RESPONSE TO SELECTION FOR BODY WEIGHT OR FEED EFFICIENCY IN MICE TESTED ON CORN, RYE AND WHEAT DIETS

1986 ◽  
Vol 66 (2) ◽  
pp. 389-397
Author(s):  
R. I. McKAY ◽  
R. J. PARKER ◽  
W. GUENTER
Keyword(s):  
Body Weight ◽  
Feed Efficiency ◽  
Mass Selection ◽  
Response To Selection ◽  
Initial Weight ◽  
Commercial Diet ◽  
Final Weight ◽  
Dc Line ◽  
Selection For ◽  
Seven Generations

Mass selection for adjusted feed efficiency (AFE, g gain/g feed) and adjusted body weight (ABW, g) of male mice was practiced for seven generations on each of three diets: corn, rye and wheat. The three experimental diets, fed between 21 and 35 d, were isocaloric (approximately 16.5 MJ GE kg−1) and isonitrogenous (CP approximately 13%). A common commerical diet (PC) was fed at all other times. With each diet two control lines, randomly mated, were tested on either the experimental diets (DC) or a commercial diet (PC). Selection was based upon linear adjustment to a common initial weight (10 g) for either final weight (ABW) or feed efficiency (AFE) measured between 21 and 35 d of age. Response was determined as a deviation from the appropriate DC line. All animals were placed in specially designed individual cages during the test period. Half-sib estimates of heritability in the PC line were 0.13(± 0.11) for ABW and 0.19(± 0.10) for AFE. Half-sib estimates pooled across lines and diets were 0.16(± 0.07) for ABW and 0.28(± 0.07) for AFE. Realized heritabilities for ABW were 0.24(± 0.06), 0.06(± 0.07) and 0.14(± 0.06) for the corn, rye and wheat diets, respectively. Response to selection for AFE was poor with the highest heritability obtained on the wheat diet (h2 = 0.13 ± 0.02). Key words: Selection, mice, body weight, feed efficiency, diets

scholarly journals RESPONSE TO SELECTION FOR BODY WEIGHT IN THE THIRD GENERATION OF MASS SELECTION OF THE AFRICAN CATFISH (Clarias gariepinus) AT RESEARCH INSTITUTE FOR FISH BREEDING SUKAMANDI

2016 ◽  
Vol 11 (1) ◽  
pp. 15
Author(s):  
Bambang Iswanto ◽  
Imron Imron ◽  
Huria Marnis ◽  
Rommy Suprapto
Keyword(s):  
Body Weight ◽  
Second Generation ◽  
Clarias Gariepinus ◽  
Mass Selection ◽  
African Catfish ◽  
Larval Rearing ◽  
Third Generation ◽  
Response To Selection ◽  
The Third ◽  
Selection For

Genetic improvement of the African catfish (Clarias gariepinus) in Indonesia for increasing growth performance has been conducted by Research Institute for Fish Breeding at Sukamandi through mass selection. Collection and characterizations of the founder populations, building the synthetic base population, first generation and second generation through mass selection were conducted during 2010-2013. Later, in 2014 it was followed by building the third generation. The present study aimed to find out the genetic gain in the third generation in term of response to selection for body weight. Fifty-two pairs of the selected (fast growing) individuals from the second generation were mated to produce the third generation. As a comparison, five pairs of average-sized individuals were mated to produce the control population, as a second generation representative. Larval rearing, nursery and grow-out phases were respectively held for 25 days in the aquaria, 30 days in the concrete ponds and 60 days in the concrete ponds. At the end of each phase, individual samplings of body weight were undertaken. The results showed that mean body weight of the third generation was higher than that of control population at the end of larval rearing phase (0.21 ± 0.26 g versus 0.20 ± 0.15 g), nursery phase (6.12 ± 2.93 g versus 5.80 ± 3.50 g) and grow-out phase (198.67 ± 82.82 g versus 165.22 ± 71.09 g). Those results revealed that response to selection for body weight of the third generation was positive, i.e. about 20.24% (33.45 g).

scholarly journals MASS SELECTION FOR POST-WEANING GROWTH IN SWINE: II. RESPONSE TO SELECTION

1971 ◽  
Vol 51 (2) ◽  
pp. 497-502 ◽  
Author(s):  
G. W. RAHNEFELD
Keyword(s):  
Genetic Variance ◽  
Additive Genetic Variance ◽  
Average Daily Gain ◽  
Mass Selection ◽  
Realized Heritability ◽  
Response To Selection ◽  
Components Of Variance ◽  
Selection For ◽  
Seven Generations ◽  
Daily Gain

Recurrent mass selection for post-weaning average daily gain was practiced for seven generations in a population of Lacombe swine. Response to selection was positive, but the observed response was estimated to be only 0.33 of the predicted. The pooled estimate of additive genetic variance was 0.0013 ± 0.0002. Realized heritability was 0.126 ± 0.029. The pooled estimate of heritability obtained from components of variance and parent-offspring regression was 0.377 ± 0.058. Litter size was positively correlated with average daily gain (0.14 piglet per generation). No significant effects of selection in reducing additive genetic variance were observed.

GENOTYPE BY DIET INTERACTION IN MICE SELECTED ON THREE DIETARY REGIMENS

1986 ◽  
Vol 66 (2) ◽  
pp. 399-404
Author(s):  
R. I. McKAY ◽  
R. J. PARKER ◽  
W. GUENTER
Keyword(s):  
Body Weight ◽  
Crossover Study ◽  
Key Words ◽  
Feed Efficiency ◽  
Selected Lines ◽  
Dc Line ◽  
Diet Control ◽  
Seven Generations

The effect on 10-wk body weight of seven generations of selection in three nutritional regimens (corn, rye and wheat) for two growth related traits, adjusted body weight (ABW) or adjusted feed efficiency (AFE) was evaluated. Selected mice were 3.2 g heavier (P < 0.01) than mice from the diet control (DC) lines. No effects of selection regimen or differences between the two selected lines for 10-wk weight were significant (P > 0.05). During generation 8 a crossover study was undertaken. Mice from each line (ABW, AFE or DC) from each selection regimen were fed the corn, rye and wheat diets. Response was estimated as a deviation from the DC line fed the same diet. No significant (P > 0.05) regimen by diet interactions were detected in either the ABW or the AFE lines. However, mice in the ABW line tended (P = 0.18) to have higher final weights on test (approximately 1 g) when fed the selection diet compared to the two alternative diets. Key words: Mice, genotype by diet interaction, body weight, feed efficiency

Simulation of Response to Selection for Body Weight in Rainbow Trout

1981 ◽  
Vol 31 (4) ◽  
pp. 426-432 ◽  
Author(s):  
Sampo Sirkkomaa ◽  
Ulf B. Lindström
Keyword(s):  
Body Weight ◽  
Rainbow Trout ◽  
Response To Selection ◽  
Selection For

scholarly journals EFFECTS OF ANCESTRAL X IRRADIATION FOLLOWED BY RANDOM MATING ON BODY WEIGHT OF RATS

Genetics ◽  
1977 ◽  
Vol 86 (4) ◽  
pp. 849-860
Author(s):  
Daniel Gianola ◽  
A B Chapman ◽  
J J Rutledge
Keyword(s):  
Body Weight ◽  
Random Mating ◽  
Rapid Response ◽  
Response To Selection ◽  
Previous Evidence ◽  
Selection Responses ◽  
Inbred Rats ◽  
X Irradiation ◽  
Selection For ◽  
Variance Estimates

ABSTRACT Effects of nine generations of 450r per generation of ancestral spermatogonial X irradiation of inbred rats on body weight were examined. After six generations of random mating (avoiding inbreeding) following the termination of irradiation, descendants of irradiated males (R) were significantly lighter than their controls (C) at 3 and 6 weeks, but not at 10 weeks of age. However, differences in growth between R and C populations were small. Among-litter and within-litter variance estimates were generally larger in the R lines than in the C lines, suggesting that selection responses would be greater in R than in C lines. In conjunction with previous evidence—obtained during the irradiation phase of the experiment—this suggested that more rapid response to selection for 6-week body weight, in particular, might accrue in the R lines.

scholarly journals PSVIII-38 Late-Breaking Abstract: Estimating genetic parameters of feed efficiency traits in American mink

2020 ◽  
Vol 98 (Supplement_4) ◽  
pp. 347-347
Author(s):  
Pourya Davoudi ◽  
Duy Ngoc Do ◽  
Guoyu Hu ◽  
Siavash Salek Ardestani ◽  
Younes Miar
Keyword(s):  
Body Weight ◽  
Genetic Correlation ◽  
Feed Intake ◽  
Feed Efficiency ◽  
Fixed Effects ◽  
Genetic Parameters ◽  
American Mink ◽  
Genetic Correlations ◽  
Final Body Weight ◽  
Selection For

Abstract Feed cost is the major input cost in the mink industry and thus improvement of feed efficiency through selection for high feed efficient mink is necessary for the mink farmers. The objective of this study was to estimate the heritability, phenotypic and genetic correlations for different feed efficiency measures, including final body weight (FBW), daily feed intake (DFI), average daily gain (ADG), feed conversion ratio (FCR) and residual feed intake (RFI). For this purpose, 1,088 American mink from the Canadian Center for Fur Animal Research at Dalhousie Faculty of Agriculture were recorded for daily feed intake and body weight from August 1 to November 14 in 2018 and 2019. The univariate models were used to test the significance of sex, birth year and color as fixed effects, and dam as a random effect. Genetic parameters were estimated via bivariate models using ASReml-R version 4. Estimates of heritabilities (±SE) were 0.41±0.10, 0.37±0.11, 0.33±0.14, 0.24±0.09 and 0.22±0.09 for FBW, DFI, ADG, FCR and RFI, respectively. The genetic correlation (±SE) was moderate to high between FCR and RFI (0.68±0.15) and between FCR and ADG (-0.86±0.06). In addition, RFI had low non-significant (P &gt; 0.05) genetic correlations with ADG (0.04 ± 0.26) and BW (0.16 ± 0.24) but significant (P &lt; 0.05) high genetic correlation with DFI (0.74 ± 0.11) indicating that selection for lower RFI will reduce feed intake without adverse effects on the animal size and growth rate. The results suggested that RFI can be implemented in genetic/genomic selection programs to reduce feed intake in the mink production system.

Mass selection for 70-day body weight in rabbits.

1996 ◽  
Vol 74 (7) ◽  
pp. 1481 ◽  
Author(s):  
S D Lukefahr ◽  
H B Odi ◽  
J K Atakora
Keyword(s):  
Body Weight ◽  
Mass Selection ◽  
Selection For

scholarly journals EFFECT OF SELECTION ON HERITABILITY AND GENETIC CORRELATION OF TWO QUANTITATIVE TRAITS IN MICE

1974 ◽  
Vol 16 (3) ◽  
pp. 599-609 ◽  
Author(s):  
T. K. Cheung ◽  
R. J. Parker
Keyword(s):  
Body Weight ◽  
Genetic Correlation ◽  
Quantitative Traits ◽  
Random Mating ◽  
Tail Length ◽  
Control Group ◽  
Mass Selection ◽  
Initial Population ◽  
Significant Difference ◽  
Selection For

The effects of different intensities of single trait directional selection on the heritability and genetic correlation of two quantitative traits in random mating populations of mice were observed during 14 generations. The initial population was divided at random into five groups (A, B, C, D and E). Group A and Group B were under 30% and 60% mass selection for large 6-week body weight, respectively. Group C and Group D were under 30% and 60% mass selection for long 6-week tail length, respectively. Group E acted as control group with no selection applied. In all groups, the parent population consisted of 15 males and 30 females each generation, mated at random.Direct selection had no apparent effect on the heritability of either the trait under selection or the correlated trait over the 14 generations. Heritability of 6-wk tail length was higher than the heritability of 6-wk body weight. Estimates of heritability of 6-wk tail length ranged from 0.15 ± 0.22 to 0.68 ± 0.24, while estimates of heritability of 6-wk body weight ranged from 0.05 ± 0.17 to 0.33 ± 0.09. There was no significant difference among the estimates of genetic correlation between the two traits in the five selection groups. Estimates of realized genetic correlation between 6-wk body weight and 6-wk tail length seemed to indicate that more intense selection led to some decrease in genetic correlation between the two traits.

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