scholarly journals Maternal reactivity of ewes at lambing is genetically linked to their behavioral reactivity in an arena test

2020 ◽  
Author(s):  
Dominique Hazard ◽  
Amandine Kempeneers ◽  
Eric Delval ◽  
Jacques Bouix ◽  
Didier Foulquie ◽  
...  
Keyword(s):  
Reaction Time ◽  
Genetic Variability ◽  
Maternal Behavior ◽  
Genetic Improvement ◽  
Genetic Correlations ◽  
Flight Distance ◽  
Human Presence ◽  
Aggressive Reaction ◽  
Behavioral Reactivity ◽  
Arena Test

In sheep, the bond between the dam and her lambs is established during the first hours of a lamb s life. Genetic variability for behavioral reactivity of ewes assessed in an arena test performed 24 h after lambing has already been reported. However, there is no evidence that this reactivity represents the ewe s maternal reactivity at lambing in outdoor conditions. The objective of this study was to investigate whether or not the behavioral reactivity of ewes in the arena test is genetically related to their maternal reactivity measured at lambing. A total of 935 Romane ewes were studied. The maternal reactivity of ewes at the outdoor lambing site was recorded in response to a human approach and to the handling of the lambs. Their behavioral reactivity was also recorded 24 h post-lambing in the arena test that involved a separation from the litter and a human presence. Flight distance, aggressive reaction, time to restore contact with the litter at the lambing site and maternal behavior scores were moderately heritable (0.18 to 0.34), and vocalizations were slightly heritable (0.16). All of these behaviors were genetically correlated with the behavioral reactivity in the arena test. The highest genetic correlations (from 0.60 to 0.90) were found for maternal behavioral scores, flight distance and high-pitched bleats. In conclusion, behavioral reactivity in the arena test can be used to assess early maternal reactivity in standardized conditions. Such phenotyping could be used for genetic improvement of maternal behavior in sheep.

Quantitative study of genetic gain for growth, carcass, and morphological traits of Nelore cattle

2019 ◽  
Vol 99 (2) ◽  
pp. 296-306
Author(s):  
Daniel Duarte da Silveira ◽  
Lucas De Vargas ◽  
Rodrigo Junqueira Pereira ◽  
Gabriel Soares Campos ◽  
Ricardo Zambarda Vaz ◽  
...  
Keyword(s):  
Genetic Variability ◽  
Carcass Traits ◽  
Genetic Correlations ◽  
Correlated Response ◽  
Genetic Associations ◽  
Muscle Area ◽  
Genetic Gains ◽  
Fat Thickness ◽  
Nelore Cattle ◽  
Genetic Trends

The aim of this study was to evaluate the genetic variability, genetic and phenotypic associations, and genetic gains of birth (BW), weaning (WW), and yearling (YW) weights, loin muscle area (LMA), backfat thickness (BF), rump fat thickness (RF), scores of body structure (BS), finishing precocity (FS), and muscling (MS) in Nelore cattle. Genetic parameters were obtained through Bayesian inference using BLUPF90 programs. All studied traits showed genetic variability, with heritability ranging from 0.29 to 0.47. In all studied ages, weights presented positive genetic correlations with LMA (ranging from 0.13 to 0.53), being generally stronger in comparison with the other carcass traits analyzed (BF and RF). Similarly, weights were higher genetic associated with BS (0.47–0.92) than with FS (0.18–0.62) and MS (0.22–0.65), respectively. The BF and RF showed positive and moderate genetic associations with FS and MS (0.31–0.36). Genetic trends were significant (P < 0.05) and favorable for WW, YW, and visual scores. Selection for increasing BW, WW, YW, and LMA will result in modest or no change in BF and RF (correlated response ranging from −0.04 to 0.07 mm per generation). In this population, carcass traits must be included in the selection indexes to obtain genetic gains in carcass quality, if desired.

scholarly journals Potential exists to change, through breeding, the yield of individual primal carcass cuts in cattle without increasing overall carcass weight1

2019 ◽  
Vol 97 (7) ◽  
pp. 2769-2779 ◽  
Author(s):  
Michelle M Judge ◽  
Thierry Pabiou ◽  
Jessica Murphy ◽  
Stephen B Conroy ◽  
P J Hegarty ◽  
...  
Keyword(s):  
Genetic Variation ◽  
Genetic Variability ◽  
Genetic Correlations ◽  
Carcass Weight ◽  
High Heritability ◽  
The Mean ◽  
Estimated Breeding Values ◽  
Coefficient Of Genetic Variation ◽  
Selection Of ◽  
Carcass Cuts

Abstract The ability to alter the morphology of cattle towards greater yields of higher value primal cuts has the potential to increase the value of animals at slaughter. Using weight records of 14 primal cuts from 31,827 cattle, the objective of the present study was to quantify the extent of genetic variability in these primal cuts; also of interest was the degree of genetic variability in the primal cuts adjusted to a common carcass weight. Variance components were estimated for each primal cut using animal linear mixed models. The coefficient of genetic variation in the different primal cuts ranged from 0.05 (bavette) to 0.10 (eye of round) with a mean coefficient of genetic variation of 0.07. When phenotypically adjusted to a common carcass weight, the coefficient of genetic variation of the primal cuts was lesser ranging from 0.02 to 0.07 with a mean of 0.04. The heritability of the 14 primal cuts ranged from 0.14 (bavette) to 0.75 (topside) with a mean heritability across all cuts of 0.48; the heritability estimates reduced, and ranged from 0.12 (bavette) to 0.56 (topside), when differences in carcass weight were accounted for in the statistical model. Genetic correlations between each primal cut and carcass weight were all ≥0.77; genetic correlations between each primal cut and carcass conformation score were, on average, 0.59 but when adjusted to a common carcass weight, the correlations weakened to, on average, 0.27. The genetic correlations among all 14 primal cut weights was, on average, strong (mean correlation of 0.72 with all correlations being ≥0.37); when adjusted to a common carcass weight, the mean of the genetic correlations among all primal cuts was 0.10. The ability of estimated breeding values for a selection of primal cuts to stratify animals phenotypically on the respective cut weight was demonstrated; the weight of the rump, striploin, and fillet of animals estimated to be in the top 25% genetically for the respective cut, were 10 to 24%, 12 to 24%, and 7 to 17% heavier than the weight of cuts from animals predicted to be in the worst 25% genetically for that cut. Significant exploitable genetic variability in primal carcass cuts was clearly evident even when adjusted to a common carcass weight. The high heritability of many of the primal cuts infers that large datasets are not actually required to achieve high accuracy of selection once the structure of the data and the number of progeny per sire is adequate.

scholarly journals Genetic improvement and population structure of the Nelore breed in Northern Brazil

2010 ◽  
Vol 45 (10) ◽  
pp. 1109-1116 ◽  
Author(s):  
Carlos Henrique Mendes Malhado ◽  
Paulo Luiz Souza Carneiro ◽  
Ana Claudia Mendes Malhado ◽  
Raimundo Martins Filho ◽  
Riccardo Bozzi ◽  
...  
Keyword(s):  
Population Structure ◽  
Genetic Variability ◽  
Genetic Improvement ◽  
Selective Breeding ◽  
Growth Traits ◽  
Management Strategies ◽  
Pedigree Information ◽  
Effective Number ◽  
Northern Brazil ◽  
Nelore Cattle

The objective of this work was to evaluate the population structure and the genetic and phenotypic progress of Nelore cattle in Northern Brazil. Pedigree information concerning animals born between 1942 and 2006 were analyzed. Population structure was performed using the Endog program. Out of the 140,628 animals studied, 67.7, 14.52 and 3.18% had complete pedigree record of the first, second and third parental generation, respectively. Inbreeding and average relatedness coefficients were low: 0.2 and 0.13%, respectively. However, these parameters may have been underestimated, since information on pedigree was incomplete. The effective number of founders was 370 and the genetic contribution of 10, 50 and 448 most influent ancestors explained 13.2, 28 and 50% of the genetic variability in the population, respectively. The genetic variability for growth traits and population structure demonstrates high probability of increasing productivity through selective breeding. Moreover, management strategies to reduce the currently observed age at first calving and generation intervals are important for Nelore cattle genetic improvement.

Estimates of genetic parameters for ultrasound-measured carcass traits in sheep

2004 ◽  
Vol 84 (3) ◽  
pp. 361-365 ◽  
Author(s):  
T. L. Fernandes ◽  
J. W. Wilton ◽  
J. J. Tosh
Keyword(s):  
Genetic Improvement ◽  
Variance Component ◽  
Genetic Parameters ◽  
Genetic Correlations ◽  
Genetic Effect ◽  
Backfat Thickness ◽  
Additive Genetic Effect ◽  
Multiple Trait ◽  
Breed Group ◽  
Variance Component Estimates

Data on ultrasound traits (loin depth, average backfat thickness, and loin width) were collected from lambs (n = 3483) across Ontario, born between 1997 and 1999. The data were analysed with a REML procedure in a multiple-trait mixed-animal model to obtain (co)variance component estimates. Analyses of all traits included the additive genetic effect of the lamb, sex of the lamb, contemporary group, and breed group effects. Weight or age was included as a covariate in two separate analyses. Estimates of direct additive heritabilities for loin depth, average backfat thickness, and loin width were 0.29, 0.29 and 0.26 respectively, with genetic correlations of -0.17 between loin depth and average backfat thickness, 0.43 between loin depth and loin width, and 0.23 between loin width and average backfat thickness for the weight constant analysis. When the data were analysed using age in the regression analysis, corresponding estimates of direct additive heritabilities were 0.38, 0.35 and 0.30, and genetic correlations between traits were all positive, 0.29 between loin depth and average backfat thickness, 0.61 between loin depth and loin width, and 0.44 between loin width and average backfat thickness. Results indicate that it is possible to make genetic improvement if selection is based on ultrasound information. Key words: Sheep, genetic parameters, heritability, ultrasound

EFFECT OF SELECTION FOR CARCASS SCORE ON THE GENETIC IMPROVEMENT OF ITS COMPONENTS IN SWINE

1970 ◽  
Vol 50 (3) ◽  
pp. 585-592 ◽  
Author(s):  
M. H. FAHMY ◽  
C. BERNARD
Keyword(s):  
Analysis Of Variance ◽  
Genetic Improvement ◽  
Genetic Correlations ◽  
Feed Utilization ◽  
Backfat Thickness ◽  
Yorkshire Pigs ◽  
Selection For ◽  
Heritability Estimates ◽  
Sole Criterion ◽  
Three Components

Selection for carcass score was practiced for ten generations in two separate lines of Yorkshire pigs. Three components of the score were studied: carcass length, loin eye area, and backfat thickness. In line 2, carcass score was the sole criterion of selection, while in line 3, it was combined with feed utilization into an overall merit. Line 1, selected solely for feed utilization, served as a control. Carcass length and loin eye area increased by approximately 2 and 9%, respectively, in both lines. However, backfat thickness also increased by about 3% in line 2 and 0.4% in line 3. Pooled heritability estimates derived from the analysis of variance and the regression of offspring on mid-parent were 0.64 for carcass length, 0.48 for loin eye area and 0.67 for backfat thickness. Genetic correlations among the components of carcass score, between the components and carcass score and between the components and feed utilization were moderately high and favorable for combined genetic improvement of all traits.

scholarly journals Sire evaluation of milk producers’ co-operative union limited of Bangladesh

2013 ◽  
Vol 41 (2) ◽  
pp. 74-78
Author(s):  
MS Hossen ◽  
SS Hossain ◽  
AKFH Bhuiyan ◽  
MA Hoque ◽  
MAS Talukder
Keyword(s):  
Birth Weight ◽  
Genetic Variability ◽  
Genetic Improvement ◽  
Great Opportunity ◽  
Selection Scheme ◽  
Breeding Values ◽  
High Genetic Variability ◽  
Genetic Groups ◽  
Sire Evaluation

Data on 3637 cows of seven genetic groups at Baghabarighat milk shed area, from 1991 to 2000 were analyzed. The genetic groups were Pabna Milking (PM) cows, ½PM×½ Sahiwal (PM×SL), ½PM×½Frisian (PM×FN), Australian Friesian Sahiwal (AFS), ½Sahiwal×¼PM×¼ Friesian [SL(PM×FN)], ½Friesian ×¼PM×¼Sahiwal [FN(PM×SL)] and ½Friesian×¼Sahiwal×¼ Jersey [FN(SL×JR)]. The purpose of this study was to predict breeding values (PBV) of dairy sires using individual daughters performance (birth weight, lactation yield, fat% and SNF%) records at Baghabarighat milk shed area. The heritability values were estimated as 0.27±0.05 for birth weight, 0.45±0.03 for lactation yield, 0.37±0.04 for fat% and 0.46±0.01 for SNF%. The high genetic variability of birth weight, lactation yield, fat and SNF% indicates that there is a great opportunity or genetic improvement when these traits are included in a selection scheme. The first 3 top sires were 24, 14 and 20 for birth weight; sire number 19, 36 and 23 for lactation yield; sire number 16, 11 and 26 for fat % and sire number 14, 19 and 16 for SNF% were ranked on the basis of PBV.DOI: http://dx.doi.org/10.3329/bjas.v41i2.14104Bang. J. Anim. Sci. 2012. 41 (2): 74-78 

scholarly journals Genetic parameters, phenotypic, genotypic and environmental correlations and genetic variability on sunflower in the Brazilian Savannah

2017 ◽  
Vol 47 (8) ◽  
Author(s):  
Ellen Grippi Lira ◽  
Renato Fernando Amabile ◽  
Marcelo Fagioli ◽  
Ana Paula Leite Montalvão
Keyword(s):  
Genetic Variability ◽  
Genetic Parameters ◽  
Environmental Control ◽  
Genetic Correlations ◽  
Phenotypic Selection ◽  
Phenotypic Variance ◽  
Environmental Correlations ◽  
High Genetic Variability ◽  
Brazilian Savannah ◽  
Main Component

ABSTRACT: Sunflower (Helianthus annuus L.) is an annual crop that stands out for its production of high quality oil and for an efficient selection, being necessary to estimate the components of genetic and phenotypic variance. This study aimed to estimate genetic parameters, phenotypic, genotypic and environmental correlations and genetic variability on sunflower in the Brazilian Savannah, evaluating the characters grain yield (YIELD), days to start flowering (DFL) based on flowering date in R5, chapter length (CL), weight of a thousand achenes (WTA), plant height (H) and oil content (OilC) of 16 sunflower genotypes. The experiment was conducted at Embrapa Cerrados, Planaltina, DF, situated at 15º 35’ 30”S latitude, 47º 42’ 30”W longitude and 1.007m above sea level, in soil classified as dystroferric Oxisol. The experimental design used was a complete randomized block with four replicates. The nature for the effects of genotypes and blocks was fixed. Except for the character chapter length, genetic variance was the main component of the phenotypic variance among the genotypes, indicating high genetic variability and experimental efficiency with proper environmental control. In absolute terms, the genetic correlations were superior to phenotypic and environmental. The high values reported for heritability and selective accuracy indicated efficiency of phenotypic selection. Results showed high genetic variability among genotypes, which may contribute to the genetic improvement of sunflower.

Genetic improvement for pulpwood and peeled veneer in Eucalyptus nitens

2012 ◽  
Vol 42 (9) ◽  
pp. 1724-1732 ◽  
Author(s):  
David Blackburn ◽  
Ross Farrell ◽  
Matthew Hamilton ◽  
Peter Volker ◽  
Chris Harwood ◽  
...  
Keyword(s):  
Genetic Improvement ◽  
Genetic Correlations ◽  
Basic Density ◽  
Wood Properties ◽  
General Interest ◽  
Cellulose Content ◽  
Standing Tree ◽  
Eucalyptus Nitens ◽  
Stem Straightness ◽  
Veneer Sheet

Genetic improvement of wood properties affecting the quality of pulpwood and peeled veneer products is of general interest to tree breeders worldwide. If the wood properties of Eucalyptus nitens (H. Deane & Maiden) Maiden are under genetic control and the correlations between them are favourable, it may be possible to breed to simultaneously improve the plantation resource for both products. Acoustic wave velocity (AWV) measured in standing trees can predict wood stiffness, basic density, and kraft pulp yield (KPY) and therefore has the potential for use in tree breeding programs. From an E. nitens progeny trial in Tasmania, 540 trees were selected for rotary peeling. Of the wood properties assessed, there were significant differences among races in diameter, stem straightness, standing-tree, log, and billet AWV, and near infrared predicted cellulose content (CC). All traits displayed significant within-race genetic variation, and genetic correlations between AWV and veneer sheet modulus of elasticity (MOE) and between AWV and KPY and CC were strongly positive and highly significant. A similar relationship was found between veneer sheet MOE and KPY and between diameter at breast height and veneer sheet MOE. Basic density was genetically correlated with AWV and veneer sheet MOE. Results indicate that it should be possible for breeders to simultaneously improve properties in pulpwood and peeled veneer products and that AWV measured in the standing tree shows promise as a breeding selection criterion for both pulpwood and peeled veneer products.

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

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