!’II.
-HOUSING
AND ENVIRONMENTRearing houses for early weaned piglets. Realization,
control of environment, investment and energy expenditure
A. AUMAITRE
J.
LE PAN, L. BINAStation de Rechevches suv
l’lÎ1evage
des Povcs, I. N. 7!.A.,
C. lV. R. Z., 78350Jouy
enJosas
Rearing
houses forpiglets
weaned at 12days
andplaced by
litter in batteries( 3
tiers with3
cages
each)
were constructed forhousing
theproduction
in successive batches of 25 to 30sows.On account of the
particular
environmental conditionsrequired by
the animals(mean tempe-
rature of the air :
2 j o C,
relativehumidity
50to 70 p. ioo,velocity
of the air as slow aspossible
andclose to o. ro ne
s-’),
the thermic isolation of thefloors,
walls andceilings
wasgood (mean
k =0 .6 0 )
and the rooms were heated either
electrically (with accumulation) ( 2 houses)
orby
propane gas( 3
houses).
Thesepiggeries
were used for anexperiment
onearly weaning
in batteries conducted in j farms in the Cotes du Nord» region.
Inspite
ofheating
andconditioning
costs, thehousing
costprice
per animalalways
remained lower than that of an animal of sameweight
suckledby
thedam or reared on the floor in a classical
piggery. Using
theprincipal
valuesregistred
for airtempe-
rature, relativehumidity (by
means of thetemperature
of thedry
and moistbulb)
andvelocity
ofthe air
(by
means of the katathermometer)
it waspossible
to check thehomogeneity
of the preco- nized environmental standard conditions. However, it was noticed in theregion
with sea climatewhere the relative
humidity
of the air washigh (go
to 95 p.ioo)
that the saturation level of the air inside the houses was low in winter and veryhigh
in summer ; such a resultmight
beexplained by
thenecessity
oftreating
the roomsduring
the winter.Measurements of the amounts of energy consumed were made over 2 years from a total of 403
days
ofrecordings
in 2piggeries
fitted with electric radiators and 1 _505days
in 3piggeries
fitted with a propane gas
generator
and calculated for eachpiglet produced.
Thedaily expenditure perpiglet
forheating
was estimated to 5oo kcal( 93 p.
100of the electric current atnight price)
andi ooo kcal for the
buildings
fitted with gasheating, corresponding
in rg!3 to 1.22F/piglet
andi. j8 F/piglet, respectively,
which was lessexpensive
than theheating
costs of an infra-redlamp.
According
to the datacollected,
thefollowing
microclimatic standardconditions ;
- airtemperature 23-26!C ;
- relative
humidity ranging
from 30 to 70 p. 100 ; - airvelocity
under o.io m s-1 ;allow obtention of
good performances
inpiglets placed
in batteries with wire-floor. Therhythm
ofventilation should be very low in winter
( 5
renewals per hour or 3. jm l /piglet
seem to besufficient),
but in summer should
depend
notonly
on thehigh temperatures,
but also on the relativehumidity
of the air.