• Aucun résultat trouvé

ml 2 o

N/A
N/A
Protected

Academic year: 2022

Partager "ml 2 o"

Copied!
1
0
0

Texte intégral

(1)

!’II.

-

HOUSING

AND ENVIRONMENT

Rearing houses for early weaned piglets. Realization,

control of environment, investment and energy expenditure

A. AUMAITRE

J.

LE PAN, L. BINA

Station de Rechevches suv

l’lÎ1evage

des Povcs, I. N. 7!.

A.,

C. lV. R. Z., 78350

Jouy

en

Josas

Rearing

houses for

piglets

weaned at 12

days

and

placed by

litter in batteries

( 3

tiers with

3

cages

each)

were constructed for

housing

the

production

in successive batches of 25 to 30sows.

On account of the

particular

environmental conditions

required by

the animals

(mean tempe-

rature of the air :

2 j o C,

relative

humidity

50to 70 p. ioo,

velocity

of the air as slow as

possible

and

close to o. ro ne

s-’),

the thermic isolation of the

floors,

walls and

ceilings

was

good (mean

k =

0 .6 0 )

and the rooms were heated either

electrically (with accumulation) ( 2 houses)

or

by

propane gas

( 3

houses).

These

piggeries

were used for an

experiment

on

early weaning

in batteries conducted in j farms in the Cotes du Nord

» region.

In

spite

of

heating

and

conditioning

costs, the

housing

cost

price

per animal

always

remained lower than that of an animal of same

weight

suckled

by

the

dam or reared on the floor in a classical

piggery. Using

the

principal

values

registred

for air

tempe-

rature, relative

humidity (by

means of the

temperature

of the

dry

and moist

bulb)

and

velocity

of

the air

(by

means of the kata

thermometer)

it was

possible

to check the

homogeneity

of the preco- nized environmental standard conditions. However, it was noticed in the

region

with sea climate

where the relative

humidity

of the air was

high (go

to 95 p.

ioo)

that the saturation level of the air inside the houses was low in winter and very

high

in summer ; such a result

might

be

explained by

the

necessity

of

treating

the rooms

during

the winter.

Measurements of the amounts of energy consumed were made over 2 years from a total of 403

days

of

recordings

in 2

piggeries

fitted with electric radiators and 1 _505

days

in 3

piggeries

fitted with a propane gas

generator

and calculated for each

piglet produced.

The

daily expenditure perpiglet

for

heating

was estimated to 5oo kcal

( 93 p.

100of the electric current at

night price)

and

i ooo kcal for the

buildings

fitted with gas

heating, corresponding

in rg!3 to 1.22

F/piglet

and

i. j8 F/piglet, respectively,

which was less

expensive

than the

heating

costs of an infra-red

lamp.

According

to the data

collected,

the

following

microclimatic standard

conditions ;

- air

temperature 23-26!C ;

- relative

humidity ranging

from 30 to 70 p. 100 ; - air

velocity

under o.io m s-1 ;

allow obtention of

good performances

in

piglets placed

in batteries with wire-floor. The

rhythm

of

ventilation should be very low in winter

( 5

renewals per hour or 3. j

m l /piglet

seem to be

sufficient),

but in summer should

depend

not

only

on the

high temperatures,

but also on the relative

humidity

of the air.

Références

Documents relatifs

In order to determine the impact of O 2 contamination on the test solution, several permeation tests were conducted with continuous pH measurement and periodic sampling of

In terms of the temperature dependence of the quenching rate, previous work has shown that the rate constant for this process displays a negative temperature

Also the comparison of monthly averaged columns (b) shows consistent seasonal variations, with high NO 2 in winter and low NO 2 in summer. Quantitatively speaking, both data sets

The simulation of the vertically integrated column of hydrogen peroxide (H 2 O 2 ) is compared to the complete set of available data [3] and provides an exceptionally good result,

Here, we report on the first synthesis of Ce 2 O 2 S nanoparticles and on their characterization by transmission electron microscopy (TEM) and x-ray diffraction (XRD). In situ

Un premier chapitre bibliographique d’introduction assez exhaustif détaille les divers paramètres sensibles dans la compréhension de la chimie multiphase à l’échelle

resembles mostly the two largest species of the genus, Palaeopython cadurcensis from the late Eocene of the Phosphorites du Quercy, France, and Palaeopython ceciliensis from the

labelled 15 N 2 O were flowing through each soil sample, containing a background of 0.82 mg to 1.91 mg of 15 N in organic matter (Table 1).. Figure 2 presents the fraction of