Genetic correlation during growth of twin cattle

1965 ◽  
Vol 7 (1) ◽  
pp. 83-102 ◽  
Author(s):  
C. S. Taylor ◽  
Jean Craig
Keyword(s):  
Genetic Correlation ◽  
Genetic Correlations ◽  
Growth Curves ◽  
Body Part ◽  
Body Parts ◽  
Dairy Heifers ◽  
Significant Difference ◽  
Mean Size ◽  
Degree Of Maturity ◽  
Linear Body

SUMMARYAll possible inter-age genetic correlations were calculated for each of twelve linear body measurements taken at 3-monthly intervals up to 2 years of age on 120 pairs of uniformly reared, liberally fed one-egg and two-egg twin dairy heifers. Genetic correlations between first and second-year mean size are also given. The influences of age, age interval, degree of maturity and body part on genetic correlation are examined.Genetic correlation was in general very high. No significant difference was found between body parts in mean genetic correlation over the period studied. For a fixed age interval, genetic correlation increased with age; from a fixed age, it decreased with lengthening age-interval.The main systematic trends found in the data were accounted for in terms of the amount of development taking place. Genetic correlation appeared to decrease exponentially with difference in degree of maturity, and a formula is given for calculating an approximate value for the expected genetic correlation between size at any two ages. Its range of applicability and its place in a general study of the genetic properties of a population of growth curves are discussed.

Identical twins and developmental stability

1962 ◽  
Vol 4 (1) ◽  
pp. 144-164 ◽  
Author(s):  
C. S. Taylor
Keyword(s):  
Growth Curves ◽  
Identical Twins ◽  
Body Measurements ◽  
Frequency Distributions ◽  
Stability Of Development ◽  
Mean Size ◽  
Degree Of Maturity ◽  
The Stability ◽  
Average Size ◽  
Slow Growing

1. The stability with which dairy cattle develop in body size up to 2 years of age was studied in 60 pairs of uniformly treated identical twins, i.e. an assessment was made of the influence of season, genotype, mean size of twin pair, age and degree of maturity on the level of within-pair variability.2. The frequency distributions of size differences shown by one-egg twins were in many cases decidedly leptokurtic.3. The similarity in size of the identical twins studied was only slightly, if at all, influenced by season. Within-pair variability under free outdoor grazing was certainly not any greater than under semi-controlled conditions indoors.4. The stability with which cattle grew appeared to depend on their genotype. Identical twins of the Shorthorn breed were somewhat more alike in size than were the twins of other breed-types; crossbreds were, on average, 50 % less stable than purebreds in average size () ; although crossbreds grew with somewhat greater stability ().5. Whatever their mean size, all pairs of identical twins of the same breed appeared to grow postnatally with more or less equal stability (). Small, slow growing pairs showed a greater disparity in average size ().6. Stability of development continually changed with age but not violently. Each body measurement appeared to have its own characteristic age trend. It is false to believe that variation automatically increases with increasing age. As they grew older, identical twins tended to become less alike in their later maturing body measurements whereas their early maturing body measurements tended to decline in variability. There was an overall trend with degree of maturity; variability steadily increased to a maximum and subsequently declined.7. It is suggested that environmentally induced instability of development may remain at a minimum level so long as growth curves are not seriously distorted from their exponential path to maturity.

Variation during growth of twin cattle

1967 ◽  
Vol 9 (1) ◽  
pp. 35-60 ◽  
Author(s):  
C. S. Taylor ◽  
Jean Craig
Keyword(s):  
Genetic Variation ◽  
Body Part ◽  
Body Measurements ◽  
Body Parts ◽  
Genetic Variances ◽  
Average Value ◽  
Coefficients Of Variation ◽  
Rate Of Increase ◽  
Early Maturing ◽  
Degree Of Maturity

Phenotypic variances within pairs of monozygotic and dizygotic twin heifers and also genetic variances and heritabilities were calculated for 12 linear body measurements at a sequence of eight ages up to two years old. The 60 pairs of fraternal and 60 pairs of identical twins used were reared as part of a larger uniformity trial in which feeding was effectively ad libitum throughout.Size differences between members of DZ twin pairs were found to be approximately normally distributed with about the same variance for all breeds and crosses. The variance within DZ pairs increased strongly with age, with a marked increase between 9 and 12 months of age and with most body measurements showing a broadly similar trend. On a logarithmic scale DZ variances increased roughly linearly with degree of maturity and at about the same rate in each body measurement. Coefficients of variation within DZ pairs corrected for measuring error had an average value of 2%. They did not change greatly with age, and were roughly the same for most body measurements although width measurements tended to be more variable than average.Coefficients of variation within MZ pairs had a corresponding overall average of 1·4%; they declined rapidly with age from 2·0% to 1·1%, were roughly the same for all body measurements, but at early ages tended to be greater in late than in early maturing body parts. However, they showed no association with the earliness of maturing of a body part provided variation was measured at the same degree of maturity for each body part.Genetic variation increased rapidly with age in all body measurements. The rate of increase with age was greater for late than for early maturing parts. The rate of increase with degree of maturity, however, was about the same for all body measurements. Coefficients of genetic variation increased slowly with age; they had an average value of 1·6%.Estimates of heritability are given at a sequence of eight ages for each of 12 body measurements. They increased strongly with age from 0·14 on average at three months of age to 0·67 on average at two years of age. At any fixed age, early maturing body parts tended to have higher heritabilities than later maturing body parts. However, if heritability was measured at the same degree of maturity in each body part, early and late maturing parts had about equal heritabilities.The present results are compared with those obtained from twin cattle studies in New Zealand, Sweden and Wisconsin, U.S.A.Inferences from twins about genetic variances and heritabilities for unrelated animals are discussed.

Body size and conformation in identical twin cattle

1963 ◽  
Vol 5 (1) ◽  
pp. 77-86 ◽  
Author(s):  
C. S. Taylor ◽  
W. C. Rollins
Keyword(s):  
Body Size ◽  
Monozygotic Twin ◽  
Identical Twin ◽  
Body Measurements ◽  
Body Parts ◽  
Single Factor ◽  
Size And Shape ◽  
Mean Size ◽  
Linear Body

SUMMARYThe variation and covariation of 12 linear body measurements within 60 pairs of monozygotic twin heifers is analysed in terms of a twin's mean size over a two-year period.Possibly all the covariation, and two thirds, on average, of the variation can be accounted for by a single factor common to all the measurements.Interpretation of this factor shows that a twin is a more or less proportional replicate of its identical co-twin. This proportionality, however, is somewhat distorted because of relatively greater differences in the later maturing body parts.Finally it is shown that the predominant differences in both size and shape can simultaneously be described as twin lagging behind identical co-twin by 0±11·8 days' growth.

scholarly journals Bacteria associated with jellyfish during bloom and post-bloom periods

2018 ◽  
Author(s):  
Maja Kos Kramar ◽  
Tinkara Tinta ◽  
Davor Lučić ◽  
Alenka Malej ◽  
Valentina Turk
Keyword(s):  
Community Structure ◽  
Bacterial Community ◽  
Community Composition ◽  
Bacterial Community Structure ◽  
Bacterial Community Composition ◽  
Body Part ◽  
Body Parts ◽  
Population Peak ◽  
Significant Difference ◽  
Jellyfish Population

AbstractThis study is the first to investigate bacterial community associated with live medusaAurelia sp. in the Gulf of Trieste (northern Adriatic Sea) using both culture independent and culture-based methods. We have analysed bacterial community composition of different body parts of medusa: exumbrella surface, oral arms (‘outer’ body parts) and of gastric cavity (‘inner’ body part) and investigated possible differences in medusa associated bacterial community structure at the time of jellyfish population peak and during senescent phase at the end of bloom, when jellyfish start to decay. Based on 16S rRNA clone libraries and denaturing gradient gel electrophoresis (DGGE) analysis, we demonstrated significant difference between bacterial community associated withAureliaand the ambient seawater bacterial assemblage. Comparing bacterial community composition between differentAureliamedusa body parts, communities differed significantly, especially the one within the gastral cavity. The pronounced difference is dominance ofBetaproteobacteria(Burkholderia, CupriavidusandAchromobacter) in gastral cavity of medusa andAlpha- (Phaeobacter, Ruegeria) andGamma-proteobacteria(Stenotrophomonas, Alteromonas, PseudoalteromonasandVibrio) on ‘outer’ body parts. This suggests that body-part specific bacterial association might have an important functional roles for the host. The results of bacterial isolates showed the dominance ofGammaproeteobacteria, especiallyVibrioandPseudoalteromonasin all body parts. Finally, comparison of medusa associated bacterial community structure, at the time of jellyfish population peak and during senescent phase at the end of bloom showed increased abundance ofGammaproteobacteria, especiallyVibrio. Our results suggest members ofVibriogroup are possible commensal opportunistic visitors, later becoming consumer of moribund jellyfish biomass and that the structure of jellyfish bacterial community might be affected by anthropogenic pollution in the marine environment.

scholarly journals Genetic and phenotypic aspects of the body measured traits in merinolandschaf breed of sheep

2012 ◽  
Vol 28 (4) ◽  
pp. 733-741 ◽  
Author(s):  
M.P. Petrovic ◽  
V. Caro-Petrovic ◽  
D. Ruzic-Muslic ◽  
Z. Ilic ◽  
Z. Spasic ◽  
...  
Keyword(s):  
Body Weight ◽  
Genetic Correlation ◽  
Body Length ◽  
Genetic Correlations ◽  
The Body ◽  
Sheep Breed ◽  
Standard Errors ◽  
Phenotypic Correlations ◽  
Genetic And Phenotypic Correlations ◽  
Linear Body

Merinolandschaf sheep breed was used to estimate relationship between the next traits: Body weight of adult ewes (BW), Height to withers (HW), Body length (BL), Girth of Chest (GC), Rump Width (RW), Body weight of lambs at birth (BWB), Body weight of lambs at weaning (BWW). The collected data were from 750 sheep and their lambs during the period of three year. Estimates of means and standard errors for linear body measures and body weight of adult ewes and lambs, were obtained using the software program SPSS (2006). To estimate genetic and phenotypic correlations of observed traits, the ASREML program was used. Research has shown that genetic correlations between BW and all body measures of dams, ranging from 0.728 (BW-GC) to 0.976 (BW-HW). Genetic correlation between body measures of dams have also been positive and ranged in the interval from 0.873 (HW-GC) to 0.999 (BL-GC). Values for phenotypic correlations were lower compared with the genetic and the range varied from 0.183 (RW-BWB) to 0.421 (GC-BWW). The weaker phenotype correlations can be interpreted as play of more complex genetic and residual factors.

scholarly journals Genomic prediction by considering genotype × environment interaction using different genomic architectures

2017 ◽  
Vol 17 (3) ◽  
pp. 683-701 ◽  
Author(s):  
Mehdi Bohlouli ◽  
Sadegh Alijani ◽  
Ardashir Nejati Javaremi ◽  
Sven König ◽  
Tong Yin
Keyword(s):  
Genetic Correlation ◽  
Genomic Prediction ◽  
Genetic Correlations ◽  
Environment Interaction ◽  
Training Set ◽  
Multiple Trait ◽  
Snp Chip ◽  
Genotype Environment Interaction ◽  
Significant Difference ◽  
Accuracy Of Prediction

Abstract In this study, accuracies of genomic prediction across various scenarios were compared using single- trait and multiple-trait animal models to detect genotype × environment (G × E) interaction based on REML method. The simulated high and low linkage disequilibrium (HLD and LLD) genome consisted of 15,000 and 50,000 SNP chip applications with 300 and 600 QTLs controlling the trait of interest. The simulation was done to create the genetic correlations between the traits in 4 environments and heritabilities of the traits were 0.20, 0.25, 0.30 and 0.35 in environments 1, 2, 3 and 4, respectively. Two strategies were used to predict the accuracy of genomic selection for cows without phenotypes. In the first strategy, phenotypes for cows in three environments were kept as a training set and breeding values for all animals were estimated using three-trait model. In the second one, only 25, 50 or 75% of records in the fourth environment and all the records in the other three environments were used to predict GBV for non-phenotyped cows in the environment 4. For the first strategy, the highest accuracy of 0.695 was realized in scenario HLD with 600 QTL and 50K SNP chip for the fourth environment and the lowest accuracy of 0.495 was obtained in scenario LLD with 600QTL and 15K SNP chips for the first environment. Generally, the accuracy of prediction increased significantly (P<0.05) with increasing the number of markers, heritability and the genetic correlation between the traits, but no significant difference was observed between scenarios with 300 and 600 QTL. In comparison with models without G × E interaction, accuracies of the GBV for all environments increased when using multi-trait models. The results showed that the level of LD, number of animals in training set and genetic correlation across environments play important roles if G × E interaction exists. In conclusion, G × E interaction contributes to understanding variations of quantitative trait and increasing accuracy of genomic prediction. Therefore, the interaction should be taken into account in conducting selection in various environments or across different genotypes.

The growth of Ayrshire cattle: an analysis of linear body measurements

1975 ◽  
Vol 21 (3) ◽  
pp. 217-226 ◽  
Author(s):  
W. S. Russell
Keyword(s):  
Growth Curves ◽  
Growth Period ◽  
Body Measurements ◽  
Allometric Relationship ◽  
Mean Values ◽  
Systematic Pattern ◽  
The Mean ◽  
Degree Of Maturity ◽  
Close Fit ◽  
Linear Body

SUMMARYThe growth of 12 linear body measurements in Ayrshire cattle was analysed by least-squares methods. Measurements were taken at 3-monthly intervals up to 48 mo of age. Adjustments were made for month and year of birth and for type of birth (twin-born animals comprised 40% of the data). The state of pregnancy or lactation in heifers was also taken in account. Growth curves were fitted to the mean values at the 16 ages and were found to give a close fit. Residual deviations, though small, did show a systematic pattern. The estimated degree of maturity at birth ranged from about 25% for measures of width to 50% for measures of height, body length being intermediate at 40%.To a large extent the different body measurements maintained a uniform pattern of maturing and their ranking for earliness of maturity tended to remain constant throughout the growth period. The application of allometry to the measurements is examined and the error introduced by extrapolating an allometric relationship between characters of different maturing rates is illustrated.

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.

Some key body parts and polysemy

2017 ◽  
Author(s):  
Carol Priestley
Keyword(s):  
Human Life ◽  
Body Part ◽  
Cultural Bias ◽  
Body Parts ◽  
Visible Body

This chapter discusses body part nouns, a part of language that is central to human life, and the polysemy that arises in connection with them. Examples from everyday speech and narrative in various contexts are examined in a Papuan language called Koromu and semantic characteristics of body part nouns in other studies are also considered. Semantic templates are developed for nouns that represent highly visible body parts: for example, wapi ‘hands/arms’, ehi ‘feet/legs’, and their related parts. Culture-specific explications are expressed in a natural metalanguage that can be translated into Koromu to avoid the cultural bias inherent in using other languages and to reveal both distinctive semantic components and similarities to cross-linguistic examples.

scholarly journals Reduction of body-weight gain enhances in vitro embryo production in overfed superovulated dairy heifers

Reproduction ◽  
2006 ◽  
Vol 131 (4) ◽  
pp. 783-794 ◽  
Author(s):  
S Freret ◽  
B Grimard ◽  
A A Ponter ◽  
C Joly ◽  
C Ponsart ◽  
...  
Keyword(s):  
Weight Gain ◽  
Dietary Intake ◽  
Live Weight ◽  
Reproductive Hormones ◽  
Embryo Production ◽  
Live Weight Gain ◽  
Dairy Heifers ◽  
Period 2 ◽  
Significant Difference

The aim of our study was to test whether a reduction in dietary intake could improve in vitro embryo production in superovulated overfed dairy heifers. Cumulus–oocyte complexes of 16 Prim’ Holstein heifers (14 ± 1 months old) were collected by ovum pick-up (OPU), every 2 weeks following superovulation treatment with 250 μg FSH, before being matured and fertilized in vitro. Embryos were cultured in Synthetic Oviduct Fluid medium for 7 days. Heifers were fed with hay, soybean meal, barley, minerals and vitamins. From OPU 1 to 4 (period 1), all heifers received individually for 8 weeks a diet formulated for a 1000 g/day live-weight gain. From OPU 5 to 8 (period 2), the heifers were allocated to one of two diets (1000 or 600 g/day) for 8 weeks. Heifers’ growth rates were monitored and plasma concentrations of metabolites, metabolic and reproductive hormones were measured each week. Mean live-weight gain observed during period 1 was 950 ± 80 g/day (n = 16). In period 2 it was 730 ± 70 (n = 8) and 1300 ± 70 g/day (n = 8) for restricted and overfed groups respectively. When comparing period 1 and period 2 within groups, significant differences were found. In the restricted group, a higher blastocyst rate, greater proportions of grade 1–3 and grade 1 embryos, associated with higher estradiol at OPU and lower glucose and β-hydroxybutyrate, were observed in period 2 compared with period 1. Moreover, after 6 weeks of dietary restriction (OPU 7), numbers of day 7 total embryos, blastocysts and grade 1–3 embryos had significantly increased. On the contrary, in the overfed group, we observed more <8 mm follicles 2 days before superovulation treatment, higher insulin and IGF-I and lower nonesterified fatty acids in period 2 compared with period 1 (no significant difference between periods for embryo production). After 6 weeks of 1300 g/day live-weight gain (OPU 7), embryo production began to decrease. Whatever the group, oocyte collection did not differ between period 1 and 2. These data suggest that following a period of overfeeding, a short-term dietary intake restriction (6 weeks in our study) may improve blastocyst production and embryo quality when they are low. However, nutritional recommendations aiming to optimize both follicular growth and embryonic development may be different.

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