Outdoor sows are very much at the mercy of increasing and decreasing
seasonal light patterns. Their hormone system cannot be fooled by controlled
indoor lighting to get breeding 24/7. Still, autumn fertility can be
Breeders who have their sows outdoors are in the minority - even so, these
notes are for them. Outdoor breeders have to have plenty of land with the right
well-drained soil, the right mild climate, dedicated 'all-weather' stockpeople
and I believe the right breed of tough, hardy well-milking mothers with strong
Such breeders benefit from far lower housing costs, and usually
have their own supply of grain which has enabled them to survive - so far - the
present severe feed price crisis.
What is a
disadvantage, however, is that their sows are very much at the mercy of
increasing and decreasing seasonal light patterns. Not for them are the benefits
of controlled indoor lighting to 'fool' the sow's age-old hormone system into
thinking it is eternal springtime and thus time to get breeding 24/7.
did hear that floodlighting outdoor rebreeding paddocks might be helpful, but
that came to nothing, even ignoring the high power costs).
Living as I do
in the middle of a primary outdoor sow breeding area, over the years I've
suspected that we 'outdoorers' get more late summer/ early autumn infertility
(as distinct from the more common early winter performance dropaway) than the
majority who keep their sows indoors. Why might this be?
light in spring?
In a northern hemisphere spring, as the romantic poets
from Bunyan and Shakespeare onwards remind us, we get 'April showers'. Periods
of intermittent, short showers followed by the brightest of blue skies. The
half-hourly bouts of rain wash the atmosphere as clear as crystal and the
ultra-violet from the intense periods of very bright sunshine is obvious - I
burn very quickly during a day spent on the downs inspecting paddocks. So do the
Very few outdoor breeders put up temporary sunshades as early as
"For the hot months of June to August maybe - but April? It's not
hot then," they say.
Correct - but the light
intensity is high. I'm pretty sure it is a contributory factor. But seasonal
infertility is a very complicated, interrelated subject and there is a lot we
don't know, even now. Any suggestions?
For the past three years I have
been measuring light levels inside breeding barns with a redundant
photographer's light meter (I will describe what to buy and how to calibrate it
next time). While I get a reading of around 350 lux (lumens) in a really
well-lit indoor breeding unit, I'm getting 600 lux outside on those April days
A sunshade area can be
four strong 4 m high poles (old redundant telephone poles are often free for the
asking) joined by 100 x 100 mm battens. These are covered by a 'roof' of double
'Galebreaker' netting - double for wind resistance, not so much
Not expensive, and sows can be encouraged to use it by providing a
modicum of straw into which a few feed nuts are scattered. Sows get tired
walking about 'fossicking' - one authority suggests as much as 6 km in a day -
and can prefer the shaded area to rest up rather than a sunbaked, overhot and
airless outside ark, which is a shelter from bad weather and for cosy
sleepy-byes at night-time.
So get those sunshades up for our increasingly
hot summers, sure, but get them up far earlier.
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