Genetic relationships between water loss and shell deaths in ostrich eggs, assessed as traits of the female

2008 ◽  
Vol 48 (10) ◽  
pp. 1326 ◽  
Author(s):  
Z. Brand ◽  
S. W. P. Cloete ◽  
I. A. Malecki ◽  
C. R. Brown
Keyword(s):  
Genetic Variation ◽  
Water Loss ◽  
Genetic Relationships ◽  
Genetic Correlations ◽  
High Standard ◽  
High Rate ◽  
Standard Errors ◽  
Evaporative Water ◽  
Genetic Level ◽  
Artificial Incubation

The ostrich industry suffers from a high rate of embryonic mortality during artificial incubation of eggs. Data from 34 285 eggs were used to derive 969 female-year records for evaporative water loss (WL), treated as a trait of the female. Heritability was significant for WL at a level of 0.40–0.41 (both after 21 and 35 days of incubation). WL at 21 and 35 days was negatively correlated on the genetic level with chick weight at hatching (–0.84 and –0.81, respectively). Shell deaths did not exhibit high levels of genetic variation (0.06), but were affected by the permanent environment of the female (0.33). Shell deaths were correlated with WL on a genetic level (–0.34 to –0.41), but the estimated genetic correlations were associated with high standard errors and are, therefore, not very robust. Further research is needed to obtain more accurate genetic relationships between traits influencing incubation.

ALTERNATIVE SELECTION CRITERIA FOR THE GENETIC IMPROVEMENT OF FEED EFFICIENCY IN BROILER CHICKENS

1988 ◽  
Vol 68 (3) ◽  
pp. 611-618
Author(s):  
L. N. IRWIN ◽  
G. W. FRIARS ◽  
R. J. JULIAN
Keyword(s):  
Feed Intake ◽  
Feed Efficiency ◽  
Genetic Improvement ◽  
Broiler Chickens ◽  
Genetic Correlations ◽  
High Standard ◽  
Abdominal Fat ◽  
Feed Consumption ◽  
Standard Errors ◽  
Compensatory Gain

A hierarchical mating of 25 sires and 192 dams produced 862 progeny that yielded complete records to market age in two hatches of broiler chickens. These progeny were housed in two levels of cages. Half of the birds were subjected to a compensatory feed treatment which was used as an indicator of appetite. Increased feed consumption, following fasting, resulted in increased deposition of abdominal fat. Various approaches were investigated with respect to maximizing the genetic improvement of feed efficiency. Estimates of the heritabilities of feed:gain, gain:feed, total feed intake, compensatory feed intake and compensatory gain were all low (0.24 or less), with generally high standard errors. The estimated heritabilities of gain and gain corrected for feed intake at 0.46 suggests that selection for the latter trait has potential for improving gain at a statistically fixed feed intake. The standard errors on estimates of genetic correlations were too wide to allow predicted selection changes in correlated traits, and thus these correlations were not presented. Key words: Broiler chickens, feed efficiency, compensatory feed intake, abdominal fat deposition

Genetic variation in serum copper concentration in Angus cattle

2006 ◽  
Vol 82 (6) ◽  
pp. 799-803 ◽  
Author(s):  
C. A. Morris ◽  
N. C. Amyes ◽  
S. M. Hickey
Keyword(s):  
Genetic Variation ◽  
Genetic Correlations ◽  
Heritability Estimate ◽  
Serum Copper ◽  
Phenotypic Correlation ◽  
Environmental Correlations ◽  
Angus Cattle ◽  
Supplementation Period ◽  
Zn Concentration ◽  
Genetic Level

AbstractFollowing the discovery of low serum copper (Cu) concentrations in 9-month-old beef calves at pasture in autumn (50% of animals had values <7·5 μmol/l), genetic variation in serum Cu concentration was studied in an experimental Angus herd in New Zealand, monitoring at intervals from about 7 to 17 months of age. The study was initiated in autumn when animals were supplemented with zinc (Zn) salts (to protect against liver injury from toxin-producing facial eczema spores on the pasture), and later in the production year after Cu supplementation but without Zn supplementation. Heritabilities of Cu concentration were estimated in 837 calves from six calf crops, the progeny of 47 sires, using restricted maximum likelihood procedures with an animal model. Correlations between Cu concentration and Zn concentration were also estimated, along with correlations between Cu concentration and 6-month, 9-month and yearling live weights. The heritability estimate for Cu concentration at all times outside the autumn Zn supplementation period was 0·28±0·08 (between-animal repeatability, 0·30±0·05), and the heritability estimates for autumn Cu concentration and Zn concentration were 0·35±0·11 and 0·26±0·13, respectively. The genetic and environmental correlations between autumn Cu concentration and Zn concentration were ?0·29±0·31 and 0·15±0·11, respectively, suggesting antagonistic effects between Zn and Cu only at the genetic level, with a net (phenotypic) correlation of 0·02±0·06. Genetic correlations between Cu concentration (outside the autumn season) and 6-month, 9-month and yearling weights ranged from 0·15±0·15 to 0·17±0·16. It was concluded that serum Cu and Zn concentrations in calves were heritable traits under the grazing conditions encountered, and that index selection to increase live weights and Cu concentrations could be applied if desired.

Genetic and phenotypic parameters between yearling, hoggetand adult reproductive performance and age of first oestrus in sheep

2014 ◽  
Vol 54 (6) ◽  
pp. 753 ◽  
Author(s):  
J. E. Newton ◽  
D. J. Brown ◽  
S. Dominik ◽  
J. H. J. van der Werf
Keyword(s):  
Reproductive Performance ◽  
Evaluation System ◽  
Genetic Correlations ◽  
High Standard ◽  
Genetic Evaluation ◽  
Standard Errors ◽  
Adult Performance ◽  
Genetic And Phenotypic Correlations ◽  
Heritability Estimates ◽  
Lamb Survival

The aims of this study were to quantify the relationship between age of first oestrus and yearling reproductive performance in maternal-cross ewes in the Information Nucleus Flock data and to estimate genetic and phenotypic correlations between early and later reproductive performance defined as three ages, yearling, hogget and adult in both Merino and maternal-cross ewes. Information on 2218 yearling records, 2047 hogget records and 910 age of first oestrus records were used in the analysis of maternal-cross ewes, whereas 3286 hogget and 2518 adult reproductive records were used in analysis of Merino ewes. Heritability estimates for yearling reproductive performance in maternal-cross ewes ranged from 0.08 ± 0.09 for ewe fecundity to 0.16 ± 0.05 for number of lambs born and were generally higher than hogget heritability estimates for both maternal-cross and Merino ewes. Age at first oestrus was found to have a low heritability, 0.02 with standard errors of 0.07 and 0.06 with and without weight fitted as a covariate. Genetic correlations between age at first oestrus with and without weight fitted as a covariate and yearling reproductive performance were positive, ranging from 0.07 ± 0.49 with lamb survival to 0.94 ± 0.39 with number of lambs born, which was unexpected. Correlations between traits from the same age class were high in both breed groups. Genetic correlations between yearling and hogget performance in maternal-cross ewes were generally lower than one, ranging from 0.46 ± 0.68 for lamb survival and 0.79 ± 0.50 for fertility suggesting that yearling and later reproductive performance are related but genetically different traits. In Merino ewes, the genetic correlations between hogget and adult performance followed a similar pattern. The small number of records in this study generated high standard errors for estimates, which restricts the conclusions that can be drawn. Overall, this study supports current practice used by ‘Sheep Genetics’, the Australian genetic evaluation system for sheep, in considering yearling reproductive performance as a trait separate from later parities for genetic evaluation purposes.

Genetic variation in cambial phenology of coastal Douglas-fir

1994 ◽  
Vol 24 (9) ◽  
pp. 1864-1870 ◽  
Author(s):  
Peng Li ◽  
W.T. Adams
Keyword(s):  
Genetic Variation ◽  
Genetic Relationships ◽  
Genetic Correlations ◽  
Douglas Fir ◽  
Stem Volume ◽  
Diameter Growth ◽  
Bud Burst ◽  
Diameter Increment ◽  
Increased Risk ◽  
Growth Initiation

The objectives of this study were to (i) determine the extent of genetic variation and genetic control of cambial phenology in coastal Douglas-fir (Pseudotsugamenziesii var. menziesii (Mirb.) Franco), (ii) assess the degree to which cambial phenology is genetically related to bud-burst timing, (iii) examine genetic relationships between cambial phenology and growth traits, and (iv) evaluate the potential for indirectly altering cambial phenology in breeding programs when selection is for stem volume. Dates of diameter-growth initiation and cessation, and duration of diameter growth (i.e., cambial phenology traits), as well as diameter increment for a single growing season (1987, at the age of 15 years from seed), were estimated from cumulative diameter growth curves of individual trees of 60 open-pollinated families growing in one plantation. Data on stem height and diameter (DBH), and date of bud burst in 1987 were also collected. Dates of diameter-growth initiation and cessation differed significantly among families, but had lower estimated individual heritabilities (≤0.23) than date of bud burst (0.87). Weak genetic correlations between date of bud burst and dates of diameter-growth initiation and cessation (range −0.09 to 0.26) indicate that timing of diameter growth cannot be reliably predicted from observations on the more easily measured bud burst. Cambial phenology traits were weakly correlated with 1987 diameter increment and moderately correlated with 15-year DBH and volume. Selection of parents in this study for stem volume at age 15 and subsequent crosses among them, would be expected to lead to earlier initiation of diameter growth in the offspring, and possibly later cessation as well. The practical implications of these indirect responses in terms of increased risk of frost damage are unclear, since projected changes are small (i.e., a few days).

scholarly journals Genetic and genomic relationship between methane production measured in breath and fatty acid content in milk samples from Danish Holsteins

2016 ◽  
Vol 56 (3) ◽  
pp. 298 ◽  
Author(s):  
J. Lassen ◽  
N. A. Poulsen ◽  
M. K. Larsen ◽  
A. J. Buitenhuis
Keyword(s):  
Fatty Acid ◽  
Fatty Acid Content ◽  
Genetic Correlations ◽  
High Standard ◽  
Standard Errors ◽  
Genomic Relationship Matrix ◽  
Relationship Matrix ◽  
Genomic Relationship ◽  
Milk Fatty Acids ◽  
Heritability Estimates

In this study the objective was to estimate the genetic and genomic relationship between methane-related traits and milk fatty acid profiles. This was done using two different estimation procedures: a single nucleotide polymorphism-based genomic relationship matrix and a classical pedigree-based relationship matrix. Data was generated on three Danish Holstein herds and a total of 339 cows were available for the study. Methane phenotypes were generated in milking robots during milking over a weekly period and the milk phenotypes were quantified from milk from one milking. Genetic and genomic parameters were estimated using a mixed linear model. Results showed that heritability estimates were comparable between models, but the standard error was lower for genomic heritabilities compared with genetic heritabilities. Genetic as well as genomic correlations were highly variable and had high standard errors, reflecting a similar pattern as for the heritability estimates with lower standard errors for the genomic correlations compared with the pedigree-based genetic correlations. Many of the correlations though had a magnitude that makes further studies on larger datasets worthwhile. The results indicate that genotypes are highly valuable in studies where limited number of phenotypes can be recorded. Also it shows that there is some significant genetic association between methane in the breath of the cow and milk fatty acids profiles.

Shared genetic architecture across psychiatric disorders

2021 ◽  
pp. 1-7
Author(s):  
Andrew D. Grotzinger
Keyword(s):  
Risk Factors ◽  
Psychiatric Disorders ◽  
Genetic Correlations ◽  
Fine Grained ◽  
Level Data ◽  
Symptom Level ◽  
Genetic Level ◽  
Genetic Signal ◽  
Family Based ◽  
Shared Genetic

Abstract Psychiatric disorders overlap substantially at the genetic level, with family-based methods long pointing toward transdiagnostic risk pathways. Psychiatric genomics has progressed rapidly in the last decade, shedding light on the biological makeup of cross-disorder risk at multiple levels of analysis. Over a hundred genetic variants have been identified that affect multiple disorders, with many more to be uncovered as sample sizes continue to grow. Cross-disorder mechanistic studies build on these findings to cluster transdiagnostic variants into meaningful categories, including in what tissues or when in development these variants are expressed. At the upper-most level, methods have been developed to estimate the overall shared genetic signal across pairs of traits (i.e. single-nucleotide polymorphism-based genetic correlations) and subsequently model these relationships to identify overarching, genomic risk factors. These factors can subsequently be associated with external traits (e.g. functional imaging phenotypes) to begin to understand the makeup of these transdiagnostic risk factors. As psychiatric genomic efforts continue to expand, we can begin to gain even greater insight by including more fine-grained phenotypes (i.e. symptom-level data) and explicitly considering the environment. The culmination of these efforts will help to inform bottom-up revisions of our current nosology.

Shell Resistance and Evaporative Water Loss from Bird Eggs: Effects of Wind Speed and Egg Size

1981 ◽  
Vol 54 (2) ◽  
pp. 195-202 ◽  
Author(s):  
James R. Spotila ◽  
Christina J. Weinheimer ◽  
Charles V. Paganelli
Keyword(s):  
Wind Speed ◽  
Water Loss ◽  
Egg Size ◽  
Evaporative Water Loss ◽  
Evaporative Water ◽  
Bird Eggs

Scaling of Evaporative Water Loss in Marsupials

1986 ◽  
Vol 59 (1) ◽  
pp. 1-9 ◽  
Author(s):  
David S. Hinds ◽  
Richard E. MacMillen
Keyword(s):  
Water Loss ◽  
Evaporative Water Loss ◽  
Evaporative Water

Genetic Relationships of Cory's Shearwater: Parentage, Mating Assortment, and Geographic Differentiation Revealed by DNA Fingerprinting

The Auk ◽  
2000 ◽  
Vol 117 (3) ◽  
pp. 651-662 ◽  
Author(s):  
Corinne Rabouam ◽  
Vincent Bretagnolle ◽  
Yves Bigot ◽  
Georges Periquet
Keyword(s):  
Genetic Variation ◽  
Genetic Structure ◽  
Dna Fingerprinting ◽  
Genetic Relatedness ◽  
Isolation By Distance ◽  
Genetic Relationships ◽  
Cory’S Shearwater ◽  
Genetic Structure Of Populations ◽  
The Social ◽  
Calonectris Diomedea

Abstract We used DNA fingerprinting to assess genetic structure of populations in Cory's Shearwater (Calonectris diomedea). We analyzed mates and parent-offspring relationships, as well as the amount and distribution of genetic variation within and among populations, from the level of subcolony to subspecies. We found no evidence of extrapair fertilization, confirming that the genetic breeding system matches the social system that has been observed in the species. Mates were closely related, and the level of genetic relatedness within populations was within the range usually found in inbred populations. In contrast to previous studies based on allozymes and mtDNA polymorphism, DNA fingerprinting using microsatellites revealed consistent levels of genetic differentiation among populations. However, analyzing the two subspecies separately revealed that the pattern of genetic variation among populations did not support the model of isolation by distance. Natal dispersal, as well as historic and/or demographic events, probably contributed to shape the genetic structure of populations in the species.

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