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Seasonal Variation in Quality of Eggs Laid by Caged Layers and Their Sisters on the Floor
Seasonal Variation in Quality of Eggs Laid byCaged Layers and Their Sisters on the Floor GLENN W. FRONING* AND E. M. FUNK Department of Poultry Husbandry, University of Missouri, Columbia, Missouri (Received for publication August 14, 1957)
T f XPERIMENTAL work comparing -*—' egg quality characteristics of caged and floor layers is rather limited. Jeffrey and Pino (1943) compared blood spot incidence of caged and floor birds. Their work showed caged birds to have a lower incidence of blood spots than did the birds on the floor. The incidence of blood spots in the eggs from caged birds was 4.01 percent as compared to 11.09 percent in eggs from the floor birds. Jeffrey (1945) reported results contrary to his earlier work when Rhode Island Reds in cages produced eggs with a higher percentage of blood spots than did the floor birds. Gowe (1955) reported no significant differences in egg weight of caged and floor layers. Lower egg production was observed in the caged layers than in the birds on the floor. Lowry el al. (1956) reported higher production in caged birds. The birds had significantly lower mortality, larger eggs, and higher incidence of blood spots. Grotts (1956) reported higher egg weight and increased incidence of blood spots in caged birds. No differences were observed in albumen quality and shell thickness. This paper presents data comparing egg quality characteristics of caged layers and their sisters on the floor within the various months of the year. Contributed from the Missouri Agricultural Experiment Station, Journal Series No. 1769. Approved by Director. This project was supported by NCM-7. * Poultry Department, University of Minnesota St. Paul 1, Minnesota.
EXPERIMENTAL PROCEDURE
From November, 1955, through March, 1957, interior quality measurements were made on 1,563 eggs. Forty-eight April hatched, Single Comb White Leghorns were used. On November 1, 1955, 24 of these pullets were housed in cages and 24 on the floor in the same room. Seventeen of the 24 pairs housed were full sisters. During the experiment, six of the caged birds died and four of the floor birds died. All birds were fed an all-mash ration containing 16 percent protein and 860 Calories of productive energy. The room in which the layers were housed was a windowless, insulated 20'X20' room. An overhead fan was installed in the ceiling to aid ventilation. Although this was not strictly a controlled environmental room, the temperature was maintained more uniformly than the normal laying pen. The temperature on the hottest summer days never exceeded 90°F. in the room. In the winter, a heating unit in the room switched on automatically at 45°F. Light in the room was maintained on a 14-hour basis throughout the year. The 24 caged layers were placed in 10"X18"X15" individual laying cages. An 8'X10' corner of the same room housed the 24 floor birds. Beginning in November, eggs were broken in alternating months until March, 1957. From November through May, eggs were allowed to remain in the cages until 4:00 p.m. The floor birds were trapnested hourly and their eggs allowed to set on a filler flat in an outer egg room until 4:00
215
216
G. W. FRONING AND E. M. FUNK
p.m. At 4:00 p.m. eggs from both groups were stored in a 55°F. cooler. Commencing in July, a new procedure of gathering was introduced. This new procedure involved gathering the eggs four times daily and placing them directly into a 55°F. cooler. Three eggs per hen per month were saved for measurements. The following measurements were made: 1. Egg weight in grams, 2. Shell thickness .001", 3. Albumen height (mm.), 4. Volume of thick and thin albumen (ml.), and 5. Blood and meat spots. All measurements were made after three days storage at 55°F. Egg weight was obtained to the nearest 0.1 of a gram on a simple trip balance. Subsequently, the egg was broken with a breaking knife and contents placed on to a flat glass plate supported by a metal stand. Shell thickness was ascertained with a paper thickness gage (Brant and Schrader, 1952). Measurements were made around the periphery of the shell in three places, and the average was recorded in .001 of an inch. Albumen height was observed with a tripod micrometer as described by Brant and Shrader (1952). Volume of thick and thin albumen was obtained as reported by Hoist and Almquist (1932). From the respective volumes obtained, the percentage thick albumen was ascertained. All eggs were examined closely for blood and meat spots. Spots were considered blood spots only when they were bright red in color. Any other spots were recorded as meat spots. Blood or meat spots below | " were reported as "small" and those above | " were reported as "large." Comparisons of blood and meat spot incidence in caged and floor layers were
made on 1,398 eggs. Eggs from the following hatches were used in this study. Hatch Date Months included April, 1954 May, 1956 and July, 1956 April, 1955 May, 1956 through March, 1957 (Alternate months) April, 1956 September, 1956 through March, 1957 (Alternate months)
All of the above birds represent full sister comparisons. The April, 1955, hatch was employed for studying seasonal fluctuations in blood spot and meat spot incidence. Blood and meat spot incidence for both environment and season were analysed statistically by the chi-square method (Snedecor, 1953). Albumen height and egg weight were used to compute Haugh units (Haugh, 1937). A circular calculator as described by Brant et al. (1952) was employed for Haugh unit computation. Haugh units and egg weight were analysed statistically for both season and environment by employing analysis of variance (Snedecor, 1953). Egg production was calculated on a hen day basis. Egg production of the caged layers averaged 224 eggs, whereas the floor layers averaged 237 eggs. Local climatological data was obtained from the Columbia, Missouri, Weather Bureau. RESULTS AND DISCUSSIONS
A complete summary of all the quality measurements appears in Table 1. Egg weight. A graphic presentation of egg size, average maximum temperature at time of measurement, and month of the year is shown in Figure 1. A study of this graph indicates egg size to be higher in caged layers throughout the experiment. Temperature apparently exhibited an influence on egg size. Egg size was lowest in July when the average temperature was highest. Although the data shows very
217
EGG QUALITY OF CAGED AND FLOOR LAYERS TABLE 1.—Seasonal variation in egg quality characteristics of hens in cages and their sisters on the floor Shell Ht. of thick No. of Habi- a « , . thickalbuMonth eggs tat ?*&* ness (gins.) (.001 men in.) (mm.) Nov. 19SS Jan. 1956 Mar. 1956 May 1956 July 1956 Sept. 1956 Nov. 1956 Jan. 1957 Mar. 1957
Totals &Ave.
TABLE 2.—Percentage distribution of the various market sizes of eggs from caged layers and their sisters on the floor
Percent of thick uH a u .h albu.? men units (mm.)
51 51 51 48 48 45 45 48 45 45 39 42 36 42 39 33 42 33
Cage Floor Cage Floor Cage Floor Cage Floor Cage Floor Cage Floor Cage Floor Cage Floor Cage Floor
53.9 53.2 57.5 55.8 58.8 56.3 60.3 58.9 58.7 57.0 59.1 58.9 61.1 59.9 64.6 61.5 62.2 61.3
15.9 15.0 15.1 14.6 15.4 14.7 16.5 16.4 13.8 13.6 12.5 13.5 14.4 14.3 14.4 14.2 14.0 13.4
6.26 5.94 6.02 5.48 5.69 5.65 5.32 5.25 5.74 5.60 5.73 5.02 5.38 5.11 5.73 5.28 5.53 5.02
60.3 57.7 58.6 56.4 59.3 57.5 61.4 59.2 64.6 60.2 61.3 57.2 66.0 60.8 66.8 61.2 64.7 62.2
80.2 78.2 77.2 73.6 74.0 74.8 70.3 70.5 74.5 74.2 74.0 68.5 70.0 68.5 72.3 69.6 71.4 67.0
396 387
Floor
59.6 58.1
14.7 14.4
5.71 5.37
62.6 59.2
73.8 71.7
little drop in average temperature during September, it is interesting to note that during the period of break out in September the average minimum temperature was down to 58°F. This possibly may be the cause of the smaller egg size in September. The lower temperatures of November and January appeared to increase egg weight. These results are in agreement with the earlier work of Warren et al.
Market Size Small Cage Floor
3.8 2.6
Medium Large 27.3 38.5
49.7 51.9
Extra Large 19.2 7.0
(1950), and Hutchinson (1953). To further study the difference in egg size, the eggs produced under the two environments were divided into market size classifications. The standard market classifications were used to designate the various sizes. These divisions were as follows: Size Small Medium Large Extra Large
Ounces per dozen 18-20.9 21-23.9 24-26.9 27 up
The results of the market size classifications are reported in Table 2. The caged layers produced considerably more extra large eggs over the period observed. Taking into consideration large and extra
Nov. 1956
Jan. 1957
FIG. 1. Seasonal variation of egg weight of hens in cages and sisters on the floor.
Mar. 1957
218
G. W. FRONING AND E. M. FUNK
TABLE 3.—Summary of egg quality measurements °f eiP laid by five hens in cages and their sisters on the floor (Hens laid throughout experiment) Habi
E
«e
She
"
?hickf
Percent
?tet •
weight (gm.)
thickness (.001 in.)
f , , , „n„ ao ll ( ^
thick albumen
Cage Floor
61.2 58.3
14.6 14.4
S.93 5.61
66.1 63.9
Haugh units 74.7 73.4
large eggs only, the caged birds laid 10 percent more large and extra large eggs than did the floor birds. To statistically analyse the egg weight data, results were examined to locate all the birds which had given a complete set of data for the nine-month period. Five pairs of sisters were found to have laid throughout the experiment. Since mortality and hens out of production would obscure the data, it was believed that the data from these five sister pairs would furnish more reliable results for statistical purposes. The performance of the five pairs of sisters is shown in Table 3. Eggs from the five pairs of sisters were also divided into the market sizes. The percentage of eggs falling within the various sizes are reported in Table 4. The egg weight of the five pairs of sisters was tested by using analysis of variance. Differences due to season and management were shown to be significant at the 1% level. Management and period interaction were found to be insignificant. The consistent results of the two habitats TABLE 4.—Market size distribution of eggs from five pairs of sisters (Hens laid throughout experiment) Market Size
Cage Floor
Small
Medium
Large
Extra Large
%
% 28.1 34.8
% 41.5 56.3
% 30.4 8.2
.7
would indicate very little interaction. Each of the management groups reacted similarly within the various seasons, and differences between cage and floor layers were continually in favor of the caged layers. Shell thickness. Shell thickness observations are reported in Table 1. Considerable variation in egg shell thickness was encountered in this experiment. Nevertheless, the cage and floor layers reacted approximately the same to seasonal fluctuations. Shell thickness was highest in May; but from May to September, a marked decrease in egg shell thickness was observed. The floor layers' eggs had dropped to .0135" by September, whereas their sisters' eggs in cages had reached a low of .0125". Brant (1953) reported egg breakage to increase rapidly when egg shell thickness drops below .013". Assuming this to be true, the eggs produced by the cage layers in September would probably have a high incidence of breakage in the market channels. The data illustrated in Figure 2 shows some relationship of shell thickness to average monthly temperature. The average temperature in September was lower than July, and a decrease in shell thickness was observed in each of the two habitats. Nevertheless, if the general high and low temperature trends are followed, greater shell thickness is associated rather closely with cooler temperatures, and low shell thickness occurs in periods of high temperatures. Although shell thickness did increase in November, the increase was not sufficient to bring shell quality to that observed in May. This would tend to indicate that some factor in addition to season is responsible for the decrease in shell quality. The earlier work of Warren el al. (1950) also indicated some of the decrease in shell thickness to be associated with the meta-
EGG QUALITY OF CAGED AND FLOOR LAYERS
219
FIG. 2. Seasonal variation of shell thickness of eggs laid by hens in cages and their sisters on the floor.
bolic changes in the bird itself. Shell thickness was slightly higher in eggs from the caged birds in all months except September. In September the caged layers produced eggs having considerably lower shell quality. Due to the small differences, it was concluded that egg shell thickness was probably about the same in the two environments. Height of thick albumen. The caged
layers had a higher height of thick albumen during all months in which this characteristic was observed. A study of Figure 3 indicates differences in albumen height to be less at certain seasons of the year. Height of thick albumen was approximately the same in May; but as the season progressed, differences become more pronounced. Both habitats experienced an increase in July. The increase in July
Temperature
Nov. 1955
Jan. 1956
Mar. 1956
May 1956
July 1956
Sept. 1956
Nov. 1956
Jan. 1957
FIG. 3. Seasonal variation of height of thick albumen in eggs laid by hens in cages and their sisters on the floor.
Mar. 1957
220
Nov. 1955
G. W. FRONING AND E. M. FUNK
Jan. 1956
Mar. 1956
Hay 1956
July 1956
Sept. 1956
Nov. 1956
Jan. 1957
Mar. 1957
FIG. 4. Seasonal variation of Haugh units in eggs laid by hens in cages and their sisters on the floor.
could possibly have been due to the more frequent gathering of the eggs. Haugh units. The seasonal trend in Haugh units of eggs from caged and floor layers appears in Figure 4. No definite relationship of Haugh units to the average maximum temperature was established. Seasonal variations were about the same for the two environments except in March, 1956. As the graph illustrates, the caged layers declined in egg quality from November through May. The eggs from the floor birds exhibited somewhat the same trend except for a slight upswing in March. As observed in the albumen height studies, each of the habitats increased in egg quality in July. Egg quality progressively declined in September and November, and this was followed by a slight increase in January, 1957. A decline in Haugh units was again observed in March, 1957. A study of the graph illustrated in Figure 4 indicates that the sharpest decline in quality occurred from November, 1955, to May, 1956. During this period, the caged layers' eggs lost approximately
ten Haugh units while the floor layers' eggs were losing about eight Haugh units. For the remainder of the experiment, the egg quality of each of the management groups remained within three or four units of 70 Haugh units. These data would indicate that the pullet probably loses most of her egg quality during the first six or seven months of lay. The average Haugh units of each of the habitats for the entire period was 73.8 in the caged layers and 71.7 in the floor layers. Haugh units were practically the same in two management groups from March through July. In March the egg quality actually measured one Haugh unit higher in eggs from the floor layers. The greatest differences were in September, 1956, and March, 1957, when the caged layers' eggs measured about five Haugh units higher. Analysis of variance of the Haugh unit data showed variations between management systems to be nonsignificant. This would be expected because of the small differences encountered within certain months. Management and period interac-
221
EGG QUALITY OF CAGED AND FLOOR LAYERS
tion were negligible. The data would also indicate that the two habitats reacted very similarly within the seasons. Period variations were found to be significant at the one percent level. Percent of thick albumen. These observations do not indicate much of a seasonal trend in percent of thick albumen. Results were in close agreement with the work of Knox and Godfrey (1938). Their work showed a higher percent of firm albumen in July and August than that observed in June. Knox and Godfrey also reported older hens to possess a higher percent of thick albumen. This study indicated a similar gradual increase in percent of thick albumen as the hen grew older. Through this study, percent of thick ablumen was consistently higher in eggs from the caged layers. The caged layers averaged 62.6 percent of thick albumen as compared to 59.2 percent of thick albumen in eggs from floor layers. Each of the management systems followed similar seasonal trends throughout the experiment. The seasonal variation of percent of thick albumen is shown in Table 1. Blood and meat spots. The April, 1955, hatched birds were employed to study the
TABLE 5.—Effect Month May 1956 July 1956 Sept. 1956 Nov. 1956 Jan. 1957 March 1957 Totals & Averages
Habitat
Number of eggs
effect of season on blood and meat spot incidence. Seasonal incidence of blood and meat spot is reported in Table 5. The highest percent of blood and meat spots was observed in March when caged and floor birds had 16.7 percent and 11.9 percent spots, respectively. Peaks were also reached in September and November, 1956. Seasonal trends observed by previous workers are extremely variable. Nevertheless, the high incidence observed in March concurs with the earlier work of Sauter el al. (1952) and Strain and Johnson (1956). The chi-square test of meat and blood spots incidence showed seasonal trends to be significant at the five percent level. Cage versus floor comparison of blood and meat spot incidence is shown in Table 6. Caged layers produced eggs with 3.80 percent more blood and meat spots. It is interesting to observe that the caged layers produced eggs with over twice as many small blood spots as were produced by their sisters on the floor. The incidence of large blood spots was about the same for each of the habitats, but the incidence of small and large meat spots was considerably higher in the caged layers'
of season on meat and blood spot incidence
Small blood Large blood Small meat spots spots spots
Large meat spots
%
%
%
1.59
1.59
— —
— — — — —
3.17 1.52 3.33 3.17 3.70 1.85
% — — —
Cage Floor Cage Floor Cage Floor Cage Floor Cage Floor Cage Floor
63 66 60 63 54 54 51 54 48 42 54 42
1.59 5.56 3.70 1.96 7.41
Cage Floor
330 321
Total
%
2.08
2.38 7.41 2.38
2.08 2.38 3.70 4.76
1.85 2.38
3.70 2.38
6.35 1.52 3.33 6.35 11.11 5.56 9.80 7.41 6.25 4.76 16.67 11.90
2.73 2.80
1.82 .93
2.43 1.56
1.82 .62
8.79 5.92
—
3.92
—
— — —
1.59 1.85
—
3.92
—
2.08
—
222
G. W. FRONING AND E. M. FUNK
FIG. 5. Seasonal variation of percent of thick albumen of eggs laid by hens in cages and their sisters on the floor.
eggs. Results obtained in this study consistently show higher incidence of spots in eggs from caged layers. The chi-square test of blood and meat spot incidence of cage versus floor indicated differences were significant. The reason for higher incidence of blood and meat spots in caged layers is unexplained. It would appear that the restricted movement of caged layers should decrease the incidence of blood and meat spots rather than increase them. Higher incidence of spots in eggs from caged layers may possibly result from some nutritional deficiency. SUMMARY
Forty-eight April hatched, Single Comb White Leghorns were used to study seaTABLE 6.—Blood and meat spot incidence of eggs from cage birds and their sisters on the floor -^ TTah'tat
Cage Floor
oif 6ggS
Small Large Small Large blood blood meat meat Total . t
%
726 3.99 672 1.93
%
%
%
%
.83 3.17 1.93 9.92 .89 2.23 1.04 6.10
sonal variations in the quality of eggs laid by caged layers and their sisters on the floor. The results of this experiment indicated the following: 1. A comparison of caged and floor birds showed egg weight to be higher in caged layers throughout the study. The differences in egg weight between caged and floor layers were found to be significant at the one percent level. 2. Warm temperatures apparently had an adverse effect on egg shell thickness. Recovery in the fall was not sufficient to bring the thickness back to the original level observed in May. Egg shell thickness was concluded to be about the same in caged and floor layers. 3. Thick albumen height was higher in eggs from caged layers throughout the experiment. 4. No significant differences in egg quality were observed between caged layers and their sisters on the floor. Seasonal variations in Haugh units were found to be significant at the one percent level.
EGG QUALITY OF CAGED AND FLOOR LAYERS
5. No seasonal trend was indicated in the percent of thick albumen. Throughout this study, percent of thick albumen was consistently higher in the caged layers. 6. Meat and blood spots were found to be highest in March in each of the management systems. Caged layers produced eggs with significantly more meat and blood spots than their sisters on the floor. REFERENCES Brant, A. W., A. W. Otte and G. Chin, 1953. A survey of egg quality at two egg laying tests. U.S.D.A. Tech. Bull. No. 1066. Brant, A. W., and H. L. Schrader, 1952. How to measure egg I.Q. (interior quality). P. A. 202, U.SJD.A. Grotts, R. F., 1956. Seasonal variations in egg quality. Thesis, University of Missouri Poultry Dept. 66 pp. Gowe, R. S., 1955. A comparison of the egg production of seven White Leghorn strains housed in two environments—floor pens and laying battery. Poultry Sci. 34: 1198. Haugh, R. R. 1937. The Haugh unit for measuring egg quality. U. S. Egg Poultry Magazine, 43: 552-573.
223
Hoist, W. F., and H. J. Almquist, 1932. Measurement of deterioration in the stored hens egg. U. S. Egg Poultry Magazine, 38: (2): 70-77. Hutchinson, J. C. D., 1953. Effect of hot climates on egg weight. Poultry Sci. 31: 586-588. Jeffrey, E. P., 1945. Blood and meat spots in chicken eggs. Poultry Sci. 24: 363-374. Jeffrey, E. P., and J. Pino, 1943. The effects of heredity and certain environmental factors on incidence of blood spots in chicken eggs. Poultry Sci. 22: 230-234. Knox, C. W., and A. B. Godfrey, 1938. Factors influencing the percentage of thick albumen of hen's eggs. Poultry Sci. 17:159-162. Lowry, D. C , I. M. Lerner and D. W. Taylor, 1956. Intra-flock genetic merit under floor and cage managements. Poultry Sci. 35: 1034-1043. Sauter, E. A., W. J. Stadelman and J. S. Carver, 1952. Factors affecting the incidence of blood spots and their detection in hen's egg. Poultry Sci. 35: 1042-1049. Snedecor, G. W., 1956. Statistical Methods Applied to Experiments in Agriculture and Biology. The Iowa State College Press, Ames, Iowa. 513 pp. Strain, J. H., and A. S. Johnson, 1956. Seasonal, hatch, and strain effects on egg quality. Poultry Sci. 35: 1174. Warren, D. C , R. Conard, A. E. Schumacher and T. B. Avery, 1950. Effects of fluctuating environment on laying hens. Kansas Agr. Exp. Sta. Tech. Bull. 68.
The Effect of Furazolidone Consumption on Drug Content of Chicken Tissues and Eggs, Color of Shell, Yolkfand Whole Eggs Homogenate G. B. BELLOFF,* J. BUZARD AND H. D. B. ROBERTS Medical and Research Departments, Eaton Laboratories, Division of The Norwich Pharmacol Company, Norwich, New York (Received for publication August IS, 1957)
F
URAZOLIDONE [Furoxone or 5(nitro-2-furfurylidene)-3-amino-2-oxazolidone] is a synthetic antimicrobial nitrofuran which has recently become widely used as a poultry feed additive, * Presently Senior Research Veterinarian, CIBA Pharmaceutical Products, Inc., Summit, N. J.
serving to prevent or treat various common infectious diseases, including salmonellosis in both turkeys (Grumbles et al., 1954), and chickens (Lucas, 1955). The prevalence of carriers of Salmonella gallinarum among hens treated with furazolidone is low (Smith, 1955) and the drug shows similar effect in S. pullorum infec-
T f XPERIMENTAL work comparing -*—' egg quality characteristics of caged and floor layers is rather limited. Jeffrey and Pino (1943) compared blood spot incidence of caged and floor birds. Their work showed caged birds to have a lower incidence of blood spots than did the birds on the floor. The incidence of blood spots in the eggs from caged birds was 4.01 percent as compared to 11.09 percent in eggs from the floor birds. Jeffrey (1945) reported results contrary to his earlier work when Rhode Island Reds in cages produced eggs with a higher percentage of blood spots than did the floor birds. Gowe (1955) reported no significant differences in egg weight of caged and floor layers. Lower egg production was observed in the caged layers than in the birds on the floor. Lowry el al. (1956) reported higher production in caged birds. The birds had significantly lower mortality, larger eggs, and higher incidence of blood spots. Grotts (1956) reported higher egg weight and increased incidence of blood spots in caged birds. No differences were observed in albumen quality and shell thickness. This paper presents data comparing egg quality characteristics of caged layers and their sisters on the floor within the various months of the year. Contributed from the Missouri Agricultural Experiment Station, Journal Series No. 1769. Approved by Director. This project was supported by NCM-7. * Poultry Department, University of Minnesota St. Paul 1, Minnesota.
EXPERIMENTAL PROCEDURE
From November, 1955, through March, 1957, interior quality measurements were made on 1,563 eggs. Forty-eight April hatched, Single Comb White Leghorns were used. On November 1, 1955, 24 of these pullets were housed in cages and 24 on the floor in the same room. Seventeen of the 24 pairs housed were full sisters. During the experiment, six of the caged birds died and four of the floor birds died. All birds were fed an all-mash ration containing 16 percent protein and 860 Calories of productive energy. The room in which the layers were housed was a windowless, insulated 20'X20' room. An overhead fan was installed in the ceiling to aid ventilation. Although this was not strictly a controlled environmental room, the temperature was maintained more uniformly than the normal laying pen. The temperature on the hottest summer days never exceeded 90°F. in the room. In the winter, a heating unit in the room switched on automatically at 45°F. Light in the room was maintained on a 14-hour basis throughout the year. The 24 caged layers were placed in 10"X18"X15" individual laying cages. An 8'X10' corner of the same room housed the 24 floor birds. Beginning in November, eggs were broken in alternating months until March, 1957. From November through May, eggs were allowed to remain in the cages until 4:00 p.m. The floor birds were trapnested hourly and their eggs allowed to set on a filler flat in an outer egg room until 4:00
215
216
G. W. FRONING AND E. M. FUNK
p.m. At 4:00 p.m. eggs from both groups were stored in a 55°F. cooler. Commencing in July, a new procedure of gathering was introduced. This new procedure involved gathering the eggs four times daily and placing them directly into a 55°F. cooler. Three eggs per hen per month were saved for measurements. The following measurements were made: 1. Egg weight in grams, 2. Shell thickness .001", 3. Albumen height (mm.), 4. Volume of thick and thin albumen (ml.), and 5. Blood and meat spots. All measurements were made after three days storage at 55°F. Egg weight was obtained to the nearest 0.1 of a gram on a simple trip balance. Subsequently, the egg was broken with a breaking knife and contents placed on to a flat glass plate supported by a metal stand. Shell thickness was ascertained with a paper thickness gage (Brant and Schrader, 1952). Measurements were made around the periphery of the shell in three places, and the average was recorded in .001 of an inch. Albumen height was observed with a tripod micrometer as described by Brant and Shrader (1952). Volume of thick and thin albumen was obtained as reported by Hoist and Almquist (1932). From the respective volumes obtained, the percentage thick albumen was ascertained. All eggs were examined closely for blood and meat spots. Spots were considered blood spots only when they were bright red in color. Any other spots were recorded as meat spots. Blood or meat spots below | " were reported as "small" and those above | " were reported as "large." Comparisons of blood and meat spot incidence in caged and floor layers were
made on 1,398 eggs. Eggs from the following hatches were used in this study. Hatch Date Months included April, 1954 May, 1956 and July, 1956 April, 1955 May, 1956 through March, 1957 (Alternate months) April, 1956 September, 1956 through March, 1957 (Alternate months)
All of the above birds represent full sister comparisons. The April, 1955, hatch was employed for studying seasonal fluctuations in blood spot and meat spot incidence. Blood and meat spot incidence for both environment and season were analysed statistically by the chi-square method (Snedecor, 1953). Albumen height and egg weight were used to compute Haugh units (Haugh, 1937). A circular calculator as described by Brant et al. (1952) was employed for Haugh unit computation. Haugh units and egg weight were analysed statistically for both season and environment by employing analysis of variance (Snedecor, 1953). Egg production was calculated on a hen day basis. Egg production of the caged layers averaged 224 eggs, whereas the floor layers averaged 237 eggs. Local climatological data was obtained from the Columbia, Missouri, Weather Bureau. RESULTS AND DISCUSSIONS
A complete summary of all the quality measurements appears in Table 1. Egg weight. A graphic presentation of egg size, average maximum temperature at time of measurement, and month of the year is shown in Figure 1. A study of this graph indicates egg size to be higher in caged layers throughout the experiment. Temperature apparently exhibited an influence on egg size. Egg size was lowest in July when the average temperature was highest. Although the data shows very
217
EGG QUALITY OF CAGED AND FLOOR LAYERS TABLE 1.—Seasonal variation in egg quality characteristics of hens in cages and their sisters on the floor Shell Ht. of thick No. of Habi- a « , . thickalbuMonth eggs tat ?*&* ness (gins.) (.001 men in.) (mm.) Nov. 19SS Jan. 1956 Mar. 1956 May 1956 July 1956 Sept. 1956 Nov. 1956 Jan. 1957 Mar. 1957
Totals &Ave.
TABLE 2.—Percentage distribution of the various market sizes of eggs from caged layers and their sisters on the floor
Percent of thick uH a u .h albu.? men units (mm.)
51 51 51 48 48 45 45 48 45 45 39 42 36 42 39 33 42 33
Cage Floor Cage Floor Cage Floor Cage Floor Cage Floor Cage Floor Cage Floor Cage Floor Cage Floor
53.9 53.2 57.5 55.8 58.8 56.3 60.3 58.9 58.7 57.0 59.1 58.9 61.1 59.9 64.6 61.5 62.2 61.3
15.9 15.0 15.1 14.6 15.4 14.7 16.5 16.4 13.8 13.6 12.5 13.5 14.4 14.3 14.4 14.2 14.0 13.4
6.26 5.94 6.02 5.48 5.69 5.65 5.32 5.25 5.74 5.60 5.73 5.02 5.38 5.11 5.73 5.28 5.53 5.02
60.3 57.7 58.6 56.4 59.3 57.5 61.4 59.2 64.6 60.2 61.3 57.2 66.0 60.8 66.8 61.2 64.7 62.2
80.2 78.2 77.2 73.6 74.0 74.8 70.3 70.5 74.5 74.2 74.0 68.5 70.0 68.5 72.3 69.6 71.4 67.0
396 387
Floor
59.6 58.1
14.7 14.4
5.71 5.37
62.6 59.2
73.8 71.7
little drop in average temperature during September, it is interesting to note that during the period of break out in September the average minimum temperature was down to 58°F. This possibly may be the cause of the smaller egg size in September. The lower temperatures of November and January appeared to increase egg weight. These results are in agreement with the earlier work of Warren et al.
Market Size Small Cage Floor
3.8 2.6
Medium Large 27.3 38.5
49.7 51.9
Extra Large 19.2 7.0
(1950), and Hutchinson (1953). To further study the difference in egg size, the eggs produced under the two environments were divided into market size classifications. The standard market classifications were used to designate the various sizes. These divisions were as follows: Size Small Medium Large Extra Large
Ounces per dozen 18-20.9 21-23.9 24-26.9 27 up
The results of the market size classifications are reported in Table 2. The caged layers produced considerably more extra large eggs over the period observed. Taking into consideration large and extra
Nov. 1956
Jan. 1957
FIG. 1. Seasonal variation of egg weight of hens in cages and sisters on the floor.
Mar. 1957
218
G. W. FRONING AND E. M. FUNK
TABLE 3.—Summary of egg quality measurements °f eiP laid by five hens in cages and their sisters on the floor (Hens laid throughout experiment) Habi
E
«e
She
"
?hickf
Percent
?tet •
weight (gm.)
thickness (.001 in.)
f , , , „n„ ao ll ( ^
thick albumen
Cage Floor
61.2 58.3
14.6 14.4
S.93 5.61
66.1 63.9
Haugh units 74.7 73.4
large eggs only, the caged birds laid 10 percent more large and extra large eggs than did the floor birds. To statistically analyse the egg weight data, results were examined to locate all the birds which had given a complete set of data for the nine-month period. Five pairs of sisters were found to have laid throughout the experiment. Since mortality and hens out of production would obscure the data, it was believed that the data from these five sister pairs would furnish more reliable results for statistical purposes. The performance of the five pairs of sisters is shown in Table 3. Eggs from the five pairs of sisters were also divided into the market sizes. The percentage of eggs falling within the various sizes are reported in Table 4. The egg weight of the five pairs of sisters was tested by using analysis of variance. Differences due to season and management were shown to be significant at the 1% level. Management and period interaction were found to be insignificant. The consistent results of the two habitats TABLE 4.—Market size distribution of eggs from five pairs of sisters (Hens laid throughout experiment) Market Size
Cage Floor
Small
Medium
Large
Extra Large
%
% 28.1 34.8
% 41.5 56.3
% 30.4 8.2
.7
would indicate very little interaction. Each of the management groups reacted similarly within the various seasons, and differences between cage and floor layers were continually in favor of the caged layers. Shell thickness. Shell thickness observations are reported in Table 1. Considerable variation in egg shell thickness was encountered in this experiment. Nevertheless, the cage and floor layers reacted approximately the same to seasonal fluctuations. Shell thickness was highest in May; but from May to September, a marked decrease in egg shell thickness was observed. The floor layers' eggs had dropped to .0135" by September, whereas their sisters' eggs in cages had reached a low of .0125". Brant (1953) reported egg breakage to increase rapidly when egg shell thickness drops below .013". Assuming this to be true, the eggs produced by the cage layers in September would probably have a high incidence of breakage in the market channels. The data illustrated in Figure 2 shows some relationship of shell thickness to average monthly temperature. The average temperature in September was lower than July, and a decrease in shell thickness was observed in each of the two habitats. Nevertheless, if the general high and low temperature trends are followed, greater shell thickness is associated rather closely with cooler temperatures, and low shell thickness occurs in periods of high temperatures. Although shell thickness did increase in November, the increase was not sufficient to bring shell quality to that observed in May. This would tend to indicate that some factor in addition to season is responsible for the decrease in shell quality. The earlier work of Warren el al. (1950) also indicated some of the decrease in shell thickness to be associated with the meta-
EGG QUALITY OF CAGED AND FLOOR LAYERS
219
FIG. 2. Seasonal variation of shell thickness of eggs laid by hens in cages and their sisters on the floor.
bolic changes in the bird itself. Shell thickness was slightly higher in eggs from the caged birds in all months except September. In September the caged layers produced eggs having considerably lower shell quality. Due to the small differences, it was concluded that egg shell thickness was probably about the same in the two environments. Height of thick albumen. The caged
layers had a higher height of thick albumen during all months in which this characteristic was observed. A study of Figure 3 indicates differences in albumen height to be less at certain seasons of the year. Height of thick albumen was approximately the same in May; but as the season progressed, differences become more pronounced. Both habitats experienced an increase in July. The increase in July
Temperature
Nov. 1955
Jan. 1956
Mar. 1956
May 1956
July 1956
Sept. 1956
Nov. 1956
Jan. 1957
FIG. 3. Seasonal variation of height of thick albumen in eggs laid by hens in cages and their sisters on the floor.
Mar. 1957
220
Nov. 1955
G. W. FRONING AND E. M. FUNK
Jan. 1956
Mar. 1956
Hay 1956
July 1956
Sept. 1956
Nov. 1956
Jan. 1957
Mar. 1957
FIG. 4. Seasonal variation of Haugh units in eggs laid by hens in cages and their sisters on the floor.
could possibly have been due to the more frequent gathering of the eggs. Haugh units. The seasonal trend in Haugh units of eggs from caged and floor layers appears in Figure 4. No definite relationship of Haugh units to the average maximum temperature was established. Seasonal variations were about the same for the two environments except in March, 1956. As the graph illustrates, the caged layers declined in egg quality from November through May. The eggs from the floor birds exhibited somewhat the same trend except for a slight upswing in March. As observed in the albumen height studies, each of the habitats increased in egg quality in July. Egg quality progressively declined in September and November, and this was followed by a slight increase in January, 1957. A decline in Haugh units was again observed in March, 1957. A study of the graph illustrated in Figure 4 indicates that the sharpest decline in quality occurred from November, 1955, to May, 1956. During this period, the caged layers' eggs lost approximately
ten Haugh units while the floor layers' eggs were losing about eight Haugh units. For the remainder of the experiment, the egg quality of each of the management groups remained within three or four units of 70 Haugh units. These data would indicate that the pullet probably loses most of her egg quality during the first six or seven months of lay. The average Haugh units of each of the habitats for the entire period was 73.8 in the caged layers and 71.7 in the floor layers. Haugh units were practically the same in two management groups from March through July. In March the egg quality actually measured one Haugh unit higher in eggs from the floor layers. The greatest differences were in September, 1956, and March, 1957, when the caged layers' eggs measured about five Haugh units higher. Analysis of variance of the Haugh unit data showed variations between management systems to be nonsignificant. This would be expected because of the small differences encountered within certain months. Management and period interac-
221
EGG QUALITY OF CAGED AND FLOOR LAYERS
tion were negligible. The data would also indicate that the two habitats reacted very similarly within the seasons. Period variations were found to be significant at the one percent level. Percent of thick albumen. These observations do not indicate much of a seasonal trend in percent of thick albumen. Results were in close agreement with the work of Knox and Godfrey (1938). Their work showed a higher percent of firm albumen in July and August than that observed in June. Knox and Godfrey also reported older hens to possess a higher percent of thick albumen. This study indicated a similar gradual increase in percent of thick albumen as the hen grew older. Through this study, percent of thick ablumen was consistently higher in eggs from the caged layers. The caged layers averaged 62.6 percent of thick albumen as compared to 59.2 percent of thick albumen in eggs from floor layers. Each of the management systems followed similar seasonal trends throughout the experiment. The seasonal variation of percent of thick albumen is shown in Table 1. Blood and meat spots. The April, 1955, hatched birds were employed to study the
TABLE 5.—Effect Month May 1956 July 1956 Sept. 1956 Nov. 1956 Jan. 1957 March 1957 Totals & Averages
Habitat
Number of eggs
effect of season on blood and meat spot incidence. Seasonal incidence of blood and meat spot is reported in Table 5. The highest percent of blood and meat spots was observed in March when caged and floor birds had 16.7 percent and 11.9 percent spots, respectively. Peaks were also reached in September and November, 1956. Seasonal trends observed by previous workers are extremely variable. Nevertheless, the high incidence observed in March concurs with the earlier work of Sauter el al. (1952) and Strain and Johnson (1956). The chi-square test of meat and blood spots incidence showed seasonal trends to be significant at the five percent level. Cage versus floor comparison of blood and meat spot incidence is shown in Table 6. Caged layers produced eggs with 3.80 percent more blood and meat spots. It is interesting to observe that the caged layers produced eggs with over twice as many small blood spots as were produced by their sisters on the floor. The incidence of large blood spots was about the same for each of the habitats, but the incidence of small and large meat spots was considerably higher in the caged layers'
of season on meat and blood spot incidence
Small blood Large blood Small meat spots spots spots
Large meat spots
%
%
%
1.59
1.59
— —
— — — — —
3.17 1.52 3.33 3.17 3.70 1.85
% — — —
Cage Floor Cage Floor Cage Floor Cage Floor Cage Floor Cage Floor
63 66 60 63 54 54 51 54 48 42 54 42
1.59 5.56 3.70 1.96 7.41
Cage Floor
330 321
Total
%
2.08
2.38 7.41 2.38
2.08 2.38 3.70 4.76
1.85 2.38
3.70 2.38
6.35 1.52 3.33 6.35 11.11 5.56 9.80 7.41 6.25 4.76 16.67 11.90
2.73 2.80
1.82 .93
2.43 1.56
1.82 .62
8.79 5.92
—
3.92
—
— — —
1.59 1.85
—
3.92
—
2.08
—
222
G. W. FRONING AND E. M. FUNK
FIG. 5. Seasonal variation of percent of thick albumen of eggs laid by hens in cages and their sisters on the floor.
eggs. Results obtained in this study consistently show higher incidence of spots in eggs from caged layers. The chi-square test of blood and meat spot incidence of cage versus floor indicated differences were significant. The reason for higher incidence of blood and meat spots in caged layers is unexplained. It would appear that the restricted movement of caged layers should decrease the incidence of blood and meat spots rather than increase them. Higher incidence of spots in eggs from caged layers may possibly result from some nutritional deficiency. SUMMARY
Forty-eight April hatched, Single Comb White Leghorns were used to study seaTABLE 6.—Blood and meat spot incidence of eggs from cage birds and their sisters on the floor -^ TTah'tat
Cage Floor
oif 6ggS
Small Large Small Large blood blood meat meat Total . t
%
726 3.99 672 1.93
%
%
%
%
.83 3.17 1.93 9.92 .89 2.23 1.04 6.10
sonal variations in the quality of eggs laid by caged layers and their sisters on the floor. The results of this experiment indicated the following: 1. A comparison of caged and floor birds showed egg weight to be higher in caged layers throughout the study. The differences in egg weight between caged and floor layers were found to be significant at the one percent level. 2. Warm temperatures apparently had an adverse effect on egg shell thickness. Recovery in the fall was not sufficient to bring the thickness back to the original level observed in May. Egg shell thickness was concluded to be about the same in caged and floor layers. 3. Thick albumen height was higher in eggs from caged layers throughout the experiment. 4. No significant differences in egg quality were observed between caged layers and their sisters on the floor. Seasonal variations in Haugh units were found to be significant at the one percent level.
EGG QUALITY OF CAGED AND FLOOR LAYERS
5. No seasonal trend was indicated in the percent of thick albumen. Throughout this study, percent of thick albumen was consistently higher in the caged layers. 6. Meat and blood spots were found to be highest in March in each of the management systems. Caged layers produced eggs with significantly more meat and blood spots than their sisters on the floor. REFERENCES Brant, A. W., A. W. Otte and G. Chin, 1953. A survey of egg quality at two egg laying tests. U.S.D.A. Tech. Bull. No. 1066. Brant, A. W., and H. L. Schrader, 1952. How to measure egg I.Q. (interior quality). P. A. 202, U.SJD.A. Grotts, R. F., 1956. Seasonal variations in egg quality. Thesis, University of Missouri Poultry Dept. 66 pp. Gowe, R. S., 1955. A comparison of the egg production of seven White Leghorn strains housed in two environments—floor pens and laying battery. Poultry Sci. 34: 1198. Haugh, R. R. 1937. The Haugh unit for measuring egg quality. U. S. Egg Poultry Magazine, 43: 552-573.
223
Hoist, W. F., and H. J. Almquist, 1932. Measurement of deterioration in the stored hens egg. U. S. Egg Poultry Magazine, 38: (2): 70-77. Hutchinson, J. C. D., 1953. Effect of hot climates on egg weight. Poultry Sci. 31: 586-588. Jeffrey, E. P., 1945. Blood and meat spots in chicken eggs. Poultry Sci. 24: 363-374. Jeffrey, E. P., and J. Pino, 1943. The effects of heredity and certain environmental factors on incidence of blood spots in chicken eggs. Poultry Sci. 22: 230-234. Knox, C. W., and A. B. Godfrey, 1938. Factors influencing the percentage of thick albumen of hen's eggs. Poultry Sci. 17:159-162. Lowry, D. C , I. M. Lerner and D. W. Taylor, 1956. Intra-flock genetic merit under floor and cage managements. Poultry Sci. 35: 1034-1043. Sauter, E. A., W. J. Stadelman and J. S. Carver, 1952. Factors affecting the incidence of blood spots and their detection in hen's egg. Poultry Sci. 35: 1042-1049. Snedecor, G. W., 1956. Statistical Methods Applied to Experiments in Agriculture and Biology. The Iowa State College Press, Ames, Iowa. 513 pp. Strain, J. H., and A. S. Johnson, 1956. Seasonal, hatch, and strain effects on egg quality. Poultry Sci. 35: 1174. Warren, D. C , R. Conard, A. E. Schumacher and T. B. Avery, 1950. Effects of fluctuating environment on laying hens. Kansas Agr. Exp. Sta. Tech. Bull. 68.
The Effect of Furazolidone Consumption on Drug Content of Chicken Tissues and Eggs, Color of Shell, Yolkfand Whole Eggs Homogenate G. B. BELLOFF,* J. BUZARD AND H. D. B. ROBERTS Medical and Research Departments, Eaton Laboratories, Division of The Norwich Pharmacol Company, Norwich, New York (Received for publication August IS, 1957)
F
URAZOLIDONE [Furoxone or 5(nitro-2-furfurylidene)-3-amino-2-oxazolidone] is a synthetic antimicrobial nitrofuran which has recently become widely used as a poultry feed additive, * Presently Senior Research Veterinarian, CIBA Pharmaceutical Products, Inc., Summit, N. J.
serving to prevent or treat various common infectious diseases, including salmonellosis in both turkeys (Grumbles et al., 1954), and chickens (Lucas, 1955). The prevalence of carriers of Salmonella gallinarum among hens treated with furazolidone is low (Smith, 1955) and the drug shows similar effect in S. pullorum infec-