Sire x ecological region interaction in Bonsmara cattle

Nephawe, Khathutshelo Agree; Neser, F.W.C.; Roux, C. Z.; Theron, H.E.; Westhuizen, J. Van der; Erasmus, G.J.

doi:10.4314/sajas.v29i3.44203

Cited by 5 publications

(16 citation statements)

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“…The greater relative importance of S × CG during the subsequent phase of life of the animal might be explained by cumulative environmental effects on animal performance. These results agree with those reported by Bradfield et al (1997) for WW of Santa Gertrudis cattle (10% to 13%), by Nephawe et al (1999) for WW of Bonsmara cattle (6% to 14%) and by Neser et al (1996) for WW of Bonsmara cattle (8%).…”

Section: Resultssupporting

confidence: 92%

“…Nephawe et al (1999) observed consistently negative correlations between direct and maternal genetic effects for BW of Bonsmara cattle raised in four regions of South Africa when S × CG was omitted, whereas the correlations were mainly positive when S × CG was included in the model. Eler et al (2000) reported genetic correlations between direct and maternal effects for growth traits of Nelore cattle in Brazil that were close to zero or even positive when sire × herd interaction was included in the model, and that were always negative when this parameter was omitted.…”

Section: Resultsmentioning

confidence: 84%

“…Maternal heritability for BW and WW was overestimated on average by 36% and 24%, respectively, when S × CG was omitted. Nephawe et al (1999) reported 30% overestimation of maternal heritability for WW in Bonsmara cattle, corresponding to an average overestimation of total heritability for WW of 34%. In the present study, average overestimation of this parameter was 7% for BW and 13% for WW.…”

Section: Resultsmentioning

confidence: 94%

“…In that study, the genetic correlation of WW between two production environments was 0.66 when S × CG was omitted and 0.83 when this parameter was included. Nephawe et al (1999) estimated genetic correlations of 0.39 to 0.54 between WW of Bonsmara cattle across different regions of Africa when S × CG was omitted and these correlations ranged from 0.79 to 0.85 when S × CG was included in the model. In a study on Limousin cattle in the United States, Bertrand et al (1987) observed that the genetic correlations of BW and WW across regions increased when the effect of S × CG and cow × contemporary group interaction was included in the model.…”

Section: Resultsmentioning

confidence: 98%

“…Eler et al (2000) found that direct heritability estimates for BW and WW of Nelore cattle were overestimated by 76% and 22%, respectively, when sire × herd interaction was not included in the model. In a study on South African Bonsmara Genotype by production environment interaction cattle, Nephawe et al (1999) reported that the omission of S × CG in the model can overestimate direct heritability for WW by 180%. Maternal heritability estimates were also affected by inclusion of S × CG in the model.…”

Section: Resultsmentioning

confidence: 99%

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Genotype by production environment interaction for birth and weaning weights in a population of composite beef cattle

Júnior

Eler

Bignardi

et al. 2014

Animal

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The objectives of the present study were: (1) to evaluate the importance of genotype × production environment interaction for the genetic evaluation of birth weight (BW) and weaning weight (WW) in a population of composite beef cattle in Brazil, and (2) to investigate the importance of sire × contemporary group interaction (S × CG) to model G × E and improve the accuracy of prediction in routine genetic evaluations of this population. Analyses were performed with one, two (favorable and unfavorable) or three (favorable, intermediate, unfavorable) different definitions of production environments. Thus, BW and WW records of animals in a favorable environment were assigned to either trait 1, in an intermediate environment to trait 2 or in an unfavorable environment to trait 3. The (co)variance components were estimated using Gibbs sampling in single-, bi-or three-trait animal models according to the definition of number of production environments. In general, the estimates of genetic parameters for BW and WW were similar between environments. The additive genetic correlations between production environments were close to unity for BW; however, when examining the highest posterior density intervals, the correlation between favorable and unfavorable environments reached a value of only 0.70, a fact that may lead to changes in the ranking of sires across environments. The posterior mean genetic correlation between direct effects was 0.63 in favorable and unfavorable environments for WW. When S × CG was included in two-or three-trait analyses, all direct genetic correlations were close to unity, suggesting that there was no evidence of a genotype × production environment interaction. Furthermore, the model including S × CG contributed to prevent overestimation of the accuracy of breeding values of sires, provided a lower error of prediction for both direct and maternal breeding values, lower squared bias, residual variance and deviance information criterion than the model omitting S × CG. Thus, the model that included S × CG can therefore be considered the best model on the basis of these criteria. The genotype × production environment interaction should not be neglected in the genetic evaluation of BW and WW in the present population of beef cattle. The inclusion of S × CG in the model is a feasible and plausible alternative to model the effects of G × E in the genetic evaluations.

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Section: Resultssupporting

confidence: 92%

Section: Resultsmentioning

confidence: 84%

Section: Resultsmentioning

confidence: 94%

Section: Resultsmentioning

confidence: 98%

Section: Resultsmentioning

confidence: 99%

See 3 more Smart Citations

Genotype by production environment interaction for birth and weaning weights in a population of composite beef cattle

Júnior

Eler

Bignardi

et al. 2014

Animal

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Genotype by environment interaction for birth and weaning weights of composite beef cattle in different regions of Brazil

et al. 2012

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Importance of adaptation and genotype × environment interactions in tropical beef breeding systems

Burrow

2012

Animal

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This paper examines the relative importance of productive and adaptive traits in beef breeding systems based on Bos taurus and tropically adapted breeds across temperate and (sub)tropical environments. In the (sub)tropics, differences that exist between breeds in temperate environments are masked by the effects of environmental stressors. Hence in tropical environments, breeds are best categorised into breed types to compare their performance across environments. Because of the presence of environmental stressors, there are more sources of genetic variation in tropical breeding programmes. It is therefore necessary to examine the genetic basis of productive and adaptive traits for breeding programmes in those environments. This paper reviews the heritabilities and genetic relationships between economically important productive and adaptive traits relevant to (sub)tropical breeding programmes. It is concluded that it is possible to simultaneously genetically improve productive and adaptive traits in tropically adapted breeds of beef cattle grazed in tropical environments without serious detrimental consequences for either adaptation or production. However, breed-specific parameters are required for genetic evaluations. The paper also reviews the magnitude of genotype 3 environment (G 3 E) interactions impacting on production and adaptation of cattle, where 'genotype' is defined as breed (within a crossbreeding system), sire within breed (in a within-breed selection programme) or associations between economically important traits and single nucleotide polymorphisms (SNPs -within a marker-assisted selection programme). It is concluded that re-ranking of breeds across environments is best managed by the use of the breed type(s) best suited to the particular production environment. Re-ranking of sires across environments is apparent in poorly adapted breed types across extreme tropical and temperate environments or where breeding animals are selected in a temperate environment for use in the (sub)tropics. However, G 3 E interactions are unlikely to be of major importance in tropically adapted beef cattle grazed in either temperate or (sub)tropical environments, although sex 3 environment interactions may provide new opportunities for differentially selecting to simultaneously improve steer performance in benign environments and female performance in harsher environments. Early evidence suggests that re-ranking of SNPs occurs across temperate and tropical environments, although their magnitude is still to be confirmed in well-designed experiments. The major limitation to genetic improvement of beef cattle over the next decade is likely to be a deficiency of large numbers of accurately recorded phenotypes for most productive and adaptive traits and, in particular, for difficult-to-measure adaptive traits such as resistance to disease and environmental stressors.

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Sire x ecological region interaction in Bonsmara cattle

Cited by 5 publications

References 0 publications

Genotype by production environment interaction for birth and weaning weights in a population of composite beef cattle

Genotype by production environment interaction for birth and weaning weights in a population of composite beef cattle

Genotype by environment interaction for birth and weaning weights of composite beef cattle in different regions of Brazil

Importance of adaptation and genotype × environment interactions in tropical beef breeding systems

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