Direct and correlated responses to individual selection for large adult weight in the edible snailHelix aspersa M�ller

2000 ◽  
Vol 287 (1) ◽  
pp. 80-85 ◽  
Author(s):  
M. Dupont-Nivet ◽  
J. Mallard ◽  
J.C. Bonnet ◽  
J.M. Blanc
Keyword(s):  
Individual Selection ◽  
Correlated Responses ◽  
Adult Weight ◽  
Selection For ◽  
Large Adult

COMPONENTS OF GROWTH IN GENETICALLY DIVERSE POPULATIONS OF TRIBOLIUM CASTANEUM

1969 ◽  
Vol 11 (4) ◽  
pp. 896-907 ◽  
Author(s):  
DuWayne C. Englert ◽  
A. E. Bell
Keyword(s):  
Tribolium Castaneum ◽  
Adult Emergence ◽  
Pupal Weight ◽  
Diverse Populations ◽  
Correlated Responses ◽  
Larval Weight ◽  
Developmental Patterns ◽  
Adult Weight ◽  
Total Growth ◽  
Selection For

The growth and developmental patterns of 19 genetically diverse populations of Tribolium castaneum were examined. Measurements were obtained on three primary traits (13-day larval weight, pupation time and pupal weight) and three secondary traits (number of larval molts, adult emergence time and adult weight). The populations were chosen on the basis of their previous selection histories. Selection for different primary traits produced profound effects upon the total growth and development complex.Genetic and environmental relationships between primary traits were estimated within each population, and a consistent asymmetry of correlated responses was observed to be determined by the direction of selection.Possible effects upon the disruption of an intricate balance of the three metamorphosis hormones (activation, molting and juvenile) through selection were postulated.

Selection for Increased Rate or Efficiency of Lean Growth in Rats: Correlated Responses in Reproductive Performance

1981 ◽  
Vol 53 (6) ◽  
pp. 1458-1464 ◽  
Author(s):  
R. D. Allrich ◽  
C. T. Wang ◽  
G. E. Dickerson ◽  
Dwane R. Zimmerman
Keyword(s):  
Reproductive Performance ◽  
Correlated Responses ◽  
Or Efficiency ◽  
Lean Growth ◽  
Selection For

Correlated Responses to Selection for Greater β-Glucan Content in Two Oat Populations

Crop Science ◽  
2002 ◽  
Vol 42 (3) ◽  
pp. 730 ◽  
Author(s):  
C. T. Cervantes-Martinez ◽  
K. J. Frey ◽  
P. J. White ◽  
D. M. Wesenberg ◽  
J. B. Holland
Keyword(s):  
Correlated Responses ◽  
Selection For

Selection for rate and efficiency of lean gain in Hereford cattle 1. Selection pressure applied and direct responses

1990 ◽  
Vol 51 (1) ◽  
pp. 23-34 ◽  
Author(s):  
R. A. Mrode ◽  
C. Smith ◽  
R. Thompson
Keyword(s):  
Genetic Parameters ◽  
Control Line ◽  
Correlated Responses ◽  
Direct Response ◽  
Lean Growth ◽  
Hereford Cattle ◽  
Frozen Semen ◽  
Phenotypic Standard Deviation ◽  
Selection For ◽  
Selection Of

ABSTRACTSelection of bulls for rate and efficiency of lean gain was studied in a herd of Hereford cattle. There were two selection lines, one selected for lean growth rate (LGR) from birth to 400 days and the other for lean food conversion ratio (LFCR) from 200 to 400 days of age, for a period of 8 years. A control line bred by frozen semen from foundation bulls was also maintained. Generation interval was about 2·4 years and average male selection differentials, per generation were 1·2 and — 1·1 phenotypic standard deviation units for LGR and LFCR respectively.Genetic parameters and responses to selection were estimated from the deviation of the selected lines from a control line and by restricted maximum likelihood (REML) techniques on the same material. Realized heritabilities were 0·40 (s.e. 0·12) for LGR and 0·40 (s.e. 0·13) for LFCR using the control line. Corresponding estimates from REML were 0·42 (s.e. 0·10) and 0·37 (s.e. 0·14). The estimate of the genetic correlation between LGR and LFCR was about — 0·69 (s.e. 0·12) using REML.The estimates of direct annual genetic change using deviations from the control were 3·6 (s.e. 1·3) g/day for LGR and — 0·14 (s.e. 0·07) kg food per kg lean gain for LFCR. Corrsponding estimates from REML were similar but more precisely estimated. The correlated responses for LFCR in the LGR line was higher than the direct response for LFCR.

Selection for lean growth rate and correlated responses in litter traits in a synthetic line of Yorkshire-Meishan pigs

2001 ◽  
Vol 81 (2) ◽  
pp. 205-214 ◽  
Author(s):  
P. Chen ◽  
T. J. Baas ◽  
J. C. M. Dekkers ◽  
L. L. Christian
Keyword(s):  
Growth Rate ◽  
Regression Coefficients ◽  
Correlated Response ◽  
Selection Line ◽  
Control Line ◽  
Correlated Responses ◽  
Lean Growth ◽  
Litter Traits ◽  
Selection For ◽  
Synthetic Line

Selection for lean growth rate (LGR) was conducted for four generations in a synthetic line of Yorkshire-Meishan pigs to study the effectiveness of selection for LGR and correlated responses in litter traits. Lean growth rate was estimated from ultrasound measurements of 10th-rib backfat thickness and longissimus muscle area. In the selection line, 7 boars and 20 gilts with the highest LGR were selected to produce the next generation. The generation interval was 13 mo and the average selection differential per generation was 1.1 phenotypic standard deviation units. A contemporaneous control line was maintained by randomly selecting 5 boars and 15 gilts. Data from a total of 1057 pigs sired by 58 boars and out of 133 sows were available from the two lines. Selection responses were estimated from deviations of the selection line from the control line using least squares (LS) and by multiple trait derivative-free restricted maximum likelihood analysis using an animal model (AM). The estimate of response to selection per generation using LS was 9.4 ± 0.95 g d–1 for LGR. The corresponding estimate from the AM was 9.8 ± 0.51 g d–1. Correlated responses in litter traits were regressed on generation. For the LS method, regression coefficients were negative but not significant (P > 0.05) for total number born, number born alive, and number at 21 d and at 42 d. Significant, positive correlated responses occurred in 42-d litter weight and 21-d piglet weight (P < 0.05). For the AM method, the regression coefficients were also negative, but were not significant (P > 0.05) for numberalive at birth, at 21 d, and at 42 d. A significant positive correlated response occurred only for 42-d litter weight (P < 0.05). Although results are based on a population of limited size, it can be concluded that selection for LGR in a synthetic line is effective and should have little effect on litter traits. Key words: Pigs, selection, lean growth rate, correlated response

scholarly journals Direct and Correlated Responses to Multitrait, Divergent Selection for Immunocompetence

1994 ◽  
Vol 73 (1) ◽  
pp. 18-32 ◽  
Author(s):  
R.P. KEAN ◽  
A. CAHANER ◽  
A.E. FREEMAN ◽  
S.J. LAMONT
Keyword(s):  
Divergent Selection ◽  
Correlated Responses ◽  
Selection For

scholarly journals Correlated Response on Growth Traits and Their Variabilities to Selection for Ovulation Rate in Rabbits Using Genetic Trends and a Cryopreserved Control Population

Animals ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 2591
Author(s):  
Rosa Peiró ◽  
Celia Quirino ◽  
Agustín Blasco ◽  
María Antonia Santacreu
Keyword(s):  
Growth Traits ◽  
Ovulation Rate ◽  
Control Population ◽  
Individual Growth ◽  
Correlated Response ◽  
Phenotypic Variance ◽  
Correlated Responses ◽  
Growth Variability ◽  
Selection For ◽  
Genetic Trends

The aim of this work was to estimate correlated responses in growth traits and their variabilities in an experiment of selection for ovulation rate during 10 generations in rabbits. Individual weight at 28 days old (IW28, kg) and at 63 days old (IW63, kg) was analyzed, as well as individual growth rate (IGR = IW63 − IW28, kg). The variability of each growth trait was calculated as the absolute value of the difference between the individual value and the mean value of their litter. Data were analyzed using Bayesian methodology. The estimated heritabilities of IW28, IW63 and IGR were low, whereas negligible heritabilities were obtained for growth variability traits. The common litter effect was high for all growth traits, around 30% of the phenotypic variance, whereas low maternal effect for all growth traits was obtained. Low genetic correlations between ovulation rate and growth traits were found, and also between ovulation rate and the variability of growth traits. Therefore, genetic trends methods did not show correlated responses in growth traits. A similar result was also obtained using a cryopreserved control population.

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