PHENOTYPIC AND GENETIC PARAMETER ESTIMATES FOR GESTATION LENGTH, CALVING EASE AND BIRTH WEIGHT IN SIMMENTAL CATTLE

1988 ◽  
Vol 68 (1) ◽  
pp. 291-294 ◽  
Author(s):  
R. A. KEMP ◽  
J. W. WILTON ◽  
L. R. SCHAEFFER
Keyword(s):  
Birth Weight ◽  
Random Mating ◽  
Genetic Parameter ◽  
Parameter Estimates ◽  
Gestation Length ◽  
Calving Ease ◽  
Phenotypic Correlations ◽  
Large Numbers ◽  
Genetic And Phenotypic Correlations ◽  
Variance And Covariance Components

Variance components, heritabilities and genetic and phenotypic correlations were estimated using progeny records of 73 sires on the Young Sire Proving Program (YSPP) of the Canadian Simmental Association. The YSPP was based on random mating of 58 test and 15 reference sires to cows in cooperating herds. Data were collected on several traits but the ones of interest in this study were gestation length (GL), calving ease (CE) and birth weight (BW). Variance and covariance components were estimated using Henderson's method 3. Heritability estimates were 0.24, 0.06 and 0.19 for GL, CE and BW, respectively. Genetic and phenotypic correlations were negative between GL and CE and CE and BW. Correlations between GL and BW were moderate and positive. Selection programs, utilizing large numbers of progeny per sire, would be effective but should incorporate the correlations between these traits. Key words: Heritabilities, genetic and phenotypic correlations, selection

scholarly journals Realized Sampling Variances of Estimates of Genetic Parameters and the Difference Between Genetic and Phenotypic Correlations

Genetics ◽  
1996 ◽  
Vol 143 (3) ◽  
pp. 1409-1416 ◽  
Author(s):  
Kenneth R Koots ◽  
John P Gibson
Keyword(s):  
Genetic Correlation ◽  
Genetic Parameters ◽  
Genetic Parameter ◽  
Genetic Correlations ◽  
Phenotypic Correlation ◽  
Parameter Estimates ◽  
Sampling Variance ◽  
Phenotypic Correlations ◽  
Genetic And Phenotypic Correlations ◽  
Heritability Estimates

Abstract A data set of 1572 heritability estimates and 1015 pairs of genetic and phenotypic correlation estimates, constructed from a survey of published beef cattle genetic parameter estimates, provided a rare opportunity to study realized sampling variances of genetic parameter estimates. The distribution of both heritability estimates and genetic correlation estimates, when plotted against estimated accuracy, was consistent with random error variance being some three times the sampling variance predicted from standard formulae. This result was consistent with the observation that the variance of estimates of heritabilities and genetic correlations between populations were about four times the predicted sampling variance, suggesting few real differences in genetic parameters between populations. Except where there was a strong biological or statistical expectation of a difference, there was little evidence for differences between genetic and phenotypic correlations for most trait combinations or for differences in genetic correlations between populations. These results suggest that, even for controlled populations, estimating genetic parameters specific to a given population is less useful than commonly believed. A serendipitous discovery was that, in the standard formula for theoretical standard error of a genetic correlation estimate, the heritabilities refer to the estimated values and not, as seems generally assumed, the true population values.

Genetic parameter estimates (full sib and half sib analysis) of fertility and hatchability in two strains of Rhode Island chickens

2021 ◽  
Vol 38 (1) ◽  
pp. 14-22
Author(s):  
M. Orunmuyi ◽  
I. A. Adeyinka ◽  
O.O Oni
Keyword(s):  
Rhode Island ◽  
Additive Genetic Variance ◽  
Genetic Parameter ◽  
Genetic Correlations ◽  
Reproductive Traits ◽  
Parameter Estimates ◽  
Phenotypic Correlations ◽  
Poultry Breeding ◽  
Genetic And Phenotypic Correlations ◽  
Heritability Estimates

A study was conducted to estimate the genetic parameters of fertility and hatchability in two strains of Rhode Island Red (RIR) Chickens denoted as Strain A and Strain B respectively using the full-sib (sire +dam variance) and maternal half-sib (dam variance) components. The birds were obtained from the selected populations of RIR Chickens kept at the poultry breeding programme of National Animal Production Research Institute, Shika, Zaria, Nigeria. Settable eggs were collected from mating 28 cocks to 252 hens in a ratio of 1cock:9 hens from each strain. Eggs were pedigreed according to sire and dam. Results showed that values obtained for number of egg set (EGGSET), number of fertile eggs (NFERT), number of hatched chicks (NHATCH), percentage of chicks hatched from total eggs set (PHATCH) and percentage of chicks hatched from fertile eggs (PHATCHBL) were all higher in strain A than strain B. Heritability estimates obtained from the full-sib and maternal half-sib analysis ranged from medium to high for the two strains (0.24-0.96). The maternal half sib estimates were higher (0.40-0.96) than the estimates obtained from full sibs (0.24- 0.48). Genetic and phenotypic correlations obtained for both strains were positive and similar regardless of method of estimation. Genetic correlations between EGGSET and PFERT were low in strain A using both full-sib and maternal half-sib analyses (0.09-0.14). Phenotypic correlations between EGGSET and PFERT, PHATCH and PHATCHBL were also low in both strains and regardless of method of analyses. Moderate to high heritability estimates suggest that genetic improvement can be obtained by selection of these reproductive traits. The full-sib analysis for estimating heritability will be preferred since it is assumed that only additive genetic variance contributes to the covariance between family members.

scholarly journals Genetic parameter estimates for birth and weaning weights in Raeini goats

2010 ◽  
Vol 55 (No. 1) ◽  
pp. 30-36 ◽  
Author(s):  
M. Gholizadeh ◽  
G. Rahimi Mianji ◽  
M. Hashemi ◽  
H. Hafezian
Keyword(s):  
Birth Weight ◽  
Genetic Parameters ◽  
Genetic Parameter ◽  
Residual Effects ◽  
Parameter Estimates ◽  
Genetic Covariance ◽  
Weaning Weight ◽  
Variance And Covariance Components ◽  
Estimate Variance ◽  
Additive Genetic Effects

The aim of the present study was to estimate variance components and genetic parameters for birth and weaning weights in Raeini goats. The data were collected from the Breeding Centre of Raeini (BCR) cashmere goats in Kerman province of Iran from 1986 to 2008. Random effects included direct and maternal additive genetic effects, maternal permanent environmental effects with direct-maternal genetic covariance and random residual effects. Variance and covariance components and genetic parameters were estimated using the DFREML program by fitting six single-trait animal models. Depending on the model, h<sub>d</sub><sup>2</sup> varied from 0.057 to 0.323 for birth weight and from 0.043 to 0.229 for weaning weight. Estimates of <I>m</I><sup>2</sup> ranged from 0.016 to 0.289 for birth weight and from 0.01 to 0.184 for weaning weight. The maternal permanent environmental effect was significant for both traits and ignoring maternal effects in the model caused the overestimation of direct heritability.

scholarly journals BREED OF DAM, AGE OF DAM AND SEX OF CALF EFFECTS IN THE CANADIAN SIMMENTAL YOUNG SIRE PROVING PROGRAM

1984 ◽  
Vol 64 (1) ◽  
pp. 1-8
Author(s):  
R. A. KEMP ◽  
L. R. SCHAEFFER ◽  
J. W. WILTON
Keyword(s):  
Birth Weight ◽  
Key Words ◽  
Mixed Model ◽  
Genetic Relationships ◽  
Residual Effects ◽  
Gestation Length ◽  
Calving Ease ◽  
Sire Evaluation ◽  
Unbiased Estimates ◽  
Best Linear Unbiased

Canadian Simmental Association Young Sire Proving Program records (1978–1982) were used to estimate breed of dam by age of dam by sex of calf effects for several traits. Two models were used. Model 1 included fixed herd-years, breed of dam by age of dam by sex of calf (BAX) plus random sire and residual effects. Model 2 included fixed herd-year by sex of calf and breed of dam by age of dam (BA) plus random sire and residual effects. Both models included additive genetic relationships among sires and maternal grandsires. Traits used with Model 1 were gestation length (GL), calving ease (CE), birth weight (BW), gain on dam (GD) and 200-day weight (WW). Model 2 was used for gain on test (GT) and 365-day weight (YW). Mixed model techniques were used to obtain best linear unbiased estimates of BAX and BA from models 1 and 2, respectively. Hypothesis tests were conducted using two breed of dam groups ([Formula: see text] Simmental (S) and [Formula: see text] British breeds (B)) and four age of dam groups (2, 3, 4 and 5 + yr which correspond to < 31, 31–42, 43–54 and > 54 mo, respectively). Three-way subclasses (BAX) were significant (P < 0.01) for GL, CE, BW, GD and WW as were two-way subclasses (BA) for YW. Estimated differences for breed of dam by age of dam by six of calf subclasses (for GL, CE, BW, GD, WW) and breed of dam by age of dam subclasses (for YW) generally increased as age of dam increased. Accounting for breed of dam, age of dam, sex of calf and interaction effects are important in sire evaluation. Estimated differences of these effects, a by-product of sire evaluation, can be used to increase the accuracy of procedures for individual and dam evaluation. Key words: Breed of dam by age of dam by sex of calf effects, sire evaluation, mixed model techniques

scholarly journals GENETIC ASPECTS OF PREWEANING PERFORMANCE OF NDAMA CATTLE

2021 ◽  
Vol 11 (2) ◽  
pp. 151-155
Author(s):  
A. O. Leigh ◽  
O. Akinokun ◽  
S. A. Adeyanju
Keyword(s):  
Birth Weight ◽  
Beef Cattle ◽  
Genetic Parameters ◽  
Weaning Weight ◽  
Livestock Farm ◽  
Phenotypic Correlations ◽  
Genetic And Phenotypic Correlations ◽  
Daily Gain

Records on birth weight (BW), preweaning daily gain (PWG) and weaning weight (WW) of Ndama beef cattle were obtained from the Fashola Livestock Farm in Oyo State of Nigeria between 1954 and 1964 and were analyzed to estimate the phenotypic and genetic parameters of preweaning performances of this breed of cattle. For birth weight, preweaning daily gain and weaning weight respectively heritability was estimated as 0.13 ± 0.08, 0.30 ± 0.14 and 0.25 ± 0.12 from paternal half-sib relationship. The estimates of genetic and phenotypic correlations obtained from these data among the three pre-weaning traits were found to be similar to those already in the general literature on beef cattle.

Estimation genetic and phenotypic correlations between weight traits pre and post weaning weight in Baluchi sheep

2007 ◽  
Vol 2007 ◽  
pp. 71-71
Author(s):  
Mojtaba Hosseinpour Mashhadi ◽  
Mehdi Aminafshar ◽  
Nafise Tabasi
Keyword(s):  
Genetic Parameters ◽  
Genetic Parameter ◽  
Harsh Environment ◽  
Economic Traits ◽  
Weaning Weight ◽  
Sheep Population ◽  
Phenotypic Correlations ◽  
Native Breed ◽  
Hot Climate ◽  
Genetic And Phenotypic Correlations

Baluchi is the most common native breed of sheep in Iran, comprising 30% of the sheep population. This breed is native to the eastern part of the country, which has a dry and hot climate. The animals have had to adapt to the harsh environment. In order to improve efficiency, the performance of the animals for economic traits is used to estimate genetic parameters and selection in some nucleus flocks. The genetic and phenotypic correlations between weight traits have been reported for different breeds. The objective of this investigation is to estimate the genetic parameter and genetic and phenotypic correlations between weight traits.

scholarly journals Calf birth weight, gestation length, calving ease, and neonatal calf mortality in Holstein, Jersey, and crossbred cows in a pasture system

2013 ◽  
Vol 96 (1) ◽  
pp. 690-698 ◽  
Author(s):  
K. Dhakal ◽  
C. Maltecca ◽  
J.P. Cassady ◽  
G. Baloche ◽  
C.M. Williams ◽  
...  
Keyword(s):  
Birth Weight ◽  
Gestation Length ◽  
Crossbred Cows ◽  
Calving Ease ◽  
Neonatal Calf ◽  
Calf Mortality
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