Derivation of economic values for the Simmentaler breed in South Africa

Kluyts, Johan Francois; Neser, F.W.C.; Bradfield, M.J.

doi:10.4314/sajas.v37i2.4035

Cited by 4 publications

(6 citation statements)

References 39 publications

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“…Albera et al (2004) e Kluyts et al (2007) destacaram a importância econômica de características reprodutivas em sistemas de cria, em comparação às características de produto final, tais como conformação da carne ao abate, rendimento de cortes cárneos, espessura de gordura subcutânea, maciez e marmoreio.…”

Section: Introductionunclassified

Altura da garupa e sua associação com características reprodutivas e de crescimento na raça Nelore

Pereira

Yokoo

Bignardi

et al. 2010

Pesq. agropec. bras.

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Resumo -O objetivo deste trabalho foi determinar os fatores que afetam a altura da garupa em diferentes idades, em bovinos Nelore, e estimar a herdabilidade e as correlações genéticas entre esse caractere e as características reprodutivas e de crescimento. Os caracteres avaliados foram: altura da garupa à desmama, altura da garupa ao sobreano, peso à desmama, peso ao sobreano, perímetro escrotal e idade ao primeiro parto. Os fatores considerados foram: ano e mês de nascimento, rebanho, sexo, idade da vaca ao parto e idade do bezerro. Os componentes de variância e covariância foram estimados pela metodologia de máxima verossimilhança restrita, tendo-se utilizado um modelo animal. Todos os efeitos foram significativos para altura de garupa nas diferentes idades. As estimativas de herdabilidade quanto ao efeito genético direto indicaram que as características de crescimento e reprodutivas respondem à seleção, exceto a idade ao primeiro parto. As correlações genéticas entre as características de crescimento foram todas positivas e elevadas, de 0,42 a 0,90, o que indica que são determinadas em grande parte pelos mesmos conjuntos de genes de ação aditiva. Em razão das baixas magnitudes das estimativas de correlação genética (entre -0,14 e 0,16), a eficiência reprodutiva é pouco influenciada pela seleção quanto à altura de garupa.Termos para indexação: componentes de variância, correlações genéticas, herdabilidade, idade da vaca, idade do bezerro. Hip height and its relationships with reproductive and growth traits in Nelore cattleAbstract -The objective of this work was to determine factors that affect hip height at different ages, in Nelore cattle, and to estimate the heritability and the genetic correlation between this character and reproductive and growth traits. The analyzed traits were: hip height at weaning, hip height at post weaning, weight at weaning, weight at post weaning, scrotal circumference, and age at first calving. The analyzed factors were: year and month of birth, herd, sex, age of dam at calving, and calf age. The variance covariance components were estimate by the restrict maximum likelihood methodology using animal model. All effects were significant for hip height at different ages. The heritability estimates for direct genetic effects indicated that the growth and reproductive traits respond to selection, except for age at first calving. The genetic correlations between growth traits were positive and high, from 0.42 to 0.90, which indicates that they are mostly determined by the same group of genes with additive action. Due to the low magnitude of the estimated genetic correlations, from -0.14 to 0.16, the reproductive efficiency is little influenced by selection for hip height.

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Section: Introductionunclassified

Altura da garupa e sua associação com características reprodutivas e de crescimento na raça Nelore

Pereira

Yokoo

Bignardi

et al. 2010

Pesq. agropec. bras.

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“…According to Kluyts et al (2007) These index coefficients can now be multiplied with each EBV and summed to obtain the index value for an animal. Animals can then be ranked according to these index values and selection based on these rankings.…”

Section: Resultsmentioning

confidence: 99%

“…These parameters were provided by Breedplan International for the South African Simmentaler breed as well as from literature reports (Koots et al, 1994a;Gregory et al, 1995a;b;Barwick & Henzell, 1999;Meyer & Johnston, 2001;Devitt et al, 2002;Martinez-Velazquez et al, 2003;Cundiff et al, 2004). Economic values were derived by Kluyts et al (2007) The economic value (Table 1) of a trait was defined by Hazel (1943) as the amount by which profit may be expected to change for each unit of improvement in the trait concerned, independent of effects from changes in other traits included in the definition of the breeding objective. Therefore, the economic value (a) of a given trait (i) was defined as the partial derivative (δ) of the profit equation (π) with respect to the trait concerned whereby all traits (x) are assumed to take their mean (µ) values: Koots et al (1994b), Graser et al (1994), Nitter et al (1994) and Johnston & Bunter (1996) are summarized in Table 2.…”

Section: Methodsmentioning

confidence: 99%

“…Economic values have already been derived for economically important traits for the Simmentaler breed (Kluyts et al, 2007). Therefore, the objectives of this paper were (1) the construction of economic selection indices for the Simmentaler breed in South Africa and (2) to test the accuracy and efficiency of these indices, depending on which selection criteria are measured.…”

Section: Introductionmentioning

confidence: 99%

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Proposed economic selection indices for the Simmentaler breed in South Africa

Kluyts¹,

Neser

Bradfield³

2007

SA J. An. Sci.

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The development of economic selection indices for an integrated Simmentaler production system was described. The breeding objective was defined in terms of production-, functional-and product quality traits. Criteria included in the total index were birth-and weaning weight (direct and maternal), final weight, mature cow weight, days-to-calving, backfat thickness, tenderness and marbling. The total merit index was termed as I T = -1.60 BW D -1.95 BW M + 2.23 WW D + 1.75 WW M -0.54 FW -2.01 MCW -13.21 CD + 4.97 BF -2.36 T + 12.66 M. The correlation between this index and the aggregate breeding objective was 0.988. The economic superiority of the progeny from the top 40% of animals selected on their ranking in the total index, relative to the average progeny, is expected to be R 119.51.

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“…Timber from trees logged and disposed of in landfills is mainly recovered by the informal sector and used as firewood. DoA, 2009;Demirbas, 2004;Muller et al, 1999;Grasoline South Africa, 2009;Kluyts et al, 2007;Pordesimo et al, 2004;DME, 2005;Sezela Cane Growers' Association, n.d.;DME, 2004;Meyer and Rusk, 2003;Forestry South Africa, 2008;DWAF, 2008 If additional land was made available for forestry, then short rotation coppice of Eucalyptus, Wattle or other tree species could theoretically be grown for dedicated second-generation biofuel production. But even though about 120 000 ha in the Eastern Cape are potentially available for additional plantations (ECDC, n.d.), it is unlikely that they would be dedicated to energy production under current economic conditions.…”

Section: Feedstock and Cultivation Areamentioning

confidence: 99%

Sustainable Production of Second-Generation Biofuels

Eisentraut

2010

IEA Energy Papers

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The lead author and coordinator of this report is Anselm Eisentraut, Biofuels Researcher with the Renewable Energy Division of the International Energy Agency (IEA). The study also draws on contributions of Franziska Mueller-Langer, Jens Giersdorf and Anastasios Perimenis of the German Biomass Research Centre (DBFZ), who provided parts of the sustainability chapter and four country profiles commissioned by the Deutsche Gesellschaft für Technische Zusammenarbeit (GTZ). Dr. Antonio Pflüger, former head of the IEA Energy Technology Collaboration Division as well as Dr. Paolo Frankl, head of the Renewable Energy Division, and Dr. Mike Enskat, Senior Programme Manager for Energy at GTZ, provided guidance and input. Several IEA colleagues also provided useful data and comments on the draft, in particular

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Derivation of economic values for the Simmentaler breed in South Africa

Cited by 4 publications

References 39 publications

Altura da garupa e sua associação com características reprodutivas e de crescimento na raça Nelore

Altura da garupa e sua associação com características reprodutivas e de crescimento na raça Nelore

Proposed economic selection indices for the Simmentaler breed in South Africa

Sustainable Production of Second-Generation Biofuels

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