scholarly journals Effect of disruptive selection for body conformation on age variations of femoral morphometrie traits, in mice

1999 ◽  
Vol 42 (2) ◽  
pp. 201-210
Author(s):  
L. Hinrichsen ◽  
D. Mana ◽  
R. Di Masso ◽  
M. T. Font
Keyword(s):  
Body Weight ◽  
Tail Length ◽  
Whole Body ◽  
Disruptive Selection ◽  
Phenotypic Correlation ◽  
Control Line ◽  
Genetic Determination ◽  
Body Conformation ◽  
Age Variations ◽  
Selection For

Abstract. The effect of disruptive selection for body conformation on body weight and length, tail length, and femur weight and length at different stages of development (21, 42, 63, and 120 days of age) was analysed in four mouse lines of the CBi stock selected for (CBi+, CBi-) and against (CBi/L, CBi/C) the phenotypic correlation between body weight and tail length, and die unselected control line CBi. As expected, body weight and tail length distributed according to the selection criteria; rrunk length (whole body length minus tail length) behaved as body welght at all ages. CBi/L had the highest femoral length (p < 0.01), and CBi/C attained the highest femoral weight (p < 0.01). CBi+ and CBi-, harmonically large or small, differed between them and from the control line in both variables (p < 0.001). These findings further corroborate the proposal that bone mass is markedly affected by the skeleton function as support of soft tissues. The allometric analysis ofthe regression of femur weight on femur length suggests that, in this model, a) the demand posed by the selective pressure forced each genotype to find a unique Solution, b) this response is sex-dependent, and c) genetic determination ofthe parameters involved in this allometric relationship is, at least, partially independent.

CARCASS COMPOSITION OF MICE AFTER LONG-TERM SELECTION FOR LARGE SIX-WEEK BODY WEIGHT OR LONG SIX-WEEK TAIL LENGTH

1985 ◽  
Vol 65 (1) ◽  
pp. 239-242 ◽  
Author(s):  
R. I. McKAY ◽  
A. D. GRAHAM ◽  
R. J. PARKER
Keyword(s):  
Body Weight ◽  
Key Words ◽  
Tail Length ◽  
Fat Deposition ◽  
Carcass Composition ◽  
Control Line ◽  
Selected Lines ◽  
Term Selection ◽  
Selection For

Carcass analysis of mice selected for large 6-wk body weight (BW6) or long 6-wk tail length (TL6) is reported. There was no evidence of excessive fat deposition in the selected lines when compared to a randomly bred control line. Key words: Mice, carcass composition, selection, fat

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.

EFFECT OF SELECTION ON FEED UTILIZATION AND CARCASS SCORE EN SWINE

1970 ◽  
Vol 50 (3) ◽  
pp. 575-584 ◽  
Author(s):  
C. BERNARD ◽  
M. H. FAHMY
Keyword(s):  
Body Weight ◽  
Genetic Correlation ◽  
Genetic Improvement ◽  
Body Weight Gain ◽  
Feed Utilization ◽  
Phenotypic Correlation ◽  
Population Selection ◽  
Yorkshire Pigs ◽  
Selection For ◽  
Selection Differentials

Selection for feed utilization (FU) and carcass score (CS) based on full sib performance was practiced within three lines of Yorkshire pigs during ten generations. Line 1 was selected solely for FU, line 2 for CS and line 3 for the two traits combined in an index. Line 2 served as a control for lines 1 and 3 in FU and line 1 as a control for lines 2 and 3 in CS. Feed utilization was expressed as the amount of feed required per kilogram body weight gain. Carcass score was based on length, backfat thickness, loin eye area and belly grade measured on pigs marketed at 90 kg liveweight. Selection differentials for FU averaged 0.198 and 0.208 kg per generation for lines 1 and 3, respectively, while CS differentials were 7.2 and 7.4 points per generation for lines 2 and 3, respectively. Heritability estimates based on full sib performance and converted to individual bases were 0.16 for FU and 0.43 for CS. The phenotypic correlation between the two traits was −0.25 and the genetic correlation −0.55. Responses to selection for FU were 0.09 and 0.24 kg per generation for lines 1 and 3, respectively, while for CS they were 0.77 and 0.97 points for lines 2 and 3, respectively. Compared with the parental means, this represented a genetic improvement of 0.25 and 0.66% per generation for FU in lines 1 and 3, and 1.06 and 1.33% per generation for CS in lines 2 and 3, respectively. The realized responses in lines 1 and 3 to selection for FU Were 58 and 148% of the expectation, and 58 and 72% for lines 2 and 3 in CS. Due to larger selection differentials in line 3, along with a strong positive genetic correlation between the two traits observed in this particular population, selection for the combined traits was 1.35 and 1.10% more effective in improving FU and CS, respectively, than selection for these traits individually.

Relationships between whole-body chemical composition, physically dissected carcass parts and backfat measurements in pigs

1987 ◽  
Vol 44 (2) ◽  
pp. 263-273 ◽  
Author(s):  
A. J. Rook ◽  
M. Ellis ◽  
C. T. Whittemore ◽  
P. Phillips
Keyword(s):  
Body Weight ◽  
Weight Distribution ◽  
Subcutaneous Fat ◽  
Sex Selection ◽  
Whole Body ◽  
Selection Line ◽  
Control Line ◽  
Body Lipid ◽  
Large White ◽  
Intermuscular Fat

ABSTRACTLog-linear relationships between various measurements of the chemical and physical body composition of the pig were obtained in four datasets representing a range of sexes, genotypes and feeding treatments. One of these datasets (dataset 1) comprised genetic control and selection line Large White pigs. There were significant differences between datasets for most of the relationships investigated. The causes of the differences cannot be determined. Within datasets, relationships between various body components and the weight of crude protein in the whole body were unaffected by genotype or sex. The relationships of both intermuscular fat and trimmed carcass lipid with whole body lipid differed significantly between the control and selection lines in dataset 1. Fat thickness measurements taken over the m. longissimus at the last rib were less at the same body lipid in the selection line than the control line suggesting a redistribution of fat away from this area as a result of selection. Relationships between viscera, lungs and empty body weight were significantly affected by line while those between trimmed carcass, liver, kidneys and empty body weight were significantly affected by sex. Selection line pigs had less perinephric and retroperitoneal fat than controls at the same whole body fat weight and less subcutaneous fat at the same cold carcass weight. There were no significant line effects on lean or bone weight distribution. Selection line pigs had significantly less subcutaneous fat in the collar joint and more intermuscular fat in the ham. There were few significant sex effects on tissue weight distribution.

scholarly journals Genetic and phenotypic relationships between ovulation rate and body weight in the mouse

1970 ◽  
Vol 15 (2) ◽  
pp. 171-182 ◽  
Author(s):  
R. B. Land
Keyword(s):  
Body Weight ◽  
Genetic Correlations ◽  
Ovulation Rate ◽  
Phenotypic Correlation ◽  
Laboratory Mice ◽  
Induced Ovulation ◽  
Selection For ◽  
The Absolute

SUMMARYThe genetic and phenotypic regressions and correlations between ovulation rate and body weight were examined in a random bred strain (Q) of laboratory mice during the course of three experiments. These experiments were (1) a sib analysis; (2) selection for natural and induced primiparous ovulation rate; and (3) replicated selection for 6-week weight. The following results were obtained:(a) The genetic correlations between body weight and natural and induced ovulation rate were positive, and approximately equal to 0·4 and 0·6 respectively.(b) The genetic regressions of natural and of induced ovulation rate on body weight were approximately 0·4 and 0·9 eggs per gram respectively.(c) The genetic regressions of body weight on natural and on induced ovulation rate were approximately 0·5 and 0·25 g per egg respectively.(d) The phenotypic correlation between natural ovulation rate and body weight was approximately 0·4 and the corresponding regression of ovulation rate on body weight approximately 0·4 eggs per gram.(e) The phenotypic correlation between induced ovulation rate and body weight declined from 0·4 at 6 weeks of age to zero at the time of scoring, the corresponding regressions of ovulation rate on body weight declining from 0·1 eggs per gram to zero.It was concluded that natural ovulation rate itself, and both its components (FSH activity and ovarian sensitivity) are positively genetically correlated with body weight. Furthermore, the observation that large mice shed at least as many eggs as small ones in response to the same dose of PMS showed that the response was more closely related to the absolute dose than to the resultant concentration.

scholarly journals Long-term selection for protein amount over 70 generations in mice

1998 ◽  
Vol 72 (2) ◽  
pp. 93-109 ◽  
Author(s):  
LUTZ BÜNGER ◽  
ULLA RENNE ◽  
GERHARD DIETL ◽  
SIEGFRIED KUHLA
Keyword(s):  
Body Weight ◽  
Selection Response ◽  
Direct Selection ◽  
Control Line ◽  
Phenotypic Variance ◽  
Effective Population ◽  
Term Selection ◽  
General Importance ◽  
Selection For

Based on the outbred mouse strain Fzt: Du, which has been obtained by systematic crossing of four inbred and four outbred lines, a long-term selection experiment was carried out for total protein amount (PA) in the carcass, starting in 1975. An unselected control line (CO) was kept under the same management but without continuous protein analysis. The protein amount of male carcasses at 42 days of age (P42) increased from 2·9 g in generation 0 to 5·2 g at generation 70, representing 97% of a theoretical selection limit. The total selection response amounts to 2·3 g, which is about 80% above the initial value and corresponds to 9σp or 12σA . The estimated realized heritability of protein amount decreased from 0·56 to 0·03 at generation 70, which was due to an increase in phenotypic variance from 0·065 to 0·24 g2 and a reduction in genetic variance from 0·04 to 0·01 g2. Half the selection response was obtained after about 18 to 23 generations, a half-life of 0·25 to 0·3 Ne. The maximum selection response was 0·094 g/generation and the response was 0·01 g/generation at generation 70. The measurements of body weights at 0, 10, 21, 42 and 63 days throughout the experiment showed a strong correlated effect for all weights. The PA mice are one of the heaviest lines of mice ever reported, and do not differ significantly in their body composition from control mice at 42 days. The direct selection response was due primarily to increased general growth. Body weight and protein amount are phenotypically and genetically highly correlated (rp=0·82, rA≈1); however, selection for body weight led to fatter animals, whereas selection for protein opposed increased fatness (at least until selection age). This may be of general importance in animal breeding. The comparatively high selection response in this experiment seems due to the heterogeneity of the base population, the relatively high effective population size, and the duration of the experiment.

Genetic and phenotypic relationships between fertility and wool production in 2-year-old Merino sheep

1967 ◽  
Vol 18 (3) ◽  
pp. 515 ◽  
Author(s):  
JP Kennedy
Keyword(s):  
Body Weight ◽  
Genetic Correlations ◽  
Standard Errors ◽  
Phenotypic Correlation ◽  
Correlated Responses ◽  
Merino Sheep ◽  
Wool Production ◽  
Phenotypic Correlations ◽  
Selection For ◽  
Fertility Traits

Records of the lambing and weaning performance (fertility) of 2-year-old Peppin Merino ewes were analysed. Repeatability and heritability of number of lambs born and weaned were low. Heritability of number of lambs born was significantly different from zero (0.20 ± 0.10). Phenotypic and genetic correlations between the fertility traits and greasy wool weight, all measured at approximately 15 months of age, were calculated. Phenotypic correlations between number of lambs born or weaned and greasy wool weight were negative and significant. The phenotypic correlation between number of lambs weaned and clean wool weight was negative and significant. Significant negative genetic correlations were found between number of lambs born and both greasy wool weight and clean wool weight. Genetic correlations between number of lambs weaned and the fleece and body traits had very large standard errors. The results were used to estimate correlated responses in fertility resulting from selection for greasy wool weight, clean wool weight, and body weight of –0.08i, –0.13i, and 0.03i respectively.

scholarly journals Overlap of quantitative trait loci for early growth rate, and for body weight and age at onset of sexual maturity in chickens

Reproduction ◽  
2011 ◽  
Vol 141 (3) ◽  
pp. 381-389 ◽  
Author(s):  
B K Podisi ◽  
S A Knott ◽  
I C Dunn ◽  
A S Law ◽  
D W Burt ◽  
...  
Keyword(s):  
Growth Rate ◽  
Body Weight ◽  
Quantitative Trait Loci ◽  
Quantitative Trait ◽  
Sexual Maturity ◽  
The Body ◽  
Chromosome 1 ◽  
Phenotypic Correlation ◽  
Genetic Determination ◽  
Trait Loci

Critical age, weight and body composition have been suggested as necessary correlates of sexual maturity. A genome scan to identify quantitative trait loci (QTL) for age and body weight at first egg (AFE and WFE) was conducted on 912 birds from an F2broiler–layer cross using 106 microsatellite markers. Without a covariate, QTL for body WFE were detected on chromosomes 2, 4, 8, 27 and Z and a single QTL for AFE was detected on chromosome 2. With AFE as a covariate, additional QTL for body WFE were found on chromosomes 1 and 13, with abdominal fat pad as covariate a QTL for body WFE was found on chromosome 1. With body WFE as covariate, additional QTL for AFE were found on chromosomes 1, 3, 4, 13 and 27. The QTL generally acted additively and there was no evidence for epistasis. Consistent with the original line differences, broiler alleles had positive effects on body WFE and negative effects on AFE, whereas the phenotypic correlation between the two traits was positive. The mapped QTL for body WFE cumulatively accounted for almost half the body weight difference between the chicken lines at puberty. Overlapping QTL for body WFE and body weight to 9 weeks of age indicate that most QTL affecting growth rate also affect body WFE. The co-localisation of QTL for body weight, growth and sexual maturity suggests that body weight and growth rate are closely related to the attainment of sexual maturity and that the genetic determination of growth rate has correlated effects on puberty.

scholarly journals Uterine and Postnatal Maternal Effects in Mice Selected for Differential Rate of Early Development

Genetics ◽  
1999 ◽  
Vol 153 (2) ◽  
pp. 905-917 ◽  
Author(s):  
Brian K Rhees ◽  
Cynthia A Ernst ◽  
Christina H Miao ◽  
William R Atchley
Keyword(s):  
Postnatal Development ◽  
Maternal Effects ◽  
Tail Length ◽  
Postnatal Growth ◽  
Correlated Response ◽  
Control Line ◽  
Differential Rate ◽  
Early Postnatal Development ◽  
Specific Effects ◽  
Selection For

Abstract A series of mouse lines was produced by long-term restricted index selection for divergent rate of growth during early and late postnatal development. The selection program was based on the following treatments: E+ and E- lines were selected to alter birth to 10-day weight gain while holding late gain for both lines constant and a control line was established via random selection. Using embryo transfer and crossfostering methodology, we partitioned postnatal growth for E+, E-, and C lines into progeny genetic, uterine maternal, and nurse maternal components. Selection for differential early growth resulted in correlated response in uterine and nurse maternal effects on body weights, with significant genetic-by-environment interactions. Significant uterine effects were also observed in tail length measurements. Direct uterine effects on body weight were relatively small and resulted in growth rate differences early in development. Nurse effects were large, resulting in modification of progeny growth trajectory especially during early postnatal development. Genetic-by-uterine interactions were large and demonstrate progeny-specific effects of the prenatal uterine environment.

Sign in / Sign up

Export Citation Format

Share Document