scholarly journals Conventional and Mixed Model Approach to Estimate Heterosis of the Growth Traits in Boer Goat’s Crossbred Offspring Populations

2019 ◽  
Vol 34 (1) ◽  
pp. 55
Author(s):  
Nuzul Widyas ◽  
Sigit Prastowo ◽  
Tristianto Nugroho ◽  
Adi Ratriyanto

Heterosis is often utilized as a success indicator in a crossbreeding program. It is defined as the deviation of the crossbred means relative to their parental breeds. Heterosis mechanism is highly dependent on the genetic factors and thus, we incorporated genetic information in its estimation. The objective of this article was to compare heterosis estimated with conventional and mixed model approaches. In total, phenotypes of 3804 individuals were recorded. Data were obtained from a crossbreeding experiment involving Boer bucks and Jawarandu does. Observed traits were birth weight, weaning weight and average daily gain. Conventional and mixed model methods were used to estimate the heterosis. The heterosis values (%) between B×B vs B×J, estimated with conventional method were -11.38, -10.51 and -10.39; with mixed model were -6.23, -9.27 and -9.68 for BW, WW and ADG respectively. Heterosis values in B×(B×J) relative to B×B, estimated with conventional method were -6.16, -10.35 and -11.69; whereas with mixed model were -8.01, -10.82 and -9.14 for BW, WW and ADG respectively. Conventional method tends to underestimate the means phenotype with lower standard errors compared to mixed model analysis results in all traits. Conventional method also introduces biased heterosis estimates compared to the mixed model. Conventional method ignores any potential effects in the estimation procedures; whereas mixed model approach incorporates all the systematic and random effect including family relationship information. Thus, mixed model produced more reliable results in genetic parameters estimation. We recommend employing mixed model analysis in estimating heterosis.

2004 ◽  
Vol 53 (1-6) ◽  
pp. 26-33 ◽  
Author(s):  
N. Aletà ◽  
A. Ninot ◽  
J. Voltas

Summary Results of early testing in Juglans regia performed over the period 1993-2002 are presented. A total of 37 progenies were evaluated for establishment, growth traits, and phenology at ages one and two during two or more sowing years in the nursery. Independent culling selection was applied on parental trees to the family-mean values using specific truncation points for establishment, diameter and total height. In addition, parental selection was performed on unbiased predictions (BLUPs) of parental breeding values using a multivariate mixed model analysis in order to account for the unbalanced nature of the entire data set. Genetic parameters (heritabilities, correlations) of juvenile traits were also estimated. Except for second year growth traits, the genetic control of most characters was quite high, with heritability estimates ranging from 0.51 (establishment) to 0.93 (flushing date). Growth performance and establishment did not bear a common genetic control according to non-significant genetic correlations, but a higher growth was typical of early flushing families. Changes in parental ranking for growth after comparison of familymean and BLUP-based estimates of parental performance were considerable. This observation, together with the larger proportion of culled progenies in the former method (about 70%), suggests a sizeable loss of genetic gain by using unadjusted parental means. It is concluded that current evaluation and selection schemes using family-mean values should be reconsidered by i) relaxing truncation points for selection on establishment and growth traits and ii) re-evaluating progeny test data using a mixed model framework to unveil valuable material otherwise neglected due to unaccounted environmental influence on family performance.


2006 ◽  
Vol 144 (5) ◽  
pp. 393-409 ◽  
Author(s):  
A. B. SMITH ◽  
P. LIM ◽  
B. R. CULLIS

Despite the importance of selection for quality characteristics in plant improvement programmes, literature on experimental design and statistical analysis for these traits is scarce. Most quality traits are obtained from multi-phase experiments in which plant varieties are first grown in a field trial then further processed in the laboratory. In the present paper a general mixed model approach for the analysis of multi-phase data is described, with particular emphasis on quality trait data that are often highly unbalanced and involve substantial sources of non-genetic variation and correlation. Also detailed is a new approach for experimental design that employs partial replication in all phases. The motivation for this was the high cost of obtaining quality trait data, thus the need to limit the total number of samples tested, but still allow use of the mixed model analysis. A simulation study is used to show that the combined use of the new designs and mixed model analysis has substantial benefits in terms of the genetic gain from selection.


2020 ◽  
Vol 98 (Supplement_4) ◽  
pp. 459-460
Author(s):  
Frank W Abrahamsen ◽  
Nar Gurung ◽  
Woubit Abdela ◽  
Gopal Reddy ◽  
Kim Mullenix

Abstract Hempseed meal (HSM) is a byproduct of hemp oil production and is high in crude protein, fiber, and fat, making it a potential feedstuff for ruminants. The objective of this study was to evaluate the effect of HSM supplementation on growth performance, rumen fermentation and blood chemistry profile of growing meat goats. Forty castrated, Boer cross goats were randomly assigned to one of the four treatments (n = 10): control, 10%, 20%, and 30% HSM supplementation. Data collected over a period of a 60-day feeding trial were analyzed utilizing the mixed model analysis function of SYSTAT, version 13. The result revealed total live weight gain decreased with the increasing levels of HSM supplementation 10.75, 9.53, 8.48, and 7.80 kg, for 0, 10, 20, and 30%, respectively. Average daily gain followed the same trend 0.179, 0.159, 0.141, and 0.13 kg, with a significant difference (P < 0.05) observed between the control and 30 % supplementation. Conversely, feed to gain ratio increased with the increasing levels of supplementation 9.0, 10.2, 11.9, 12.2, likewise a significant difference was observed (P < 0.05) between the control and 30% supplementation. Acetic, propionic, butyric, valeric, iso-valeric, and iso-butyric acid concentrations as well as the total VFA concentration decreased significantly (P < 0.05) with the increasing level of supplementation. Acetic to propionic acid ratios increased with increasing level of supplementation 3.43, 4.36, 4.52, and 4.59, significant differences (P < 0.05) were observed between control-20% and 30% HSM group. Serum glucose concentration decreased with an increasing rate of HSM supplementation while BUN concentration increased with no significant differences. These findings provide new insights into the feeding value of HSM for meat goats; however, further research needs to be conducted to determine the optimal level of supplementation.


Toxins ◽  
2021 ◽  
Vol 13 (3) ◽  
pp. 214
Author(s):  
Agathe Roucou ◽  
Christophe Bergez ◽  
Benoît Méléard ◽  
Béatrice Orlando

The levels of fumonisins (FUMO)—mycotoxins produced by Fusarium verticillioides—in maize for food and feed are subject to European Union regulations. Compliance with the regulations requires the targeting of, among others, the agroclimatic factors influencing fungal contamination and FUMO production. Arvalis-Institut du végétal has created a national, multiyear database for maize, based on field survey data collected since 2003. This database contains information about agricultural practices, climatic conditions and FUMO concentrations at harvest for 738 maize fields distributed throughout French maize-growing regions. A linear mixed model approach highlights the presence of borers and the use of a late variety, high temperatures in July and October, and a water deficit during the maize cycle as creating conditions favoring maize contamination with Fusarium verticillioides. It is thus possible to target a combination of risk factors, consisting of this climatic sequence associated with agricultural practices of interest. The effects of the various possible agroclimatic combinations can be compared, grouped and classified as promoting very low to high FUMO concentrations, possibly exceeding the regulatory threshold. These findings should facilitate the creation of a national, informative and easy-to-use prevention tool for producers and agricultural cooperatives to manage the sanitary quality of their harvest.


2004 ◽  
Vol 83 (8) ◽  
pp. 1253-1259 ◽  
Author(s):  
R.L. Sapp ◽  
R. Rekaya ◽  
I. Misztal ◽  
T. Wing

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