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

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.

Genetics ◽  
1996 ◽  
Vol 143 (3) ◽  
pp. 1409-1416 ◽  
Author(s):  
Kenneth R Koots ◽  
John P Gibson

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.


2021 ◽  
Vol 11 (2) ◽  
pp. 151-155
Author(s):  
A. O. Leigh ◽  
O. Akinokun ◽  
S. A. Adeyanju

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.


1969 ◽  
Vol 11 (3) ◽  
pp. 361-367 ◽  
Author(s):  
M. H. Fahmy ◽  
E. Salah E. Galal ◽  
Y. S. Ghanem ◽  
S. S. Khishin

SUMMARYRecords on 695 lambs were collected over a period of 5 years from 1961/62 to 1965/66, at Ras El-Hekma Desert Research Station, 230 km west of Alexandria. The characters studied were birth, weaning and yearling body weights, pre- and post-weaning daily gains and greasy fleece weight.Birth, 120-day and 365-day body weights were 3·4, 18·2 and 33·4 kg respectively. Greasy fleece weight at 16 months of age was 3·29 kg. Heritability estimates of birth, weaning, yearling weights, pre- and post-weaning daily gains and greasy fleece weight were 0·22, 0·45, 0·41,0·45 and 0·29 respectively. Genetic and phenotypic correlations between birth, weaning and yearling weights were all positive and significant. Genetic correlations between fleece weight and body characteristics were negative and low.


2021 ◽  
Vol 38 (1) ◽  
pp. 14-22
Author(s):  
M. Orunmuyi ◽  
I. A. Adeyinka ◽  
O.O Oni

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.


2007 ◽  
Vol 2007 ◽  
pp. 89-89
Author(s):  
A. B. Doeschl-Wilson ◽  
D. Vagenas ◽  
S.C. Bishop ◽  
I. Kyriazakis

In recent years there has been an increased interest for breeding lambs resistant to gastrointestinal parasites due to the reduced efficacy of anthelminthics. Furthermore, protein supplementation alleviates the adverse effects of parasitism since more protein is available for the satisfaction of the competing body functions of growth and resistance to parasites. Therefore, differences in dietary protein might result in the expression of genotype x environment interaction. Additionally the estimates of genetic and phenotypic correlations obtained from populations kept under different nutritional conditions might differ with implications for the breeding programmes. The aim here is to explore the effect of dietary protein level on the estimates of genetic and phenotypic correlations of a population of growing lambs infected with gastrointestinal parasites using a simulation model.


1980 ◽  
Vol 30 (2) ◽  
pp. 271-276 ◽  
Author(s):  
A. P. Mavrogenis ◽  
A. Louca ◽  
O. W. Robison

ABSTRACTData on 792 Chios lambs born during the 1972/73 and 1973/74 lambing seasons were used to estimate genetic and phenotypic parameters for birth weight, weaning weight, age at weaning, pre-weaning daily gain, body weight at 5, 10, 15 and 20 weeks of age, and postweaning daily gain. Body weight at 15 weeks of age had the highest heritability estimate (0·73 ± 0·17) and that of post-weaning daily gain was also high (0·56 ± 0·15). Selection for either weight at 15 weeks or post-weaning daily gain would be expected to yield a greater response than selection for pre-weaning daily gain or weaning weight. Genetic correlations among weights and/or gains were positive (approximately 0·20). Phenotypic correlations among weights and gains were generally higher than genetic correlations. However, the correlation between pre— and post-weaning daily gain was small (0·08). Likewise, post-weaning daily gain had low correlations with all weights before 10 weeks. Age at weaning had moderate negative associations with all weights but a very low positive correlation with post-weaning daily gain.


1988 ◽  
Vol 68 (1) ◽  
pp. 291-294 ◽  
Author(s):  
R. A. KEMP ◽  
J. W. WILTON ◽  
L. R. SCHAEFFER

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


2019 ◽  
Vol 50 (6) ◽  
Author(s):  
Hermiz & Baper

Body weights at birth (469), weaning (394) and at six month of age (358) for kids utilized in this study were raised at private project in Duhok governorate, Iraq during two kidding season (2016-2017) and (2017-2018). GLM within SAS programme was used to analyze the data which include the fixed effects (age of doe, year and season of kidding, sex of kid and type of birth, regression on doe weight at kidding, and the regression of later weights of kids on earlier weights) influencing the studied traits. Restricted Maximum Likelihood Method was used to estimate repeatability, heritability, genetic and phenotypic correlations after adjusting the records for fixed effects. Variance components of random effects were tested for positive definite. Overall mean of weights at birth (BWT), weaning (WWT) and 6 month of age (WT6M) were 2.92, 15.32 and 24.45 kg, respectively. Differences among groups of age of doe in all studied traits were not significant, while year of kidding and sex of kid affect all traits significantly (p<0.01). Season of kidding affect BWT and WWT significantly (P<0.01). Single born kids were heavier (P<0.01) than twins in BWT only. Regression of BWT on doe weight at kidding (0.033 kg/kg) was significant (P<0.01), while the regressions of WWT and WT6M were not significant. The regression coefficients of WWT on BWT (1.906 kg/kg) and of WT6M on WWT (0.835 kg/kg) were highly significant (P<0.01). Repeatability estimates for BWT, WWT and WT6M were 0.47, 0.45 and 0.35, respectively; on the same order the estimates of heritability were 0.41, 0.61 and 0.79. Genetic correlations between BWT with each of WWT (0.45) and WT6M (0.55), and between WWT and WT6M (0.68) were highly significant. All phenotypic correlations between each pair of body weights were higher than genetic correlations and ranged between 0.48 and 0.73.


2019 ◽  
Vol 19 (3) ◽  
pp. 595-604 ◽  
Author(s):  
Magdalena Szyndler-Nędza ◽  
Robert Eckert ◽  
Mirosław Tyra ◽  
Grzegorz Żak ◽  
Karolina Szulc ◽  
...  

AbstractThe aim of the study was to determine genetic parameters of live performance traits in pigs of three native breeds maintained in Poland. As part of the conservation programmes, the Puławska (Puł), Złotnicka White (ZW) and Złotnicka Spotted (ZS) breeds are monitored for productivity based on performance test results of these breeds. The study included 6042 gilts and 2406 boars of the Puławska breed, 866 Złotnicka White gilts, and 903 Złotnicka Spotted gilts. The genetic parameters were estimated separately for each breed, and also separately for sexes in the case of the Puławska breed. The components (co)variance and genetic parameters were estimated using the REML method for the animal model taking into account different combination of fixed and random effects. Convergence of the iterative process was achieved by the selection of AIREML algorithm. The coefficients of genetic and phenotypic correlations between measurements of slaughter traits and daily gain were low for all breed groups. In turn, the relationships between backfat thickness measurements and carcass meat percentage were estimated as high. Only the correlations of slaughter traits with loin eye height were not uniform for the analysed breed groups. The coefficients of heritability (h2) were high and intermediate for all breeds and sexes. The highest heritability coefficients were obtained for daily gain (0.58 in ZW to 0.80 in Puł gilts), followed by backfat thickness (0.37 in Puł gilts to 0.64 in ZW) and carcass meat percentage (0.40 in ZS to 0.56 in ZW). The lowest coefficients were obtained for loin eye height (0.24 in Puł boars to 0.40 in ZW). The estimated genetic parameters could be used to verify selection indices of the breeds included in the genetic resources conservation programmes.


2012 ◽  
Vol 34 (3) ◽  
pp. 138
Author(s):  
Veronika Yuneriati Beyleto ◽  
Sumadi (Sumadi) ◽  
Tety Hartatik

<p>This research was conducted to estimate heritability, repeatability and genetic correlation values on growth traits of Boerawa goat at Sumber Rejeki farmer group at Campang Village, Gisting District and Karya Makmur I and Karya Makmur II farmer group at Wonoharjo and Sukoharjo Village, Sumber Rejo District, Tanggamus regency, Lampung province. Data consisted of production record and 238 Boerawa goat derived from 93 PE and 7 Boer buck.<br />The research was started on October 30, 2009 up to January 30, 2010. The results indicated that heritability value of birth weight, weaning weight, yearling weigth, average of preweaning daily gain, and average of postweaning weight<br />analyzed by paternal half-sibs correlation were 0.80±0.40; 0.30±0.17; 0.80±0.04; 0.32±0.18 and 0.30±0.17, respectively. The repeatability values of birth weight, weaning weight and yearling weight analyzed based on two<br />recording per every dam were 0.42±0.07; 0.32±0.08; 0.30±0.08; 0.30±0.08 and 0.53±0.06. The genetic correlation values among birth weight and weaning weight, birth weight and yearling weight, weaning weight and yearling weight,<br />average of preweaning weight and postweaning weight daily gain analyzed by paternal half-sibs correlation were 0.50±0.04; 0.44±0.08; 0.21±0.03 and 0.20±0.05, respectively. The result also indicated that the heritability and<br />repeatability values was high and the genetic correlation values were moderate to high.</p><p>(Key words: Boerawa goat, Genetic parameter, Growth character)</p>


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