Erratum: Experimental comparison of restricted selection index and restricted independent culling levels in Tribolium castaneum

Genome ◽  
1987 ◽  
Vol 29 (5) ◽  
pp. 806-806
Author(s):  
J. L. Campo ◽  
B. Villanueva
Keyword(s):  
Tribolium Castaneum ◽  
Selection Index ◽  
Experimental Comparison ◽  
Independent Culling ◽  
Restricted Selection

Experimental comparison of restricted selection index and restricted independent culling levels in Tribolium castaneum

Genome ◽  
1987 ◽  
Vol 29 (1) ◽  
pp. 91-96 ◽  
Author(s):  
J. L. Campo ◽  
B. Villanueva
Keyword(s):  
Tribolium Castaneum ◽  
Selection Index ◽  
Egg Laying ◽  
Experimental Comparison ◽  
Pupal Weight ◽  
Selection Methods ◽  
Adult Weight ◽  
Antagonistic Selection ◽  
Independent Culling ◽  
Restricted Selection

A selection index (I) method was compared with independent culling levels (N), with a restriction in the selection program, using two replicated single generation experiments in Tribolium castaneum, which are considered forms of antagonistic selection. The first experiment was designed to increase adult weight without changing pupal weight, while the second experiment was intended to improve egg laying without changing adult weight. In both experiments the genetic correlation between the traits involved were positive but were higher in experiment 1 than in experiment 2. The proportion of selection was 10%. In experiment 1, the effect of restriction was as expected in both lines since the changes in pupal weight were not significant. Adult weight change was positive for the I line and negative for the N line, showing that the index was a superior method to improve adult weight. In experiment 2, the effect of restriction was also as expected in both lines and changes in adult weight were not significant. Egg laying changed positively in both lines. Therefore, both selection methods were similar in this experiment, even though egg laying change was higher in the I than the N line. Key words: restricted index, restricted culling levels, antagonistic selection, Tribolium.

Realized genetic parameters from an antagonistic selection index in Tribolium castaneum

1986 ◽  
Vol 28 (3) ◽  
pp. 358-364 ◽  
Author(s):  
J. L. Campo ◽  
L. G. Raya
Keyword(s):  
Genetic Correlation ◽  
Tribolium Castaneum ◽  
Selection Index ◽  
Selection Response ◽  
Pupal Weight ◽  
Base Population ◽  
Adult Weight ◽  
Antagonistic Selection ◽  
Individual Trait ◽  
Highly Correlated

Simultaneous selection of two highly correlated traits was practiced in Tribolium castaneum in a replicated experiment for six generations. Two lines were selected in each of three replicates: P+A− for an antagonistic selection index to increase pupal weight at 21 days and decrease adult weight at 31 days, and P−A+ for an antagonistic selection index to decrease pupal weight and increase adult weight. Genetic correlation between pupal and adult weights estimated in the base population was 0.95. Estimates of realized heritabilities and genetic correlation were obtained and compared with full-sib estimates. For the aggregate genotype, the P+A− line had a significant positive selection response, while the P−A+ line showed a significant negative response as would be expected. The response to divergent selection was asymmetrical, being less for the low pupal weight and high adult weight line than vice versa. Less asymmetry was found for the realized heritability, which agreed very well with the index heritability estimated in the base population. Both individual traits changed in the same direction, increasing for the P+A− line and decreasing for P−A+ line, even though a significant response was found only for pupal weight in the P+A− line. Therefore, the response to antagonistic selection for each individual trait seems to be heavily controlled by the strength of the genetic correlation between them. The realized genetic correlation between pupal weight and adult weight obtained from antagonistic selection index was in excellent agreement with full-sib estimates. Realized heritabilities for each trait were overestimated, especially for adult weight, even though there were essentially no differences between realized and estimated values.Key words: selection (artificial), antagonistic index, parameters (realized), Tribolium.

scholarly journals Restricted Selection Index to Relieve the Negative Repercussion in Reproductive Performance of Holstein Cows

2021 ◽  
Vol 10 (3) ◽  
pp. 202-207
Keyword(s):  
Repeated Measures ◽  
Selection Index ◽  
Reproductive Traits ◽  
Breeding Value ◽  
Holstein Cows ◽  
Sources Of Information ◽  
True Breeding ◽  
Productive Traits ◽  
Restricted Selection ◽  
True Breeding Value

The aim of this investigation was to develop restricted selection index aiming to improve 305-day yields of milk (MY), fat (FY) and protein (PY), while keeping the deterioration in days open (DO), calving interval (CI) and number of services per conception (NSPC) at minimum levels in Holstein cows. The data represent 3682 records of 1122 cows, daughters of 95 sires and 712 dams. The data were analyzed by multi-trait animal model with repeated measures. Eight selection indexes (five unrestricted and three restricted) were derived using MY, FY, PY, CI, DO and NSPC in various combinations as sources of information in the indexes. However, the true breeding value included MY, FY and PY. The highest accuracy of selection (0.60) resulted from selection based on the full index. Milk yield and SPC appeared to be the most valuable traits in the full index. Combining the two traits into one index (the best reduced index) gave 0.57 accuracy of selection. The index based on MY alone (the most accurate single trait index) gave 0.53 accuracy. It seems possible to reduce the expected genetic deterioration in the reproductive traits by restricting the full index to result in zero genetic change in NSPC (rTI=0.48). This restriction will allow the breeder to mitigate the deterioration in DO and CI by 12 and 16 days respectively, by sacrificing with part of the expected genetic improvement in productive traits (29, 40 and 48% in MY, FY and PY, respectively).

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