Heritability of Chick Viability for Two Breeds of the Domestic Fowl

Morris, J. A.

doi:10.3382/ps.0380481

Cited by 6 publications

(5 citation statements)

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“…The heritability estimates presented in Tables 2, 3 and 4 are similar to the ones obtained for viability of chickens during the early growing period (Wilson, 1948;Morris, 1959;Hale, 1954;and Brunson et al, 1956).…”

Section: Resultssupporting

confidence: 56%

“…The estimates based on levels of mortality greater than 10 percent were higher than corresponding estimates in chickens. However, since the estimates were based on the differences between full sib families, maternal effects may have been important (Hale, 1954: Moultrie et al, 1953Brunson et al, 1956;Dickerson, 1957;and Morris, 1959). The linear regression coefficients of heritability estimates on mortality level were .011 and .020 for the medium weight and large weight strains, respectively.…”

Section: Resultsmentioning

confidence: 98%

“…Hale (1954) reported estimates of .07, .14 and .10 for eight week viability of White Wyandottes based on variance between sires, variance between dams, and variance between sires and dams, respectively. Morris (1959) estimated the heritability of chick viability in two flocks of White Leghorns and one flock of Australorps during three periods: 0 to 3 weeks, 3 to 6 weeks, and 0 to 6 weeks of age. The estimates were low, ranging from 0 to .05.…”

Section: Introductionmentioning

confidence: 99%

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Heritability of Viability During the Early Growing Period of Turkeys

1973

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Heritability estimates of viability of turkeys from 0 to 4 weeks of age averaged .080 ± .014 with a confidence interval (P < .01) of .044 to .094. Estimates of viability during cold stress and collection of blood at four weeks of age averaged .002 ± .012 with a confidence interval (P < .01) of -.028 to .032. The heritability estimate for viability from 0 to 8 weeks of age in several lines of medium weight and large weight turkeys was .117 ± .008 with a confidence interval (P < .01) of .096 to .138. Heritability estimates of the medium weight strains (.130 ± .010) averaged slightly higher than that of large weight strains (.096 ± .012). The magnitude of the heritability estimates increased with increases in mortality.

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Section: Resultssupporting

confidence: 56%

Section: Resultsmentioning

confidence: 98%

Section: Introductionmentioning

confidence: 99%

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Heritability of Viability During the Early Growing Period of Turkeys

1973

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“…Genetic correlations and standard deviations were those calculated from these data by Emsley et al (1977) from sire components of variance and covariance for all traits except EMRT and AMRT. The correlations of genotypes and progeny phenotypes were estimated with heritabilities of .029 per EMRT and .066 for AMRT and correlations among fullsibs of .053 for EMRT and .041 for AMRT, along with the appropriate numbers of progeny for each type of progeny average (Lush et al, 1948;Brunson et al, 1955;Dickerson, 1957;Morris, 1959). The genetic correlation for AMRT and PR72 was taken to be -.355 (Hill et al, 1954;Nordskog and Hill, 1958).…”

Section: Ofmentioning

confidence: 99%

Effectiveness of Progeny Test Index Selection for Field Performance of Strain-Cross Layers

1981

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Selection for egg production and egg quality traits in two sets (TX1 and TX2) of pedigreed strain-cross White Leghorns was based on strain-cross progeny performance averaged over field environments. Retrospect index weightings, selection intensities, and genetic parameters were used to predict genetic responses in TX1 and TX2 for a 5-year period. Predicted genetic responses were compared with realized genetic responses.Retrospect index weightings for 13 component traits showed less emphasis on early mortality (EMORT) and adult mortality (AMRT) and more emphasis on Haugh units and early shell texture than was intended. Selection intensity was about 1.5 o for males in male lines and about 1.0 o for females and males in female lines and for females in male lines. Average intensity of selection was 20% greater for retrospect than for intended selection index. Average intensity of selection among 3-year-old parents was no greater than that among 2-year-old parents, because 3-year-old parents had lower egg production, reduced fertility, and greater mortality.Predicted yearly change was in the desired direction for all traits except for a slightly negative predicted change in specific gravity. Predicted change in economic value (ECON) was $.09 for TX1 and $.12 forTX2. Most predicted change in ECON was due to traits affecting egg numbers (EGGS). Predicted changes in EGGS were 1.83 for TX1 and 2.33 for TX2.Estimated genetic changes were $.21 and 4.95 eggs for TX1 and $.21 and 5.00 eggs for TX2. Significant or near significant differences between predicted and estimated genetic changes indicated that EMRT, AMRT, egg weight, EGGS, and ECON changed more favorably than predicted and that excitability and blood spots changed less favorably than predicted. (

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“…appear to be important to some degree for body weight (Hazel and Lamoreux, 1947); for hatchability and early liability (Brunson et al, 1955); for the production index (Diizgunes and Yao, 1956); for chick viability (Morris, 1959); for laying house viability (Hale, 1959); and for age at 1st egg, 32 week egg weight, 32 week body weight, % production to Jan. 1 and to 72 weeks of age, and U.S.D.A. albumen score (King, 1961).…”

mentioning

confidence: 98%