Measurement of Color Difference Values of Hair of Different Ornamental Animals Using a Handheld Color Difference Meter

Measurement of Color Difference Values of Hair of Different Ornamental Animals Using a Handheld Color Difference Meter

There is no non-destructive and rapid instrument measurement method for the fur color of ornamental animals, especially pets. The author used healthy and quiet fur ornamental animals as the experimental subjects and measured the fur color difference values in four areas: the head, neck, back, left rear leg, and right rear leg, using a handheld color difference meter (CS 260 Handheld Colorimeter) in a room with room temperature and sunlight.

With the improvement of people’s living standards, the pet industry is gradually developing. The status of pets in the family is constantly improving, and people are paying more and more attention to their health and beauty. For most pet dogs, having bright hair is necessary for their beauty. In evaluating animal husbandry product production, more methods must be used to measure the color of animal fur. The brightness and other indicators of the fur of ornamental animals are subjectively rated by pet owners or observers. There are many professional fur determination techniques on the market, which observe fiber structure, stress, and curl after in vitro (cutting off fur), and also require testing for amino acids and fatty acids. Although the results are relatively accurate, objective, and accurate, measurement requires a lot of workforce and material resources. Ding Lijun and others evaluated the effectiveness of the formula of dog hair beauty additives. This study observed the brightness of hair color and the degree of hair disorder and scored them. At the same time, the morphology of the hair was observed by scanning electron microscopy after being detached.

The colorimeter has a wide range of applications in industrial production, used for color correction of products such as advertising boards, printed matter, textiles, etc. In animal husbandry and food production, colorimeters are used to evaluate the color of meat products. The color difference meter has obvious advantages in measuring color, with the characteristics of fast and accurate measurement. It can be measured on the spot, and results can be obtained immediately. It should be noted that using colorimeters involves multiple indicators, including a light source and duration angle. According to the theory of color difference meters, chromaticity indicators are divided into brightness (L *), redness (a *), and yellowness (b *). These indicators can help clinical veterinarians, pet owners, and pet researchers quickly, conveniently, and accurately determine the color status of pet fur, which is of great significance for judging the health status of pet fur and even predicting diseases.

Test materials and methods

Experimental animals

This study focuses on healthy, non-dermatological, and other infectious ornamental animals. Including a 1-year-old adult blue cat (pure gray) and a 1-year-old adult Linqing lion cat (pure white). Simultaneously selected New Zealand white rabbits (pure white) and Fujian Southwest black rabbits (bright black) over the age of 1 year. Three animals of each type were selected as experimental replicates. The experiment was conducted at the Key Laboratory of Livestock and Poultry Diseases Prevention and Breeding in Shandong Province. Remove dirt and gravel from the handheld colorimeter and pet fur surface before measurement.

Experimental Environment Setting and Posture Measurement

The test is conducted in a normal room temperature environment (15-23 ℃), with a light intensity of 100-300 lux under normal lighting—measured using the CS 260 Handheld Colorimeter. Perform blank calibration on the equipment before measurement. Observe the angle of view at 10 °, observe the light source D65, and measure the aperture at 10mm. The tested animal is in a normal anatomical position (standing) and cannot lie down.

Measurement indicators

Use a color difference analyzer to analyze the four parts of the animal’s head, back, left hind leg, and right hind leg. The head area of an animal is defined as the epidermis at the midpoint of the line connecting the back of the animal’s head and ears. The neck and back of an animal are defined as the epidermis of the crossed area between the forelegs and back vertebrae. The legs of an animal are defined as the epidermis of the area connecting the base of the hind legs and the trunk, measured separately on the left and right legs. Measure 3 times for each fur part that does not show significant color differences. Read the brightness value L *, redness value a *, and yellowness value b * through a color difference meter. Obtain the average value by repeating three techniques, denoted as the color difference saturation of an animal at a certain location C *=(a^*2+b^*2) 0.5, and the chromaticity angle H °=arctan (b */a *) × 180 °.

Statistical Data Analysis

After using Excel to organize all data, calculate the average value of the measurement indicators. The experimental data were analyzed using software for bivariate correlation (Pearson method detection, double-tailed detection). The correlation analysis will determine the color difference value (brightness value, redness value, yellowness value, saturation value, and chromaticity angle value) and obtain the correlation coefficient R2 and significance P value with the data measured from different breeds of animals and different parts, respectively.

Results and Discussion

The specific results are shown in Tables 1 to 5. The above research indicates that different species of animals have significant differences in color difference values in the same parts, especially between gray-black animals and pure-white animals. There are significant differences in color difference values among animals of the same species in different parts. But this difference is smaller than the difference between different animal species. Specifically, the brightness values from high to low are Linqing Lioncat, New Zealand White Rabbit, Blue Cat, and Fujian Southwest Black Rabbit. The color saturation values, from high to low, are Linqing Lion Cat, New Zealand White Rabbit, Blue Cat, and Fujian Southwest Black Rabbit. The above results indicate that using a color difference meter can measure the color difference of animal fur, which is simple to operate and can be used for in vivo measurement. The correlation analysis measurement shows a certain correlation between the yellowness value and saturation value and animal species. Specifically, the correlation coefficient R₂ between yellowness value b * and different animal species is 0.482 (P<0.05); The correlation coefficient R₂ between saturation value C * and different animal species is 0.521 (P<0.05). In addition, there was no significant correlation between different measurement sites (head, neck, back, left and right hind legs) and color difference values.

Table.1 Color Difference Values of Head Hair of Different Fur Animals

Project	Fur animal
	English Short Blue Cat (Grey)	Linqing Lion Cat (White)	New Zealand White Rabbit	Southwest Fujian Black Rabbit
Brightness value L*	31.05	90.34	74.34	17.68
The a value a*	2.68	1.39	0.58	2.02
Yellowness value b*	4.99	8.93	7.17	1.79
Saturation value C*	5.67	9.04	.20	2.74
Chroma angle value H0	170.9	179.9	180	90.2

Table.2 Color Difference Values of Neck and Back Hair of Different Fur Animals

Fur animal
Project	English Short Blue Cat (Grey)	Linqing Lion Cat (White)	New Zealand White Rabbit	Southwest Fujian Black Rabbit
Brightness value L*	28.16	94.73	74.34	15.25
The a value a*	2.68	1.90	0.95	1.47
Yellowness value b*	4.24	9.55	8.41	0.91
Saturation value C*	5.67	9.04	7.20	2.7 4
Chroma angle value H0	165.39	179.9	180	90.2

Table.3 Color Difference Values of the Left Rear Leg of Different Fur Animals

Fur animal
Project	English Short Blue Cat (Grey)	Linqing Lion Cat (White)	New Zealand White Rabbit	Southwest Fujian Black Rabbit
Brightness value L*	33.83	90.9	71.09	20.63
The a value a*	2 .90	1.25	0.62	2.4 8
Yellowness value b*	5.31	8. 15	7.10	3.25
Saturation value C*	6.05	8.24	7.13	4.09
Chroma angle value H0	170.93	180	180	155.67

Table.4 Color difference values of the right hind legs of different fur animals

Fur animal
Project	English Short Blue Cat (Grey)	Linqing Lion Cat (White)	New Zealand White Rabbit	Southwest Fujian Black Rabbit
Brightness value L*	29.78	90.89	64.11	19.39
The a value a*	2 .90	1.45	0.14	2.34
Yellowness value b*	5. 11	8.78	5.5	2.00
Saturation value C*	5.65	8.9	5.5	3.08
Chroma angle value H0	172.93	180	180	124.97

Table.5 Correlation coefficients between different color difference values and animal species and parts

Project	Breeds		Different parts
	R2	P–values	R2	P–values
Brightness value L*	0.420	0.065	0.110	0.962
The a value a*	0.313	0.179	0.121	0.612
Yellowness value b*	0.482	0.031*	0.066	0.783
Saturation value C*	0.521	0.019*	0.131	0.581
Chroma angle value H0	0.307	0.188	0.069	0.774

At present, handheld color difference meters are widely used in traditional and color-related industries such as printing, textile, and materials industries. In animal husbandry production, handheld color difference meters are widely used for color information of cold fresh meat, processed meat, and fats of livestock and poultry. The color difference value information of meat color is not only related to consumers’ sensory perception but also has an important relationship with the health status of animals and poultry before slaughter and post-slaughter processing technology. The glossiness and brightness of ornamental animal fur are related to the health status of animals. At the same time, shiny hair can also delight the animal owner. Healthy fur animals should have shiny, not dull fur, with stable and pure colors. The handheld color difference meter is of great significance as a non-destructive and rapid detection method to evaluate the color of the wool.

The brightness value L *, redness value a *, and yellowness value b * can describe single color information. Generally speaking, the brightness value is related to the brightness of the fur color, the moisture content of the fur color, and the oil content. The higher the brightness value, the better the glossiness of the fur and animals may have a better health state. Saturation (C *) is an important indicator that describes whether a color is pure and free from gray or black pollution. When C *=0, it represents no color and is gray or black. The higher the C * value, the higher the saturation of the color. Fur with higher color saturation can attract attention, bring better pleasure, and is also related to health. Hueangle (H °) is the one-to-one angle value information of a specific color at a saturation value of 100%. The above measurement and calculation indicators can accurately describe color information. This study indicates that the chromaticity value, yellowness value (b *), and saturation value (C *) can be used to evaluate and distinguish the fur color difference information between different species of animals. Next, in-depth research should be conducted on the effects of different fur treatments, including dietary nutrition, daily washing, and maintenance, on the color difference of ornamental animal fur.

Conclusion

The author used a handheld color difference meter to measure the fur color difference values of the British short blue cat, Linqing lion cat, New Zealand white rabbit, and Fujian southwest black rabbit, and measured different parts of the animals. Research has shown that the measured color difference values can reflect the color information of animal fur. The yellowing value b * and saturation value C * have significant correlations with different animal species and can be used to indicate color information of different fur animals. There is no significant correlation between the color difference value and different observation positions.

Author: Liu Ce