michael jinsoo yoo advisor: professor kifle g. gebremedhin hair-coat characteristics of cattle m....
TRANSCRIPT
Michael Jinsoo Yoo
Advisor: Professor
Kifl e G. Ge-bremedhin
HAIR-COAT CHARACTERISTICS OF
CATTLE
M. Eng Project
Input to heat and mass transfer models
Help us to select animal breed for different envi-ronments
Useful to identify heat tolerant cows
WHY ARE HAIR AND HAIR-COAT PROPER-TIES IMPORTANT?
Physical properties
Optical properties
HAIR COAT PROPERTIES
Hair length (mm)
Hair diameter (µm)
Density of hair coat (hairs/cm2)
Depth of hair coat (mm)
Weight of hair coat (mg/cm2)
PHYSICAL PROPERTIES
VARIATIONS IN PHYSICAL PROPERTIES
Climate conditions
Breed of cows
Body location
Climate conditions
SOURCE OF VARIATION IN PHYSICAL PROP-ERTIES
Weight of hair coat
Depth of hair coat
Hair diameter
January
December
December
Greatest
Maia et al. (2005), Berman et al. (1961)
Breed of cows
SOURCE OF VARIATION IN PHYSICAL PROP-ERTIES
Holstein cow
Braford cow
Sahiwal cow
Jersey cow
Holstein
Cow
Braford
Cow
10.5 mm – 18.33 mmHair length
26 µm – 65.15 µmHair diameter
1.3 mm – 19mmDepth of hair
coat
4.13 mm – 26.50 mmHair length
11.00 µm – 69.00 µmHair diameter
1.00 mm – 13.00 mmDepth of hair
coat
700 hairs/cm2 - 3600 hairs/cm2
Density of hair coat
319 hairs/cm2 - 4851 hairs/cm2
Density of hair coat
SOURCE OF VARIATION IN PHYSICAL PROP-ERTIES
Breed of cows
Rump
Lumbar
Lateral
Belly
Rib
Leg
SOURCE OF VARIATION IN PHYSICAL PROP-ERTIES
Body location
Greatest Location
Hair Length (mm)
Rump
Lumbar
Lateral
Rib
10.18
9.98
9.66
10.70
6.86
Body location (Jersey cow, April)
Belly
Leg
SOURCE OF VARIATION IN PHYSICAL PROP-ERTIES
6.96 8.97
Pan Y.S. (1964)
Hair Diameter (µm)
68.55
63.72
57.56
59.96
46.47
Body location (Jersey cow, April)
SOURCE OF VARIATION IN PHYSICAL PROP-ERTIES
Greatest Location
Rump
Lumbar
Lateral
Rib
Belly
Leg
84.36 98.28
Pan Y.S. (1964)
Density of Hair Coat (hairs/cm2)
2591.5
2179.5
Body location (Bison cow, Febru-ary)
SOURCE OF VARIATION IN PHYSICAL PROP-ERTIES
Greatest Location
Rump
Lumbar
Lateral
Rib
Belly
Leg2325.5
Peters et al. (1964)
Weight of Hair Coat (mg/cm2)
55.34
64.79
Body location (Bison cow, February)
SOURCE OF VARIATION IN PHYSICAL PROP-ERTIES
Greatest Location
Rump
Lumbar
Lateral
Rib
Belly
Leg64.79
Peters et al. (1964)
HAIR-COAT DENSITY PROFILE
Rump 5300hairs/cm2
1.18cm
Lumbar 7300hairs/cm2
1.36cm
Gebremedhin K.G. (unpublished report)
HAIR-COAT DENSITY PROFILE
Lateral 6300hairs/cm2
1.18cm
Belly 6400hairs/cm2
1.3cm
Gebremedhin K.G. (unpublished report)
HAIR-COAT DENSITY PROFILE
Head 3900hairs/cm2
1.06cm
Gebremedhin K.G. (unpublished report)
Absorptivity (α) Amount of incident energy absorbed by the hair coat
Reflectivity (ρ) Fraction of the incident energy reflected back by the hair coat
Transmissivity (τ) Energy transmitted through the hair coat to the skin surface
Absorptivity + Reflectivity + Transmissivity = 1α + ρ + τ = 1
OPTICAL PROPERTIES OF HAIR COAT
SOURCE OF VARIATIONS IN OPTICAL PROP-ERTIES
Color of hair coat
Black hair coatα = 0.98
Dark-red hair coatα = 0.92
Tan hair coatα = 0.75
White hair coatα = 0.37
Gebremedhin et al. (2011)
REFLECTIVITY AS A FUNCTION OF WAVELENGTH FOR DIFFER-ENT COLORS
da Silva et al. (2003)
da Silva et al. (2003)
ABSORPTIVITY AS A FUNCTION OF WAVELENGTH FOR DIF-FERENT COLORS
ABSORPTIVITY OF DIFFERENT HAIR-COAT COLOR
Gebremedhin et al. (2011)
OPTICAL PROPERTIES
Maia et al. (2003)
Pigmented vs. Non-pigmented
CONCLUSION
Physical properties Range
Hair length (mm) 3.46 – 60
Hair diameter (µm) 11 – 123
Depth of hair coat (mm) 1 – 25
Density of hair coat (hairs/cm2) 221 – 7300
Weight of hair coat (mg/cm2) 7 – 108
Factors that affect properties are : body loca-tion, climate condition, and breed of cows.
CONCLUSION
The optical properties of hair coat of cows are sig-nificantly affected by color.
Optical properties Hair-coat color Range
AbsorptivityWhite 0.36 – 0.72
Black 0.88 – 0.98
ReflectivityWhite 0.45 – 0.53
Black 0.046 – 0.089
TransmissivityWhite 0.003 – 0.043
Black 0.01 – 0.019
THANK YOU!