A genetic study on sexual dimorphism of bodyweight in sheep

2015 ◽  
Vol 55 (1) ◽  
pp. 101 ◽  
Author(s):  
Farhad Ghafouri-Kesbi ◽  
Ghodratollah Rahimi Mianji ◽  
Zarbakht Ansari Pirsaraei ◽  
Seyed Hasan Hafezian ◽  
Hasan Baneh ◽  
...  
Keyword(s):  
Sexual Dimorphism ◽  
Maternal Effects ◽  
Variance Components ◽  
Genetic Basis ◽  
Sexual Size Dimorphism ◽  
Genetic Correlations ◽  
Male And Female ◽  
Low Levels ◽  
Age Estimates ◽  
Zandi Sheep

The aim of the present study was to investigate the genetic basis of sexual dimorphism of bodyweight in Zandi sheep. To do this, a pedigree including 1450 dams and 170 sires was used. Six bivariate animal models were applied for investigating direct and maternal effects for three age-specific bodyweights (bodyweight at birth, 3 and 6 months of age) in male and female Zandi lambs. The variance components were estimated via REML procedure. Males were, respectively, 6%, 7% and 9% heavier than females at birth, weaning and 6 months of age. Estimates of sexual dimorphism levels (expressed as M/F) were 1.11 at birth, 1.07 at weaning and 1.09 at 6 months of age, which indicated relatively low levels of sexual size dimorphism in the traits studied. Except for birthweight, for which estimates of additive genetic, residual and phenotypic variances as well as direct heritability and additive coefficient of variation were higher in females, for other traits studied, estimates were higher in males. However, regarding direct and maternal effects, none of the differences between the sexes was significant, indicating no need for sexual selection. Cross-sex genetic correlations were 0.862 at birth, 0.918 at weaning and 0.922 at 6 months of age, which highlighted birthweight as the most dimorphic trait. It was concluded that, owing to possible contribution of sexual chromosomes to variation of growth-related traits, bodyweight in male and female lambs may not be under the exactly same genetic control.

scholarly journals Sex influence on genetic expressions of early growth in Afshari lambs

2016 ◽  
Vol 59 (1) ◽  
pp. 9-17 ◽  
Author(s):  
F. Ghafouri-Kesbi ◽  
D. R. Notter
Keyword(s):  
Sexual Dimorphism ◽  
Fixed Effects ◽  
Early Growth ◽  
Domestic Sheep ◽  
Environmental Correlations ◽  
Male And Female ◽  
Selection Strategies ◽  
Genetic Components ◽  
Low Levels ◽  
Male To Female

Abstract. Very little is known about the genetic aspects of sexual dimorphism of body weight in domestic sheep, and therefore this study was conducted to quantify the genetic basis of sexual dimorphism for early-growth-related traits in Afshari lambs. Traits evaluated included birth weight (BW), weaning weight (WW), and growth rate (GR) in male and female lambs. Male lambs were 6.6 % heavier at birth, had 14.4 % higher preweaning growth rates and were 16.0 % heavier at weaning compared to female lambs. Levels of sexual-size dimorphism (SSD), expressed as the ratio of male to female means, for BW, WW and GR were 1.07, 1.14 and 1.15, respectively, which indicated low levels of SSD in the traits studied. Fixed effects of year of birth and type of birth interacted with sex effects, with greater variability in birth and weaning weights among years and birth types in male lambs, suggesting greater environmental sensitivity in the males. Bivariate animal models and restricted maximum likelihood (REML) procedures were used to estimate phenotypic variances and their genetic and non-genetic components in male and female lambs. Estimates of the direct heritability (h2) and additive coefficient of variation (CVA) for BW were higher in males. However, for WW and GR, heritability estimates were higher in females. In contrast, whereas the contribution of maternal permanent environmental effects (c2) to variation of BW was higher in females, for WW and GR higher estimates of c2 were observed in males. Respective genetic and maternal permanent environmental correlations between records on males and females were 0.986 and 0.723 for BW, 0.995 and 0.983 for WW, and 0.995 and 0.966 for GR, indicating possible sexual dimorphism only for maternal effects on BW. Based on an approximate 95 % confidence interval, none of the observed differences in variance components between sexes differed from zero and none of the observed genetic or maternal correlations differed from 1.0, indicating no need or opportunity for sex-specific selection strategies.

scholarly journals Sex-specific microhabitat use is associated with sex-biased thermal physiology in Anolis lizards

2020 ◽  
pp. jeb.235697
Author(s):  
Michael L. Logan ◽  
Lauren K. Neel ◽  
Daniel J. Nicholson ◽  
Andrew J. Stokes ◽  
Christina L. Miller ◽  
...  
Keyword(s):  
Sexual Dimorphism ◽  
Habitat Use ◽  
Thermal Tolerance ◽  
Sexual Size Dimorphism ◽  
Microhabitat Use ◽  
Thermal Physiology ◽  
Male And Female ◽  
Size Dimorphism ◽  
Heterogeneous Habitats ◽  
Males And Females

If fitness optima for a given trait differ between males and females in a population, sexual dimorphism may evolve. Sex-biased trait variation may affect patterns of habitat use, and if the microhabitats used by each sex have dissimilar microclimates, this can drive sex-specific selection on thermal physiology. Nevertheless, tests of differences between the sexes in thermal physiology are uncommon, and studies linking these differences to microhabitat use or behavior are even rarer. We examined microhabitat use and thermal physiology in two ectothermic congeners that are ecologically similar but differ in their degree of sexual size dimorphism. Brown anoles (Anolis sagrei) exhibit male-biased sexual size dimorphism and live in thermally heterogeneous habitats, whereas slender anoles (Anolis apletophallus) are sexually monomorphic in body size and live in thermally homogeneous habitats. We hypothesized that differences in habitat use between the sexes would drive sexual divergence in thermal physiology in brown anoles, but not slender anoles, because male and female brown anoles may be exposed to divergent microclimates. We found that male and female brown anoles, but not slender anoles, used perches with different thermal characteristics and were sexually dimorphic in thermal tolerance traits. However, field-active body temperatures and behavior in a laboratory thermal arena did not differ between females and males in either species. Our results suggest that sexual dimorphism in thermal physiology can arise from phenotypic plasticity or sex-specific selection on traits that are linked to thermal tolerance, rather than from direct effects of thermal environments experienced by males and females.

scholarly journals Estimates of direct and maternal genetic parameters for weight traits and backfat thickness in a multibreed population of beef cattle

1999 ◽  
Vol 79 (4) ◽  
pp. 433-439 ◽  
Author(s):  
J. J. Tosh ◽  
R. A. Kemp ◽  
D. R. Ward
Keyword(s):  
Beef Cattle ◽  
Maternal Effects ◽  
Variance Components ◽  
Genetic Parameters ◽  
Genetic Correlations ◽  
Backfat Thickness ◽  
Residual Effects ◽  
Parameter Estimates ◽  
Ratio Test ◽  
Environmental Correlations

Variance components were estimated for weight at birth, weaning, and 365 d of age, and yearling ultrasonic backfat thickness in a multibreed population of beef cattle. Data (n = 5880) were available on F1 animals and various crosses leading up to, and including, a composite breed (7/16 British, 1/4 Charolais, 1/4 Simmental, and 1/16 Limousin). Single- and two-trait analyses were conducted using an animal model and derivative-free REML procedures. Covariates representing fractional contributions of each of the four purebred groups and average heterotic effects, both direct and maternal, accounted for breed composition. Direct and maternal genetic, maternal permanent environmental, and residual effects were the random variables. Only minor differences existed between parameter estimates obtained from the various analyses. Mean direct heritabilities were 0.51, 0.33, 0.48, and 0.37 for weight at birth, weaning, and 365-d, and backfat, respectively, which, though well within the range of published estimates, seemed higher than average, indicating diversity in the founding purebreds. Mean maternal heritabilites were 0.09, 0.13, and 0.08 for the three consecutive weights. A likelihood ratio test showed maternal heritability and(or) the direct-maternal correlation was important (P < 0.001) for 365-d weight. Averaged across weights, the direct-maternal correlation was 0.07, lacking evidence of genetic antagonism. No age of dam or random maternal effects on backfat were apparent. Phenotypic correlations between weight at birth and weaning and weight at weaning and 365-d were 0.46 and 0.76, respectively. Though moderate between birth and weaning weight, maternal genetic and permanent environmental correlations between weaning and 365-d weight approached unity, demonstrating maternal carryover effects. Phenotypic and genetic correlations of 0.19 and –0.13, respectively, implied a limited association between 365-d weight and backfat, which possibly would have been stronger had fat been measured later in life. Estimates of variance components suitable for general use can be obtained from data from multibreed animals by considering breed and heterotic effects. Key words: Beef cattle, crossbreds, genetic parameters, heritability, maternal effects

A measure for predicting genetic merit for milking and nursing ability in beef cattle

1997 ◽  
Vol 65 (1) ◽  
pp. 39-43 ◽  
Author(s):  
N. Yokoi ◽  
K. Moriya ◽  
Y. Sasaki
Keyword(s):  
Beef Cattle ◽  
Maternal Effects ◽  
Maternal Effect ◽  
Genetic Correlations ◽  
Japanese Black Cattle ◽  
Calf Growth ◽  
Genetic Merit ◽  
Livestock Breeding ◽  
Breeding Station ◽  
Age Estimates

AbstractTo determine a best measure for predicting genetic merit for milking and nursing ability in beef cattle, restricted maximum likelihood (REML) estimates of variances and covariances for direct and maternal effect were obtained by using pre-weaning growth records of calves at various stages after parturition until weaning in Japanese Black cattle. Data used in this study were pre-weaning growth records of 1892 Japanese Black calves obtained from the Tottori National Livestock Breeding Station covering the period from 1960 to 1985. Traits analysed were adjusted monthly weights, adjusted monthly heights and cumulative daily gains (DGs) from birth to 1, 2, 3, 4, 5 and 6 months of age. Estimates of variances and covariances were obtained by REML using the DFREML program of Meyer. Results indicate that: (1) the direct effects on pre-weaning growth of calves are the smallest at birth to 1 month of age and then increase; (2) the maternal effects of the dams are the largest for the first 2 months, and then decrease; (3) the contribution of these two effects on calf growth is reversed at 3 or 4 months of age; (4) the non-additive maternal effects exist but are small; and (5) the genetic correlations between direct and maternal effects are low for weight and cumulative DG, whereas those for height are relatively high. These results suggest that DGfrom birth to 2 months of age (DGO-2) is most influenced by the additive maternal effect. Thus, DGO-2 is concluded to be the best measure for predicting genetic merit for milking and nursing ability in beef cattle.

scholarly journals Analysis of (co) variance components and estimation of breeding value of growth and production traits in Dahlem Red chicken using pedigree relationship in an animal model

PLoS ONE ◽  
2021 ◽  
Vol 16 (3) ◽  
pp. e0247779
Author(s):  
U. Rajkumar ◽  
L. Leslie Leo Prince ◽  
K. S. Rajaravindra ◽  
S. Haunshi ◽  
M. Niranjan ◽  
...  
Keyword(s):  
Animal Model ◽  
Maternal Effects ◽  
Variance Components ◽  
Egg Production ◽  
Genetic Correlations ◽  
The Body ◽  
Breeding Value ◽  
Egg Mass ◽  
Residual Variance ◽  
Production Traits

Variance and covariance components of growth and production traits were analyzed employing REML animal model to assess the Dahlem Red (PD-3) chicken population for direct additive genetic, maternal effects and to estimate the estimated breeding value (EBV), genetic parameters, genetic trends and rate of inbreeding (ΔF) utilizing seven generation’s data. The generation and hatch had significant (P≤0.01) effect on the body weight at 0 day (BW0), 2 (BW2), 4 (BW4) and 6 weeks (BW6) and shank length at six weeks of age (SL6). The average least squares means (LSM) for BW6 and SL6 were 273.93±0.62 g and 53.97±0.05 mm, respectively. All the production traits were significantly (P≤0.01) influenced by generation and hatch. The average LSM for age at sexual maturity (ASM), egg production up to 40 weeks (EP40) and egg mass up to 40 weeks (EM40) were 168.82±0.25 d, 72.60±0.41 eggs and 4.21±0.07 kg, respectively. Model 5 with additive direct, maternal genetic, maternal permanent environmental and residual variance components was the best for BW0, BW2 and BW4 based on the AIC values obtained in WOMBAT. Model 4 was the best model for BW6, SL6, ASM, EP40 and EM40 with additive direct, maternal permanent environmental and residual variance components. Maternal effects were higher during early age, decreased with age, and remained present until 20 weeks of age. The heritability (h2) estimates were low to moderate in magnitude for all the growth traits and ranged from 0.02±0.03 to 0.19±0.03. The maternal heritability was high at hatch (0.35±0.06), decreased gradually until 4th week (0.02±0.01) and ceased afterwards. The heritabilities of EP40 (0.11±0.03) and EM40 (0.12±0.04) were low. The direct additive genetic correlations (ra) between BW2, BW4, BW6 and SL6 were high and positive (P≤ 0.05). The additive genetic and maternal permanent environmental correlation between EP40 and EM40 were high and positive (P≤ 0.05). The EBV of EM40 was significant (P≤ 0.05) with 0.48 kg/generation in PD-3 chicken at the end of the seventh generation. The EBV of EP40 showed an increasing trend with a genetic gain of 1.87 eggs per generation. The average inbreeding coefficient of the population was 0.019 and average ΔF was 0.007 over the last seven generations of selection. The EBV trends for primary and associated traits showed linear trends in the desired direction and negligible inbreeding.

Genetic parameters of growth of Ethiopian Boran cattle

1987 ◽  
Vol 44 (2) ◽  
pp. 201-208 ◽  
Author(s):  
Th. Arnason ◽  
H. Kassa-Mersha
Keyword(s):  
Birth Weight ◽  
Maternal Effects ◽  
Variance Components ◽  
Genetic Parameters ◽  
Genetic Correlations ◽  
Genetic Covariance ◽  
Weaning Weight ◽  
Genetic Components ◽  
Selection Indices ◽  
The Individual

ABSTRACTRecords on birth weight and pre-weaning growth of 3959 Boran calves, which were progeny of 51 sires and 979 dams, were analysed by least-squares analysis of variance. The variance components for sires, dams and maternal grandsires were estimated from the data. On the basis of assumed genetic correlations −0·44 and −0·55 between direct and maternal effects on birth weight and weaning weight, respectively, the maternal genetic component and the genetic covariance between direct and maternal effects were estimated. The heritabilities for direct effects on birth weight and weaning weight were 0·11 and 0·22, respectively, while the heritabilities of maternal effects were estimated as 0·02 and 0·11, respectively for the same traits. Selection indices for direct and maternal genetic components of weaning weight were constructed for practical use. These selection indices combined information on the individual, the parents and sibs.

Rat liver carbonic anhydrase I is not sexually dimorphic but is estrogen repressible

1985 ◽  
Vol 5 (9) ◽  
pp. 735-738 ◽  
Author(s):  
S. Jeffery ◽  
N. D. Carter ◽  
C. A. Wilson
Keyword(s):  
Sexual Dimorphism ◽  
Carbonic Anhydrase ◽  
Sex Hormones ◽  
Rat Liver ◽  
Female Rats ◽  
Sexually Dimorphic ◽  
Male And Female ◽  
Carbonic Anhydrase I ◽  
Male And Female Rats ◽  
Low Levels

Carbonic anhydrase (CA) isozymes CAII and CAIII are known to exhibit sexual dimorphism in rat liver, and the levels of these isozymes are affected by sex hormones. In this paper we show that the isozyme CAI is present at low levels in rat liver, with no difference in concentration between male and female rats. Estrogen and diethylstilbestrol reduce CAI levels in both sexes.

Evaluating animal models comprising direct and maternal effects associated with growth rates and the Kleiber ratio in Harnali sheep

Zygote ◽  
2021 ◽  
pp. 1-5
Author(s):  
Ashish Chauhan ◽  
S.P. Dahiya ◽  
Ankit Magotra ◽  
Yogesh C. Bangar
Keyword(s):  
Animal Models ◽  
Maternal Effects ◽  
Growth Rates ◽  
Variance Components ◽  
Average Daily Gain ◽  
Genetic Correlations ◽  
Ratio Test ◽  
Kleiber Ratio ◽  
Managerial Strategies ◽  
Daily Gain

Summary The present work evaluated animal models comprising direct and maternal effects to estimate (co)variance components and genetic parameters of growth rates and Kleiber ratio in Harnali sheep. The information on pedigree and targeted traits of 1862 lambs born to 144 sires and 591 dams was collected for the period from 1998 to 2018. The traits studied were average daily gain from birth to 3 months of age (ADG1), 3 months to 6 months of age (ADG2), and 6 months to 12 months of age (ADG3) and their corresponding Kleiber ratios as KR1, KR2 and KR3, respectively. The statistical methods included the general linear model for analyzing the effects of fixed factors and animal models for deriving variance components for targeted traits. According to best model evaluated on the basis of likelihood ratio test, the estimated direct heritability was low in magnitude and ranged from 0.04 to 0.14. Direct heritability estimates for ADG1, ADG2, ADG3, KR1, KR2 and KR3 were 0.06, 0.14, 0.05, 0.04, 0.11 and 0.05, respectively. The maternal genetic effects contributed (4–7%) significantly for ADG1, KR1 and KR2 traits. The genetic correlations ranged from −0.35 ± 0.11 (ADG1-KR2) to 0.98 ± 0.01 (ADG2-KR2 and ADG3-KR3) and phenotypic correlations ranged from −0.36 ± 0.02 to 0.98 ± 0.01 for ADG1-KR2 and ADG2-KR2, respectively. The significant maternal effects along with low levels of direct effects for average daily gain and Kleiber ratio at different age group should be considered while setting selection and managerial strategies to achieve anticipated growth rates in Harnali sheep.

XXI.—Sex-linked Association of Egg Weight and Body Weight in Brown Leghorns

1955 ◽  
Vol 65 (3) ◽  
pp. 317-326 ◽  
Author(s):  
Robert Osborne
Keyword(s):  
Body Weight ◽  
Regression Analysis ◽  
Maternal Effects ◽  
Variance Components ◽  
Present Report ◽  
Additive Effects ◽  
Sex Linkage ◽  
Egg Weight ◽  
Male And Female ◽  
Marked Dependence

SynopsisThe present report is submitted as an illustration of the utility of variance and covariance analysis in the detection of specific modes of inheritance in quantitative genetics.The techniques are discussed with reference to the existence of sex-linkage, maternal effects, non-additivity, and the confounding of these. Comparison of variance components due to male and female parents has revealed marked evidence of sex-linked variation of egg weight in a population of Brown Leghorns, but no obviously associated variation of body weight. Subsequent analysis reveals large sex-linked covariance, and it appears that sex-linked variation of body weight is masked by non-additive effects.Similar conclusions follow from regression analysis of offspring on parent. For egg weight there is marked dependence of offspring on paternal variation, whilst for body weight, heritability from regression analysis is substantially lower than that estimated from correlations between offspring, in accordance with the existence of sex-linked and non-additive effects.

scholarly journals Sexual Dimorphism in A Cross River Ecotype Local Chicken – Rose Comb (Gallus gallus domesticus)

2020 ◽  
Vol 8 (3) ◽  
Author(s):  
Hannah Edim Etta ◽  
Henry Kogbara Barizigakol
Keyword(s):  
Sexual Dimorphism ◽  
Sexual Size Dimorphism ◽  
Gallus Gallus ◽  
Gallus Domesticus ◽  
Gallus Gallus Domesticus ◽  
Morphometric Traits ◽  
Male And Female ◽  
Cross River ◽  
Relative Contribution ◽  
Local Chicken

Sexual dimorphism in the local chicken (Gallus gallus domesticus)-Rose Comb- in Cross River was investigated. Sixty (60) male and female Gallus gallus domesticus chickens were evaluated for the effect of sex on body weight (BW), body length (BL), body girth (BG), thigh length(TL), shank length (SL) and keel length (KL) which were measured fortnightly for twelve (12) weeks. Sexual Size Dimorphism Index (SSDI) and Sexual Dimorphism Index (SDI) were used to confirm relative contribution of each trait to total dimorphism. The values obtained for SSDI and SDI respectively were 1.61 and 61% for BW; 1.26 and 26.52% for TL; 1.23 and 23.81% for SL; 1.22 and 21.50% for BL; 1.18 and 18.20% for BG; 1.17 and 17.94% for KL. To identify the best trait for predicting sex, stepwise discriminate analysis was employed and the Wilk’s Lamda values obtained were BW(0.471); TL(0.452); SL(0.401); BL(0.283); BG(0.272) and KL(0.271). Results showed that there were significant (p<0.05) differences in all measured parameters at week 6 with mean BW, BL, BG, SL, KL and TL of 300.01 and 253.24; 22 and 18.62; 5.20 and 3.98; 4.60 and 3.50; 5.50 and 3.90; 13.10 and 11.20  for both male and female birds respectively. These results indicate that sexual dimorphism is exhibited in all morphometric traits in favor of the male with BW as the highest dimorphic trait.  

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