Genetic control of the environmental variance for birth weight in seven generations of a divergent selection experiment in mice

2015 ◽  
Vol 133 (3) ◽  
pp. 227-237 ◽  
Author(s):  
N. Formoso-Rafferty ◽  
I. Cervantes ◽  
N. Ibáñez-Escriche ◽  
J.P. Gutiérrez
Keyword(s):  
Birth Weight ◽  
Genetic Control ◽  
Divergent Selection ◽  
Selection Experiment ◽  
Environmental Variance ◽  
Seven Generations

scholarly journals Selection Response in a Divergent Selection Experiment for Birth Weight Variability in Mice Compared with a Control Line

Animals ◽  
2020 ◽  
Vol 10 (6) ◽  
pp. 920
Author(s):  
Nora Formoso-Rafferty ◽  
Katherine Natalia Chavez ◽  
Candela Ojeda ◽  
Isabel Cervantes ◽  
Juan Pablo Gutiérrez
Keyword(s):  
Birth Weight ◽  
Litter Size ◽  
Laboratory Mouse ◽  
Selection Response ◽  
Divergent Selection ◽  
Suitable Model ◽  
Control Line ◽  
Selection Experiment ◽  
High Line ◽  
Third Line

Birth weight (BW) in animal production is an economically important trait in prolific species. The laboratory mouse (Mus musculus) is used as an experimental animal because it is considered a suitable model for prolific species such as rabbits and pigs. Two mouse lines were divergently selected for birth weight variability with a third line of non-selected control population of the same origin as the animals starting the experiment. The objective of this study was, therefore, to compare and evaluate the differential response of each line. The animals were from the 17th generation of both low and high BW variability lines of the divergent selection experiment, including in addition animals from the control line. The dataset contained 389 records from 48 litters of the high line, 734 records from 73 litters of the low line, and 574 records from 71 litters of the control line. The studied traits were as follows: the BW, the BW variance, the BW standard deviation, the BW coefficient of variation within-litter, the weaning weight (WW), the litter size at birth and at weaning, the weight gain, and the preweaning survival. The model included the line effect jointly with the parturition number and its interaction, the linear and quadratic LS as covariates except for the LS trait itself when analyzing litter traits, as well as the pup sex when analyzing individual traits. The low line had a lower BW and WW, but a higher litter size, and greater robustness owing to a higher survival at weaning. As a model of livestock animals, the findings from this experiment led to a proposal of selection for pig production that would combine an increase in litter size with higher survival and welfare. Compared with the control line, a much higher response was observed in the low variability line than in the high line, making it extremely satisfactory given that homogeneity provides advantages in terms of animal welfare and robustness.

Genetic analyses of piglet survival and individual birth weight on first generation data of a selection experiment for piglet survival under outdoor conditions

2007 ◽  
Vol 2007 ◽  
pp. 65-65
Author(s):  
R. Roehe ◽  
N. P. Shrestha ◽  
W. Mekkawy ◽  
P. W. Knap ◽  
K. M. Smurthwaite ◽  
...  
Keyword(s):  
Birth Weight ◽  
Litter Size ◽  
Genetic Improvement ◽  
First Generation ◽  
Genetic Parameters ◽  
Selection Experiment ◽  
Postnatal Mortality ◽  
Breeding Programmes ◽  
Potential Benefits ◽  
Piglet Survival

Peri- and postnatal mortality of piglets is reported to be around 20% and genetic improvement in piglet survival has great potential benefits in terms of animal welfare, economics and the environment. The indication of an unfavourable genetic correlation between litter size and survival in particular points to the importance of including piglet survival in those pig breeding programmes that currently only aim to increase litter size. Phenotypically, individual birth weight is closely associated with piglet survival (Roehe and Kalm, 2000). Genetic parameters for piglet survival traits and individual birth weight therefore need to be estimated in order to genetically improve piglet survival efficiency

Genetic Studies of the Offspring of Identical Twins - A Model for the Analysis of Quantitative Inheritance in Man

1976 ◽  
Vol 25 (1) ◽  
pp. 103-113 ◽  
Author(s):  
Walter E. Nance
Keyword(s):  
Birth Weight ◽  
Genetic Variance ◽  
Genetic Model ◽  
Genetic Effect ◽  
Identical Twins ◽  
Additive Genetic Effect ◽  
Quantitative Inheritance ◽  
Ridge Count ◽  
Environmental Variance ◽  
Genetic Studies

In conjunction with full-sib and parental observations, half-sib analysis permits an estimation of the genetic and environmental variance as well as a partitioning of the genetic variance into its additive, dominance and epistatic components. The offspring of identical twins are a unique class of human half-sibs who provide an unusual opportunity to resolve and measure several additional potentially important sources of human variation including maternal effects, the influences of common environmental factors and assortative mating.The genetic model thus developed for the analysis of quantitative inheritance in man has been applied to the analysis of total ridge count and birth weight, confirming the existence of a major additive genetic effect on ridge count and a significant maternal effect on birth weight.

scholarly journals Evaluation of the sensory attributes along rabbit loin by a trained panel

2018 ◽  
Vol 26 (1) ◽  
pp. 43
Author(s):  
Marina Martínez-Álvaro ◽  
Pilar Hernández
Keyword(s):  
Descriptive Analysis ◽  
Intramuscular Fat ◽  
Sensory Attributes ◽  
Divergent Selection ◽  
Reference Standards ◽  
Longissimus Dorsi ◽  
Selection Experiment ◽  
Trained Panel ◽  
Rabbit Meat ◽  
Sensory Studies

The aim of this study was to evaluate and quantify variation in sensory attributes along the <em>Longissimus dorsi</em> (LD) muscle in rabbits. A descriptive analysis was performed by a panel of 8 assessors previously trained in the evaluation of rabbit meat. Reference standards used in training for the evaluation of rabbit meat are also described. Sensory attributes rabbit and liver odour, rabbit and liver flavour, toughness, juiciness and fibrousness were assessed in 56 rabbits from a divergent selection experiment for intramuscular fat (28 slaughtered at 9 wk and 28 slaughtered at 13 wk). Immediately after cooking, loins were cut lengthwise into 4 equidistant pieces from caudal to cranial end (LD<sub>1</sub>, LD<sub>2</sub>, LD<sub>3</sub> and LD<sub>4</sub>). Assessors were able to detect and quantify a longitudinal sensory variation in muscle LD. Caudal extreme LD<sub>1</sub> was tougher and more fibrous than LD<sub>2</sub>, LD<sub>3</sub> and LD<sub>4</sub>, and less juicy than LD<sub>3</sub> and LD<sub>4</sub>. The greatest variation was found between caudal and cranial ends, with LD<sub>1</sub> being 9% tougher (P=0.99), 11% more fibrous (P=1.00) and 12% less juicy (P=0.99) than LD<sub>4</sub>. Assessors found few variations along LD muscle in flavour and odour attributes. Location LD<sub>3</sub> showed 9% greater rabbit odour (P=0.99) and flavour (P=0.97) than LD<sub>4</sub>, and 8% greater rabbit odour than LD<sub>2</sub> (P=0.97). Our results highlight the importance of randomisation within muscle location in sensory studies on rabbit LD muscle, as there is considerable sensory variation along this muscle.

scholarly journals Genetic analysis of environmental variation

2010 ◽  
Vol 92 (5-6) ◽  
pp. 381-395 ◽  
Author(s):  
WILLIAM G. HILL ◽  
HAN A. MULDER
Keyword(s):  
Genetic Variation ◽  
Genetic Control ◽  
Genetic Variance ◽  
Environmental Variation ◽  
Alternative Methods ◽  
Trait Variation ◽  
Environmental Variance ◽  
Breeding Programmes ◽  
Genetic Coefficient Of Variation ◽  
Genetic Coefficient

SummaryEnvironmental variation (VE) in a quantitative trait – variation in phenotype that cannot be explained by genetic variation or identifiable genetic differences – can be regarded as being under some degree of genetic control. Such variation may be either between repeated expressions of the same trait within individuals (e.g. for bilateral traits), in the phenotype of different individuals, where variation within families may differ, or in both components. We consider alternative models for defining the distribution of phenotypes to include a component due to heterogeneity ofVE. We review evidence for the presence of genetic variation inVEand estimates of its magnitude. Typically the heritability ofVEis under 10%, but its genetic coefficient of variation is typically 20% or more. We consider experimental designs appropriate for estimating genetic variance inVEand review alternative methods of estimation. We consider the effects of stabilizing and directional selection onVEand review both the forces that might be maintaining levels ofVEand heritability found in populations. We also evaluate the opportunities for reducingVEin breeding programmes. Although empirical and theoretical studies have increased our understanding of genetic control of environmental variance, many issues remain unresolved.

scholarly journals Estimates of genetic parameters of growth traits of Nellore cattle in the Midwest region of Brazil

2014 ◽  
Vol 15 (4) ◽  
pp. 846-853 ◽  
Author(s):  
Cláudio Vieira de Araújo ◽  
Raysildo Barbosa Lôbo ◽  
Luis Gustavo Girardi Figueiredo ◽  
Cláudio Jonasson Mousquer ◽  
Monyka Marianna Massoloni Laureano ◽  
...  
Keyword(s):  
Birth Weight ◽  
Fixed Effects ◽  
Growth Traits ◽  
Genetic Correlations ◽  
Environmental Variance ◽  
Weaning Weight ◽  
Nellore Cattle ◽  
Midwest Region ◽  
Estimate Variance ◽  
Genetic Value

Records of birth weight (BW) and weights standardized to 210 (W210); 365 (W365) and 550 (W550) of age in the Nellore breed were used to estimate variance components of genetic effects and predict genetic values of sires. The model included the fixed effects of contemporary group and cow age at calving as co-variable, and the additive and maternal genetic, permanent maternal environmental, and temporary environmental random effects. Estimates of means and standard deviations for BW, W210; W365 and W550 were 32.76 ± 3.74; 184.30 ± 29.02; 240.31 ± 41.85 and 322.12 ± 60.77, respectively. A significant additive genetic variability was detected for all weights. The permanent maternal environmental variance showed greater relevance on weaning weight, and it was practically inexistent after weaning. For the maternal genetic variance, the estimate for birth weight was more significant as compared with weaning weight. The estimated heritability values for BW, W210; W365 and W550 were 0.37 ± 0.02; 0.36 ± 0.03; 031 ± 0.01 and 0.38 ± 0.02, respectively. Genetic correlations between birth weight and other weights were of low magnitude, with high values of weights at other ages. The use of sires of higher genetic value for total maternal effect makes it possible to use sires that are more positive for weaning weight and also for year and yearling weight.

scholarly journals Response to somatic cell count-based selection for mastitis resistance in a divergent selection experiment in sheep

2009 ◽  
Vol 92 (3) ◽  
pp. 1203-1219 ◽  
Author(s):  
R. Rupp ◽  
D. Bergonier ◽  
S. Dion ◽  
M.C. Hygonenq ◽  
M.R. Aurel ◽  
...  
Keyword(s):  
Somatic Cell ◽  
Cell Count ◽  
Somatic Cell Count ◽  
Divergent Selection ◽  
Selection Experiment ◽  
Selection For

INFLUENCE OF BODY WEIGHT AND CHANGES IN BODY WEIGHT OF THE COW ON PREWEANING TRAITS OF THE CALF

1980 ◽  
Vol 60 (3) ◽  
pp. 599-607
Author(s):  
G. W. RAHNEFELD ◽  
R. J. PARKER ◽  
S. YODSERANEE ◽  
E. W. STRINGAM
Keyword(s):  
Body Weight ◽  
Birth Weight ◽  
Average Daily Gain ◽  
Control Line ◽  
Selection Experiment ◽  
Weight Changes ◽  
Apparent Effect ◽  
Weaning Weight ◽  
Factors Affecting ◽  
Daily Gain

This study was designed to estimate and evaluate environmental factors affecting birth weight, weaning weight and preweaning average daily gain (ADG) of purebred Shorthorn calves from the control line of a selection experiment. Nine years of data consisted of 635 birth weight and 607 weaning weight records. Least squares analysis of variance revealed that sex of the calf was the most important source of variation: males averages 2.31 kg heavier at birth, were 14.3 kg heavier at weaning and gained 0.08 kg more per day from birth to weaning than females. Heavier cows in June, October, and December prior to parturition and at parturition produced heavier calves at birth. Heavier cows in October prior to parturition, at parturition, and in June or October following parturition produced calves which grew more rapidly from birth to weaning and were heavier at weaning. There was no apparent effect of cow weight changes before or after parturition on preweaning traits. Correlations of birth weight with weaning weight, preweaning ADG and cow weight at parturition were 0.56 ± 0.03, 0.43 ± 0.04 and 0.24 ± 0.04 respectively. Correlations of weaning weight and preweaning average daily gain with cow weights at parturition were 0.42 ± 0.04 and 0.40 ± 0.04. Correlations among cow weights in June, October, and December prior to parturition, at parturition, and in June and October following parturition were estimated.

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