Effects of divergent selection for body weight on bone length and diameter in mice

1977 ◽  
Vol 24 (1) ◽  
pp. 77-82 ◽  
Author(s):  
A. C. B. Hooper
Keyword(s):  
Body Weight ◽  
Genetic Control ◽  
Maternal Effects ◽  
General Pattern ◽  
Intramembranous Ossification ◽  
Correlated Responses ◽  
Bone Length ◽  
Quantitative Genetic ◽  
Selection For ◽  
Genetically Determined

SUMMARYThe length and diameter of the humerus, ulna, femur and tibia were studied at generations 10 and 14 in lines of mice selected for high and low body weight at 10 weeks of age.Although some deviations from control were not significant, a general pattern of correlated responses was evident. The divergences of high and low line means for bone length and diameter were significant in the four bones, confirming the contribution of these parameters to genetically determined alterations in body weight. Maternal effects did not affect bone length and diameter and heterosis was not important in the genetic control of these parameters. Unlike bone length, bone diameter continued to diverge in response to the additional four generations of selection. There may therefore be differences in the quantitative genetic control of bone length and diameter and consequently in the control of endochondral and intramembranous ossification.

Predicted and realized responses to selection for an index of bone length and body weight in Scottish Blackface sheep 2. Correlated responses in lifetime productivity

1986 ◽  
Vol 43 (3) ◽  
pp. 437-445 ◽  
Author(s):  
K. D. Atkins ◽  
R. Thompson
Keyword(s):  
Body Weight ◽  
Population Genetic ◽  
Genetic Correlations ◽  
Reproduction Rate ◽  
Base Population ◽  
Correlated Responses ◽  
Genetic Response ◽  
Bone Length ◽  
Body Weights ◽  
Selection For

ABSTRACTA selection experiment with Scottish Blackface sheep was used to compare predicted and realized correlated responses to selection. Three lines were maintained between 1956 and 1974 in which selection was either at random or for high and low values of an index of cannon-bone length at 8 weeks of age adjusted for body weight at the same age.There was no evidence of asymmetrical responses in any trait. Selection for increased cannon-bone length, adjusted for body weight, resulted in (i) increased body weights at all ages between birth and maturity, (ii) increased reproduction rate, principally from increased litter size but also from small responses in ewe fertility and lamb survival and (iii) decreased survival of adult ewes. The realized genetic correlations were relatively small (up to 0·3) but mostly significantly different from zero, whereas base population genetic correlation estimates were very imprecise. The realized responses in reproduction rate were probably a consequence of the genetic response in body weight.

Response to selection in Australian Merino sheep. III. Single character selection for high and low values of wool weight and its components

1970 ◽  
Vol 21 (6) ◽  
pp. 955 ◽  
Author(s):  
HN Turner ◽  
MG Brooker ◽  
CHS Dolling
Keyword(s):  
Body Weight ◽  
Unit Area ◽  
Genetic Correlations ◽  
Fibre Diameter ◽  
Initial Response ◽  
Skin Area ◽  
Correlated Responses ◽  
Fibre Number ◽  
Selection For ◽  
Staple Length

Direct and correlated responses are reported for 10 traits in eight pairs of lines under selection for high and low values of single characteristics : clean wool weight per head, clean wool weight per unit skin area (measured only in the groups under selection for it), body weight, wrinkle score, fibre number per unit skin area (adjusted for body weight), fibre diameter, staple length, and percentage clean yield. All groups showed overall divergence in the character under selection, though response was not always symmetrical, and in two cases (long staple and low fibre number) there was no continuing response after the initial response to extreme selection of the base parents. In all except one case, whenever previous estimates of genetic correlation were at the level of 0.2 or higher, correlated responses were in the predicted direction, though not always symmetrical in magnitude. The exception was a previously reported negative correlation between fibre number and staple length, which was not exhibited under selection for either character. Where two characters of a pair were under selection, reciprocal responses agreed in sign; magnitude will be examined in a later paper. Wool per unit area was shown to have a greater influence on clean wool weight than that of surface area, with staple length on this occasion being the most important component of wool per unit area. Reasons for an apparent decrease in the relative importance of fibre number are discussed. Three other points of importance in sheep breeding are again emphasized by these results : 1. Crimp in several pairs of groups was a poor indicator of fibre diameter. 2. Increases in clean wool weight were associated with falls in crimp number, even though fibre diameter actually became finer; diameter, not crimp, should therefore be used as a guide to wool quality. 3. The absence of genetic correlations DL and NL indicates that selection can be for high N (fibre number) with high L (staple length) and low D (fibre diameter) -in other words, a desirable fleece -with no impeding genetic correlations.

CORRELATED RESPONSES IN EGG QUALITY TRAITS TO SELECTION FOR EARLY BODY WEIGHT IN MEAT-TYPE CHICKENS

1972 ◽  
Vol 14 (3) ◽  
pp. 477-482 ◽  
Author(s):  
V. Buvanendran ◽  
E. S. Merritt
Keyword(s):  
Body Weight ◽  
Egg Quality ◽  
Correlated Response ◽  
Quality Traits ◽  
Correlated Responses ◽  
Egg Weight ◽  
Shell Color ◽  
Blood Spots ◽  
Selection For ◽  
Meat Type

The correlated responses in egg quality traits to selection for high early body weight were studied in seven meat-type populations comprising five selected and two control lines. Traits studied were specific gravity, egg weight, albumen height, Haugh units, shell color, egg shape, shell roughness, wrinkling and asymmetry, and incidence of blood spots, meat spots and double yolks. Significant (P < 0.05 or < 0.01) correlated changes, as determined by the regression of correlated response (egg quality traits) on primary response (body weight), were obtained for egg weight, albumen height, Haugh units, asymmetry of shell and blood spots. All but blood spots increased with selection for high body weight. Shell color showed a consistent trend towards a darker color with increasing body weight. Scores for roughness of shell and, with one minor exception, the incidence of double yolks, also showed consistent trends (positive) with increasing body weight. Estimates of genetic correlations, derived directly from intra-line genetic analyses of the six pedigreed populations in the experiment, were in most cases in reasonable agreement with realized estimates.

Selection for litter size, body weight, and pelt quality in mink (Mustela vison): correlated responses

1994 ◽  
Vol 72 (5) ◽  
pp. 1126-1137 ◽  
Author(s):  
Gabrielle Lagerkvist ◽  
K. Johansson ◽  
N. Lundeheim
Keyword(s):  
Body Weight ◽  
Litter Size ◽  
Mustela Vison ◽  
Correlated Responses ◽  
Selection For

Studies on Growth Performance and Genetic Parameters of Three Varieties of Domesticated Japanese Quail

2020 ◽  
Author(s):  
M Monika ◽  
J J Rokade ◽  
R Narayan ◽  
V K Saxena ◽  
Snehasmita Panda ◽  
...  
Keyword(s):  
Body Weight ◽  
Genetic Parameters ◽  
Genetic Correlations ◽  
Field Testing ◽  
Pure Line ◽  
Japanese Quails ◽  
Quantitative Genetic ◽  
Body Weights ◽  
Selection For ◽  
Mortality Percentage

The quantitative genetic study involving a pure line mating of 160 pairs of three varieties of domesticated Japanese quails (CARI-Ujjawal; CARI-Suneheri and CARI-Brown) were maintained under individual pedigree cages for breeding. A total of 6221 quail chicks from three hatches comprising three varieties were used for this study. Among them, CARI-Ujjawal has higher hatchability with less rearing mortality percentage. CARI-Ujjawal had highest (plessthan0.01) body weight at all ages when compared to the other two varieties. The heritability estimates on body weight (0-5 weeks) among the varieties range from low to moderate in all the three varieties. The positive correlation was observed among all the varieties at different ages. High genetic correlations between body weights at early as well as later ages confirms that selection for body weight at early ages would improve body weight at later (maturity) ages. Amongst all, CARI-Suneheri was having better heritability values and during further generations of selections it performed also well to improve because of its better heritability. Also from above results this variety could be recommended for broiler quail breeding after field testing.

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