Biomedical Engineering Reference
In-Depth Information
Fig. 3
Wallowing pond
(Shearer et al.
1999
). The man-made pond has a
continuous inflow of water with an overflow at the
end of the pool. Buffaloes, because of their black
skin and less number of sweat glands than cows,
especially like to wallow in water for alleviation
of heat stress (Chauhan et al.
1998
; Aggarwal and
Singh
2008
) .
is important that the tunnel ventilation system
is properly designed (Tyson et al.
1998
) .
3.3.8 Zone Cooling
Inspired air or zone cooling applies a jet of cooled
air onto the head and neck of the animal. The air
may be cooled by evaporative cooling or by
mechanical refrigeration. Because of the installa-
tion costs and lack of compatibility with housing
systems, this has not become a common cooling
system (Bucklin et al.
1991
) . Air cooled by refrig-
eration to around 15°C, supplied at a rate of 0.7-
0.85 m
3
/min, has been observed to increase milk
production.
3.3.7 Tunnel Ventilation
The advantage of tunnel ventilation is that the
cows get access to fresh airflow in the whole
building, while the disadvantage is the electric-
ity consumption (Stowell et al.
2001
; Bray
et al.
2003
). The system provides a combina-
tion of high air exchange rates and high airflow
speeds to help the cows to remove body heat by
increasing the heat loss by convection. In tun-
nel-ventilated barns, large exhaust fans are
placed at one end of the barn blast the airflow
and large openings are placed at the other end.
The fans pull outside fresh air through the inlet
openings. All windows, doors and other open-
ings remain closed along the sidewalls. To pro-
vide a uniform air movement along the barn, it
3.3.9 Underground Pipes
If the ground temperature is lower than the atmo-
spheric temperature, air can be passed through
underground pipes and the air can be cooled. The
pipes are normally placed at a depth of 1.5-2 m
under the ground. A temperature reduction of
8-10°C can occur in the peak summer day. The
main effect of the system is to reduce extremes of
the temperatures (Chiappini and Christiaens
