Genetic Parameters for Yield Traits of Cows Treated or Not Treated with Bovine Somatotropin

Alseaf, A. M.; Keown, Jeffrey F.; Vleck, L.D. Van

doi:10.3168/jds.s0022-0302(07)72652-8

Cited by 4 publications

(3 citation statements)

References 17 publications

(21 reference statements)

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“…, where n = the number of test-day records, to weight the residuals was introduced to account for the different number of testday records per cow and lactation in the test-day model. The heritability h 2 for the yield traits was set to 0.25, and the h 2 for the content traits was set to 0.5 (an estimated average for the heritabilities was taken from Suzuki and Van Vleck, 1994;Visscher and Goddard, 1995;Al-Seaf et al, 2007;Stoop et al, 2007).…”

Section: Discussionmentioning

confidence: 99%

Lactation curve models for estimating gene effects over a timeline

Strucken

Koning

Rahmatalla

et al. 2011

Journal of Dairy Science

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The effects of genes are commonly estimated using random regression models based on test-day data and only give a general gene effect. Alternatively, lactation curve models can be used to estimate biological and environmental effects, or to predict missing test-day data and perform breeding value estimation. This study combines lactation curve models and estimation of gene effects to represent gene effects in different stages of lactation. The lactation curve models used were based on the Wood, Wilmink, and Ali and Schaeffer models. A random regression test-day model was used to compare estimated gene effects with the results of commonly used models. The well-characterized DGAT1 gene with known effects on milk yield, milk fat, and milk protein production was chosen to test this new approach in a Holstein-Friesian dairy cattle population. The K232A polymorphism and the promoter VNTR (variable number of tandem repeats) of the DGAT1 gene were used. All lactation curve models predicted the production curves sufficiently. Nevertheless, for predicting genotype effects, the Wilmink curve indicated the closest fit to the data. This study shows that the characteristic gene effects for DGAT1 genotypes occur after lactation d 40, which might be explained by a link to other genes affecting metabolic traits. Furthermore, allele substitution effects of allele K of the K232A locus showed that the typical effect of low milk and protein yield is due mainly to a lower overall production level, whereas the higher fat and protein content is reached by increased production toward its peak and fat yield is increased because of a higher production after this peak. Predicting gene effects with production curves gives better insight into the timeline of gene effects. This can be used to form genetic groups, in addition to feeding groups, for managing livestock populations in a more effective way.

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Section: Discussionmentioning

confidence: 99%

Lactation curve models for estimating gene effects over a timeline

Strucken

Koning

Rahmatalla

et al. 2011

Journal of Dairy Science

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“…The range of heritability in present study was obtained at 0.13 to 0.28 for milk yield and 0.05 to 0.15 for fat yield. Heritability estimations were imperceptibly upper than those from some literature (Alijani et al 2012, Bahreini Behzadi et al 2013 and lower than other literatures (Meyer 1984, Dedkova andWolf 2001;AL-Seaf et al 2007). Heritability estimates of milk and fat yields had decreasing trend by lactations.…”

Section: Resultsmentioning

confidence: 58%

Estimation of genetic parameters of milk and fat yields using different animal models in Iranian Holstein dairy cattle

Behzadi

Mehrpoor

2017

Indian J of Anim Sci

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Milk and fat yield records of the first 4 lactations from 58 herds of Holstein cows recorded from 1999 to 2015 were analyzed. Genetic parameters were estimated by using univariate, repeatability and multivariate animal models. The fixed effects of herd-year-season as contemporary group and age at calving as covariate were fitted in the model of analyses. Heritability estimates under univariate model for lactations 1 to 4 were 0.28, 0.20, 0.19 and 0.13 for milk yield and for fat yield were 0.15, 0.12, 0.12 and 0.05, respectively. The repeatability and heritability values under the repeatability model for milk and fat yield were 0.48 and 0.24, and 0.38 and 0.17, respectively. Estimated heritabilities using a bivariate model for lactations 1 to 4 were 0.29, 0.20, 0.20 and 0.15 for milk yield and 0.12, 0.11, 0.13 and 0.05 for fat yield, respectively. Heritability estimates for lactations 1 to 4 by multivariate model were 0.30, 0.23, 0.22 and 0.19 for milk yield, and 0.17, 0.16, 0.17 and 0.12 for fat yield, respectively. Genetic, phenotypic and environmental correlations of milk yield were 0.91, 0.50 and 0.36 for first and second lactation; and 0.87, 0.45 and 0.31 for first and third lactation; and 0.79, 0.39 and 0.26 for first and fourth lactation; and 0.97, 0.53 and 0.41 for second and third lactation; and 0.91, 0.50 and 0.39 for second and fourth lactation; and 0.96, 0.56 and 0.46 for third and fourth lactation, respectively. These parameters for fat yield were 0.87, 0.35, 0.25 and 0.91, 0.29, 0.16 and 0.83, 0.26, 0.17 and 0.96, 0.45, 0.35 and 0.90, 0.40, 0.32 and 0.98, 0.47, 0.38, respectively. Results from this study confirm that multivariate analysis is recommended for estimating the genetic parameter of milk and fat yield, because it considers the effects of selection bias of the first lactation.

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“…Esses resultados corroboram com o estudo de WEIGEL et al (1998), que analisaram dados de produção de leite de vacas holandesas utilizando modelos estatís-ticos que consideravam ou não os efeitos de bST e os valores estimados de herdabilidade foram de 0,20 e 0,21. Assim como AL-SEAF et al (2007a) que também estimaram parâmetros genéticos de vacas Holandesas para PL305 em 3 grupos de lactações (1ª. 2ª e de 3ª a 5ª) e relataram, respectivamente, os valores de herdabilidade iguais a 0,18; 0,18 e 0,14 para o modelo com ausência de bST e 0,13; 0,16 e 0,09 para o modelo que incluiu o efeito do bST.…”

Section: Parâmetros Genéticos Para a Produção De Leite E O Uso De Bstunclassified

Impacto da utilização da somatotropina bovina (bST) sobre a produção de leite e a avaliação genética de bovinos da raça Holandesa

Rodrigues¹,

Moreira²,

Faro³

et al. 2013

Bol. Ind. Anim.

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RESUMO: O objetivo do presente trabalho foi estudar a influência do uso da somatotropina bovina (bST) sobre a produção de leite (PL305) e a avaliação genética da PL305 de bovinos da raça Holandesa. Foram utilizados dados referentes a 474 touros e observações referentes a 3341 lactações de 1271 vacas, durante o período de 1999 a 2003. A análise de variância foi realizada pelo procedimento GLM do SAS (2003) e os parâmetros genéticos sob modelo animal unicaracterístico. As estimativas de herdabilidades para o modelo 1 (bST como efeito fixo) e modelo 2 (ausência desse efeito) foram respectivamente de 0,26 e 0,23 e a correlações entre os valores genéticos preditos para os conjuntos de touros a (todos avaliados), b (os melhores 20%), c (os melhores 10%) e d (os melhores 5%) foram, respectivamente, 0,9484, 0,9829, 0,9752 e 0,8974. A análise de variância demonstrou que as médias de PL305 aumentaram significativamente (P<0,0001), com o aumento do número de aplicações do bST. As altas correlações de Spearman entre os valores genéticos dos touros, considerando-se ou não o uso do bST no modelo, indicam que o uso desta tecnologia não interfere na classificação dos touros avaliados geneticamente.Palavras-chave: avaliação genética, bovinos leiteiros, somatotropina bovina. IMPACT OF BOVINE SOMATOTROPIN (bST) ON THE MILK PRODUCTION AND GENETIC EVALUATION OF HOLSTEIN CATTLEABSTRACT: The objective of this work was to study the influence of the use of bovine somatotropin (bST) on milk yield (MP305)

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Genetic Parameters for Yield Traits of Cows Treated or Not Treated with Bovine Somatotropin

Cited by 4 publications

References 17 publications

Lactation curve models for estimating gene effects over a timeline

Lactation curve models for estimating gene effects over a timeline

Estimation of genetic parameters of milk and fat yields using different animal models in Iranian Holstein dairy cattle

Impacto da utilização da somatotropina bovina (bST) sobre a produção de leite e a avaliação genética de bovinos da raça Holandesa

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