Are breech strike, dags and breech wrinkle genetically the same trait in crutched, uncrutched and mulesed Merino sheep?

2019 ◽  
Vol 59 (10) ◽  
pp. 1777
Author(s):  
J. C. Greeff ◽  
L. J. E. Karlsson ◽  
A. C. Schlink
Keyword(s):  
Genetic Correlation ◽  
Standard Error ◽  
Lower Risk ◽  
Genetic Correlations ◽  
High Standard ◽  
Breeding Value ◽  
Strongly Correlated ◽  
Merino Sheep ◽  
Skin Wrinkles ◽  
Indicator Traits

Breech strike is caused by the infestation of maggots from Lucilia cuprina on the skin of susceptible sheep. Crutching and mulesing modify the potential expression of breech strike, because crutched and mulesed sheep have a lower risk of being struck than uncrutched sheep. The inheritance of and genetic correlations among breech strike from birth to hogget shearing, and dags (breech soiling) and skin wrinkles scored at yearling age were estimated in unmulesed and crutched, unmulesed and uncrutched, and in mulesed and uncrutched Merino sheep to determine whether these traits were genetically the same under these three husbandry systems. The heritability estimates of breech strike in uncrutched, crutched and mulesed sheep were very similar (0.11 ± 0.02, 0.09 ± 0.02 and 0.08 ± 0.05 respectively). Breech strike in uncrutched sheep is genetically strongly correlated with breech strike in crutched sheep (0.80 ± 0.16). The genetic correlation between breech strike in uncrutched and in mulesed sheep was high (0.98 ± 0.40), but the high standard error makes this estimate unreliable. Dags and wrinkles are genetically moderately to strongly correlated with breech strike, which confirms that they are indicator traits for breech strike. Dags in uncrutched sheep was genetically strongly correlated with dags in mulesed sheep (0.84 ± 0.11). Breech wrinkle in uncrutched and crutched sheep, and tail wrinkle in mulesed sheep were not genetically strongly correlated with each other, as the correlations varied between zero and 0.48 (±0.18). The key outcome from this study indicates that all breech strike, wrinkle and dag data in mulesed, crutched or uncrutched flocks may be used in future to estimate a breeding value directly for breech strike.

scholarly journals Analysis of non-genetic and genetic influences underlying the growth of Kajli lambs

2020 ◽  
Vol 50 (4) ◽  
pp. 613-625
Author(s):  
A. Ali ◽  
K. Javed ◽  
I. Zahoor ◽  
K.M. Anjum
Keyword(s):  
Birth Weight ◽  
Genetic Correlation ◽  
Fixed Effects ◽  
Genetic Correlations ◽  
Breeding Value ◽  
Season Of Birth ◽  
Genetic Trend ◽  
Breeding Values ◽  
Heritability Estimates ◽  
Birth Type

Data on 2931 Kajli lambs, born from 2007 to 2018, were used to quantify environmental and genetic effects on growth performance of Kajli sheep. Traits considered for evaluation were birth weight (BWT), 120-day adjusted weight (120DWT), 180-day adjusted weight (180DWT), 270-day adjusted weight (270DWT), and 365-day adjusted weight (365DWT). Fixed effects of year of birth, season of birth, sex, birth type, and dam age on these traits were evaluated using linear procedures of SAS, 9.1. Similarly, BWT, 120DWT, 180DWT, and 270DWT were used as fixed effects mixed model analyses. Variance components, heritability and breeding values were estimated by restricted maximum likelihood. The genetic trend for each trait was obtained by regression of the estimated breeding values (EBV) on year of birth. Analyses revealed substantial influence of birth year on all traits. Sex and birth type were the significant sources of variation for BWT and 120DWT. Season of birth did not influence birth weight meaningfully, but had a significant role in the expression of 120DWT, 180DWT, and 270DWT. Heritability estimates were generally low (0.003 ± 0.018 to 0.099 ± 0.067) for all traits. With the exception of the genetic correlation of 180DWT and 365DWT, the genetic correlations between trait were strong and positive. Only 365DWT had a positive genetic trend. Although the heritability estimates for almost all weight traits were low, high and positive genetic correlations between BWT and other weight traits suggest that selection based on BWT would result in the improvement of other weight traits as a correlated response.Keywords: bodyweight, breeding value, genetic correlation, sheep

scholarly journals Genetic parameters of drinking and feeding traits of wean-to-finish pigs under a polymicrobial natural disease challenge

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Jian Cheng ◽  
Austin M. Putz ◽  
John C. S. Harding ◽  
Michael K. Dyck ◽  
Frederic Fortin ◽  
...  
Keyword(s):  
Genetic Correlation ◽  
Water Intake ◽  
Production Efficiency ◽  
Genetic Parameters ◽  
Severe Disease ◽  
Genetic Correlations ◽  
Clinical Signs ◽  
Treatment Rate ◽  
Number Of Visits ◽  
Indicator Traits

Abstract Background The pork industry faces unprecedented challenges from disease, which increases cost of production and use of antibiotics, and reduces production efficiency, carcass quality, and animal wellbeing. One solution is to improve the overall resilience of pigs to a broad array of common diseases through genetic selection. Behavioral changes in feeding and drinking are usually the very first clinical signs when animals are exposed to stressors such as disease. Changes in feeding and drinking behaviors in diseased pigs may reflect the way they cope with the challenge and, thus, could be used as indicator traits to select for disease resilience. The objectives of this study were to estimate genetic parameters of feeding and drinking traits for wean-to-finish pigs in a natural polymicrobial disease challenge model, to estimate genetic correlations of feeding and drinking traits with growth rate and clinical disease traits, and to develop indicator traits to select for disease resilience. Results In general, drinking traits had moderate to high estimates of heritability, especially average daily water dispensed, duration, and number of visits (0.44 to 0.58). Similar estimates were observed for corresponding feeding traits (0.35 to 0.51). Most genetic correlation estimates among drinking traits were moderate to high (0.30 to 0.92) and higher than among feeding traits (0 to 0.11). Compared to other drinking traits, water intake duration and number of visits had relatively stronger negative genetic correlation estimates with treatment rate and mortality, especially across the challenge nursery and finisher (− 0.39 and − 0.45 for treatment rate; − 0.20 and − 0.19 for mortality). Conclusion Most of the recorded drinking and feeding traits under a severe disease challenge had moderate to high estimates of heritability, especially for feed or water intake duration and number of visits. Phenotypic and genetic correlations among the recorded feeding traits under disease were generally low but drinking traits showed high correlations with each other. Water intake duration and number of visits are potential indicator traits to select for disease resilience because of their high heritability and had moderate genetic correlations with treatment and mortality rates under severe disease.

scholarly journals Association Between Backfat Thickness at 28 Weeks Old and Production Traits of Primiparous Landrace Sows Raised Under Tropical Conditions

2021 ◽  
Author(s):  
Praew Thiengpimol ◽  
Skorn Koonawootrittriron ◽  
Thanathip Suwanasopee
Keyword(s):  
Genetic Correlation ◽  
Selection Index ◽  
Genetic Correlations ◽  
High Standard ◽  
Backfat Thickness ◽  
Pedigree Information ◽  
Production Traits ◽  
Population Means ◽  
Maximum Likelihood Procedure ◽  
Tropical Conditions

Abstract Backfat thickness could reflex energy reserve of the female pigs that is required for their productivity, especially gilts that might be selected for the replacements. Therefore, phenotypic and genetic correlations between backfat thickness (BF) and production traits were estimated and considered for the possibility of using BF at pre-selective stage as an early indicator for productivity of the sow. Pedigree information, BF and body weight (BW) at 28 weeks old, age at first farrowing (AFF), transformed proportion of piglet loss at birth (tPL) and transformed weaning to first service interval (tWSI) of 806 primiparous Landrace sows were used to estimate the variance components by restricted maximum likelihood procedure with an average information algorithm for multivariate analysis. Genetic correlation between BF and BW was 0.70 ± 0.13. Both BF and BW had negative genetic correlation with AFF, but not tWSI. Unfortunately, genetic correlation estimates between tPL and other traits was unclear due to high standard error. The genetic correlation between AFF and tWSI was 0.78 ± 0.36. Besides 19.35% of sires, 26.34% of dams and 25.81% of sows had genetic ability for BF, BW, AFF and WSI above the population means. The genetic association between BF, BW, AFF and tWSI indicated the feasibility of using selection index to improve BF and BW at pre-selective stage and reduce AFF and tWSI of replacement gilt simultaneously. However, the estimation of genetic correlation between PL and other traits should be repeated in a larger population.

scholarly journals Nutzung des Ultraschalls in der Schlachtleistungsprüfung und Zuchtwertschätzung für Schafe

2005 ◽  
Vol 48 (2) ◽  
pp. 174-184
Author(s):  
E. Gernand ◽  
H. Lenz
Keyword(s):  
Genetic Correlation ◽  
Selection Index ◽  
Genetic Correlations ◽  
Carcass Composition ◽  
The Other ◽  
Breeding Value ◽  
Other Hand ◽  
Kidney Fat ◽  
Increase Efficiency

Abstract. Title of the paper: Using of Ultrasound for estimation of carcass composition and prediction of breeding value for sheep’s In Thuringia the subjective visual conformation scores of carcasses for blade (BL), leg (K), back (R), fat overlay (OF) and kidney fat (NF) were added by ultrasonic muscle (USK) and fat (USF) depths of living lambs. Heritabilitity estimates were carried out on 2654 slaughtered and 3228 living and ultrasonic-tested Merinolongwool lambs. Estimates of the subjective conformation scores were very low with 0.178 (BL); 0.143 (K); 0.165 (R) and 0.118 (OF). Slightly higher heritabilities could be estimated for NF (0.234), USK (0.26) and USF (0.174). The genetic correlations between conformation scores for muscle on one hand and OF and USF on the other hand were between 0.313 and 0.848. In contrast, the genetic correlation between USK on one hand and OF and USF on the other hand was rA = 0.022 and rA = −0.110, respectively). This may increase efficiency of breeding . By means of selection differences, it is recommended to use USK instead of blade and back, and USF instead of fat overlay in selection index.

Genetic and Environmental Influences on Executive Functions and Intelligence in the ABCD Study

2020 ◽  
Author(s):  
Samantha M Freis ◽  
Claire Morrison ◽  
Jeffrey M. Lessem ◽  
John K. Hewitt ◽  
Naomi P. Friedman
Keyword(s):  
Cognitive Development ◽  
Executive Functions ◽  
Genetic Correlation ◽  
Middle Childhood ◽  
Middle Age ◽  
Environmental Influences ◽  
Genetic Correlations ◽  
Twin Studies

Executive functions (EFs) and intelligence (IQ) are phenotypically correlated and heritable; however, they show variable genetic correlations in twin studies spanning childhood to middle age. We analyzed data from over 11,000 children (9-10-year-olds, including 749 twin pairs) in the Adolescent Brain Cognitive Development (ABCD) Study to examine the phenotypic and genetic relations between EFs and IQ in childhood. We identified two EF factors – Common EF and Updating-Specific, which were both related to IQ (rs = .64-.81). Common EF and IQ were heritable (53-67%), and their genetic correlation (rG = .86) was not significantly different than 1. These results suggest that EFs and IQ are phenotypically but not genetically separable in middle childhood.

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.

Genotype by environment interaction for yearling weight in Nellore cattle applying reaction norms models

2018 ◽  
Vol 58 (11) ◽  
pp. 1996
Author(s):  
S. Ribeiro ◽  
J. P. Eler ◽  
V. B. Pedrosa ◽  
G. J. M. Rosa ◽  
J. B. S. Ferraz ◽  
...  
Keyword(s):  
Genetic Correlation ◽  
Environmental Gradient ◽  
Genotype By Environment Interaction ◽  
Reaction Norms ◽  
Breeding Value ◽  
Environment Interaction ◽  
Genotype By Environment ◽  
Genotype Environment Interaction ◽  
Nellore Cattle ◽  
Gradient Variation

In the present study, a possible existence of genotype × environment interaction was verified for yearling weight in Nellore cattle, utilising a reaction norms model. Therefore, possible changes in the breeding value were evaluated for 46 032 animals, from three distinct herds, according to the environmental gradient variation of the different contemporary groups. Under a Bayesian approach, analyses were carried out utilising INTERGEN software resulting in solutions of contemporary groups dispersed in the environmental gradient from –90 to +100 kg. The estimates of heritability coefficients ranged from 0.19 to 0.63 through the environmental gradient and the genetic correlation between intercept and slope of the reaction norms was 0.76. The genetic correlation considering all animals of the herds in the environmental gradient ranged from 0.83 to 1.0, and the correlation between breeding values of bulls in different environments ranged from 0.79 to 1.0. The results showed no effect of genotype × environment interaction on yearling weight in the herds of this study. However, it is important to verify a possible influence of the genotype × environment in the genetic evaluation of beef cattle, as different environments might cause interference in gene expression and consequently difference in phenotypic response.

Breeding for improved growth and juvenile corewood stiffness in slash pine

2007 ◽  
Vol 37 (10) ◽  
pp. 1886-1893 ◽  
Author(s):  
Xiaobo Li ◽  
Dudley A. Huber ◽  
Gregory L. Powell ◽  
Timothy L. White ◽  
Gary F. Peter
Keyword(s):  
Genetic Correlation ◽  
Growth Traits ◽  
Low Cost ◽  
Genetic Correlations ◽  
Volume Growth ◽  
Pinus Elliottii ◽  
Tree Improvement ◽  
Slash Pine ◽  
Narrow Sense Heritability ◽  
Improvement Programs

The importance of integrating measures of juvenile corewood mechanical properties, modulus of elasticity in particular, with growth and disease resistance in tree improvement programs has increased. We investigated the utility of in-tree velocity stiffness measurements to estimate the genetic control of corewood stiffness and to select for trees with superior growth and stiffness in a progeny trial of 139 families of slash pine, Pinus elliottii Engelm. grown on six sites. Narrow-sense heritability estimates across all six sites for in-tree acoustic velocity stiffness at 8 years (0.42) were higher than observed for height (0.36) and diameter at breast height (DBH) (0.28) at 5 years. The overall type B genetic correlation across sites for velocity stiffness was 0.68, comparable to those found for DBH and volume growth, indicating that family rankings were moderately repeatable across all sites for these traits. No significant genetic correlations were observed between velocity stiffness, DBH, and volume growth. In contrast, a significant, but small, favorable genetic correlation was found between height and velocity stiffness. Twenty percent of the families had positive breeding values for both velocity stiffness and growth. The low cost, high heritability and nearly independent segregation of the genes involved with in-tree velocity stiffness and growth traits indicate that acoustic methods can be integrated into tree improvement programs to breed for improved corewood stiffness along with growth in slash pine.

Genetic analysis of docility score of Australian Angus and Limousin cattle

2018 ◽  
Vol 58 (2) ◽  
pp. 213 ◽  
Author(s):  
S. F. Walkom ◽  
M. G. Jeyaruban ◽  
B. Tier ◽  
D. J. Johnston
Keyword(s):  
Adverse Effect ◽  
Animal Model ◽  
Genetic Analysis ◽  
Genetic Parameters ◽  
Genetic Correlations ◽  
Production Costs ◽  
Breeding Value ◽  
Maternal Behaviour ◽  
Production Traits ◽  
Subjective Score

The temperament of cattle is believed to affect the profitability of the herd through impacting production costs, meat quality, reproduction, maternal behaviour and the welfare of the animals and their handlers. As part of the national beef cattle genetic evaluation in Australia by BREEDPLAN, 50 935 Angus and 50 930 Limousin calves were scored by seedstock producers for temperament using docility score. Docility score is a subjective score of the animal’s response to being restrained and isolated within a crush, at weaning, and is scored on a scale from 1 to 5 with 1 representing the quiet and 5 the extremely nervous or anxious calves. Genetic parameters for docility score were estimated using a threshold animal model with four thresholds (five categories) from a Bayesian analysis carried out using Gibbs sampling in THRGIBBS1F90 with post-Gibbs analysis in POSTGIBBSF90. The heritability of docility score on the observed scale was 0.21 and 0.39 in Angus and Limousin, respectively. Since the release of the docility breeding value to the Australian Limousin population there has been a favourable trend within the national herd towards more docile cattle. Weak but favourable genetic correlations between docility score and the production traits indicates that docility score is largely independent of these traits and that selection to improve temperament can occur without having an adverse effect on growth, fat, muscle and reproduction.

An analysis of the variation in the lean tissue distribution of sheep

1982 ◽  
Vol 34 (3) ◽  
pp. 257-264 ◽  
Author(s):  
B. T. Wolf
Keyword(s):  
Tissue Distribution ◽  
Genetic Correlation ◽  
Average Daily Gain ◽  
Genetic Correlations ◽  
Maximum Difference ◽  
Lean Tissue ◽  
Heritability Estimates ◽  
The Relationship ◽  
Daily Gain ◽  
Sire Breed

ABSTRACTThe distribution of lean tissue between eight standard joints was examined in 956 crossbred lambs slaughtered at constant live weights of either 35 or 40 kg. The sire breeds used were the Dorset Down, Ile-de-France, Oldenburg, Oxford, Suffolk and Texel. Sire breed did not have a significant effect on the proportion of total carcass lean found in the higher-priced joints but did show significant differences in the proportion of total carcass lean found in individual joints, with a maximum difference of 7·7 g total lean per kg joint being recorded. Similarly, small but significant effects due to ewe age (1 to 3 years), rearing type (single, twin, triplet), sex (male castrate, female) and weight of total lean were reported for the proportion of total carcass lean found in different joints.Heritability estimates ranged from 0·07 (s.e. 008) to 0·65 (s.e. 0·16) for the proportion of total lean in the best-end neck and higher-priced joints respectively. Phenotypic standard deviations of 5·8g/kg and 17·9g/kg were reported for the proportion of total lean found in the best-end neck and the higher-priced joints respectively. The genetic correlations between the proportion of total lean in each of the higher-priced joints and the proportion of total lean in the higher-priced joints combined were positive. A genetic correlation of 017 (s.e. 0·20) was found for the relationship between average daily gain from birth to slaughter and the proportion of total lean in the higher-priced joints.

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