Epsilon Archive for Student Projects

Abstract

There is two dairy farms in Sweden with ability to be opened on both long sides, one outside
Hjo and the other one, Brandstadholm, north of Sjöbo. When there is no measures and results
or not enough literature about natural ventilation and especially on this kind of air inlet, makes
my tests very interesting not only on Alnarp, but among other companies.
I would like to find out if there is any air movements direct on the cows, how high/low
temperature, air humidity, light intensity and noise standard inside the barn. Does
Brandstadholm fulfil the rules and regulations when it comes to climate inside the barn? Could
this system become the new dairy barn instead of the conventional barns in Sweden?
I am going to focus on the animals environment, after all they are the one who is going to
spend the most of the time in the barn.
I used five electrical loggers distributed inside the barn to measure the temperature and one of
the loggers measured the air humidity, every 15th minute. One logger were placed on the
outside which measured both temperature and air humidity. Every time I visited the farms I got
some references on the loggers by measuring the temperature, air humidity and I also got some
values on light, noise and air movements. Brandstadholm is partly an uninsulated and partly a
isolated dairy barn.
The dairy farm Brandstadholm, north of Sjöbo milk their 250 cows in a 30º angled fishbone pit
(2x10) and there is three cubicle rows on each side of the feeding table.
The roof has a regulated ridge opening which also is a light inlet. Both the roof and the gable is
isolated while the long sides consist of double transparent plastic wall which is filled with air
when the wall is closed. The air is blown in by fans and the wall can be opened in three steps.
The first step is 30 cm from the eaves, step two is when the wall is half open and the last step is
when fully open. The barn is natural ventilated.
Bollerup is the referent dairy farm, 16 km northeast off Ystad and is Sweden's largest
agricultural school.
Just as Brandstadholm, Bollerup has three cubicle rows on each side of the feeding table. The
school has two Lely milkingrobots and the barn has natural ventilation with an open ridge and a
wall hatch as an air inlet together with space boarding on one gable. The roof is uninsulated
and the walls consists of concrete from the eaves and down.
When the day and night temperature is shifting too much and occurs too often the animals is
affected by a negative thermal comfort. At a colder temperature the cows build fur to stay
warm. Then the temperature rises and the cows begins to sweat on account of the fur which
after a new temperature shift to a lower degree makes the cows freeze. Brandstadholm as
mentioned before is partly isolated and is very comfortable to be in, compared with Bollerup.
The results on the air humidity shows that the insulated roof are of importance when it keeps
the barn warmer which holds the humidity down to a lower level as in Brandstadholm.
Bollerups results are not bad if you compare to other uninsulated barns when the air humidity
can be near 100 %.
During my experiments, Bollerup has felt brighter than Brandstadholm. The results shows that
it is so, but both dairy barns fulfil the rules and regulations. The noise standards in Bollerup is a
borderline case which has to do with the two robots and the two automatic feeder together with
the space boarding at strong wind. Brandstadholm on the other hand is very quiet.
The wall hatch on the north side are the primarily air inlets together with the ridge in the west
at Bollerup. The measures at Brandstadholm shows that there is not any air movements. There
is not any air movements directly on the animals when the results I have found was under 1 m/s
in both barns. The plastic wall can during a strong wind create unnecessary noise.

Det jag vill ta reda på är om stallet uppfyller Jordbruksverkets regler och förordningar när det
gäller stallklimatet. Det är också av intresse att ta reda på om stallet är att föredra framför
konventionella djurstallar. Därför har jag valt att fokusera på djurens miljö.
Utrustningen jag använde till mina försök var fem stycken elektriska loggrar som var fördelade
inne i stallet samt en logger utomhus för varje gård. Loggrarna mätte temperaturen och den
relativa fuktigheten var 15:e minut.
Vid varje besök mättes också ljuset och ljudet. Djur som vistas inomhus ska ha tillgång till
dagsljus. Kravet på ljustillgången får inte understiga 75 lux. Ljudet anges i dB och djur i stallar
får tillfälligtvis utsättas för mekaniskt buller överstigande 65 dBA.
Brandstadholm ligger norr om Sjöbo på vägen mot Hörby. Stallet har tre liggbåsrader på varje
sida om foderbordet. Långsidorna är av transparent plast som kan öppnas och stängas efter
behov. Långsidorna fungerar som tilluftsdon då stallet har naturlig ventilation.
Bollerup är Sveriges största skoljordbruk och ligger 16 km nordöst om Ystad. Stallet har ett
körbart foderbord och korna mjölkas med hjälp av två Lely robotar. Liksom Brandstadholm har
foderbordet tre liggbåsrader på var sida. Stallet har naturlig ventilation och har tilluftsdon i
form av vippluckor samt glespanel på den västra gaveln.
Mätningarna visar att Bollerup är ett typiskt oisolerat stall medan Brandstadholm fungerar som
ett delvis isolerat stall. Genom diagrammen har jag fått fram att Bollerups innetemperatur följer
utetemperaturen. Brandstadholm håller en jämnare innetemperatur och en lägre relativ
fuktighet inne än Bollerup. Båda stallen har ett tillfredsställande ljus. Ljudnivån på Bollerup är
lite för högt medan Brandstadholm har låga mätvärden. Jag har inte lyckats hitta några
anmärkningsvärda luftrörelser i någon av stallen.