scholarly journals Multi-trait and repeatability models for genetic evaluation of litter traits in pigs considering different farrowings

2016 ◽  
Vol 17 (4) ◽  
pp. 666-676 ◽  
Author(s):  
Edson Vinícius COSTA ◽  
◽  
Henrique Torres VENTURA ◽  
Elsio Antônio Pereira FIGUEIREDO ◽  
Fabyano Fonseca e SILVA ◽  
...  
Keyword(s):  
Akaike Information Criterion ◽  
Genetic Parameters ◽  
Information Criterion ◽  
Genetic Evaluation ◽  
Litter Weight ◽  
The Third ◽  
Litter Traits ◽  
The Mean ◽  
Trait Model ◽  
Almost All

SUMMARY We aimed to compare multi-trait and repeatability models to estimate genetic parameters for the traits number of piglets born alive (NBA) and alive at 3 week of age (NP3), litter weight at birth (LW0) and at 3 week of age (LW3), and mean piglet weight at birth (MW0) and at 3 week of age (MW3), considering the first three farrowings of Landrace sows. Heritability (h2) estimates showed an increasing pattern up to the third farrowing for LW0 and MW3. For NBA, NP3, LW3, and MW0 h2 increased from the first to the second and decreased from the second to the third farrowing. In general, heritability estimated in the repeatability model was lower than the mean of the estimates in the multi-trait model. The traits LWO, MW0, and MW3 presented high genetic correlation among different farrowings (0.961–0.997), while NBA, NP3, and LW3 (0.092–0.986) presented irregular values among farrowings. The corrected Akaike information criterion shows that the repeatability model is not indicated for almost all of the studied traits. These results indicate that the multi-trait model is recommended for genetic evaluation of the traits number of piglets born alive and alive at 3 week of age, litter weight and mean piglet weight at birth and 3 week of age, in different farrowings, as different traits.

scholarly journals Genetic evaluation of laying hens under fixed regression animal models

2007 ◽  
Vol 50 (3) ◽  
pp. 279-287
Author(s):  
A. Wolc ◽  
M. Lisowski ◽  
T. Szwaczkowski
Keyword(s):  
Animal Models ◽  
Akaike Information Criterion ◽  
Regression Models ◽  
Egg Production ◽  
Genetic Parameters ◽  
Laying Hens ◽  
Information Criterion ◽  
Genetic Evaluation ◽  
Term Selection

Abstract. Monthly egg production in laying hens was studied under fixed regression models. The data of 37071 birds from three strains under long term selection were analysed. The covariates from four production curves were included in nested and non-nested form. From linearized functions the model of Ali and Schaeffer most adequately described the egg production. Akaike Information Criterion favoured models with nested covariates. The following genetic parameters were estimated: heritability 0.02–0.2, 0.03–0.06, 0.03–0.20 repeatability 0.11–0.23, 0.21–0.30, 0.34–0.43 for A22, A88 and K66 lines, respectively. In conclusion, regression models could be considered in genetic evaluation of laying hens.

scholarly journals Model comparison and estimation of genetic parameters for body weight in commercial broilers

2013 ◽  
Vol 93 (1) ◽  
pp. 67-77 ◽  
Author(s):  
G. Maniatis ◽  
N. Demiris ◽  
A. Kranis ◽  
G. Banos ◽  
A. Kominakis
Keyword(s):  
Body Weight ◽  
Akaike Information Criterion ◽  
Model Evaluation ◽  
Model Comparison ◽  
Genetic Parameters ◽  
Genetic Correlations ◽  
Information Criterion ◽  
Biological Properties ◽  
Genetic Covariance ◽  
Estimation Of Genetic Parameters

Maniatis, G., Demiris, N., Kranis, A., Banos, G. and Kominakis, A. 2013. Model comparison and estimation of genetic parameters for body weight in commercial broilers. Can. J. Anim. Sci. 93: 67–77. The availability of powerful computing and advances in algorithmic efficiency allow for the consideration of increasingly complex models. Consequently, the development and application of appropriate statistical procedures for model evaluation is becoming increasingly important. This paper is concerned with the application of an alternative model determination criterion (conditional Akaike Information Criterion, cAIC) in a large dataset comprising 203 323 body weights of broilers, pertaining to 7 (BW7) and 35 (BW35) days of age. Seven univariate and seven bivariate models were applied. Direct genetic, maternal genetic and maternal environmental (c2) effects were estimated via REML. The model evaluation criteria included conditional Akaike Information Criterion (cAIC), Bayesian Information Criterion (BIC) and the standard Akaike Information Criterion (henceforth marginal; mAIC). According to cAIC the best-fitting model included direct genetic, maternal genetic and c2 effects. Maternal heritabilities were low (0.10 and 0.03) compared to the direct heritabilities (0.17 and 0.21), while c2 was 0.05 and 0.04 for BW7 and BW35, respectively. BIC and mAIC favoured a model that additionally included a direct-maternal genetic covariance, resulting in highly negative direct-maternal genetic correlations (−0.47 and −0.64 for BW7 and BW35, respectively) and higher direct heritabilities (0.25 and 0.28 for BW7 and BW35, respectively). Results suggest that cAIC can select different animal models than mAIC and BIC with different biological properties.

scholarly journals Multiple-trait model through Bayesian inference applied to Jatropha curcas breeding for bioenergy

PLoS ONE ◽  
2021 ◽  
Vol 16 (3) ◽  
pp. e0247775
Author(s):  
Marco Antônio Peixoto ◽  
Jeniffer Santana Pinto Coelho Evangelista ◽  
Igor Ferreira Coelho ◽  
Rodrigo Silva Alves ◽  
Bruno Gâlveas Laviola ◽  
...  
Keyword(s):  
Jatropha Curcas ◽  
Repeated Measures ◽  
Bayesian Model ◽  
Genetic Parameters ◽  
Genetic Correlations ◽  
Deviance Information Criterion ◽  
Information Criterion ◽  
Monte Carlo Algorithm ◽  
Multiple Trait ◽  
Trait Model

Multiple-trait model tends to be the best alternative for the analysis of repeated measures, since they consider the genetic and residual correlations between measures and improve the selective accuracy. Thus, the objective of this study was to propose a multiple-trait Bayesian model for repeated measures analysis in Jatropha curcas breeding for bioenergy. To this end, the grain yield trait of 730 individuals of 73 half-sib families was evaluated over six harvests. The Markov Chain Monte Carlo algorithm was used to estimate genetic parameters and genetic values. Genetic correlation between pairs of measures were estimated and four selective intensities (27.4%, 20.5%, 13.7%, and 6.9%) were used to compute the selection gains. The full model was selected based on deviance information criterion. Genetic correlations of low (ρg ≤ 0.33), moderate (0.34 ≤ ρg ≤ 0.66), and high magnitude (ρg ≥ 0.67) were observed between pairs of harvests. Bayesian analyses provide robust inference of genetic parameters and genetic values, with high selective accuracies. In summary, the multiple-trait Bayesian model allowed the reliable selection of superior Jatropha curcas progenies. Therefore, we recommend this model to genetic evaluation of Jatropha curcas genotypes, and its generalization, in other perennials.

Genetic Parameters for Pre-Weaning Litter Traits in Heterogeneous Population of Rabbits (Oryctolagus cuniculus) Raised in the Humid Tropics

2019 ◽  
Author(s):  
A I Adeolu ◽  
V.U Oleforuh Okoleh ◽  
W Mathew ◽  
R U Onyeneke ◽  
R N Nwose ◽  
...  
Keyword(s):  
Litter Size ◽  
Oryctolagus Cuniculus ◽  
Selection Criteria ◽  
Genetic Parameters ◽  
Humid Tropics ◽  
Heterogeneous Population ◽  
Litter Weight ◽  
Litter Traits ◽  
Derived Savanna ◽  
Size At Birth

Data from 302 progeny in a heterogeneous population of rabbits were used to estimate the heritability and correlations (phenotypic and genetic) of pre-weaning litter traits (litter size at birth LSB, litter size at weaning LSW, litter weight birth LWB, litter weight at weaning LWW, kit weight birth KWB, and kit weight weaning KWW). Heritability estimates for litter size ranged from 0.16 (LSW) to 0.22 (LSB). LWB and LWW were more highly heritable (0.52 and 0.55 respectively) than KWB and KWW (0.36 and 0.25 respectively). The genetic (rG ) and phenotypic (rP) correlations between litter size and litter weight at birth and weaning were 0.69 to 0.88 (rG) and 0.28 to 0.88 (rP). Generally, litter traits gave higher estimates than individual kit traits implying that selection criteria based on litter performance rather than on individual kit performance should be applied in genetic improvement of pre-weaning traits in rabbits raised in derived savanna zone.

Estimation of genetic parameters for litter traits in grasscutters (Thryonomys swinderianus)

2014 ◽  
Vol 54 (10) ◽  
pp. 1762
Author(s):  
A. J. Henry ◽  
S. N. Ibe ◽  
B. O. Asuquo
Keyword(s):  
Genetic Correlation ◽  
Positive Relationship ◽  
Genetic Parameters ◽  
Heritability Estimate ◽  
Thryonomys Swinderianus ◽  
Litter Weight ◽  
Unbalanced Design ◽  
Litter Traits ◽  
Estimation Of Genetic Parameters

A study was conducted to estimate genetic parameters for litter traits in grasscutters. Data were obtained using 209 progenies from an unbalanced design of 18 does nested under six bucks. Heritability values of 0.56 ± 0.21 and 0.22 ± 0.22 were obtained for litter weight at birth from dam component and both sire and dam components, respectively. For litter weight at weaning, the heritability estimate was 0.66 ± 0.22 using the dam component of variance. Genetic correlation between litter weight at birth and litter weight at weaning was 0.59 revealing a positive relationship between both traits.

scholarly journals Estimation of genetic parameters of litter weights of Khari goats and their response towards different non-genetic factors under low input management system in Nawalparasi, Nepal

2018 ◽  
pp. 251-258
Author(s):  
N. Bhattarai ◽  
M. R. Kolachhapati ◽  
N. R. Devkota ◽  
U. C. Thakur ◽  
S. P. Neopane
Keyword(s):  
Genetic Improvement ◽  
Genetic Parameters ◽  
Genetic Factors ◽  
Least Square ◽  
Phenotypic Correlation ◽  
Litter Weight ◽  
High Heritability ◽  
The Mean ◽  
Additive Genes ◽  
Birth Type

Accurate estimates of genetic parameters are important for genetic improvement in Khari goats. In this regard, altogether 1005 adult does of Khari goat in Deurali VDC, Nawalparasi were evaluated in terms of litter weight at birth (LWB) and litter weight at weaning (LWW) and their genetic parameters from February, 2012 to January 2015. Least square means (LSM) and standard errors of the mean (SEM) for these traits were determined with respect to some non-genetic factors such as altitude, season of conception, season of kidding, dam’s parity, dam’s size at conception, and birth type. Accordingly, Overall LSM±SE of LWB and LWW in present study were determined 3.97±0.06 and 18.21±0.34 Kgs., respectively. Where, LWB did not differed significantly with altitude and dam’s parity, however, it was significantly influenced (p<0.001) by the season of conception, season of kidding, dam’s size at conception, and birth type. Similarly, LWW was significantly varied with respect to altitude (p<0.01), season of conception (<0.001), season of kidding (<0.05), dam’s parity (<0.001), dam’s size at conception (<0.001), and birth type (<0.001). Moderately high heritability estimates of LWB (0.52±0.16) and LWW (0.56±0.17) indicated that these traits were under the strong influence of additive genes and selection based the superiority of individual doe would be appropriate for successful genetic improvement. Highly significant positive genetic (rA=0.95) and phenotypic correlation (rP=0.91) between LWB and LWW suggested that selection for any of these trait would result in considerable positive change in other trait. More specifically, LWB can be used as a guide to select replacement does targeting to increased LWW within the herd. Journal of the Institute of Agriculture and Animal Science.Vol. 33-34, 2015, page: 251-258

Effects of season and breed on sow performance in the seasonal-equatorial climate of Southern Nigeria

1971 ◽  
Vol 77 (2) ◽  
pp. 331-336 ◽  
Author(s):  
J. Steinbach
Keyword(s):  
Weight Gain ◽  
Relative Humidity ◽  
Effective Temperature ◽  
Seasonal Effects ◽  
Large White ◽  
Litter Weight ◽  
Litter Traits ◽  
Southern Nigeria ◽  
The Mean ◽  
Equatorial Climate

SummaryPreweaning litter traits of 289 Large White (LW) and of 167 Landrace (LR) litters born between 1 January, 1967 and 31 December, 1969 were analysed for seasonal effects. The month during which farrowing occurred exerted highly significant effects on the average piglet weight at birth and at weaning, as well as on the preweaning piglet weight gain (P <0·001). Piglet weight at birth was higher during the hot and dry months of the year, while the preweaning piglet weight gain was greater during the cooler season. The heaviest piglets at weaning were those born in August, the coldest month of the year. Piglet weight at birth was negatively correlated with the mean relative humidity of the month of farrowing (r = -0·79; P <0·01). The percentage of stillborn piglets was high in litters born during March and April (P < 0·005), and the positive correlation between the mean physiologically effective temperature and the percentage of stillborn piglets (r = +0·57) approached significance (P < 0·10).The considerable variations in litter size and litter weight at birth and at weaning as well as the variations in preweaning mortality were not significant.The two breeds differed significantly (P < 0·005) in piglet weight at birth (LW: 2·8 lb; LR: 3·0 lb), in litter weight at birth (LW: 24 lb; LR: 28 lb), and in the percentage of stillborn piglets (LW: 4·5%; LR: 7·5%).

UPAYA MENINGKATKAN HASIL BELAJAR IPA MELALUI PENGGUNAAN VIDEO PEMBELAJARAN BAGI SISWA KELAS IV DI SDN 187/IV KOTA JAMBI

2015 ◽  
Vol 8 (2) ◽  
pp. 93
Author(s):  
Juniar Siregar
Keyword(s):  
Action Research ◽  
Research Method ◽  
Research Report ◽  
The Third ◽  
The Media ◽  
The Subject ◽  
The Mean ◽  
Classroom Action Research

This study presents a research report on improving students’ Learning results on IPA through Video. The objective was to find out whether students’ learning result improved when they are taught by using Video. It was conducted using classroom action research method. The subject of the study was the Grade IV students of SDN 187/IV Kota Jambi which is located on Jln. Adi Sucipto RT 05 Kecamatan Jambi Selatan, and the number of the students were 21 persons. The instruments used were test. In analyzing the data, the mean of the students’ score for the on fisrt sycle was 65,4 (42,85%) and the mean on cycle two was 68,5 (37,15%) and the mean of the third cycle was 81,4 (100%). Then it can be concluded that the use of video on learning IPA can improve the students’ learning result. It is suggested that teachers should use video as one of the media to improve students’ learning result on IPA.Keywords : IPA, students’ learning result, video

IMPROVING STUDENTS’ ACHIEVEMENT IN WRITING RECOUNT TEXT THROUGH THINK PAIR SHARE

2013 ◽  
Vol 2 (1) ◽  
Author(s):  
Hotria Manik ◽  
Elia Masa Ginting
Keyword(s):  
Action Research ◽  
Quantitative Data ◽  
Qualitative Data ◽  
Writing Achievement ◽  
The Third ◽  
Post Test ◽  
Class Viii ◽  
The Subject ◽  
The Mean ◽  
Writing Tests

This study attempts to improve students’ writing achievement in recount text through Think-Pair-Share Strategy. This study was conducted by using classroom action research. The subject of the research was class VIII-1 SMPN 1 Pematangsiantar. The number of the students was 32 students, consisted of 5 males and twenty seven females. The research was conducted in two cycles and consisted of six meetings. The instruments for collecting data were writing tests as the quantitative data and diary notes, observation sheet, interview sheet and questionnaire sheet as qualitative data. Based on the writing score, students’ scores kept improving in every test. In analyzing the data, the mean of the students’ score for the first test as a pre-test was 57.84, for the second test as a post test I was 73.56, for the third test as a post test II was 77.56. Based on diary notes, observation sheet and questionnaire sheet, it was found that students were actively involved in writing process. The result of the research showed that Think-Pair-Share Strategy can improve students’ achievement in writing recount text.   Keywords: Think Pair Share, Writing, Recount text, Action research

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