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Two-thirds of breeding units are badly lit

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John Gadd

Function: Blog: Pig Management
John Gadd, after training in Scotland 50 years ago, worked as stockman on several pig farms and managed several more before joining a large agricultural chemists as pig product manager. He was then technical director of a pig feed concentrate firm and also helped run their pig farm, then the largest in Britain.

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Many problems related to poor sow reproductive performance are caused by poor lighting. Improvements can be noticed when applying adequate lighting measures.

One of the commonest 'call-out' jobs I have been asked to tackle across the world over the past 30 years has been poor reproductive performance in both sows and gilts.

Poor conception rates, a fall-off in farrowing rate, returns to service, 'silent heats', a reduction in litter numbers and birthweights.

Varied
Of course the likely cause of all these (mostly female) problems are many, varied and often interrelated. But one factor which can impinge on many if not all of them is the effect of light intensity, especially after weaning, over the few vital days of breeding and - possibly - on into gestation and certainly in it's first four to six weeks.

As long as 25 years ago I started to notice improvements in many of these problem areas when suggesting to breeders that their lighting in their breeding barns was inadequate.

Inadequate
Inadequate because there wasn't enough light; inadequate because it was incorrectly placed; inadequate because the timing of the light provided wasn't under control and was at the mercy of the natural pattern of the seasons.

Since then I can show you many letters from farmers all saying more or less the same thing. "Whatever else you suggested on the farm, following your ideas about light seems to have had a beneficial effect on our breeding results."

So let's take a quick look at light, and later on in this series of blogs, go on to cover positioning and controlling light input.

Have enough light
The animals would need enough to read a newspaper in the darkest corner of the breeding barn - not just where the sows or gilts are. How much light? I suggest 150 watts for each 1.5 metres of lateral space. This is about 300-400 lux (lumens).

How much is that? Use a (now old fashioned and therefore relatively cheap) photographer's hand-held light meter to use it as a light intensity checking guide. For example, if the light meter is set at 200 ASA, 350 lux will be read off at 1/150th at f.11 and 80 lux 1/25th at f.2. if held just in front of the sows or gilts eyes.

Gobbledegook
If this is complete gobbledegook to you, don't worry - just ask a retail photographer to show you - it is really very simple.

Anyway you can decide on your own check settings to suit yourself as long as you adhere to them subsequently. Many of the breeding units I visit are at or below 60 lux on a dull day and 80-90 lux on a bright one. In my experience this is not nearly bright enough before, during and after mating/AI insemination.

Gestation barn
Where the gestation barn is concerned, the textbooks advise 40 to 60 lux but I don't think this is enough, and I advise reverting to the 'newspaper test' I described above, adding another 150 lux to this figure.

All the same this advice is from my own empirical on-farm experience and I'd love to see some proper research done on it.

But… also provide enough darkness. A correct light/ dark interface is essential, and I will deal with this equally important aspect in my next blog.

Meanwhile I would welcome any comments you may have.

by John Gadd

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8 comments

  • # 1

    Ben Slots

    Dear John,
    It is not the lux that is important, it's all about the type of light.
  • # 2

    Stephanie Birkeland

    I used to have my lights on in both the birthing room and gestation room, from 7-23 daily. I reduced this to 8-11, 17-23 and have noticed that I have more sows 'come up' again after inseminations. I am considering going back to 7-23 daily to see if this could be the source of my problems. I think light is a very broad subject, one I would like to learn more about.
  • # 3

    Gerson van der Merwe

    What about the lenght of light per day.
  • # 4

    John Gadd

    Dear Stephanie Birkeland: I presume this means from 0700 -2300 hrs ie 16 hrs on/ 8hrs off - which is what most experts advise. If I interpret her comment correctly - and I may not have done - she got better results by "reducing it to 8-11". ie O800 - 1100 hrs, which is a total of 3 hours (supplementary?) light, and "17-23 " which I assume is 1700 -2300 hrs, or another 6 hrs/day, the two together being a strange lighting pattern. Or have I got it wrong? Clarification please!
    (To make things simpler for all of us, could everyone talk in terms of the 24 hour clock)
  • # 5

    John Gadd

    Dear Gerson van der Merwe: 14 -16 hrs on per day works best for me with perhaps an hour longer for gilts. But it seems important to have a nice and dark `dark period` so that a distinct light/ dark interface is acheived. So this needs to be taken into account on lighter and longer summer evenings. As I said - I`ll deal with this problem later.
  • # 6

    John Gadd

    `Yes isn`t light interesting! I wish there was more science on its effect on reproduction.

    Ben Slots ( very well-respected in Australia) comments that type of light is important.

    I presume he means fluorescent and not incandescent. Ben - have you some data on this you can share with us?`
  • # 7

    MARLENE TAIWHATI

    I HAVE JUST READ THIS ARTICLE, I WISH YOU WERE HERE TO TELL THE GENERAL MANAGER ON LIGHT, THIS IS A ON GOING ISSUE IN THE MATING SHED, TODAY MY EYES WERE SORE THROUGH STRAINING AND THAT WAS JUST HOSING THE DRAINS WE HAVE ONLY THREE LIGHTS! YES THREE!AND THESE OVER THE WEANED SOWS AND THEY WONDER WHY I MISS RETURNS ON OCCASSIONS!
  • # 8

    John Gadd

    Marlene Taiwhati

    I suggest you show the blog on insufficient lighting in the breeding unit to your manager who seems reluctant to put in extra light bulbs or better, fluorescent strip lights to remedy the very low light levels you describe.

    A diagram of the positioning and number of lights needed to get maximum fertility response around service time is given in my book " Pig Production - What the Textbooks Don`t Tell You" ( Nottingham University Press at orders@nup.com ), page 174.

    You might also gently remind him of researcher AM Petchey`s work on the subject, where he showed that through increasing light intensity from a `substandard level` to the level suggested in the blog, sows mated within the critical 5 days after weaning increased from 68.5% to 83%.

    I calculate that using current installation costs plus power cost today allied to the extra pigs born and breeding costs saved from such an improvement (using Foxcroft`s Canadian research on what advantage in breeding performance achieving the 5-day target from weaning secures) the payback per 200 sow herd is 11 months - and after that his profit per 200 sows should improve by what it has cost him to instal the better lighting every 11 months.

    So he should not try to economise on poor breeding unit lighting on cost grounds - let alone the better lighting making your job of stockperson easier at this critical time.

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