Variation Of Skin Colour Among Holstein Friesian Cows Of Northern Thailand

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Deutscher Tropentag 2002
Witzenhausen, October 9-11, 2002
Conference on International Agricultural Research for Development
Variation of skin colour among Holstein Friesian cows of Northern Thailand
N. Chongkasikit
a
, T. Vearasilp
a
, U. ter Meulen
b
a
Department of Animal Science, Faculty of Agriculture, Chiang Mai University, Chiang Mai 50200 Thailand E-
mail: agisjtrs@chiangmai.ac.th
b Institute of Animal Physiology and Nutrition, Georg-August-University, Göttingen, Germany E-mail:
umeulen@uni-goettingen.de
Abstract
In Northern Thailand there is an increase in the replacement of the heat stress adapted
indigenous Thai cattle with improved breeds through crossbreeding with Holstein Friesian
from temperate climates. The result is a tendency to a dairy cattle population with more dark
skin color. Friesian cows with dark skins may have more difficulties to adapt because of the
high humidity and temperatures. The percentage of black and white skin color in Holstein
Friesian cows influences milk production. The black skin absorbs more environmental and
solar radiation while the white reflects more. This predisposes black cows to more heat stress.
Climatic stress especially from heat and solar radiation decreases milk production, changes
milk composition and lowers reproductive performance. Therefore the skin color is of
importance to dairy farming as it may cause significant economic losses. The objective of this
study was to determine the distribution of dark skin color among 2,107 Friesian cows in
Chiang Mai, Chiang Rai and Lamphun Provinces. The area of distribution of white and black
colored patches on the entire body was measured.
The results revealed a wide variation in skin colour. The white colour had a mean distribution
of 27% (±0.65 standard error), variance of 885.11, skewness of 0.96 and a median of 15%.
Most of the cows had larger black than white coloured skin areas. In 50% of the cows, the
white coloured skin areas covered less than 15%. The results suggest that the present Holstein
Friesian population of Northern Thailand may not be well suited for this environment and
should be investigated for heat stress.
Introduction
In recent years black and white Holstein-Friesians or their red and white genetic alternatives
have become the preferred dairy breed in many countries. The primary reasons are dairy
production economics and consumer preference for the low-fat milk which these cows
produce (George, 1993).
In Northern Thailand there is an increase in the replacement of the heat stress adapted
indigenous Thai cattle with improved breeds through crossbreeding with Holstein Friesian
from temperate climates. The result is a tendency to a dairy cattle population with more dark
skin color. Godfrey et al. (1994c) found that the percentage of black or white skin color in
Holsteins influences milk production. Climatic stress especially from excessive heat and solar
radiation decreases milk production, changes milk composition and lowers reproductive
performance. Solar radiation is a significant factor since it increases body temperature
directly. In addition they found a 4.5 pounds increase in milk production for each 1 percent
increase in white skin colored area in Holstein cows (Godfrey et al. 1994b). A larger white
skin colored area also resulted in better reproductive efficiency under heat stress. This
confirmed that predominantly white cows produce more milk than black cows, are of lower
age at first parturition, have fewer days open and experience shorter calving intervals.
Cow color isn't just personal taste or aesthetics as, for example, in the case of a Holstein
whose individual skin color is more black or more white. Biological differences among cows
with different colors influence the cow's ability to cope with environmental stress from heat,
humidity and solar radiation (Godfrey et al., 1994a). Earlier research pointed out that there are
physiological differences in adaptation and productivity, depending on the amount of black or
white in the skin. Klungland et al. (1995) found that color of dairy cattle is controlled by 3
loci of gene EE, SS and S
H_
as showed in table 1
The Holstein Friesian dairy breed (HF) has the genotype EEss whereas the Danish Red dairy
breed (RDM) has the genotype eeSS. Crosses between HF and RDM become uniformly
black. Some RDM have a different color pattern, tiger stripes, which are caused by an allele in
the e locus, they dominate over red color. The Danish beef cattle breed Hereford has a white
colored head with dominant inheritance. It is inherited from a dominant allele in the same
locus as spotted color. The gene for spotted color is situated on chromosome 6, and is tightly
linked with the kit gene with which it has interaction.
Table 1. Color controller genes in Dairy Cattle (Klungland et al.,1995)
Dominant Recessive
Colors Genotypes Colors Genotype
Black E- Red ee
Uniformly S- Spotted ss
White Head S
H_
Uniformly SS
In Northern Thailand are black and white cattle are predominant because the main breed used
for crossbreeding is Holstein Friesian. However, there is a wide variation in skin color. The
objective of this study was to determine the distribution of skin color among the cattle.
Materials and Method
Experimental animals: 2,107 Dairy cows in small farms of Chiang Mai, Chiang Rai and
Lanphun provinces.
Method: The area of distribution of white and black colored patches on the entire body was
determined by looking at both sides of the cows and then estimate the percent of white color
of each cow. The cows were divided into groups by percent of white color as shown in table
2.
Table 2. The groups of cows
Percent
of white
color
0-10
11-20
21-30
31-40
41-50
51-60
61-70
71-80
81-90
91-100
Groups 1 2 3 4 5 6 7 8 9 10
Statistical Analysis: Mean, Standard deviation, Standard error of mean, variance skewness,
standard deviation of skewness and median were used to estimate variation of skin color
(SAS, 1990).
Results and Discussion
The average percent of white skin color (mean), Standard deviation (S.D.), Standard error
(S.E.) of mean and variance were 27.00664, 29.75080, 0.64814 and 885.110 respectively as
shows in table 3.
Table 3. Mean, S.D., S.E. and variance of white skin color in the population
N
Minimum
%
Maximum
%
Mean
Std. Deviation
Std. Error o
f
Mean
Variance
2,107 0.00 100.00 27.00 29.75 0.65 885.11
Although the white color varied from 0% to 100 % among the cattle population most of the
cows had more black colored patches than white. The mean was 27.00 % white skin color.
Height of variance shows high variation of skin color in the population (table 3). The positive
skewness in table 4 support the results in the table 3. The median of 15 shows that 50% of the
cows in the population have less than 15% white color on their body.
Table 4. Skewness, Standard error of skewness and Median of
percent of white color in population
Skewness
Std. Error o
f
Skewness
Median
0.96 0.053 15.00
The distributions of cows into different groups according to percent of white skin color and
are shown in figure 1. It also supported that most of cows in population have black color more
than white color. A tendency of number of cows which have several percent of skin color
were likely inverse proportion to percent of white color. This may explains that the cows with
a few white color percent will have members in their group more than the cows which have
many percent of white color.
The obtained results that the population of dairy cows in northern Thailand have
predominantly dark skins show that these cows may have difficulties to adapt to the
environment because of the high humidity and temperatures (heat stress). The solar radiation
absorption of black colored skin is comparably higher than of white skin which leads to a high
skin temperature (Godfrey et al., 1994a) which affect body temperature. This causes the cattle
to decrease fed intake and may affect reproduction and milk production of the cows.
Conclusion
The variation of skin color in the population were high. The percent of white color ranged
from 0 % until 100 %. Most of the cows had larger black than white colored skin areas. In
50% of the cows, the white colored skin areas covered less than 15%. The results suggest that
the present Holstein Friesian population of Northern Thailand may not be well suited for this
environment and should be investigated for heat stress.
0
200
400
600
800
1000
1200
12345678910
Groups according to % white color
Number of cows
Figure 1. Distribution of cows according to % of white color
References
George F. W. (1993). What Color Should Cows Be. Dairy management column
http://bluehen.ags.udel.edu/deces/dairycol/dc11-93.htm. [24 October 2001].
Godfrey, R. W. and P. J. Hansen. (1994a). Seasonal influences on reproductive patterns
of dairy cows in the tropics. J. Anim. Sci. 72 (Suppl. 2):13.
Godfrey, R. W. and P. J. Hansen. (1994b). Effects of skin color on production and
reproduction of dairy cattle on St. Croix. Proc. Caribbean Food Crop Soc.,
30:180-185.
Godfrey, R. W. and P. J. Hansen. (1994c). Environmental influences on reproduction
and milk production of Holstein cows on St. Croix. UVI Research 6:10-12.
Klungland (1995). Memalian Genome 6:636-39.
SAS. (1990). User’s Guide. SAS Institute Inc.