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Body Weights of Gold and Silver Segregates in Chicken Broilers1
RESEARCH NOTES
tein in practical-type chick rations. Tryptophan was found by growth assay not to be the first limiting essential amino acid in the by-product protein. ACKNOWLEDGMENTS
The study was supported in part by the Virginia Oak Tannery, Luray, Virginia. The amino acid analyses were conducted by the
1763
Vitamin Technology Laboratory, Chicago, Illinois. REFERENCES Association of Official Agricultural Chemists, 1955. Methods of Analysis. 8th Ed., Washington, D.C. Duncan, D. B., 1955. Multiple range and multiple F tests. Biometrics, 11: 1-A2. Wisman, E. L., 1960. Chick growth response to fish by-products and arsanilic acid. Poultry Sci. 39: 1140-1148.
L. GRIESBACH Research Station, Research Branch, Canada Department of Agriculture, Fredericton, New Brunswick (Received for publication July 21, 1961)
It is known that certain genes affecting color of plumage in chickens are associated with a depression of body growth rate. Jerome et al. (1956) demonstrated that dominant white depressed growth and feed efficiency up to 10 weeks of age in a strain of Barred Rocks. Jaap and Grimes (1956) presented evidence that three mutant genes, the dominant white gene I (inhibition of black), E (extension of black) and B (rhythmic failure of pigment in the feather) interact to produce a suppression of body growth rate in the chicken. Body weight was suppressed through the interaction of I and E by .03 to .04 pounds in 2 to 2^2 pound chickens at eight weeks of age and was further reduced by B to .06 to .07 pounds. Evidence was also presented by Jaap and Grimes (1956) that S (silver) which suppresses red plumage pigmentation, or K which delays chick feather growth and is closely linked with S on the sex chromosome, may suppress body growth rate. When I was 1
Contribution No. 73, Research Station, Canada Department of Agriculture, Fredericton, New Brunswick.
absent, S or K reduced body weight in both males and females by .05 pounds at eight weeks of age. When I was present, growth rate was suppressed by S or K in the females but not in the males. Since the slow feathering gene K was closely linked with S in these matings and because of the lack of any difference between the growth rates of Ss and ss males in the presence of I, these authors suggest that further information is needed in order to be certain of growth suppression due to S or K. Additional information concerning the effect of S on rate of body growth was obtained at the Research Station, Fredericton, N. B. In order to eliminate any effects of K, only breeding stock homozygous for the sex-linked rapid feathering gene k was used TABLE 1.—Nine week body weights of gold and silver sibs
Chicks
Av. Body Weight (Grams)
202 199 204 204
1,622 1,595 1,278 1,258
Advantage in weight of ss or s-over Ss or S(grams) 27 20
Downloaded from http://ps.oxfordjournals.org/ at UPVA on April 30, 2015
BODY WEIGHTS OF GOLD AND SILVER SEGREGATES IN CHICKEN BROILERS1
1764
RESEARCH NOTES
in the test. Eight rapid feathering Columbian Rock X New Hampshire males were backcrossed on New Hampshire females, giving rise to approximately equal numbers of silver (Ss and S-) and gold (ss and s-) progeny. All the chicks were obtained from one hatch and all intermingled in the brooder house. They were weighed individually at nine weeks of age. The results shown in Table 1 indicate a small but definite advantage in body weight of the gold chicks over their silver sibs, the average, both sexes combined, being 23.5
grams (.05 lb.). The differences of 27 grams for males and 20 grams for females are statistically significant (P = .05). Further work is being planned to study the effects of K in association with gold and silver. REFERENCES Jerome, F. N., S. J. Slinger, C. M. Huntsman and W. F. Pepper, 1956. The relationship between dominant white and growth of chicks. Poultry Sci. 35: 488-489. Jaap, R. G., and J. F. Grimes, 1956. Growth rate and plumage color in chickens. Poultry Sci. 35: 1264-1269.
K. N. MAY, 2 P. D. RODGERS3 AND H. D. WHITE 3 University of Georgia, Athens (Received for publication July 19, 1961)
Considerable difficulty was encountered in replication of time required to cool during a study to establish accurate cooling curves of broiler carcasses in 32°F. water. Similar problems were reported by Nicholas and Havanesian (1960) who were working with freezing curves. They suggested a technic whereby the carcass was split, thermocouples were placed in exact positions, the flesh was sewn back together and the carcass was placed in a freezer bag prior to obtaining temperature changes. Since poultry carcasses are normally chilled without use of bags this method is not applicable. The purpose of this report is to outline the technic of thermocouple placement which j o u r n a l Paper No. 178, College Experiment Station, University of Georgia, Agricultural Experiment Stations, Athens, Georgia. 2 Poultry Department, University of Georgia, and Field Crops and Animal Products Branch, Market Quality Research Division, AMS, USDA. 3 Agricultural Engineering Department, University of Georgia.
was found most suitable in this laboratory and to compare it with other methods in general use. METHODS AND MATERIALS Thermocouples were mounted on a wooden probe as shown in Figure 1. Affixing the thermocouples to the probe allowed easier insertion and gave greater assurance of having a thermocouple in the exact center of the muscle(s) being tested. During various tests thermocouple probes were inserted in the following anatomical locations: 1. In the thigh, beginning at the lateral, posterior surface of the muscles at the distal end of the femur and extending to a position adjacent, parallel to, and one-half the length of the femur.
FIG. 1. Wooden thermocouple probe, showing thermocouple placement on the probe.
Downloaded from http://ps.oxfordjournals.org/ at UPVA on April 30, 2015
THERMOCOUPLE PLACEMENT IN CHICKEN CARCASSES1
tein in practical-type chick rations. Tryptophan was found by growth assay not to be the first limiting essential amino acid in the by-product protein. ACKNOWLEDGMENTS
The study was supported in part by the Virginia Oak Tannery, Luray, Virginia. The amino acid analyses were conducted by the
1763
Vitamin Technology Laboratory, Chicago, Illinois. REFERENCES Association of Official Agricultural Chemists, 1955. Methods of Analysis. 8th Ed., Washington, D.C. Duncan, D. B., 1955. Multiple range and multiple F tests. Biometrics, 11: 1-A2. Wisman, E. L., 1960. Chick growth response to fish by-products and arsanilic acid. Poultry Sci. 39: 1140-1148.
L. GRIESBACH Research Station, Research Branch, Canada Department of Agriculture, Fredericton, New Brunswick (Received for publication July 21, 1961)
It is known that certain genes affecting color of plumage in chickens are associated with a depression of body growth rate. Jerome et al. (1956) demonstrated that dominant white depressed growth and feed efficiency up to 10 weeks of age in a strain of Barred Rocks. Jaap and Grimes (1956) presented evidence that three mutant genes, the dominant white gene I (inhibition of black), E (extension of black) and B (rhythmic failure of pigment in the feather) interact to produce a suppression of body growth rate in the chicken. Body weight was suppressed through the interaction of I and E by .03 to .04 pounds in 2 to 2^2 pound chickens at eight weeks of age and was further reduced by B to .06 to .07 pounds. Evidence was also presented by Jaap and Grimes (1956) that S (silver) which suppresses red plumage pigmentation, or K which delays chick feather growth and is closely linked with S on the sex chromosome, may suppress body growth rate. When I was 1
Contribution No. 73, Research Station, Canada Department of Agriculture, Fredericton, New Brunswick.
absent, S or K reduced body weight in both males and females by .05 pounds at eight weeks of age. When I was present, growth rate was suppressed by S or K in the females but not in the males. Since the slow feathering gene K was closely linked with S in these matings and because of the lack of any difference between the growth rates of Ss and ss males in the presence of I, these authors suggest that further information is needed in order to be certain of growth suppression due to S or K. Additional information concerning the effect of S on rate of body growth was obtained at the Research Station, Fredericton, N. B. In order to eliminate any effects of K, only breeding stock homozygous for the sex-linked rapid feathering gene k was used TABLE 1.—Nine week body weights of gold and silver sibs
Chicks
Av. Body Weight (Grams)
202 199 204 204
1,622 1,595 1,278 1,258
Advantage in weight of ss or s-over Ss or S(grams) 27 20
Downloaded from http://ps.oxfordjournals.org/ at UPVA on April 30, 2015
BODY WEIGHTS OF GOLD AND SILVER SEGREGATES IN CHICKEN BROILERS1
1764
RESEARCH NOTES
in the test. Eight rapid feathering Columbian Rock X New Hampshire males were backcrossed on New Hampshire females, giving rise to approximately equal numbers of silver (Ss and S-) and gold (ss and s-) progeny. All the chicks were obtained from one hatch and all intermingled in the brooder house. They were weighed individually at nine weeks of age. The results shown in Table 1 indicate a small but definite advantage in body weight of the gold chicks over their silver sibs, the average, both sexes combined, being 23.5
grams (.05 lb.). The differences of 27 grams for males and 20 grams for females are statistically significant (P = .05). Further work is being planned to study the effects of K in association with gold and silver. REFERENCES Jerome, F. N., S. J. Slinger, C. M. Huntsman and W. F. Pepper, 1956. The relationship between dominant white and growth of chicks. Poultry Sci. 35: 488-489. Jaap, R. G., and J. F. Grimes, 1956. Growth rate and plumage color in chickens. Poultry Sci. 35: 1264-1269.
K. N. MAY, 2 P. D. RODGERS3 AND H. D. WHITE 3 University of Georgia, Athens (Received for publication July 19, 1961)
Considerable difficulty was encountered in replication of time required to cool during a study to establish accurate cooling curves of broiler carcasses in 32°F. water. Similar problems were reported by Nicholas and Havanesian (1960) who were working with freezing curves. They suggested a technic whereby the carcass was split, thermocouples were placed in exact positions, the flesh was sewn back together and the carcass was placed in a freezer bag prior to obtaining temperature changes. Since poultry carcasses are normally chilled without use of bags this method is not applicable. The purpose of this report is to outline the technic of thermocouple placement which j o u r n a l Paper No. 178, College Experiment Station, University of Georgia, Agricultural Experiment Stations, Athens, Georgia. 2 Poultry Department, University of Georgia, and Field Crops and Animal Products Branch, Market Quality Research Division, AMS, USDA. 3 Agricultural Engineering Department, University of Georgia.
was found most suitable in this laboratory and to compare it with other methods in general use. METHODS AND MATERIALS Thermocouples were mounted on a wooden probe as shown in Figure 1. Affixing the thermocouples to the probe allowed easier insertion and gave greater assurance of having a thermocouple in the exact center of the muscle(s) being tested. During various tests thermocouple probes were inserted in the following anatomical locations: 1. In the thigh, beginning at the lateral, posterior surface of the muscles at the distal end of the femur and extending to a position adjacent, parallel to, and one-half the length of the femur.
FIG. 1. Wooden thermocouple probe, showing thermocouple placement on the probe.
Downloaded from http://ps.oxfordjournals.org/ at UPVA on April 30, 2015
THERMOCOUPLE PLACEMENT IN CHICKEN CARCASSES1