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Heritability of 25-Week Body Weight in Turkeys
Heritability of 25-Week Body Weight in Turkeys B. L. GOODMAN, CLAYTON C. BRUNSON* AND GEORGE F. GODFREY Oklahoma Agricultural Experiment Station, Stillwater (Received for publication July 8, 1953)
T
A survey of the literature reveals only a few estimates of the heritability of body weight in turkeys. An estimate of about 0.23 was calculated for 26-week old male turkeys by Kentucky researchers (1950). This estimate was obtained by the intrasire regression method after correction was made for age (date of hatch?). Abplanalp and Kosin (1952), utilizing data from Broad-breasted Bronze and Beltsville Small Whites, calculated estimates by intraclass correlation and offspringdam regression methods at 4, 8, 14 and 26 weeks of age. Their estimates vary considerably because of age, sex and environmental (climatic) factors, b u t their most reliable restimates were in the medium to high range (0.16 to 0.71). Other estimates may be calculated from d a t a reported in the literature (Asmundson, 1948), b u t such a procedure can be precarious because of the inherent vagaries of most sets of d a t a . SOURCE OF DATA The majority of the Broad-breasted Bronze and White Holland progeny * Present address: Department of Poultry Industry, Louisiana State University, Baton Rouge.
hatched from pedigree matings during the 1952 season at the Oklahoma Agricultural Experiment Station turkey farm were used in this study. T h e y were weighed and sexed a t 25 weeks of age. T h e number of sires, dams and progeny were as follows: Variety B. B. B. W. H.
No. sires No. dams No. progeny 14 164 1,042 9 104 1,025
T h e Broad-breasted Bronze progeny were produced in four hatches from February 20 to M a y 1. The White Holland progeny was produced in seven hatches from J a n u a r y 31 to April 24. These data were analyzed by the analysis of variance technique as outlined by Lerner (p. 121, 1950), except t h a t variation due to different hatch dates was removed. During the past five years little or no attention has been paid to body weight in these populations of turkeys. Major emphasis in selection has been on fertility and hatchability, although only those individuals having desirable body weight and body conformation were placed in the pedigree mating pens. However, because body weights have not been secured in previous years, it is difficult to determine the exact extent to which selection for body weight has been practiced. T h e mating system has been one of restricted random mating; t h a t is, full a n d half-sib matings have not been made. Insofar as is known, environmental conditions have been as uniform as possible for all turkeys during their growing period,
305
Downloaded from http://ps.oxfordjournals.org/ at Mount Allison University on June 9, 2015
H E concept of heritability is well established among geneticists and practical breeders, b u t the information on the heritability of production traits is still quite fragmentary, especially in turkeys. This paper reports heritability estimates of 25-week body weights in Broadbreasted Bronze and White Holland turkeys.
306
B. L. GOODMAN, C. C. BRUNSON AND G. F. GODFREY
but as will be discussed in a later section, there may be some doubt on this point. RESULTS AND DISCUSSION The average 25-week body weights in pounds and their standard deviations for the Broad-breasted Bronze and White Hollands by sexes were as follows: No. 596 429 622 420
Sex M F M F
Av. Wt. 19.70 12.70 19.20 12.47
S.D. 1.821 1.050 1.753 0.971
The heritability estimates calculated from the dams, sires, combined sires and dams and maternal effects are shown in Table 1. The estimates calculated from dams tend to be higher than those calculated from sires. As pointed out by Lerner (1950), discrepancies between these two estimates may be due to non-additive gene action, maternal effects, and sexlinked effects. In these data there is a strong possibility that the estimates calculated from dams also contain some environmental effects common to the damfamily progenies but not common to the populations as a whole. This environmental effect common to dam-family progenies apparently resulted from the procedure used in taking off the several hatches. Poults from one dam would be removed from the hatcher, banded, and placed in a poult box. The poults in this box would be placed in one brooder house. Although poults were taken off about three times during the hatch due to variaTABLE 1.—Heritability of 25-week body weight in turkeys Heritability estimates Variety Sex
B.B.B. B.B.B. W.H. W.H.
M F M F
W
45
2(D+S)
Q+D+S
Q+D+S
Q+D+S
0.02 0.71 0.71 0.71
0.34 0.29 0.29 0.24
0.18 0.50 O.SO 0.47
Maternal influence D-S
Q+D+S -0.08 0.10 0.10 0.12
Heritability estimates were calculated by the analysis of variance technique for 25-week body weights of the Broadbreasted Bronze and White Holland turkeys raised in 1952 on the Oklahoma Agricultural Experiment Station turkey farm. The most reliable estimate for these two populations appears to be about 0.30. Improvement in body weight of these populations can be most efficiently accomplished by a combination of individual and family selection. REFERENCES Abplanalp, H., and I. L. Kosin, 1952. Heritability of body measurements in turkeys. Poultry Sci. 31: 781-791. Asmundson, V. S., 1948. Inherited differences in weight and conformation of Bronze turkeys. Poultry Sci. 27: 695-708.
Downloaded from http://ps.oxfordjournals.org/ at Mount Allison University on June 9, 2015
Variety B.B.B. B.B.B. W.H. W.H.
tion in hatching time, it is possible that environmental factors common to some dam-family progenies to eight weeks of age biased these data. Thus, the estimates calculated from dams would be an overestimate, and also result in maternal influences that are due to Lerner's (1950) " C " effect, rather than to maternal influences. Therefore, the heritability estimates calculated from the sires are considered to be the best estimates of the heritability of 25-week body weight in these two populations of turkeys. If there is a positive maternal effect on body weight at 25 weeks of age, the physiological basis for it needs further elaboration. It seems unlikely, in view of our data with chickens (Godfrey et al., 1953), that the size of the egg from which the poult hatches could be much of an influence on the 25-week body weight of the turkey. Experiments utilizing diallel matings would show the presence and magnitude of such maternal influences much better than the design which has been used in this paper. SUMMARY
EFFECT OF ANTIBIOTICS ON GROWTH AND FECAL MICROFLORA
Godfrey, G. F., C. Williams and C. E. Marshall, 1953. The relative influence of egg size, age at sexual maturity and mature body weight on growth to twelve weeks of age. Poultry Sci. 32: 496-500.
307
Kentucky Agr. Exp. Sta., 1950. 63rd Ann. Rpt, p. 50. Lerner, I. M., 1950. Population Genetics and Animal Improvement. Cambridge University Press, Cambridge.
The Effect of Oral and Parenteral Administration of Antibiotics on Growth and Fecal Microflora in the Turkey Poult
(Received for publication July 11, 1953)
and Jukes (1950) and STOKSTAD Whitehill et al. (1950) reported several antibiotics to increse the growth rate of chicks adequately suppled with vitamin B12. Atkinson and Couch (1951) obtained a 25% increase in both feed efficiency and growth with the addition of aureomycin to the diet of turkey poults. Elam, Gee and Couch (1951a) reported that the fecal microflora of the growing chick was influenced by the feeding of penicillin. These same workers (1951b) reported later that antibiotics may stimulate growth by some mechanism in addition to the action on the aerobic microflora. Elam et al. (1953) reported that the administration of antibiotics had significantly decreased the number of Clostridia in chick fecal material. Smith and Robinson (1945) found that sterptomycin administered orally produced a marked reduction in the coliform bacteria in the intestine of mice. Rosenberg et al. (1952) found that the addition of terramycin to the diet of chicks failed to reduce significantly the number of microorganisms in the feces, while the enterococci counts were increased and the growth of the chicks was increased. This experiment was designed to determine the effect of oral and parenteral
administration of penicillin, aureomycin, Chloromycetin and bacitracin and the oral administration of sodium arsanilate on the aerobic fecal microflora of the turkey poult. EXPERIMENTAL
Two hundred and forty Broad Breasted Bronze turkey poults were wingbanded, weighed and divided into twelve groups of twenty birds each at one day of age. The poults were kept in batteries with raised screen floors. Feed and water were supplied ad libitum. The birds were weighed at weekly intervals during the experimental period of ten weeks. The basal diet used in this study consisted of 34.75% ground yellow corn, 60.0% soybean oil meal, 2.5% steamed bone meal, 2.0% ground oyster shell, 0.5% salt, 0.25%, fortified fish oil (2,250A—300D). In addition 2 mg. riboflavin, 4 mg. calcium pantothenate, 9 mg. niacin, 10 mg. choline chloride, 45.47 vitamin B12, 120 mg. MnS0 4 and 800 AOAC chick units of vitamin D 3 were added per pound of feed. The supplementations to the basal ration were as shown in Table 1. Bacteriological counts of the microorganisms in the fecal samples were made at weekly intervals according to the pro-
Downloaded from http://ps.oxfordjournals.org/ at Mount Allison University on June 9, 2015
B. L. R E I D , J. F. ELAM AND J. R. COUCH
Department of Poultry Husbandry, Texas A & M College System, College Station, Texas
T
A survey of the literature reveals only a few estimates of the heritability of body weight in turkeys. An estimate of about 0.23 was calculated for 26-week old male turkeys by Kentucky researchers (1950). This estimate was obtained by the intrasire regression method after correction was made for age (date of hatch?). Abplanalp and Kosin (1952), utilizing data from Broad-breasted Bronze and Beltsville Small Whites, calculated estimates by intraclass correlation and offspringdam regression methods at 4, 8, 14 and 26 weeks of age. Their estimates vary considerably because of age, sex and environmental (climatic) factors, b u t their most reliable restimates were in the medium to high range (0.16 to 0.71). Other estimates may be calculated from d a t a reported in the literature (Asmundson, 1948), b u t such a procedure can be precarious because of the inherent vagaries of most sets of d a t a . SOURCE OF DATA The majority of the Broad-breasted Bronze and White Holland progeny * Present address: Department of Poultry Industry, Louisiana State University, Baton Rouge.
hatched from pedigree matings during the 1952 season at the Oklahoma Agricultural Experiment Station turkey farm were used in this study. T h e y were weighed and sexed a t 25 weeks of age. T h e number of sires, dams and progeny were as follows: Variety B. B. B. W. H.
No. sires No. dams No. progeny 14 164 1,042 9 104 1,025
T h e Broad-breasted Bronze progeny were produced in four hatches from February 20 to M a y 1. The White Holland progeny was produced in seven hatches from J a n u a r y 31 to April 24. These data were analyzed by the analysis of variance technique as outlined by Lerner (p. 121, 1950), except t h a t variation due to different hatch dates was removed. During the past five years little or no attention has been paid to body weight in these populations of turkeys. Major emphasis in selection has been on fertility and hatchability, although only those individuals having desirable body weight and body conformation were placed in the pedigree mating pens. However, because body weights have not been secured in previous years, it is difficult to determine the exact extent to which selection for body weight has been practiced. T h e mating system has been one of restricted random mating; t h a t is, full a n d half-sib matings have not been made. Insofar as is known, environmental conditions have been as uniform as possible for all turkeys during their growing period,
305
Downloaded from http://ps.oxfordjournals.org/ at Mount Allison University on June 9, 2015
H E concept of heritability is well established among geneticists and practical breeders, b u t the information on the heritability of production traits is still quite fragmentary, especially in turkeys. This paper reports heritability estimates of 25-week body weights in Broadbreasted Bronze and White Holland turkeys.
306
B. L. GOODMAN, C. C. BRUNSON AND G. F. GODFREY
but as will be discussed in a later section, there may be some doubt on this point. RESULTS AND DISCUSSION The average 25-week body weights in pounds and their standard deviations for the Broad-breasted Bronze and White Hollands by sexes were as follows: No. 596 429 622 420
Sex M F M F
Av. Wt. 19.70 12.70 19.20 12.47
S.D. 1.821 1.050 1.753 0.971
The heritability estimates calculated from the dams, sires, combined sires and dams and maternal effects are shown in Table 1. The estimates calculated from dams tend to be higher than those calculated from sires. As pointed out by Lerner (1950), discrepancies between these two estimates may be due to non-additive gene action, maternal effects, and sexlinked effects. In these data there is a strong possibility that the estimates calculated from dams also contain some environmental effects common to the damfamily progenies but not common to the populations as a whole. This environmental effect common to dam-family progenies apparently resulted from the procedure used in taking off the several hatches. Poults from one dam would be removed from the hatcher, banded, and placed in a poult box. The poults in this box would be placed in one brooder house. Although poults were taken off about three times during the hatch due to variaTABLE 1.—Heritability of 25-week body weight in turkeys Heritability estimates Variety Sex
B.B.B. B.B.B. W.H. W.H.
M F M F
W
45
2(D+S)
Q+D+S
Q+D+S
Q+D+S
0.02 0.71 0.71 0.71
0.34 0.29 0.29 0.24
0.18 0.50 O.SO 0.47
Maternal influence D-S
Q+D+S -0.08 0.10 0.10 0.12
Heritability estimates were calculated by the analysis of variance technique for 25-week body weights of the Broadbreasted Bronze and White Holland turkeys raised in 1952 on the Oklahoma Agricultural Experiment Station turkey farm. The most reliable estimate for these two populations appears to be about 0.30. Improvement in body weight of these populations can be most efficiently accomplished by a combination of individual and family selection. REFERENCES Abplanalp, H., and I. L. Kosin, 1952. Heritability of body measurements in turkeys. Poultry Sci. 31: 781-791. Asmundson, V. S., 1948. Inherited differences in weight and conformation of Bronze turkeys. Poultry Sci. 27: 695-708.
Downloaded from http://ps.oxfordjournals.org/ at Mount Allison University on June 9, 2015
Variety B.B.B. B.B.B. W.H. W.H.
tion in hatching time, it is possible that environmental factors common to some dam-family progenies to eight weeks of age biased these data. Thus, the estimates calculated from dams would be an overestimate, and also result in maternal influences that are due to Lerner's (1950) " C " effect, rather than to maternal influences. Therefore, the heritability estimates calculated from the sires are considered to be the best estimates of the heritability of 25-week body weight in these two populations of turkeys. If there is a positive maternal effect on body weight at 25 weeks of age, the physiological basis for it needs further elaboration. It seems unlikely, in view of our data with chickens (Godfrey et al., 1953), that the size of the egg from which the poult hatches could be much of an influence on the 25-week body weight of the turkey. Experiments utilizing diallel matings would show the presence and magnitude of such maternal influences much better than the design which has been used in this paper. SUMMARY
EFFECT OF ANTIBIOTICS ON GROWTH AND FECAL MICROFLORA
Godfrey, G. F., C. Williams and C. E. Marshall, 1953. The relative influence of egg size, age at sexual maturity and mature body weight on growth to twelve weeks of age. Poultry Sci. 32: 496-500.
307
Kentucky Agr. Exp. Sta., 1950. 63rd Ann. Rpt, p. 50. Lerner, I. M., 1950. Population Genetics and Animal Improvement. Cambridge University Press, Cambridge.
The Effect of Oral and Parenteral Administration of Antibiotics on Growth and Fecal Microflora in the Turkey Poult
(Received for publication July 11, 1953)
and Jukes (1950) and STOKSTAD Whitehill et al. (1950) reported several antibiotics to increse the growth rate of chicks adequately suppled with vitamin B12. Atkinson and Couch (1951) obtained a 25% increase in both feed efficiency and growth with the addition of aureomycin to the diet of turkey poults. Elam, Gee and Couch (1951a) reported that the fecal microflora of the growing chick was influenced by the feeding of penicillin. These same workers (1951b) reported later that antibiotics may stimulate growth by some mechanism in addition to the action on the aerobic microflora. Elam et al. (1953) reported that the administration of antibiotics had significantly decreased the number of Clostridia in chick fecal material. Smith and Robinson (1945) found that sterptomycin administered orally produced a marked reduction in the coliform bacteria in the intestine of mice. Rosenberg et al. (1952) found that the addition of terramycin to the diet of chicks failed to reduce significantly the number of microorganisms in the feces, while the enterococci counts were increased and the growth of the chicks was increased. This experiment was designed to determine the effect of oral and parenteral
administration of penicillin, aureomycin, Chloromycetin and bacitracin and the oral administration of sodium arsanilate on the aerobic fecal microflora of the turkey poult. EXPERIMENTAL
Two hundred and forty Broad Breasted Bronze turkey poults were wingbanded, weighed and divided into twelve groups of twenty birds each at one day of age. The poults were kept in batteries with raised screen floors. Feed and water were supplied ad libitum. The birds were weighed at weekly intervals during the experimental period of ten weeks. The basal diet used in this study consisted of 34.75% ground yellow corn, 60.0% soybean oil meal, 2.5% steamed bone meal, 2.0% ground oyster shell, 0.5% salt, 0.25%, fortified fish oil (2,250A—300D). In addition 2 mg. riboflavin, 4 mg. calcium pantothenate, 9 mg. niacin, 10 mg. choline chloride, 45.47 vitamin B12, 120 mg. MnS0 4 and 800 AOAC chick units of vitamin D 3 were added per pound of feed. The supplementations to the basal ration were as shown in Table 1. Bacteriological counts of the microorganisms in the fecal samples were made at weekly intervals according to the pro-
Downloaded from http://ps.oxfordjournals.org/ at Mount Allison University on June 9, 2015
B. L. R E I D , J. F. ELAM AND J. R. COUCH
Department of Poultry Husbandry, Texas A & M College System, College Station, Texas