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Quality and Intensity of Light in Judgement of Colors Encountered in Poultry Inspection
Quality and Intensity of Light in Judgement of Colors Encountered in Poultry Inspection D. H. SANDERS,1 J. E. THOMSON AND A. J. MERCURI United States Department of Agriculture2 (Received for publication July 10, 1967)
D
1 Present Address: Market Quality Research Division, ARS, Athens, Georgia 30601. 2 Market Quality Research Division, ARS, Beltsville, Maryland 20705.
good quality and well distributed, and sufficient ventilation for all rooms and compartments to insure sanitary conditions. (a) All rooms in which poultry is killed, eviscerated, or otherwise processed shall have at least 30 foot candles of light intensity on all working surfaces, except that at the inspection stations such light intensity shall be of 50 foot candles . . ." Thus, only very general guidelines are provided as to quality and distribution of light for this important function. Previous studies which apply indirectly to problems in poultry inspection were in the areas of cotton classing (Nickerson, 1946) and of grain (Kingsolver et al., 1963). These studies compared sources of light to a commonly acceptable standard which closely approximates north-sky daylight. Grain and cotton have long been inspected under such daylight sources, either natural or artificial, and the graders and inspectors are accustomed, through long experience and training, to this environment. In poultry inspection and grading, however, the situation is not standardized. There is no precedent for the use of north-sky daylight as a standard nor any apparent predisposition among inspectors to use this standard as a basis for comparison. As stated by Nickerson (1946), ". . . the chief concern is to find an illuminant in which color differences, if they exist, can be seen. If an illuminant makes these differences easy to see, even though the illuminant be colored or peculiar in its characteristics, and entirely changes the daylight color of the paired samples, it may be satisfactory." The present research was designed to
366
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URING inspection of market poultry for wholesomeness, inspectors in processing plants primarily use sight to evaluate the carcasses. The inspector may touch each carcass to turn and inspect it, and when a sign of unwholesomeness is seen, the area is often palpated with the fingers to evaluate the significance of the sign. Under present commercial processing conditions, an inspector may evaluate up to 23 carcasses per minute. U. S. Department of Agriculture Regulations (1965) state: "Each carcass and all parts and organs thereof which are found to be sound, wholesome, unadulterated, and fit for human food, shall be passed." Inadequate or improper light may affect the inspector's confidence that he has met these requirements, and thus reduce his efficiency. At present, the visual environment at inspection stations varies from plant to plant. There may be some delay in adjustment by an inspector who must move from one plant, where he is accustomed to the lighting, into another in which the arrangement, amount, and quality of light is different. Inspectors must work under conditions of high humidity and glistening wet surroundings; their field of view includes large areas of highly reflective metal surfaces, and a continual procession of swaying, jerking conveyor chains and shackles. U. S. Department of Agriculture Regulations (1965) also require only that "There shall be ample light, either natural or artificial or both, of
COLORS IN POULTRY INSPECTION
compare several commonly or potentially available types of lamps, set at intensities under conditions simulating problems of color comparison during poultry inspection. Lamps and intensities were evaluated by matching Munsell color chips in the color ranges of internal organs which often show pathological processes. Munsell color chips were used in preference to natural materials to eliminate possible changes in samples during the periods of observation, and to allow flexibility of presentation.
Munsell color chips were selected to approximate closely the purplish liver color of normal chickens (7.SR 3/6), the reddish purple spleen color of normal chickens (SR 3/6), and the yellowish lesions of air sac disease (SY 9/4). Using each of these chips as the midpoint, chips were chosen 2.5 hue units either side, 1/ value unit either side and /2 chroma units either side of the midpoint; thus, giving a total of 7 different chips for each color. An exception occurred for yellow because ± 1 / value chips were not available; 2.SY 9/2 and 7.SY 9/2 were substituted. Four types of 48-in. 40-watt fluorescent
FIG. 1. Relative spectral energy curves for illuminants consisting of "examolite" tubes only (1A), "examolite" plus 25W.(115V.) incandescents (IB), and "examolite" plus 33W.(11SV.) incandescents (1C) (all SO F.C.).
FIG. 2. Relative spectral energy curves for illuminants consisting of "optima" tubes alone (2A), "optima" plus 25W.(115V.) incandescents (2B), and "optima" plus 33W.(11SV.) incandescents (2C) (all SO F.C.).
tubes were evaluated. Each tube was tested alone, or when supplemented with either standard 25-watt, 115-volt incandescent lamps or with special 33-watt, 115-volt incandescent lamps. The spectral quality of each type of fluorescent tube, both alone and supplemented with incandescent lamps was determined at 50-foot candles (F.C.) intensity. Each type of fluorescent tube, either alone or supplemented with incandescent lamps, is hereafter termed an "illuminant." Figures 1 through 4 are relative spectral energy curves of each illuminant. Curves are based on readings with the spectroradiometer of the Instrumentation Research Laboratory of Market Quality Research Divison, ARS, U. S. Department of Agriculture. Tube No. 1 was a fluorescent of the 8400°K. color temperature ("examolite" tube only) type, No. 2 was of the 5500°K. ("optima") type, No. 3 the 6500°K. ("daylight") type, and No. 4 of the 4200°K. ("cool white") type. The letter "A" following each number refers to the fluorescent tube unsupplemented, " B " to the fluorescent supplemented with 25-watt 115-volt incandescent lamps, and "C" to the fluorescent supplemented with 33-watt 115-volt incandescent
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PROCEDURE
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lamps. Illuminant 1C, which was a combination of fluorescent tubes No. 1 and the 33-watt, 115-volt incandescent lamps, is the combination recommended by the manufacturer of these lamps, and has a color temperature of 7400°K. Two light intensities, 50- and 100-F.C, measured at the viewing surface, were used. The SO-F.C. level was obtained with 2 fluorescent tubes either with or without supplementation with 2 incandescent lamps. A line voltage of 115 volts was used for all illuminants. The lighting fixture used for 50-F.C. was specially built to house 2 fluorescent tubes and when used, 2 incandescent lamps. All tubes and lamps were connected by separate switches. Interior surfaces of the fixtures were enameled white. The incandescent lamp sockets were between the tubes and % of the distance from each end, thus the incandescent light was concentrated in the outer ends of the fixture. The desired intensity was obtained by placing opaque panels towards the center of the fixture. This primarily lowered the proportion of total light from the fluorescent tubes, but did not interfere to a great extent with the proportion from incandescent lamps, when the latter were used. Diffusing glass was used on the
100,
A\
!
A
» !
S50l
J
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500
600
700
WAVELENGTH
FIG. 4. Relative spectral energy curves for illuminants consisting of "cool white" tubes alone (4A), "cool white" plus 2SW.(115V.) incandescents (4B), and "cool white" plus 33W.(11SV.) incandescents (4C) (all SO F.C.).
Downloaded from http://ps.oxfordjournals.org/ at Oakland University on May 2, 2015
FIG. 3. Relative spectral energy curves for illuminants consisting of "daylight" tubes alone (3A), "daylight" plus 25W.(115V.) incandescents (3B), and "daylight" plus 33W.(115V.) incandescents (3C) (all SO F.C.).
bottom of the fixture to give a source of 12 in. X 48 in. in area. The lighting fixture used for the 100-F.C-level studies was a Macbeth "examolite" type tc-440 modified by the addition of switches to control the incandescent portion of the illumination. Four of the particular type of fluorescent, and when used, 4 incandescent lamps could be placed in the fixture. A panel of 12 observers, from among faculty and student members of the Food Science Department of the University of Georgia, were selected to match the Munsell chips. Their age range was similar to that found among plant inspectors, and they appeared well motivated. As there is no examination for marginal color deficiencies required of applicants for jobs in Poultry Inspection, no pretest for marginal color deficiency was made on the panelists. One prospective panelist was eliminated for gross deficiency when his errors exceeded his correct judgments. The illuminants at 50-F.C. were evaluated first in a series of observations, then the illuminants at 100-F.C. were evaluated in a later series. In the later series, 3 of the original 12 observers were not available, and were replaced by 3 new observers. All comparisons between intensities
369
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RESULTS AND DISCUSSION Table 1 shows that important differences existed among observers. Their pattern of error was not consistent: some made more errors when the colors observed were alike, others when colors were unlike; and still
TABLE 1.—Mean percentage of incorrect judgments as affected by intensity of illumination and whether color chips in pair observed were alike or unlike Color
Intensity
Chips
(F.C.)
Alike
50 100 50 100
Unlike
Observer 1 17.3 11.7 0.5 0.4
2
3
4
5
6
7
8
9
All
2.2 1.5 9.9 10.4
14.2 12.0 5.5 4.0
4.3 1.9 2.1 2.4
6.8 4.9 3.6 4.6
2.2 2.2 2.4 2.1
0.6 1.2 3.7 4.4
7.4 4.6 10.7 8.3
8.0 2.2 4.1 5.0
7.0 a* 4.7b 4.7b 4.6b
' Means within the column followed by the same letter are not significantly different (p = 0.05).
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each intensity, except the midpoint chip which was presented with its duplicate 3 times. Each subject was allowed to work at his own pace but was encouraged to proceed as rapidly as he could. In all instances, an entire group of 3 sets of 30 pairs was completed within 10 minutes, including the time needed between sets to load each subsequent set in the presentation device. Observers evaluated the pairs of chips for each illuminant in the same order. This order was determined by use of a random number table. Pairs were placed on sheets of grey paper and the sheet order was changed with each illuminant. A different sequence of illuminant presentation was used for each observer. This eliminated the possible effect of different learning rates among observers. No observer ever saw the same order of pairs twice under either intensity. The system of presentation for 50-F.C. intensity was repeated for 100-F.C. Data accumulated on errors by all observers, under all illuminants, for both intensities, segregated as to whether errors occurred when either like or unlike chips were presented, were subjected to analysis of variance and multiple range tests (Duncan, 1955) by electronic data-processing procedures.
were made on the basis of the 9 observers who were present for both series. Comparisons within intensities of illumination included all 12 panel members. The booth in which the Munsell color chips, lighted by the illuminant, were observed was 8 feet long, 4 feet wide and 8 feet high. The booth was completely covered with neutral grey cloth, and light leakage was below 1-F.C. in intensity. When illuminants were switched off inside of the booth, objects were distinguishable, but colors were not. The device to hold the color chips when presented consisted of a grey cardboard panel in which were cut 2 openings 1 inch square and 3 inches apart for color chips. Between these were 2 smaller openings, under which white paper could be seen. The observer placed a pencil mark in the left small opening if he decided that the 2 color chips presented were unlike, and in the right if alike. The viewing angle was 45°. Light intensity at the viewing surface was determined with a Weston Model 703 foot-candle meter corrected for visual response. Intensity was adjusted to the proper level immediately before the beginning of each session for each observer. At each sitting, each observer was presented with the 3 sets of color chips. The sets corresponded to the 3 color categories: liver, spleen, and air sac lesions. Each set consisted of 30 pairs. Each chip was presented with its duplicate and every other chip within its set. Each pair was presented to the observer once for each illuminant at
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D. H. SANDERS, J. E. THOMSON AND A. J . MERCURI
TABLE 2.—Mean percentage of incorrect judgments as affected by type of illuminant and intensity of illumination
Illuminant 1
All
Color chips unlike
Intensity (F.C.)
Intensity (F.C.)
50
100
50
100
7.8ab* 7.4ab 7.4ab 11.1 b 2.9a 7.4ab 9.5ab 6.6 ab 4.9a 7.8ab 6.6 ab 4.5a
4.9ab 4.9ab 7.4ab 3.7ab 2.Sab 3.7ab 4.5ab 4.5 ab 2.5a 7.8 b 4. l a b 5.8ab
5.1 abc 4.Sab 5.8 be 3.9ab 6.3 c 3.3ab 3.0a 4.lab 4.4ab 5.8 be 4.9abc 5.3 be
5.6a 4.2a 3.7a 3.3a 3.5a 4.1a 5.8a 5.8a 6.2a 5.3a 4.1a 3.9a
4.7
4.7
4.6
7.0
* Means within a column followed by the same letter are not significantly different (p = 0.05). 1 See text for description of illuminants.
others made about the same number of errors whether or not the colors were alike. However, one important consistency did appear; when intensity of illumination was raised from 50- to 100-F.C, significantly fewer errors were made where colors actually alike were j'udged to be unlike. Poultry inspectors thus might either make more errors or require increased judgement time to compensate for possible uncertainty at low light levels. An analysis by least squares was performed to determine whether certain pairs within each set of colors contributed to the significant differences found between 50and 100-F.C. Data were not sufficient within each set, however, to identify those specific pairs which accounted for the differences found in the overall analysis. Table 2 shows that none of the illuminants was definitely superior to the others in minimizing errors in color matching. At 50-F.C, incandescent supplementation tended to improve judgement for matching color chips actually alike, but not for
An intensity of 100-F.C. was found to be superior to 50-F.C. for discriminating among colors of importance in poultry inspection. Among the illuminants evaluated in this study, none appeared significantly superior to any other, and any of these illuminants or types similar in spectral characteristics, should provide a satisfactory light source for use in poultry inspection. SUMMARY
Four types of fluorescent tubes, both alone and supplemented with 2 types of incandescent lamps, were evaluated at intensi-
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1A IB IC 2A 2B 2C 3A 3B 3C 4A 4B 4C
Color chips alike
matching color chips actually unlike; at 100-F.C. supplementation did not improve judgement. Despite the large total number (25,920) of individual matchings, the data were insufficient to permit meaninfgul comparisons as to the relation of type of illuminant to the observers' visual acuity in differentiating between hues, chromas, or values within an individual color set. Because of the observers' high overall accuracy, the number of errors by which comparisons could be made was only about 5 percent of the total observations. When matching unlike color chips, however, observers made significantly fewer (p = 0.05) correct judgements when the unlike chips differed by only 2.5 hue units than when they differed by 5 hue units, 1 or 2 value units, 2 or 4 chroma units, or any of the combinations of hue, value, and chroma. When the only difference between chips was 2.5 hue units, and the observers were judging liver colors, at 50-F.C, 35 percent of their judgements were incorrect, at 100-F.C, 28 percent; judging spleen colors, at 50-F.C, 29 percent, at 100-F.C, 24 percent; judging air sac lesion colors, at both 50- and 100-F.C, 45 percent were incorrect. When the differences between chips were other than only 2.5 hue units, errors did not exceed 3 percent.
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COLORS IN POULTRY INSPECTION
ties of SO- and 100-foot candles. Twelve observers made 25,920 judgements of paired color chips. The color chips represented colors of importance in inspecting for poultry pathological processes. Significantly fewer errors were made at 100 F.C. than at 50 F.C. in which color chips actually alike were judged to differ. No important differences were found as a function of the types of light sources or combinations evaluated. ACKNOWLEDGEMENTS
REFERENCES Duncan, D. B., 1955. Multiple range and multiple F tests. Biometrics, 1 1 : 1-7. Kingsolver, C. H., J. N. Yeatman, R. A. Boiler and J. A. Thompson, 1963. Backgrounds and artificial lighting for standardized grain inspection. U. S. Department of Agriculture Marketing Research Report No. 606. 24 pp. Nickerson, D., 1946. Color measurement and its application to the grading of agricultural products. U. S. Department of Agriculture Misc. Pub. 580. 62 pp. U. S. Department of Agriculture, 1965. Regulations governing the inspection of poultry and poultry products. U. S. Department of Agriculture. (7CFRPart 81). 24 pp.
Blood Volume of Geese Treated With Androgen and Estrogen1'2 W A L T E R G.
HUNSAKER
Canada Department of Agriculture, Ottawa, Ontario, Canada (Received for publication October IS, 1966)
INTRODUCTION
P
REVIOUS reports have shown that packed cell volume (PCV) values for male Pilgrim geese remained fairly constant during sexual development and the initial reproductive period, but declined toward the end of the reproductive period. In contrast, values for female geese varied inversely with rate of egg production (Hunsaker et al., 1964; Hunt and Hunsaker, 1965). Although data are 1 Contribution No. 215 from the Animal Research Institute, Ottawa, Ontario, Canada. 2 Presented at the 13th World's Poultry Congress, Kiev, U.S.S.R., 1966 (Summary only printed in Congress Proceedings).
limited, the pattern of change in erythrocyte volume (EV) and plasma volume (PV) in chickens during sexual development and reproduction (Newell and Shaffner, 1950; Medway and Kare, 1959) appears to be different from that observed in geese. Since treatment with androgen or estrogen is known to affect EV and PV in chickens (Taber et al., 1943; Domm and Taber, 1946; Common et al, 1948; Campbell, 1959; Gilbert, 1963) the response to similar treatment in geese might contribute to an understanding of these apparent species differences. The objective of this experiment, therefore, was to observe the effect of exogenous androgen and estrogen
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Appreciation is expressed to the Macbeth Daylighting Corporation, Newburgh, New York for providing components for illuminant No. 1, and to Duro-Test Corporation, North Bergen, New Jersey for providing components for illuminant No. 2, for these tests. This project is a cooperative effort with
the Food Science Department of the University of Georgia. The work was done in facilities provided by the Food Science Department in Athens, Georgia and their cooperation is gratefully acknowledged.
D
1 Present Address: Market Quality Research Division, ARS, Athens, Georgia 30601. 2 Market Quality Research Division, ARS, Beltsville, Maryland 20705.
good quality and well distributed, and sufficient ventilation for all rooms and compartments to insure sanitary conditions. (a) All rooms in which poultry is killed, eviscerated, or otherwise processed shall have at least 30 foot candles of light intensity on all working surfaces, except that at the inspection stations such light intensity shall be of 50 foot candles . . ." Thus, only very general guidelines are provided as to quality and distribution of light for this important function. Previous studies which apply indirectly to problems in poultry inspection were in the areas of cotton classing (Nickerson, 1946) and of grain (Kingsolver et al., 1963). These studies compared sources of light to a commonly acceptable standard which closely approximates north-sky daylight. Grain and cotton have long been inspected under such daylight sources, either natural or artificial, and the graders and inspectors are accustomed, through long experience and training, to this environment. In poultry inspection and grading, however, the situation is not standardized. There is no precedent for the use of north-sky daylight as a standard nor any apparent predisposition among inspectors to use this standard as a basis for comparison. As stated by Nickerson (1946), ". . . the chief concern is to find an illuminant in which color differences, if they exist, can be seen. If an illuminant makes these differences easy to see, even though the illuminant be colored or peculiar in its characteristics, and entirely changes the daylight color of the paired samples, it may be satisfactory." The present research was designed to
366
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URING inspection of market poultry for wholesomeness, inspectors in processing plants primarily use sight to evaluate the carcasses. The inspector may touch each carcass to turn and inspect it, and when a sign of unwholesomeness is seen, the area is often palpated with the fingers to evaluate the significance of the sign. Under present commercial processing conditions, an inspector may evaluate up to 23 carcasses per minute. U. S. Department of Agriculture Regulations (1965) state: "Each carcass and all parts and organs thereof which are found to be sound, wholesome, unadulterated, and fit for human food, shall be passed." Inadequate or improper light may affect the inspector's confidence that he has met these requirements, and thus reduce his efficiency. At present, the visual environment at inspection stations varies from plant to plant. There may be some delay in adjustment by an inspector who must move from one plant, where he is accustomed to the lighting, into another in which the arrangement, amount, and quality of light is different. Inspectors must work under conditions of high humidity and glistening wet surroundings; their field of view includes large areas of highly reflective metal surfaces, and a continual procession of swaying, jerking conveyor chains and shackles. U. S. Department of Agriculture Regulations (1965) also require only that "There shall be ample light, either natural or artificial or both, of
COLORS IN POULTRY INSPECTION
compare several commonly or potentially available types of lamps, set at intensities under conditions simulating problems of color comparison during poultry inspection. Lamps and intensities were evaluated by matching Munsell color chips in the color ranges of internal organs which often show pathological processes. Munsell color chips were used in preference to natural materials to eliminate possible changes in samples during the periods of observation, and to allow flexibility of presentation.
Munsell color chips were selected to approximate closely the purplish liver color of normal chickens (7.SR 3/6), the reddish purple spleen color of normal chickens (SR 3/6), and the yellowish lesions of air sac disease (SY 9/4). Using each of these chips as the midpoint, chips were chosen 2.5 hue units either side, 1/ value unit either side and /2 chroma units either side of the midpoint; thus, giving a total of 7 different chips for each color. An exception occurred for yellow because ± 1 / value chips were not available; 2.SY 9/2 and 7.SY 9/2 were substituted. Four types of 48-in. 40-watt fluorescent
FIG. 1. Relative spectral energy curves for illuminants consisting of "examolite" tubes only (1A), "examolite" plus 25W.(115V.) incandescents (IB), and "examolite" plus 33W.(11SV.) incandescents (1C) (all SO F.C.).
FIG. 2. Relative spectral energy curves for illuminants consisting of "optima" tubes alone (2A), "optima" plus 25W.(115V.) incandescents (2B), and "optima" plus 33W.(11SV.) incandescents (2C) (all SO F.C.).
tubes were evaluated. Each tube was tested alone, or when supplemented with either standard 25-watt, 115-volt incandescent lamps or with special 33-watt, 115-volt incandescent lamps. The spectral quality of each type of fluorescent tube, both alone and supplemented with incandescent lamps was determined at 50-foot candles (F.C.) intensity. Each type of fluorescent tube, either alone or supplemented with incandescent lamps, is hereafter termed an "illuminant." Figures 1 through 4 are relative spectral energy curves of each illuminant. Curves are based on readings with the spectroradiometer of the Instrumentation Research Laboratory of Market Quality Research Divison, ARS, U. S. Department of Agriculture. Tube No. 1 was a fluorescent of the 8400°K. color temperature ("examolite" tube only) type, No. 2 was of the 5500°K. ("optima") type, No. 3 the 6500°K. ("daylight") type, and No. 4 of the 4200°K. ("cool white") type. The letter "A" following each number refers to the fluorescent tube unsupplemented, " B " to the fluorescent supplemented with 25-watt 115-volt incandescent lamps, and "C" to the fluorescent supplemented with 33-watt 115-volt incandescent
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PROCEDURE
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D. H. SANDERS, J. E. THOMSON AND A. J. MERCURI
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lamps. Illuminant 1C, which was a combination of fluorescent tubes No. 1 and the 33-watt, 115-volt incandescent lamps, is the combination recommended by the manufacturer of these lamps, and has a color temperature of 7400°K. Two light intensities, 50- and 100-F.C, measured at the viewing surface, were used. The SO-F.C. level was obtained with 2 fluorescent tubes either with or without supplementation with 2 incandescent lamps. A line voltage of 115 volts was used for all illuminants. The lighting fixture used for 50-F.C. was specially built to house 2 fluorescent tubes and when used, 2 incandescent lamps. All tubes and lamps were connected by separate switches. Interior surfaces of the fixtures were enameled white. The incandescent lamp sockets were between the tubes and % of the distance from each end, thus the incandescent light was concentrated in the outer ends of the fixture. The desired intensity was obtained by placing opaque panels towards the center of the fixture. This primarily lowered the proportion of total light from the fluorescent tubes, but did not interfere to a great extent with the proportion from incandescent lamps, when the latter were used. Diffusing glass was used on the
100,
A\
!
A
» !
S50l
J
400
500
600
700
WAVELENGTH
FIG. 4. Relative spectral energy curves for illuminants consisting of "cool white" tubes alone (4A), "cool white" plus 2SW.(115V.) incandescents (4B), and "cool white" plus 33W.(11SV.) incandescents (4C) (all SO F.C.).
Downloaded from http://ps.oxfordjournals.org/ at Oakland University on May 2, 2015
FIG. 3. Relative spectral energy curves for illuminants consisting of "daylight" tubes alone (3A), "daylight" plus 25W.(115V.) incandescents (3B), and "daylight" plus 33W.(115V.) incandescents (3C) (all SO F.C.).
bottom of the fixture to give a source of 12 in. X 48 in. in area. The lighting fixture used for the 100-F.C-level studies was a Macbeth "examolite" type tc-440 modified by the addition of switches to control the incandescent portion of the illumination. Four of the particular type of fluorescent, and when used, 4 incandescent lamps could be placed in the fixture. A panel of 12 observers, from among faculty and student members of the Food Science Department of the University of Georgia, were selected to match the Munsell chips. Their age range was similar to that found among plant inspectors, and they appeared well motivated. As there is no examination for marginal color deficiencies required of applicants for jobs in Poultry Inspection, no pretest for marginal color deficiency was made on the panelists. One prospective panelist was eliminated for gross deficiency when his errors exceeded his correct judgments. The illuminants at 50-F.C. were evaluated first in a series of observations, then the illuminants at 100-F.C. were evaluated in a later series. In the later series, 3 of the original 12 observers were not available, and were replaced by 3 new observers. All comparisons between intensities
369
COLORS IN POULTRY INSPECTION
RESULTS AND DISCUSSION Table 1 shows that important differences existed among observers. Their pattern of error was not consistent: some made more errors when the colors observed were alike, others when colors were unlike; and still
TABLE 1.—Mean percentage of incorrect judgments as affected by intensity of illumination and whether color chips in pair observed were alike or unlike Color
Intensity
Chips
(F.C.)
Alike
50 100 50 100
Unlike
Observer 1 17.3 11.7 0.5 0.4
2
3
4
5
6
7
8
9
All
2.2 1.5 9.9 10.4
14.2 12.0 5.5 4.0
4.3 1.9 2.1 2.4
6.8 4.9 3.6 4.6
2.2 2.2 2.4 2.1
0.6 1.2 3.7 4.4
7.4 4.6 10.7 8.3
8.0 2.2 4.1 5.0
7.0 a* 4.7b 4.7b 4.6b
' Means within the column followed by the same letter are not significantly different (p = 0.05).
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each intensity, except the midpoint chip which was presented with its duplicate 3 times. Each subject was allowed to work at his own pace but was encouraged to proceed as rapidly as he could. In all instances, an entire group of 3 sets of 30 pairs was completed within 10 minutes, including the time needed between sets to load each subsequent set in the presentation device. Observers evaluated the pairs of chips for each illuminant in the same order. This order was determined by use of a random number table. Pairs were placed on sheets of grey paper and the sheet order was changed with each illuminant. A different sequence of illuminant presentation was used for each observer. This eliminated the possible effect of different learning rates among observers. No observer ever saw the same order of pairs twice under either intensity. The system of presentation for 50-F.C. intensity was repeated for 100-F.C. Data accumulated on errors by all observers, under all illuminants, for both intensities, segregated as to whether errors occurred when either like or unlike chips were presented, were subjected to analysis of variance and multiple range tests (Duncan, 1955) by electronic data-processing procedures.
were made on the basis of the 9 observers who were present for both series. Comparisons within intensities of illumination included all 12 panel members. The booth in which the Munsell color chips, lighted by the illuminant, were observed was 8 feet long, 4 feet wide and 8 feet high. The booth was completely covered with neutral grey cloth, and light leakage was below 1-F.C. in intensity. When illuminants were switched off inside of the booth, objects were distinguishable, but colors were not. The device to hold the color chips when presented consisted of a grey cardboard panel in which were cut 2 openings 1 inch square and 3 inches apart for color chips. Between these were 2 smaller openings, under which white paper could be seen. The observer placed a pencil mark in the left small opening if he decided that the 2 color chips presented were unlike, and in the right if alike. The viewing angle was 45°. Light intensity at the viewing surface was determined with a Weston Model 703 foot-candle meter corrected for visual response. Intensity was adjusted to the proper level immediately before the beginning of each session for each observer. At each sitting, each observer was presented with the 3 sets of color chips. The sets corresponded to the 3 color categories: liver, spleen, and air sac lesions. Each set consisted of 30 pairs. Each chip was presented with its duplicate and every other chip within its set. Each pair was presented to the observer once for each illuminant at
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D. H. SANDERS, J. E. THOMSON AND A. J . MERCURI
TABLE 2.—Mean percentage of incorrect judgments as affected by type of illuminant and intensity of illumination
Illuminant 1
All
Color chips unlike
Intensity (F.C.)
Intensity (F.C.)
50
100
50
100
7.8ab* 7.4ab 7.4ab 11.1 b 2.9a 7.4ab 9.5ab 6.6 ab 4.9a 7.8ab 6.6 ab 4.5a
4.9ab 4.9ab 7.4ab 3.7ab 2.Sab 3.7ab 4.5ab 4.5 ab 2.5a 7.8 b 4. l a b 5.8ab
5.1 abc 4.Sab 5.8 be 3.9ab 6.3 c 3.3ab 3.0a 4.lab 4.4ab 5.8 be 4.9abc 5.3 be
5.6a 4.2a 3.7a 3.3a 3.5a 4.1a 5.8a 5.8a 6.2a 5.3a 4.1a 3.9a
4.7
4.7
4.6
7.0
* Means within a column followed by the same letter are not significantly different (p = 0.05). 1 See text for description of illuminants.
others made about the same number of errors whether or not the colors were alike. However, one important consistency did appear; when intensity of illumination was raised from 50- to 100-F.C, significantly fewer errors were made where colors actually alike were j'udged to be unlike. Poultry inspectors thus might either make more errors or require increased judgement time to compensate for possible uncertainty at low light levels. An analysis by least squares was performed to determine whether certain pairs within each set of colors contributed to the significant differences found between 50and 100-F.C. Data were not sufficient within each set, however, to identify those specific pairs which accounted for the differences found in the overall analysis. Table 2 shows that none of the illuminants was definitely superior to the others in minimizing errors in color matching. At 50-F.C, incandescent supplementation tended to improve judgement for matching color chips actually alike, but not for
An intensity of 100-F.C. was found to be superior to 50-F.C. for discriminating among colors of importance in poultry inspection. Among the illuminants evaluated in this study, none appeared significantly superior to any other, and any of these illuminants or types similar in spectral characteristics, should provide a satisfactory light source for use in poultry inspection. SUMMARY
Four types of fluorescent tubes, both alone and supplemented with 2 types of incandescent lamps, were evaluated at intensi-
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1A IB IC 2A 2B 2C 3A 3B 3C 4A 4B 4C
Color chips alike
matching color chips actually unlike; at 100-F.C. supplementation did not improve judgement. Despite the large total number (25,920) of individual matchings, the data were insufficient to permit meaninfgul comparisons as to the relation of type of illuminant to the observers' visual acuity in differentiating between hues, chromas, or values within an individual color set. Because of the observers' high overall accuracy, the number of errors by which comparisons could be made was only about 5 percent of the total observations. When matching unlike color chips, however, observers made significantly fewer (p = 0.05) correct judgements when the unlike chips differed by only 2.5 hue units than when they differed by 5 hue units, 1 or 2 value units, 2 or 4 chroma units, or any of the combinations of hue, value, and chroma. When the only difference between chips was 2.5 hue units, and the observers were judging liver colors, at 50-F.C, 35 percent of their judgements were incorrect, at 100-F.C, 28 percent; judging spleen colors, at 50-F.C, 29 percent, at 100-F.C, 24 percent; judging air sac lesion colors, at both 50- and 100-F.C, 45 percent were incorrect. When the differences between chips were other than only 2.5 hue units, errors did not exceed 3 percent.
371
COLORS IN POULTRY INSPECTION
ties of SO- and 100-foot candles. Twelve observers made 25,920 judgements of paired color chips. The color chips represented colors of importance in inspecting for poultry pathological processes. Significantly fewer errors were made at 100 F.C. than at 50 F.C. in which color chips actually alike were judged to differ. No important differences were found as a function of the types of light sources or combinations evaluated. ACKNOWLEDGEMENTS
REFERENCES Duncan, D. B., 1955. Multiple range and multiple F tests. Biometrics, 1 1 : 1-7. Kingsolver, C. H., J. N. Yeatman, R. A. Boiler and J. A. Thompson, 1963. Backgrounds and artificial lighting for standardized grain inspection. U. S. Department of Agriculture Marketing Research Report No. 606. 24 pp. Nickerson, D., 1946. Color measurement and its application to the grading of agricultural products. U. S. Department of Agriculture Misc. Pub. 580. 62 pp. U. S. Department of Agriculture, 1965. Regulations governing the inspection of poultry and poultry products. U. S. Department of Agriculture. (7CFRPart 81). 24 pp.
Blood Volume of Geese Treated With Androgen and Estrogen1'2 W A L T E R G.
HUNSAKER
Canada Department of Agriculture, Ottawa, Ontario, Canada (Received for publication October IS, 1966)
INTRODUCTION
P
REVIOUS reports have shown that packed cell volume (PCV) values for male Pilgrim geese remained fairly constant during sexual development and the initial reproductive period, but declined toward the end of the reproductive period. In contrast, values for female geese varied inversely with rate of egg production (Hunsaker et al., 1964; Hunt and Hunsaker, 1965). Although data are 1 Contribution No. 215 from the Animal Research Institute, Ottawa, Ontario, Canada. 2 Presented at the 13th World's Poultry Congress, Kiev, U.S.S.R., 1966 (Summary only printed in Congress Proceedings).
limited, the pattern of change in erythrocyte volume (EV) and plasma volume (PV) in chickens during sexual development and reproduction (Newell and Shaffner, 1950; Medway and Kare, 1959) appears to be different from that observed in geese. Since treatment with androgen or estrogen is known to affect EV and PV in chickens (Taber et al., 1943; Domm and Taber, 1946; Common et al, 1948; Campbell, 1959; Gilbert, 1963) the response to similar treatment in geese might contribute to an understanding of these apparent species differences. The objective of this experiment, therefore, was to observe the effect of exogenous androgen and estrogen
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Appreciation is expressed to the Macbeth Daylighting Corporation, Newburgh, New York for providing components for illuminant No. 1, and to Duro-Test Corporation, North Bergen, New Jersey for providing components for illuminant No. 2, for these tests. This project is a cooperative effort with
the Food Science Department of the University of Georgia. The work was done in facilities provided by the Food Science Department in Athens, Georgia and their cooperation is gratefully acknowledged.