the old stuff a fault may or may not reveal itself, rather than getting over involved in electrical testing what is already there.


    Presumably there is an insurance claim to consider.


    Andy Betteridge

Community Rules & Guidelines