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Correlated Responses in Body Weight and Egg Production Traits in Chickens Selected for Social Dominance1,2
1033
RESEARCH NOTES TABLE 1.—Average values of physiological criteria of BSW hens, 11-12 months of age
Gp.
Blood ]pressure
Pulse pres., Systol., Diast., mm. Hg mm. Hg mm. Hg 182 187 168 156 177 185 185
Panto. Niacin CTC Strep. S0 4 Panto.+Niacin Zn-Bac. None
139 142 130 114 131 137 136
43 45 38 42 46 48 49
Heart rate /Min.
Resp. rate /Min.
Pkd. cell volume
226 233 240 213 239 223 215
24.3 20.2 22.3 21.1 20.2 24.2 24.8
37.0 37.4 35.5 37.0 35.1 36.8 37.0
%
Wt. loss (20 wk.), kg. 0.53 0.82 0.63 0.75 0.84 0.63 0.84
1 Niacin, 176 mg./kg.; CTC (chloretetracycline), Strep. SOj (streptomycin sulfate), Panto. (D-calcium pantothenate), Zn-Bac. (zinc-bacitracin), all added at level of 220 mg./kg.
various conditions, usually for brief periods. It may be seen from the data (Table 1) that the high levels of the dietary supplements fed throughout a twenty-week period produced no statistically significant effect on blood pressure, heart rate, respiration rate, packed cell volume or body weight. REFERENCES Deacon, L. E., and E. B. Patterson, 1966. The effect of oxytetracycline on the performance of turkey breeder hens. Poultry Sci. 45: 1053-1058. Greene, D. E., R. C. Eaton, W. C. Schofield and H. L. Wilcke, 1963. Observations on the occurrence and prevention of a rapid decline in fer-
tility of turkey breeders. Poultry Sci. 42: 1273. Ringer, R. K., and K. Rood, 1959. Hemodynamic changes associated with aging in the Borad Breasted Bronze turkey. Poultry Sci. 38 : 395-397. Snedecor, G. W., 1956. Statistical Methods. 5th Ed., Iowa State College Press, Ames,Iowa Speckman, E. W., and R. K. Ringer, 1962. The influence of reserpine on plasma cholesterol, hemodynamics and arteriosclerotic lesions in the Broad Breasted Bronze turkey. Poultry Sci. 4 1 : 40-45. Weiss, H. D., and M. Sheahan, 1958. The influence of maturity and sex on the blood pressure of the turkey. Am. J. Vet. Res. 19: 209-211. White-Stevens, R., H. G. Zeibel and F. Smith, 1955. Effect of high level antibiotic feeding on production efficiency of laying and breeding chickens and turkeys. Poultry Sci. 34: 1228.
CORRELATED RESPONSES IN BODY WEIGHT AND EGG PRODUCTION TRAITS IN CHICKENS SELECTED FOR SOCIAL DOMINANCE1-2 J. V. CRAIG Kansas State University, Manhattan, Kansas (Received for publication March 11, 1968)
Selection was effective in establishing distinct high and low social aggressiveness 1 Contribution No. 701, Department of Dairy and Poultry Science Kansas Agricultural Experiment Station, Manhattan, Kansas. 2 Supported in part by Grants G7069, G19853 and GB1720 from the National Science Foundation.
strains of White Leghorns (WL) studied by Guhl et al. (1960) and of WL and Rhode Island Reds (RIR) as reported by Craig et al. (1965). The highly aggressive strain of Guhl et al. (1960) was heavier (adult) than controls. Preliminary comparisons of body and egg weights, age at first egg and part-year rate of egg production
Downloaded from http://ps.oxfordjournals.org/ at Purdue University Libraries ADMN on June 1, 2015
1 2 3 4 5 6 7
Supplements to basal diet1
1034
RESEARCH NOTES WL
R|R 5-MO. BODY WT., KG.
GENERATIONS OF SELECTION
FIG. 1. Selected strains' deviations from unselected controls for S-month body weight, age at first egg and rate of egg production by generations. Strains selected for high social dominance indicated by solid lines; for low social dominance, by broken lines.
are presented here for strains selected by Craig etal. (1965). The heterogeneous Cornell Control WL and NC-47 RIR randombred populations were sampled as foundation stocks for the selection experiment in 19S9. Additional samples were supplied annually from the NC-47 Laboratory for use as unselected controls. Chicks of all strains were hatched concurrently each year and strains within breeds were intermingled during rearing. Pullets were similarly intermingled in laying houses at Kansas State University (KSU). Birds were housed at moderate density, i.e. about 0.2 sq. m. of floor space each. Thirty-three to 85 pullets were tested per strain-generation subclass and unweighted subclass means were used for analyses of variance. Data were available from 5 and 4 generations of selection at
Downloaded from http://ps.oxfordjournals.org/ at Purdue University Libraries ADMN on June 1, 2015
RATE OF EGG PRODUCTION,*/»
KSU for body weight and other traits, respectively. Artificial selection was relaxed following the fifth generation but the strains were maintained as distinct populations. Number of breeders varied from generation to generation, but was comparable for all selected strains within generations. Inbreeding was consciously minimized, but was estimated to have a coefficient of about .15 in the final generation tested. Samples of the behavior strains were hatched at the NC-47 Laboratory in 1967, four generations after selection was relaxed. Pullets were reared with contemporary chicks of other strains, but were separated by strains in laying house pens. Pullets representing each strain were compared on the basis of 30 females per pen in each of 3 test houses, under low population density of about 0.3 sq. m. of floor space per bird. Pen means were used in analyses. Results presented in Figure 1 and Table 1 indicate that changes have occurred in body weight, age at first egg and part-year rate of egg production as indirect responses to selection for social dominance. Generation-to-generation changes are somewhat erratic (Figure 1) and are presumed due in part to large sampling errors associated with the relatively few birds tested per strain. Nevertheless, changes in the selected strains appear to be roughly symmetrical relative to the control. Body weight in the RIR is exceptional as the more dominant strain has become much smaller but the less dominant strain has not shown a corresponding and opposite gain. It is not apparent why the more aggressive strain should be larger in the WL and smaller in the RIR. Good agreement was obtained for body weight changes in the WL strains of this study and those of Guhl etal. (1960). Strains with higher levels of social dominance had earlier sexual maturity, as indi-
1035
RESEARCH NOTES TABLE 1.—Changes in body weight and egg production traits produced by selection for high and low social dominance in two breeds
Station Body wt., kg.2 Age at first egg, days
32-week egg weight, gm.
%3
Rhode Island Red Selected— Control -
.10**
HighLow -
.10** .10*
KSU NC-47
1-5 5r
0
KSU NC-47
1-4 5r
2.6 1.4
-3.7 -2.8
-3.4 2.1
-4.0 -8.4**
KSU NC-47
1-4 5r
1.4 0.5
-3.7 -5.7**
3.0 -3.1*
-2.5 1.3
NC-47
5r
-1.3
-1.0
11**
-0.8
.07** .07
j I**
1.4
1 Mean of generations 1 through 5 and 1 through 4 at KSU, fourth generation of relaxed selection at NC-47, see text. 2 5-month weight of both sexes at KSU, 32-week weight of females at NC-47. 3 First egg to 260 days and to 245 days of age at KSU, and NC-47, respectively. *P<.05. **P<.01.
cated by age at first egg, in both breeds and lower rate of egg production in the WL. Significant differences in 32-week egg weights were not detected in comparisons at the NC-47 Laboratory. Estimates of strain differences obtained at the two testing stations are relatively consistent. Differences in secondary traits produced by selection for social dominance appear to be fairly stable, as indicated by persistence after 4 generations of relaxed selection in tests at the NC-47 Laboratory. Close comparisons between results obtained at the two locations should not be made, however, as stage of selection and method of testing could be confounding. The correlated responses obtained when selection was directed towards high and low levels of social dominance imply that high social dominance is genetically associated with heavy weight in the WL and with low weight in the RIR, with earlier sexual maturity in both breeds and with lower rate of egg production in the WL. The foregoing conclusions should be regarded as tentative, however, as the results of Tindell and Craig (1959) and theoretical considerations of McBride (1962) suggest that strains differing in social behavior
may change in performance relative to each other depending on such environmental conditions as whether they are tested in intermingled vs. separate flocks or in high vs. low population density. Further investigations have been initiated to investigate those possibilities. ACKNOWLEDGMENTS
The cooperation of colleagues at the NC-47 Laboratory, Lafayette, Indiana, in supplying genetic stocks and in testing the selected strains in 1967-68 is appreciated. A. M. Guhl, C. R. Polley, L. L. Ortman and S. Wearden of Kansas State University were helpful in various ways during the study. REFERENCES Craig, J. V., L. L. Ortman and A. M. Guhl, 196S. Genetic selection for social dominance ability in chickens. Anim. Behav. 13: 114-131. Guhl, A. M., J. V. Craig and C. D. Mueller, 1960. Selective breeding for aggressiveness in chickens. Poultry Sci. 39: 970-980. McBride, G., 1962. Behaviour and a theory of poultry husbandry. X l l t h World's Poultry Congress Symposium, Sydney, 102-105. Tindell, D., and J. V. Craig, 19S9. Effects of social competition on laying house performance in the chicken. Poultry Sci. 38: 9S-10S.
Downloaded from http://ps.oxfordjournals.org/ at Purdue University Libraries ADMN on June 1, 2015
Part-year rate of egg production,
White Leghorn Genera1 tion(s) Selected—• HighControl Low
RESEARCH NOTES TABLE 1.—Average values of physiological criteria of BSW hens, 11-12 months of age
Gp.
Blood ]pressure
Pulse pres., Systol., Diast., mm. Hg mm. Hg mm. Hg 182 187 168 156 177 185 185
Panto. Niacin CTC Strep. S0 4 Panto.+Niacin Zn-Bac. None
139 142 130 114 131 137 136
43 45 38 42 46 48 49
Heart rate /Min.
Resp. rate /Min.
Pkd. cell volume
226 233 240 213 239 223 215
24.3 20.2 22.3 21.1 20.2 24.2 24.8
37.0 37.4 35.5 37.0 35.1 36.8 37.0
%
Wt. loss (20 wk.), kg. 0.53 0.82 0.63 0.75 0.84 0.63 0.84
1 Niacin, 176 mg./kg.; CTC (chloretetracycline), Strep. SOj (streptomycin sulfate), Panto. (D-calcium pantothenate), Zn-Bac. (zinc-bacitracin), all added at level of 220 mg./kg.
various conditions, usually for brief periods. It may be seen from the data (Table 1) that the high levels of the dietary supplements fed throughout a twenty-week period produced no statistically significant effect on blood pressure, heart rate, respiration rate, packed cell volume or body weight. REFERENCES Deacon, L. E., and E. B. Patterson, 1966. The effect of oxytetracycline on the performance of turkey breeder hens. Poultry Sci. 45: 1053-1058. Greene, D. E., R. C. Eaton, W. C. Schofield and H. L. Wilcke, 1963. Observations on the occurrence and prevention of a rapid decline in fer-
tility of turkey breeders. Poultry Sci. 42: 1273. Ringer, R. K., and K. Rood, 1959. Hemodynamic changes associated with aging in the Borad Breasted Bronze turkey. Poultry Sci. 38 : 395-397. Snedecor, G. W., 1956. Statistical Methods. 5th Ed., Iowa State College Press, Ames,Iowa Speckman, E. W., and R. K. Ringer, 1962. The influence of reserpine on plasma cholesterol, hemodynamics and arteriosclerotic lesions in the Broad Breasted Bronze turkey. Poultry Sci. 4 1 : 40-45. Weiss, H. D., and M. Sheahan, 1958. The influence of maturity and sex on the blood pressure of the turkey. Am. J. Vet. Res. 19: 209-211. White-Stevens, R., H. G. Zeibel and F. Smith, 1955. Effect of high level antibiotic feeding on production efficiency of laying and breeding chickens and turkeys. Poultry Sci. 34: 1228.
CORRELATED RESPONSES IN BODY WEIGHT AND EGG PRODUCTION TRAITS IN CHICKENS SELECTED FOR SOCIAL DOMINANCE1-2 J. V. CRAIG Kansas State University, Manhattan, Kansas (Received for publication March 11, 1968)
Selection was effective in establishing distinct high and low social aggressiveness 1 Contribution No. 701, Department of Dairy and Poultry Science Kansas Agricultural Experiment Station, Manhattan, Kansas. 2 Supported in part by Grants G7069, G19853 and GB1720 from the National Science Foundation.
strains of White Leghorns (WL) studied by Guhl et al. (1960) and of WL and Rhode Island Reds (RIR) as reported by Craig et al. (1965). The highly aggressive strain of Guhl et al. (1960) was heavier (adult) than controls. Preliminary comparisons of body and egg weights, age at first egg and part-year rate of egg production
Downloaded from http://ps.oxfordjournals.org/ at Purdue University Libraries ADMN on June 1, 2015
1 2 3 4 5 6 7
Supplements to basal diet1
1034
RESEARCH NOTES WL
R|R 5-MO. BODY WT., KG.
GENERATIONS OF SELECTION
FIG. 1. Selected strains' deviations from unselected controls for S-month body weight, age at first egg and rate of egg production by generations. Strains selected for high social dominance indicated by solid lines; for low social dominance, by broken lines.
are presented here for strains selected by Craig etal. (1965). The heterogeneous Cornell Control WL and NC-47 RIR randombred populations were sampled as foundation stocks for the selection experiment in 19S9. Additional samples were supplied annually from the NC-47 Laboratory for use as unselected controls. Chicks of all strains were hatched concurrently each year and strains within breeds were intermingled during rearing. Pullets were similarly intermingled in laying houses at Kansas State University (KSU). Birds were housed at moderate density, i.e. about 0.2 sq. m. of floor space each. Thirty-three to 85 pullets were tested per strain-generation subclass and unweighted subclass means were used for analyses of variance. Data were available from 5 and 4 generations of selection at
Downloaded from http://ps.oxfordjournals.org/ at Purdue University Libraries ADMN on June 1, 2015
RATE OF EGG PRODUCTION,*/»
KSU for body weight and other traits, respectively. Artificial selection was relaxed following the fifth generation but the strains were maintained as distinct populations. Number of breeders varied from generation to generation, but was comparable for all selected strains within generations. Inbreeding was consciously minimized, but was estimated to have a coefficient of about .15 in the final generation tested. Samples of the behavior strains were hatched at the NC-47 Laboratory in 1967, four generations after selection was relaxed. Pullets were reared with contemporary chicks of other strains, but were separated by strains in laying house pens. Pullets representing each strain were compared on the basis of 30 females per pen in each of 3 test houses, under low population density of about 0.3 sq. m. of floor space per bird. Pen means were used in analyses. Results presented in Figure 1 and Table 1 indicate that changes have occurred in body weight, age at first egg and part-year rate of egg production as indirect responses to selection for social dominance. Generation-to-generation changes are somewhat erratic (Figure 1) and are presumed due in part to large sampling errors associated with the relatively few birds tested per strain. Nevertheless, changes in the selected strains appear to be roughly symmetrical relative to the control. Body weight in the RIR is exceptional as the more dominant strain has become much smaller but the less dominant strain has not shown a corresponding and opposite gain. It is not apparent why the more aggressive strain should be larger in the WL and smaller in the RIR. Good agreement was obtained for body weight changes in the WL strains of this study and those of Guhl etal. (1960). Strains with higher levels of social dominance had earlier sexual maturity, as indi-
1035
RESEARCH NOTES TABLE 1.—Changes in body weight and egg production traits produced by selection for high and low social dominance in two breeds
Station Body wt., kg.2 Age at first egg, days
32-week egg weight, gm.
%3
Rhode Island Red Selected— Control -
.10**
HighLow -
.10** .10*
KSU NC-47
1-5 5r
0
KSU NC-47
1-4 5r
2.6 1.4
-3.7 -2.8
-3.4 2.1
-4.0 -8.4**
KSU NC-47
1-4 5r
1.4 0.5
-3.7 -5.7**
3.0 -3.1*
-2.5 1.3
NC-47
5r
-1.3
-1.0
11**
-0.8
.07** .07
j I**
1.4
1 Mean of generations 1 through 5 and 1 through 4 at KSU, fourth generation of relaxed selection at NC-47, see text. 2 5-month weight of both sexes at KSU, 32-week weight of females at NC-47. 3 First egg to 260 days and to 245 days of age at KSU, and NC-47, respectively. *P<.05. **P<.01.
cated by age at first egg, in both breeds and lower rate of egg production in the WL. Significant differences in 32-week egg weights were not detected in comparisons at the NC-47 Laboratory. Estimates of strain differences obtained at the two testing stations are relatively consistent. Differences in secondary traits produced by selection for social dominance appear to be fairly stable, as indicated by persistence after 4 generations of relaxed selection in tests at the NC-47 Laboratory. Close comparisons between results obtained at the two locations should not be made, however, as stage of selection and method of testing could be confounding. The correlated responses obtained when selection was directed towards high and low levels of social dominance imply that high social dominance is genetically associated with heavy weight in the WL and with low weight in the RIR, with earlier sexual maturity in both breeds and with lower rate of egg production in the WL. The foregoing conclusions should be regarded as tentative, however, as the results of Tindell and Craig (1959) and theoretical considerations of McBride (1962) suggest that strains differing in social behavior
may change in performance relative to each other depending on such environmental conditions as whether they are tested in intermingled vs. separate flocks or in high vs. low population density. Further investigations have been initiated to investigate those possibilities. ACKNOWLEDGMENTS
The cooperation of colleagues at the NC-47 Laboratory, Lafayette, Indiana, in supplying genetic stocks and in testing the selected strains in 1967-68 is appreciated. A. M. Guhl, C. R. Polley, L. L. Ortman and S. Wearden of Kansas State University were helpful in various ways during the study. REFERENCES Craig, J. V., L. L. Ortman and A. M. Guhl, 196S. Genetic selection for social dominance ability in chickens. Anim. Behav. 13: 114-131. Guhl, A. M., J. V. Craig and C. D. Mueller, 1960. Selective breeding for aggressiveness in chickens. Poultry Sci. 39: 970-980. McBride, G., 1962. Behaviour and a theory of poultry husbandry. X l l t h World's Poultry Congress Symposium, Sydney, 102-105. Tindell, D., and J. V. Craig, 19S9. Effects of social competition on laying house performance in the chicken. Poultry Sci. 38: 9S-10S.
Downloaded from http://ps.oxfordjournals.org/ at Purdue University Libraries ADMN on June 1, 2015
Part-year rate of egg production,
White Leghorn Genera1 tion(s) Selected—• HighControl Low