Correlated Response in Growth Potentiality, Tillering Capacity, and Leafiness of Barseem Clover "Trifolium alexandrium, L" following Selection for Frequent –Cutting Tolerance

AbstractResponses to divergent selection for lean growth rate with ad-libitum feeding (LGA), for lean food conversion (LFC) and for daily food intake (DFI) in Landrace pigs were studied. Selection was practised for four generations with a generation interval ofl year. A total of 2642 pigs were performance tested in the high, low and control lines, with an average of 37 boars and 39 gilts performance tested per selection line in each generation. The average within-line inbreeding coefficient at generation four was equal to 0·04. There was one control line for the DFI and LFC selection groups and another control line for the LGA selection group. Animals were performance tested in individual pens with mean starting and finishing weights of 30 kg and 85 kg respectively with ad-libitum feeding. The selection criteria had phenotypic s.d. of 32, 29 and 274 units, for LGA, LFC and DFI, respectively, and results are presented in phenotypic s.d.Cumulative selection differentials (CSD) were 5·1, 4·5 and 5·5 phenotypic s.d. for LGA, LFC and DFI, respectively. Direct responses to selection were 1·4,1·1 and 0·9 (s.e. 0·20) for LGA, LFC and DFI. In each of the three selection groups, the CSD and direct responses to selection were symmetric about the control lines. The correlated response in LFC (1·1, s.e. 0·19) with selection on LGA was equal to the direct response in LFC. In contrast, the direct response in LGA was greater than the correlated response (0·7, s.e. 0·18) with selection on LFC. There was a negative correlated response in DFI (-0·6, s.e. 0·18) with selection on LFC, but the response with selection on LGA was not significant (0·2, s.e. 0·16).Heritabilities for LGA, LFC and DFI ivere 0·25, 0·25 and 0·18 (s.e. 0·03), when estimated by residual maximum likelihood, with common environmental effects of 0·12 (s.e. 0·02). Genetic correlations for LFC with LGA and DFI were respectively positive (0·87, s.e. 0·02) and negative (-0·36, s.e. 0·09), while the genetic correlation between DFI and LGA was not statistically different from zero, 0·13 (s.e. 0·10). Selection on components of efficient lean growth has identified LGA as an effective selection objective for improving both LGA and LFC, without a reduction in DFI.

Download Full-text

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

Canadian Journal of Animal Science ◽

10.4141/a00-082 ◽

2001 ◽

Vol 81 (2) ◽

pp. 205-214 ◽

Cited By ~ 6

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

Download Full-text

CORRELATED RESPONSE IN BROWN SARSON

Canadian Journal of Genetics and Cytology ◽

10.1139/g70-114 ◽

1970 ◽

Vol 12 (4) ◽

pp. 905-913 ◽

Cited By ~ 1

Author(s):

T. Swamy Rao

Keyword(s):

Gamma Irradiation ◽

Seed Set ◽

Previous History ◽

The Self ◽

Correlated Response ◽

History Of ◽

Self Compatibility ◽

Selection For ◽

Direction Opposite ◽

Brown Sarson

The correlated response with changes in self-compatibility in three varieties of brown sarson subjected to gamma irradiation was examined. Selection for improved seed set in the irradiated populations showed that substantial correlated response can result for a constellation of other characters in which the self-compatible and self-incompatible forms differ. The correlated response was in a direction opposite to that of the previous history of selection.

Download Full-text

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

Animals ◽

10.3390/ani11092591 ◽

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.

Download Full-text

Direct and Correlated Response to Recurrent Full‐sib Selection for Prolificacy in Maize 1

Crop Science ◽

10.2135/cropsci1986.0011183x002600020012x ◽

1986 ◽

Vol 26 (2) ◽

pp. 275-278 ◽

Cited By ~ 9

Author(s):

Malkit Singh ◽

A. S. Khehra ◽

B. S. Dhillon

Keyword(s):

Correlated Response ◽

Selection For ◽

Sib Selection

Download Full-text

Multivariate analysis of litter size for multiple parities with production traits in pigs: II. Response to selection for litter size and correlated response to production traits1

Journal of Animal Science ◽

10.1093/ansci/80.10.2548 ◽

2002 ◽

Vol 80 (10) ◽

pp. 2548-2555

Author(s):

J. L. Noguera ◽

L. Varona ◽

D. Babot ◽

J. Estany

Keyword(s):

Multivariate Analysis ◽

Litter Size ◽

Correlated Response ◽

Production Traits ◽

Response To Selection ◽

Selection For

Download Full-text

Selection for growth on normal and reduced protein diets in mice: I. Direct and correlated responses for growth

Genetics Research ◽

10.1017/s0016672300023272 ◽

1987 ◽

Vol 50 (1) ◽

pp. 7-15 ◽

Cited By ~ 13

Author(s):

B. Vivi Hunnicke Nielsen ◽

Søren Andersen

Keyword(s):

Protein Level ◽

Protein Diet ◽

Correlated Response ◽

Family Selection ◽

Direct Response ◽

Protein Levels ◽

Selection Environment ◽

Normal Protein Diet ◽

Selection For ◽

Protein Diets

SummaryMice were selected for growth from 3 to 9 weeks of age on a normal protein diet (N) containing 19·3% protein and a reduced protein diet (R) containing 5·1% protein. On each diet there were 3 high (H), 3 low (L) and 3 unselected control (C) lines. After 6 generations of selection, half of the mice in each line were tested on each diet. Responses were obtained when selecting for both increased and decreased growth on both diets. The realized heritabilities from within-family selection were 33 and 26% for the divergences on the normal and reduced protein diets, respectively. Consistent genotype-environment interactions were found when all lines were tested on both diets in generation 7. Performance on each protein level was best improved by selection on that protein level. Further, the correlated response was significantly less than the direct response when selecting on both diets. The estimates of the genetic correlation between growth on the two protein levels were low, rN = 0·16 from selection on the normal protein diet and rR = 0·51 from selection on the reduced protein diet. Selection resulted in a change in environmental sensitivity in the lines, dependent on the diet and direction of selection. The average of the divergences on the two diets was not dependent on the selection environment.

Download Full-text