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The Influence of Humane Slaughter on the Tenderness of Turkey Meat1
The Influence of Humane Slaughter on the Tenderness of Turkey Meat 1 T. L. GOODWIN, W. C. MICKELBERRY AND W. J. STADELMAN Purdue University, Lafayette, Indiana (Received for publication August 26, 1960)
T
EXPERIMENTAL PROCEDURE
Thirty-six twenty-week-old male and female Broad Breasted Bronze turkeys were used in this experiment. Six treatment groups were set up with six male and six female turkeys dispatched from each group. Three males and three females from each 1
Journal paper No. 1653 of the Purdue Agricultural Experiment Station.
group were used in each of two aging times. The treatments preceding killing were: (1) carbon dioxide immobilization, (2) electrical stunning, (3) nembutal immobilization by oral administration, (4) reserpine tranquilization, (5) debraining by knife puncture of the anterior lobe of the brain, (6) and the control group of no special ante mortem treatment. The carbon dioxide chamber, constructed of wood, was 36" X 36" X 24". The entire front was a glass window through which the birds were observed. Carbon dioxide gas was administered into the chamber from a carbon dioxide container connected through a carbon dioxide gage maintained at seven pounds of pressure per square inch during the immobilization period. The birds were placed into the chamber through a 12" X 24" lid at the top. The birds remained in the chamber until they became completely unconscious. Electrical shock was administered with a Cervin stunner set at control 7. The birds were shackled and shocked for ten seconds. At the end of the ten second shock, the birds were unconscious. Nembutal was administered at the level of one grain per pound of live weight. The powder was mixed with distilled water and injected into the crop one and one-half hours prior to slaughter. The injection was made by means of a syringe and a small rubber hose forced into the crop of the turkey. Debrained birds were dispatched by piercing the medula portion of the brain through the optic foramen of the right eye. The control birds were shackled and the
921
Downloaded from http://ps.oxfordjournals.org/ at University of Alberta on April 27, 2015
HE enactment of the Humane Slaughter Law of 1958 focused attention on procedures used in meat processing plants to dispatch animals. Five methods for slaughter of livestock have been approved as humane by the U.S.D.A. These methods are electrical stunning, carbon dioxide immobilization, mechanical bolt stunning, gunshot, and ritual slaughtering methods. To date the law does not include poultry. Drewniak et at. (1955) observed that a concentration of 73-77% carbon dioxide was best for quick immobilization of turkeys without killing them. Sex and variety had an effect on the time required for immobilization. Rose (1939) observed that 400 milliamperes did not kill poultry; however, 150 milliamperes for 10 seconds were sufficient to produce unconsciousness. Wise (1960) reported chickens receiving nembutal immobilization required a longer period of time to tenderize than did the controls. The purpose of this research was to ascertain any changes in the development of tenderness of turkey meat that might result from several humane slaughter procedures.
922
T. L. GOODWIN, W. C. MICKELBERRY AND W. J. STADELMAN TABLE 1.—Summarization of experimental results (Each value the average of 3 birds)
Treatment
Aging time in hours
Shear values Breast
Thigh
%H 2 0 uptake
% cooking loss
Sex
4 4 24 24
M F M F
30.12 43.40 16.70 15.67
52.29 68.49 27.15 31.95
2.87 3.13 5.26 6.08
31.43 31.27 31.41 29.72
Debrain Debrain Debrain Debrain
4 4 24 24
M F M F
16.24 24.84 24.68 20.87
22.25 42.61 26.99 23.93
4.97 3.31 9.49 5.23
32.75 32.06 32.01 33.34
4 4 24 24
M F M F
22.50 44.32 12.98 15.03
35.15 48.47 31.46 29.60
4.58 4.12 6.64 6.70
32.57 31.59 32.56 33.62
C0 2 CO, C0 2 C0 2
4 4 24 24
M F M F
20.62 33.82 15.95 14.56
32.36 38.41 28.16 30.39
6.09 6.09 7.74 8.26
34.04 29.80 35.29 33.63
Tranquilizer Tranquilizer Tranquilizer Tranquilizer
4 4 24 24
M F M F
17.33 25.45 20.35 18.58
26.61 52.67 28.20 25.70
5.29 4.04 6.78 5.70
30.89 28.36 31.37 33.23
Control Control Control Control
4 4 24 24
M F M F
18.38 24.13 24.44 15.85
30.21 37.21 23.91 21.81
5.00 4.13 5.42 6.27
30.75 35.74 31.72 29.25
Electric Electric Electric Electric
Knife Knife Knife Knife
throats were severed. All turkeys were killed by severing of the carotid arteries and jugular vein, allowing three minutes for bleeding. The birds were processed and eviscerated by standard procedures. After aging in ice water for 4 hours or 24 hours, the thighs and breast were removed from each bird, wrapped in single thickness aluminum foil, and cooked in an oven at 32S°F. to an internal temperature of 185°F. The cooked meat was cooled for 16 hours at 40°F. Following this the pectoralis major and the biceps femoris muscles were sampled using a core cutting device developed by Dodge and Stadelman (1960). Shear was measured using a Kramer shear press. Water uptake and cooking loss were determined for each method of slaughter.
RESULTS AND DISCUSSION
Results are summarized in Table 1. As shown in Table 2 there is a close relationship between the shear values of the breast and the thigh after 4 hours of aging but none after 24 hours of aging. These results indicate that for the first 4 hours the shear values for the breast and the thigh of a particular turkey are comparable. As aging time continues and all meat becomes more tender up to 24 hours of aging time there is no correlation between the shear of the TABLE 2.—Relationship between shear values o_ cooked thigh vs. breast for 4 and 24 hour aging period Treatment Thigh vs. breast 4 hrs Thigh vs. breast 24 hrs
Values DF P.01 .5989 .0183
34 34
.425 .425
P.05 .330 .330
Downloaded from http://ps.oxfordjournals.org/ at University of Alberta on April 27, 2015
Nembutal Nembutal Nembutal Nembutal
923
HUMANE SLAUGHTER AND TENDERNESS TABLE 3.—Relationship between percentage water uptake vs. percentage cooking loss for 4 and 24 hour aging period,. Treatment % H 2 0 uptake as. % cooking loss 4 hr. % H 2 0 uptake vs. % cooking loss 24 hr.
Values DF P.Ol
P.05
Source
DF
Total Treatment Humane Time HXT Sex SXT Birds within test
71 11 5 1 5 1 11 48
.0372
34
.425
.330
.0162
34
.425
.330
TABLE 4.—Analysis of variance: Ejfect of humane slaughter methods on the tenderness of the Pectoralis Major DF
Total Treatment Humane Time HXT Sex SXT Birds within test
71 11 5 1 5 1 11 48
*P.05 ** P.Ol.
3.70** 24.98** 1.91 7.48** 1.16
(Table 5). Table 6 gives a summary of the Newman-Keuls test of slaughter treatment means. In this, nembutal treated birds were highly significantly different from the controls and debrained turkeys and significantly different from carbon dioxide and reserpine treated birds. No difference was found between the electric knife stunned and the nembutal immobilized turkeys. The difference between breast and thigh muscles might be due to different rates of aging of white and dark meat. SUMMARY In this study 72 turkeys were subjected to 6 methods of slaughter and 2 aging times to determine their effect upon tenderness using the Kramer shear press. Tenderness improved on both the pectoralis major and biceps femoris muscles as aging time increased. Method of slaugh-
for the Biceps Femoris R( ?E.K serpine Nembutal 16.69** 16.03** 12.64* 11.68* 8.8 Electric 2.88 Knife 7.89 7.23 3.84 Reserpine 5.01 4.35 0.96 C0 2 4.05 3.39 Debrain 0.66
ment
1.01 21.90** 4.63** 6.29* 1.93
596.1799 457.3352 3,089.4689 236.3668 925.4410 143.6706 123.6723
** P.Ol.
Mean square Observed
289.298 64.5122 1,390.8417 294.3679 399.8875 122.6150 63.5058
T,. Observed Mean square np»
"
Control Debrain
* P.05. ** P.Ol.
C0 2
Downloaded from http://ps.oxfordjournals.org/ at University of Alberta on April 27, 2015
thigh as compared to the breast muscle. No correlation was found between percentage of water uptake and percentage of cooking loss (Table 3). There was no difference in percentage uptake between treatments for the respective aging time, but there was a difference in water uptake between the 4 and 24 hour aging period. As can be seen from Table 1 the percentage of water uptake had little or no effect upon the percentage of cooking loss. The variations of percentage cooking loss among treatments was very slight. In the cooked pectoralis major, variance of shear values due to time was highly significant, and the variance due to sex was significant (Table 4). The first order interaction of humane X time was also highly significant. However, variance of shear values of breast muscles attributable to slaughter method was not significant. In the cooked biceps femoris, variance due to time, slaughter treatment, and sex were all found to be highly significant
Source
TABLE 5.—Analysis of variance: Effect of humane slaughter methods on the tenderness of the Biceps Femoris
924
T. L. GOODWIN, W. C. MICKELBERRY AND W. J. STADELMAN
tween percentage of water uptake and percentage of cooking loss. REFERENCES Dodge, J. W., and W. J. Stadelman, 1960. Studies on tenderness evaluation. Poultry Sci. 39: 184187. Drewniak, E. E., E. R. Baush and L. L. Adams, 1955. Carbon dioxide immobilization of turkeys before slaughter. United States Department of Agriculture, 958: 1. Rose, D. C , 1939. Canadian studies on electrical methods of killing poultry. U. S. Egg Poultry Mag. 45: 270. Snedecor, G. W., 1957. Statistical Methods, Fifth Edition, Iowa State College Press, Ames, Iowa. Wise, R. G., 1960. Some factors affecting tenderness of poultry meat. A thesis, Ph.D., Purdue University, Lafayette, Indiana.
The Effect of Different Methods of Chlortetracycline Application on the Shelf-Life of Chicken Fryers 1 M. W. EKLUND, 2 J. V. SPENCER, E. A. SAUTER3 AND M. H. GEORGE Department of Poultry Science, Washington State University, Pullman (Received for publication August 30, 1960)
T
HE effectiveness of antibiotics as food preservative has been the subject of many investigations. Tarr et al. (1952) investigated fifteen antibiotics as preservatives of fish. Of these antibiotics, chlortetracycline, oxytetracycline and chloramphenicol, in the order named, were the most effective in prolonging the freshness of fish. Kohler et al. (1955) reported an increase in the shelf-life of eviscerated and cut-up chicken of 7 to 14 days over untreated conscientific Paper No. 2005, Washington Agricultural Experiment Stations, Pullman. Project No. 1076. 2 Present Address: Department of Poultry Science, Purdue University, Lafayette, Indiana. 3 Present Address: Department of Poultry Husbandry, University of Idaho, Moscow.
trols when they were dipped in 3 to 30 ppm. chlortetracycline solutions. Ziegler and Stadelman (1955) showed similar results when concentrations of 10, 20 or 40 ppm. chlortetracycline were used in the dipping solution. Shannon and Stadelman (1957) found that 10 ppm. chlortetracycline in water as a dip for pan-ready poultry significantly extended the shelf-life over untreated controls at storage temperatures of 32° and 68°F. Recently, numerous comparisons have been made between the tetracycline antibiotics. Ayres et al. (1956) and Wells et al. (1957) reported that chlortetracycline was superior to either oxytetracycline or tetracycline. Vaughn et al. (1957) observed that tetracycline was superior to chlor-
Downloaded from http://ps.oxfordjournals.org/ at University of Alberta on April 27, 2015
ter had no significant effect on shear values of the breast muscles. Humane slaughter treatments resolved in an increased shear value for the thigh muscles. When subjected to a more critical test, a difference was noted between nembutal immobilized birds and control, debrained, reserpine and carbon dioxide treated birds. No difference was noted between nembutal immobilized and electric knife stunned birds. Positive correlation was found between the shear values of the breast and thigh muscles after four hours of aging. No correlation was obtained between shear values of these muscles after 24 hours of aging. There was no significant correlation be-
T
EXPERIMENTAL PROCEDURE
Thirty-six twenty-week-old male and female Broad Breasted Bronze turkeys were used in this experiment. Six treatment groups were set up with six male and six female turkeys dispatched from each group. Three males and three females from each 1
Journal paper No. 1653 of the Purdue Agricultural Experiment Station.
group were used in each of two aging times. The treatments preceding killing were: (1) carbon dioxide immobilization, (2) electrical stunning, (3) nembutal immobilization by oral administration, (4) reserpine tranquilization, (5) debraining by knife puncture of the anterior lobe of the brain, (6) and the control group of no special ante mortem treatment. The carbon dioxide chamber, constructed of wood, was 36" X 36" X 24". The entire front was a glass window through which the birds were observed. Carbon dioxide gas was administered into the chamber from a carbon dioxide container connected through a carbon dioxide gage maintained at seven pounds of pressure per square inch during the immobilization period. The birds were placed into the chamber through a 12" X 24" lid at the top. The birds remained in the chamber until they became completely unconscious. Electrical shock was administered with a Cervin stunner set at control 7. The birds were shackled and shocked for ten seconds. At the end of the ten second shock, the birds were unconscious. Nembutal was administered at the level of one grain per pound of live weight. The powder was mixed with distilled water and injected into the crop one and one-half hours prior to slaughter. The injection was made by means of a syringe and a small rubber hose forced into the crop of the turkey. Debrained birds were dispatched by piercing the medula portion of the brain through the optic foramen of the right eye. The control birds were shackled and the
921
Downloaded from http://ps.oxfordjournals.org/ at University of Alberta on April 27, 2015
HE enactment of the Humane Slaughter Law of 1958 focused attention on procedures used in meat processing plants to dispatch animals. Five methods for slaughter of livestock have been approved as humane by the U.S.D.A. These methods are electrical stunning, carbon dioxide immobilization, mechanical bolt stunning, gunshot, and ritual slaughtering methods. To date the law does not include poultry. Drewniak et at. (1955) observed that a concentration of 73-77% carbon dioxide was best for quick immobilization of turkeys without killing them. Sex and variety had an effect on the time required for immobilization. Rose (1939) observed that 400 milliamperes did not kill poultry; however, 150 milliamperes for 10 seconds were sufficient to produce unconsciousness. Wise (1960) reported chickens receiving nembutal immobilization required a longer period of time to tenderize than did the controls. The purpose of this research was to ascertain any changes in the development of tenderness of turkey meat that might result from several humane slaughter procedures.
922
T. L. GOODWIN, W. C. MICKELBERRY AND W. J. STADELMAN TABLE 1.—Summarization of experimental results (Each value the average of 3 birds)
Treatment
Aging time in hours
Shear values Breast
Thigh
%H 2 0 uptake
% cooking loss
Sex
4 4 24 24
M F M F
30.12 43.40 16.70 15.67
52.29 68.49 27.15 31.95
2.87 3.13 5.26 6.08
31.43 31.27 31.41 29.72
Debrain Debrain Debrain Debrain
4 4 24 24
M F M F
16.24 24.84 24.68 20.87
22.25 42.61 26.99 23.93
4.97 3.31 9.49 5.23
32.75 32.06 32.01 33.34
4 4 24 24
M F M F
22.50 44.32 12.98 15.03
35.15 48.47 31.46 29.60
4.58 4.12 6.64 6.70
32.57 31.59 32.56 33.62
C0 2 CO, C0 2 C0 2
4 4 24 24
M F M F
20.62 33.82 15.95 14.56
32.36 38.41 28.16 30.39
6.09 6.09 7.74 8.26
34.04 29.80 35.29 33.63
Tranquilizer Tranquilizer Tranquilizer Tranquilizer
4 4 24 24
M F M F
17.33 25.45 20.35 18.58
26.61 52.67 28.20 25.70
5.29 4.04 6.78 5.70
30.89 28.36 31.37 33.23
Control Control Control Control
4 4 24 24
M F M F
18.38 24.13 24.44 15.85
30.21 37.21 23.91 21.81
5.00 4.13 5.42 6.27
30.75 35.74 31.72 29.25
Electric Electric Electric Electric
Knife Knife Knife Knife
throats were severed. All turkeys were killed by severing of the carotid arteries and jugular vein, allowing three minutes for bleeding. The birds were processed and eviscerated by standard procedures. After aging in ice water for 4 hours or 24 hours, the thighs and breast were removed from each bird, wrapped in single thickness aluminum foil, and cooked in an oven at 32S°F. to an internal temperature of 185°F. The cooked meat was cooled for 16 hours at 40°F. Following this the pectoralis major and the biceps femoris muscles were sampled using a core cutting device developed by Dodge and Stadelman (1960). Shear was measured using a Kramer shear press. Water uptake and cooking loss were determined for each method of slaughter.
RESULTS AND DISCUSSION
Results are summarized in Table 1. As shown in Table 2 there is a close relationship between the shear values of the breast and the thigh after 4 hours of aging but none after 24 hours of aging. These results indicate that for the first 4 hours the shear values for the breast and the thigh of a particular turkey are comparable. As aging time continues and all meat becomes more tender up to 24 hours of aging time there is no correlation between the shear of the TABLE 2.—Relationship between shear values o_ cooked thigh vs. breast for 4 and 24 hour aging period Treatment Thigh vs. breast 4 hrs Thigh vs. breast 24 hrs
Values DF P.01 .5989 .0183
34 34
.425 .425
P.05 .330 .330
Downloaded from http://ps.oxfordjournals.org/ at University of Alberta on April 27, 2015
Nembutal Nembutal Nembutal Nembutal
923
HUMANE SLAUGHTER AND TENDERNESS TABLE 3.—Relationship between percentage water uptake vs. percentage cooking loss for 4 and 24 hour aging period,. Treatment % H 2 0 uptake as. % cooking loss 4 hr. % H 2 0 uptake vs. % cooking loss 24 hr.
Values DF P.Ol
P.05
Source
DF
Total Treatment Humane Time HXT Sex SXT Birds within test
71 11 5 1 5 1 11 48
.0372
34
.425
.330
.0162
34
.425
.330
TABLE 4.—Analysis of variance: Ejfect of humane slaughter methods on the tenderness of the Pectoralis Major DF
Total Treatment Humane Time HXT Sex SXT Birds within test
71 11 5 1 5 1 11 48
*P.05 ** P.Ol.
3.70** 24.98** 1.91 7.48** 1.16
(Table 5). Table 6 gives a summary of the Newman-Keuls test of slaughter treatment means. In this, nembutal treated birds were highly significantly different from the controls and debrained turkeys and significantly different from carbon dioxide and reserpine treated birds. No difference was found between the electric knife stunned and the nembutal immobilized turkeys. The difference between breast and thigh muscles might be due to different rates of aging of white and dark meat. SUMMARY In this study 72 turkeys were subjected to 6 methods of slaughter and 2 aging times to determine their effect upon tenderness using the Kramer shear press. Tenderness improved on both the pectoralis major and biceps femoris muscles as aging time increased. Method of slaugh-
for the Biceps Femoris R( ?E.K serpine Nembutal 16.69** 16.03** 12.64* 11.68* 8.8 Electric 2.88 Knife 7.89 7.23 3.84 Reserpine 5.01 4.35 0.96 C0 2 4.05 3.39 Debrain 0.66
ment
1.01 21.90** 4.63** 6.29* 1.93
596.1799 457.3352 3,089.4689 236.3668 925.4410 143.6706 123.6723
** P.Ol.
Mean square Observed
289.298 64.5122 1,390.8417 294.3679 399.8875 122.6150 63.5058
T,. Observed Mean square np»
"
Control Debrain
* P.05. ** P.Ol.
C0 2
Downloaded from http://ps.oxfordjournals.org/ at University of Alberta on April 27, 2015
thigh as compared to the breast muscle. No correlation was found between percentage of water uptake and percentage of cooking loss (Table 3). There was no difference in percentage uptake between treatments for the respective aging time, but there was a difference in water uptake between the 4 and 24 hour aging period. As can be seen from Table 1 the percentage of water uptake had little or no effect upon the percentage of cooking loss. The variations of percentage cooking loss among treatments was very slight. In the cooked pectoralis major, variance of shear values due to time was highly significant, and the variance due to sex was significant (Table 4). The first order interaction of humane X time was also highly significant. However, variance of shear values of breast muscles attributable to slaughter method was not significant. In the cooked biceps femoris, variance due to time, slaughter treatment, and sex were all found to be highly significant
Source
TABLE 5.—Analysis of variance: Effect of humane slaughter methods on the tenderness of the Biceps Femoris
924
T. L. GOODWIN, W. C. MICKELBERRY AND W. J. STADELMAN
tween percentage of water uptake and percentage of cooking loss. REFERENCES Dodge, J. W., and W. J. Stadelman, 1960. Studies on tenderness evaluation. Poultry Sci. 39: 184187. Drewniak, E. E., E. R. Baush and L. L. Adams, 1955. Carbon dioxide immobilization of turkeys before slaughter. United States Department of Agriculture, 958: 1. Rose, D. C , 1939. Canadian studies on electrical methods of killing poultry. U. S. Egg Poultry Mag. 45: 270. Snedecor, G. W., 1957. Statistical Methods, Fifth Edition, Iowa State College Press, Ames, Iowa. Wise, R. G., 1960. Some factors affecting tenderness of poultry meat. A thesis, Ph.D., Purdue University, Lafayette, Indiana.
The Effect of Different Methods of Chlortetracycline Application on the Shelf-Life of Chicken Fryers 1 M. W. EKLUND, 2 J. V. SPENCER, E. A. SAUTER3 AND M. H. GEORGE Department of Poultry Science, Washington State University, Pullman (Received for publication August 30, 1960)
T
HE effectiveness of antibiotics as food preservative has been the subject of many investigations. Tarr et al. (1952) investigated fifteen antibiotics as preservatives of fish. Of these antibiotics, chlortetracycline, oxytetracycline and chloramphenicol, in the order named, were the most effective in prolonging the freshness of fish. Kohler et al. (1955) reported an increase in the shelf-life of eviscerated and cut-up chicken of 7 to 14 days over untreated conscientific Paper No. 2005, Washington Agricultural Experiment Stations, Pullman. Project No. 1076. 2 Present Address: Department of Poultry Science, Purdue University, Lafayette, Indiana. 3 Present Address: Department of Poultry Husbandry, University of Idaho, Moscow.
trols when they were dipped in 3 to 30 ppm. chlortetracycline solutions. Ziegler and Stadelman (1955) showed similar results when concentrations of 10, 20 or 40 ppm. chlortetracycline were used in the dipping solution. Shannon and Stadelman (1957) found that 10 ppm. chlortetracycline in water as a dip for pan-ready poultry significantly extended the shelf-life over untreated controls at storage temperatures of 32° and 68°F. Recently, numerous comparisons have been made between the tetracycline antibiotics. Ayres et al. (1956) and Wells et al. (1957) reported that chlortetracycline was superior to either oxytetracycline or tetracycline. Vaughn et al. (1957) observed that tetracycline was superior to chlor-
Downloaded from http://ps.oxfordjournals.org/ at University of Alberta on April 27, 2015
ter had no significant effect on shear values of the breast muscles. Humane slaughter treatments resolved in an increased shear value for the thigh muscles. When subjected to a more critical test, a difference was noted between nembutal immobilized birds and control, debrained, reserpine and carbon dioxide treated birds. No difference was noted between nembutal immobilized and electric knife stunned birds. Positive correlation was found between the shear values of the breast and thigh muscles after four hours of aging. No correlation was obtained between shear values of these muscles after 24 hours of aging. There was no significant correlation be-