scholarly journals Genetic parameters of yield and morphological fruit and stone properties in apricot

Genetika ◽  
2007 ◽  
Vol 39 (3) ◽  
pp. 315-324 ◽  
Author(s):  
Evica Mratinic ◽  
Vera Rakonjac ◽  
Dragan Milatovic
Keyword(s):  
Correlation Analysis ◽  
Genetic Correlation ◽  
Genetic Parameters ◽  
Ecological Factors ◽  
Fruit Weight ◽  
Genetic Differences ◽  
Total Variance ◽  
Phenotypic Correlations ◽  
Genetic And Phenotypic Correlations ◽  
Significant Yield

Yield, fruit and stone weight and dimensions were studied in 24 apricot cultivars over a four-year period, to determine components of variability, heritability and genetic and phenotypic correlations. The analysis of the components of total variance evidenced that genetic differences between cultivars determined to the highest percentage the variability of fruit height and stone weight and dimensions, whereas the variation of yield, and fruit weight, breadth and thickness was predominantly determined by ecological factors. The values of heritability coefficients, in a broader sense, were found to be relatively high for fruit and stone weight and dimensions (88-93%), and medium for yield (48%). It was established by correlation analysis that all genetic and phenotypic coefficients of correlation between fruit and stone weight and dimensions were positive and statistically very significant. Yield was in a very significant, positive genetic correlation with a majority of studied characters except for fruit breadth. However, the phenotypic coefficients of correlation between those properties were not statistically significant.

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 parameters of Barki sheep raised under semi-arid conditions

1969 ◽  
Vol 11 (3) ◽  
pp. 361-367 ◽  
Author(s):  
M. H. Fahmy ◽  
E. Salah E. Galal ◽  
Y. S. Ghanem ◽  
S. S. Khishin
Keyword(s):  
Genetic Parameters ◽  
Genetic Correlations ◽  
Research Station ◽  
Phenotypic Correlations ◽  
Arid Conditions ◽  
Body Weights ◽  
Genetic And Phenotypic Correlations ◽  
Fleece Weight ◽  
Semi Arid ◽  
Desert Research

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.

scholarly journals Genetic parameters of production and reproduetive traits in on a farm tested Danish Large White and Landrace swine in Greece

2000 ◽  
Vol 43 (3) ◽  
pp. 287-298
Author(s):  
J. Bizelis ◽  
A. Kominakis ◽  
E. Rogdakis ◽  
F. Georgadopoulou
Keyword(s):  
Maximum Likelihood ◽  
Genetic Correlation ◽  
Genetic Parameters ◽  
Genetic Correlations ◽  
Production Traits ◽  
Likelihood Methods ◽  
Large White ◽  
Reproduction Traits ◽  
Maximum Likelihood Methods ◽  
Genetic And Phenotypic Correlations

Abstract. Production and reproduetive traits in Danish Landrace (LD) and Large White (LW) swine were analysed by restricted maximum likelihood methods to obtain heritabilities as well as genetic and phenotypic correlations. Production traits were: age, backfat thickness (BT), muscle depth (MD) and the ratio BT/MD, adjusted to Standard bodyweight of 85 kg. Reproduction traits were: number of pigs born (NB) and number of pigs weaned (NW) per sow and parity. Heritabilities for age, BT, MD and BT/MD were 0.60, 0.44, 0.51 and 0.42 for LD and 0.36, 0.44, 0.37 and 0.45 for LW, respectively. Genetic correlations between age and BT were −0.22 in LD and – 0.44 in LW. The genetic correlation between age and MD was close to zero in both breeds. Genetic correlation between BT and MD were −0.36 and −0.25 in LD and LW, respectively. Heritabilities for NB were 0.25 in LD and 0.13 in LW while heritabilities for NW were close to zero in both breeds. Genetic correlation between NB and NW was 0.46 and 0.70 in LD and LW, respectively.

In silico investigation of the effect of nutrition on the estimates of genetic parameters for lambs infected with gastro-intestinal parasites

2007 ◽  
Vol 2007 ◽  
pp. 89-89
Author(s):  
A. B. Doeschl-Wilson ◽  
D. Vagenas ◽  
S.C. Bishop ◽  
I. Kyriazakis
Keyword(s):  
Dietary Protein ◽  
Genetic Parameters ◽  
Intestinal Parasites ◽  
Protein Supplementation ◽  
Gastrointestinal Parasites ◽  
Environment Interaction ◽  
Phenotypic Correlations ◽  
Nutritional Conditions ◽  
Breeding Programmes ◽  
Genetic And Phenotypic Correlations

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.

DEVELOPMENT OF DLS BREED OF SHEEP: GENETIC AND PHENOTYPIC PARAMETERS OF DATE OF LAMBING AND LITTER SIZE

1990 ◽  
Vol 70 (3) ◽  
pp. 771-778 ◽  
Author(s):  
MOHAMED H. FAHMY
Keyword(s):  
Key Words ◽  
Genetic Correlation ◽  
Breeding Season ◽  
Litter Size ◽  
Least Square ◽  
Phenotypic Correlation ◽  
Phenotypic Correlations ◽  
Genetic And Phenotypic Correlations

Least square means, heritabilities, repeatabilities, genetic and phenotypic correlations of date of lambing and litter size in a population of DLS sheep selected for extended breeding season were estimated by different methods. Mean date of lambing for first, second and third parities was 20 Jan., 6 Jan., 31 Dec. and mean litter size was 1.20, 1.25 and 1.41 lambs, respectively. Heritabilities for date of lambing were 0.37 (sire component, 0.25 (sire and dam component), 0.52 (correlation between full sisters) and 0.17 (regression of daughter on dam). For litter size these methods gave the following estimates: 0.17, 0.14, 0.22 and 0.04, respectively. Repeatability estimates averaged 0.21 for date of lambing and 0.24 for litter size. Genetic correlation between the two traits was calculated at −0.38 (sire component), −0.25 (full sisters) and −0.07 (regression of daughter on dam) while the phenotypic correlation was estimated at −0.19 (P < 0.01). Key words: DLS sheep, heritability, repeatability, genetic correlation, phenotypic correlation, date of lambing, litter size

scholarly journals EFFECT OF FIXED FACTORS AND ESTIMATION OF GENETIC PARAMETERS OF GROWTH TRAITS FOR MOUNTAIN KIDS

2019 ◽  
Vol 50 (6) ◽  
Author(s):  
Hermiz & Baper
Keyword(s):  
Variance Components ◽  
Fixed Effects ◽  
Genetic Parameters ◽  
Maximum Likelihood Method ◽  
Growth Traits ◽  
Genetic Correlations ◽  
Likelihood Method ◽  
Phenotypic Correlations ◽  
Body Weights ◽  
Genetic And Phenotypic Correlations

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.

scholarly journals Heritability, Genetic, and Phenotypic Correlations of Several Peach Traits

HortScience ◽  
1995 ◽  
Vol 30 (4) ◽  
pp. 763B-763
Author(s):  
Valdomiro A.B. de Souza ◽  
David H. Byrne ◽  
Jeremy F. Taylor
Keyword(s):  
Skin Color ◽  
Fixed Effects ◽  
Prunus Persica ◽  
Mixed Linear Model ◽  
Fruit Weight ◽  
Soluble Solids ◽  
Genetic Progress ◽  
Multiple Trait ◽  
Phenotypic Correlations ◽  
Genetic And Phenotypic Correlations

Heritability estimates are useful to predict genetic progress among offspring when the parents are selected on their performance, but they also provide information about major changes in the amount and nature of genetic variability through generations. Genetic and phenotypic correlations, on the other hand, are useful for better planning of selection programs. In this research, seedlings of 39 families resulting from crosses among 27 peach [Prunus persica (L.) Batsch] cultivars and selections were evaluated for date of full bloom (DFB), date of ripening (DR), fruit period development (FDP), flower density (FD), node density (ND), fruit density (FRD), fruit weight (WT), soluble solids content (SS), apical protuberance (TIP), red skin color (BLUSH), and shape (SH) in 1993 and 1994. The data were analyzed using the mixed linear model. The best linear unbiased prediction (BLUP) was used to estimate fixed effects and predict breeding values (BV). Restricted maximum likelihood (REML) was used to estimate variance components, and a multiple-trait model to estimate genetic and phenotypic covariances between traits. The data indicates high heritability for DFB, DR, FDP, and BLUSH, intermediate heritability for WT, TIP, and SH, and low heritability for FD, ND, FRD, and SS. They also indicate year effect as a major environmental component affecting seedling performance. High correlation estimates were found between some traits, but further analysis is needed to determine their significance.

HERITABILITY OF TEAT NUMBER IN SWINE

1990 ◽  
Vol 70 (2) ◽  
pp. 425-430 ◽  
Author(s):  
R. M. McKAY ◽  
G. W. RAHNEFELD
Keyword(s):  
Key Words ◽  
Genetic Correlation ◽  
Genetic Correlations ◽  
Phenotypic Correlation ◽  
Data Set ◽  
Phenotypic Correlations ◽  
Teat Number ◽  
Genetic And Phenotypic Correlations ◽  
Time Periods ◽  
Selection For

Heritabilities were estimated for teat number in nine populations of swine over two time periods. From 1962 to 1974 the populations included Lacombe, Yorkshire, and Lacombe × Yorkshire. In this data set, only total teat number was recorded. From 1982 to 1988 three purebred populations (Landrace, Yorkshire, and Hampshire) and three crossbred populations (Landrace-Yorkshire rotation, Landrace × Yorkshire, and Landrace × Hampshire) were represented and total teat number and the number of teats anterior and posterior to the navel were recorded. Heritabilities for total teat number were greater in the 1982–1988 data (ranging from 0.27 to 0.47) than in the 1962–1974 data (ranging from 0.20 to 0.32). The heritability of posterior teat numbers (ranging from 0.08 to 0.39) was generally larger than the heritability of anterior teat numbers (ranging from 0.03 to 0.21) and both were considerably less than the heritability of total teat number. Genetic and phenotypic correlations were calculated for the relationships between anterior and posterior teat numbers (AP), anterior and total teat numbers (AT), and posterior and total teat numbers (PT). The relative magnitudes of the genetic and phenotypic correlations with respect to AP, AT, and PT revealed that selection for increased total teat number would increase the number of anterior and posterior teats. However, the larger genetic correlations for PT relative to AT would lead to a greater increase in posterior teat number than anterior teat number. Key words: Pigs, teat number, heritability, genetic correlation, phenotypic correlation

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.

PSXII-30 Genetic and phenotypic correlations for growth and resistance to gastrointestinal parasitism in meat goats and hair sheep

2021 ◽  
Vol 99 (Supplement_3) ◽  
pp. 491-492
Author(s):  
Yoko Tsukahara ◽  
Terry A Gipson ◽  
Steven P Hart ◽  
Lionel J Dawson ◽  
Zaisen Wang ◽  
...  
Keyword(s):  
Genetic Correlation ◽  
Average Daily Gain ◽  
Phenotypic Correlation ◽  
Hair Sheep ◽  
Phenotypic Correlations ◽  
Fecal Egg Count ◽  
Meat Goats ◽  
Genetic And Phenotypic Correlations ◽  
Moderately Resistant ◽  
On Farm

Abstract Genetic and phenotypic correlations for growth and response to parasite infection traits were estimated for growing male meat goats and hair sheep from different farms in the southcentral United States during three consecutive central performance tests (CPT). Data were collected for 7–10 wk after artificial infection with Haemonchus contortus, which included average daily gain (ADG), fecal egg count (FEC), packed cell volume (PCV), and immunoglobin (Ig) levels. Animals evaluated were selected randomly in year 1 and in years 2 and 3 progeny of CPT sires classified as highly or moderately resistant and included 46, 50, and 51 Boer, Kiko, and Spanish goats and 59, 61, 34, and 46 Dorper, Katahdin-farm A, Katahdin-farm B, and St. Croix sheep, respectively. Females were classified accordingly on-farm based on FEC and FAMACHA. Pedigree records included 4 and 10 full-sibs and 97 and 149 half-sibs for goats and sheep, respectively. Variance components and correlations were estimated by AIREML using WOMBAT with a multivariate animal model. The additive genetic correlation between FEC and PCV was negative for goats (r=-041, P &lt; 0.001) but positive for sheep (r=0.21, P = 0.004), whereas the phenotypic correlation between FEC and PCV was nonsignificant for goats but negative for sheep (r=-0.252, P &lt; 0.001). The genetic correlation between FEC and IgA was positive (r=0.39, P &lt; 0.001) for goats but nonsignificant (P = 0.439) for sheep, whereas those of FEC with IgM and IgG were both negative (r=-0.369 and -0.732 with IgM and r=-0.284 and -0.702 for goats and sheep, respectively; P &lt; 0.001). Genetic and phenotypic correlations between ADG and FEC were nonsignificant for both species. In conclusion, different relationships of FEC and PCV between species require careful attention during selection and the lack of relationship between ADG and FEC suggests that selection of growing male meat goats and hair sheep for resistance to internal parasitism will not adversely affect growth performance.

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