Biomedical Engineering Reference
In-Depth Information
Table 1
Effect of water cooling on milk yield during summer
Season
Increase in milk yield (kg/day)
References
Cows
Hot-dry
4.0
Armstrong (
1994
)
Hot-dry
2.12
Aggarwal (
2004
)
Hot-humid
1.9
Flamenbaum et al. (1995)
Hot-humid
1.5
Lin et al. (
1998
)
Hot-humid
0.85
Aggarwal (
2004
)
Buffaloes
Hot-dry
1.05
Gangwar (1985)
Hot-dry
1.0
Aggarwal and Singh (
2008
)
Hot-humid
0.58
Gangwar (1985)
Hot-humid
0.92
Aggarwal and Singh (
2008
)
Control
Experimental
30
45
44
25
43
20
42
41
15
40
10
39
38
5
37
0
36
Days of experiment
Fig. 1
Milk yield of cows of control group and experimental group (provided with mist and fan system) during hot-dry
season
during the hot daylight hours and to find meth-
ods for cooling cows during heat stress.
Ventilation is very critical. Natural ventilation
using side-wall curtains works very well. Fans
are required, especially over the feed bunk and in
the holding pen. The air speed over the cow
should be 400-600 ft (122-183 m) per minute.
Usually this requires at least one 36-in. (91 cm)
fan (with airflow of 11,000 cfm) for every 30 ft
(9.1 m). Fans should be angled downwards.
Shade should be provided to the cows. Misters
are also helpful for enhancing evaporative cool-
ing. Table
1
shows the effect of water cooling on
milk yield in cows and buffaloes during summer.
In a study, it was found that when cows in early
lactation were provided with mist and fan cool-
ing system during hot-dry and hot-humid sea-
sons from 11.00 A.M. to 4 P.M., the milk yield
was significantly increased (Aggarwal
2004
;
Figs.
1
and
2
). Various methods for cooling
