scholarly journals BREEDING INDEX MODELING FOR AIRSHIRE DAIRY CATTLE WITH APPLICATION OF EXTERIOR PARAMETRES

2021 ◽  
Vol 212 ◽  
pp. 150-155
Author(s):  
E.A. Romanova ◽  
◽  
O.V. Tulinova ◽  
Keyword(s):  
Milk Yield ◽  
Selection Index ◽  
Genetic Correlations ◽  
Original Data ◽  
Protein Yield ◽  
Leningrad Region ◽  
Ayrshire Breed ◽  
Fat Yield ◽  
Variance And Covariance Components ◽  
Index Weight

The article presents results of selection efficiency of potential parents in Ayrshire breed using IAYR multiple-factor selection index, which includes productivity traits such as milk yield, fat and protein yield and integrated exterior parametres: UDC udder index and FLC leg index. As an original data array, a sample was generated with parameters for milk productivity and exterior characteristics of 574 Ayrshire first-calf heifers, which are daughters of 21 bulls from the leading breeding farm of Leningrad region. Calculation of phenotypic and genetic correlations was carried out in the course of the study, which revealed the greatest paratypical relationship between milk yield and fat yield rp = 0.912 at p <0.001, and the highest genetic relationship was noted between milk yield and protein yield rg = 0.960 at p <0.001. A high value of heritability coefficient for milk yield was established, which amounted to h2 = 0.506, which is connected with usage of imported servicing bulls with high genetic potential for herd reproduction. To determine the values of index weight coefficients, the variance and covariance components of variability of the studied parametres were calculated. Economic components of the parametres included in the developed equation are formed. As a result of selection modeling with an intensity of 10% according to the constructed equation of the productive-exterior index IAYR, a significant and reliable advantage in milk production by 1899 kg of milk was established in comparison with other animals, in terms of fat yield - by 64.7 kg and protein yield - by 51.7 kg.

Relationship between milk composition and yield of milk, fat and protein in Red Danish cattle

1968 ◽  
Vol 10 (4) ◽  
pp. 445-450 ◽  
Author(s):  
K. Christensen
Keyword(s):  
Milk Yield ◽  
Milk Fat ◽  
Genetic Correlations ◽  
Protein Yield ◽  
Direct Selection ◽  
Correlated Response ◽  
Logarithmic Scale ◽  
Progeny Testing ◽  
Fat Yield ◽  
Selection For

The relationships among five traits in dairy cattle (milk yield, fat yield, protein, fat % and protein %) were examined on the original and on a logarithmic scale. The data comprised the records on 5333 Red Danish cows tested at the Danish Progeny Testing Stations during the years 1960–66. None of the heritabilities or the correlations among the variates were altered appreciably by transformation. For the five traits heritability estimates were 0·56, 0·80, 0·65, 0·64 and 0·56, respectively. Phenotypic and genetic correlations among milk yield, fat yield and protein yield were all very high, about 0·95. The correlations between fat % and protein % were about 0·6. The coefficient of variation of a variate proved to be a good approximation of the standard deviation of the transformed variate even for milk, fat and protein yield with coefficients of variation of 17–18%. It was concluded that little is likely to be gained by using index selection for fat yield and protein yield. However, about 90% of the response obtainable by direct selection for fat or protein yield could be obtained merely by selection for milk yield. A large correlated response for protein yield could be obtained by selecting for fat yield.

Estimates of genetic parameters for milk and fat yield for the first three lactations in British Friesian cows

1984 ◽  
Vol 38 (3) ◽  
pp. 313-322 ◽  
Author(s):  
Karin Meyer
Keyword(s):  
Milk Yield ◽  
Fixed Effects ◽  
Mixed Model ◽  
Genetic Correlations ◽  
Data Sets ◽  
Lactation Length ◽  
Maximum Likelihood Procedure ◽  
Fat Yield ◽  
Variance And Covariance Components ◽  
Estimate Variance

ABSTRACTA multivariate restricted maximum-likelihood procedure was used to estimate variance and covariance components between and within sires. This method, which considered all lactations simultaneously, accounted for the bias in later lactation records due to selection on dairy performance. Analysis was carried out for a mixed model with herd-year-seasons as fixed and sires as random effects, and fitting lactation length, calving age and month within season of calving as covariables. The data included 26 176 first, 19 978 second and 14 868 third lactation records for 679 test sires, and were analysed in 13 subsets. Additional records for proven sires, treated as fixed effects, were included to improve the data structure.Estimates for all components were higher in later than in earlier data sets, probably, to a large extent, because of a scale effect. Pooled estimates of heritabilities for lactations 1 to 3 were 0·28, 0·19 and 0·24 for milk yield, and 0·27, 0·21 and 0·25 for fat yield. Genetic correlations of 0·91, 0·91 and 0·95 for milk yield, and 0·91, 0·91 and 0·99 for fat yield, were found between lactations 1 and 2, 1 and 3, and 2 and 3, respectively. Results suggest that dairy performance in all lactations is almost identical genetically.

scholarly journals Genetic relationships between production traits and reproductive performance in Holstein dairy cows

2012 ◽  
Vol 55 (5) ◽  
pp. 458-468 ◽  
Author(s):  
S. Toghiani
Keyword(s):  
Milk Yield ◽  
Reproductive Performance ◽  
Genetic Relationships ◽  
Genetic Correlations ◽  
Protein Yield ◽  
Likelihood Method ◽  
Gestation Length ◽  
Production Traits ◽  
Breeding Center ◽  
Fat Yield

Abstract. In order to estimate genetic parameters for production traits and reproductive performance, 115465 records of production traits and 90942 records of reproductive performance from Iranian Holstein cows that were collected during 1980 to 2004 at Animal Breeding Center of Iran, were used. The estimations were performed using Restricted Maximum Likelihood method (REML) under an animal model by DF-REML and MATVEC software. Estimates of heritabilities for production traits were moderate, from 0.149 for fat yield to 0.26 for milk yield. Heritabilities for reproductive performance were low, and ranged from 0.04 for interval from calving to first service to 0.0743 for gestation length. Genetic correlations between production traits were form −0.505 for milk yield and protein percentage to 0.81 between milk yield with fat yield. Most genetic correlations between reproductive performances were found close to zero. Genetic correlation estimates of production traits with reproductive performance were from −0.513 for open days and protein yield to 0.96 for protein yield and calving interval.

SIRE BY HERD INTERACTIONS FOR MILK YIELD AND COMPOSITION TRAITS

1977 ◽  
Vol 57 (3) ◽  
pp. 383-388 ◽  
Author(s):  
A. K. W. TONG ◽  
B. W. KENNEDY ◽  
J. E. MOXLEY
Keyword(s):  
Milk Yield ◽  
Milk Fat ◽  
Genetic Parameter ◽  
Genetic Correlations ◽  
Dairy Herd ◽  
Protein Yield ◽  
Reduced Model ◽  
Parameter Estimates ◽  
Full Model ◽  
Reduced Models

A total of 13,561 Holstein 305-day lactation records from 779 Quebec and Maritime herds enrolled on the Dairy Herd Analysis Service were used to evaluate the importance of sire × herd interactions for milk yield and composition traits. Sire × herd interaction accounted for 4.1, 1.1, 0.3, 2.6 and 5.6% of the total variation of milk, fat and protein yield and fat and protein percent, respectively. Genetic parameter estimates obtained under two different models, a full model that accounted for sire × herd interaction and a reduced model that ignored it, were examined. Heritabilities of milk, fat and protein yield and fat and protein percent were, respectively: for the full model, 0.36, 0.47, 0.45, 0.59 and 0.31 and for the reduced model, 0.49, 0.50, 0.46, 0.66 and 0.46. Phenotypic correlations between the traits were not appreciably different when estimated under the full and reduced models. Genetic correlations between the yield traits were also similar when estimated under the full and reduced models, but genetic correlations between yield and percentage traits were more stongly positive, or less negative, when sire × herd interaction was accounted for. The genetic correlation between fat and protein percent was larger under the reduced model than under the full model.

scholarly journals Analyses of genetic relationships between linear type traits, fat-to-protein ratio, milk production traits, and somatic cell count in first-parity Czech Holstein cows

2014 ◽  
Vol 59 (No. 12) ◽  
pp. 539-547 ◽  
Author(s):  
V. Zink ◽  
L. Zavadilová ◽  
J. Lassen ◽  
M. Štípková ◽  
M. Vacek ◽  
...  
Keyword(s):  
Somatic Cell ◽  
Milk Yield ◽  
Somatic Cell Score ◽  
Protein Yield ◽  
Production Traits ◽  
Linear Type ◽  
Protein Percentage ◽  
Phenotypic Correlations ◽  
Type Traits ◽  
Fat Yield

Genetic and phenotypic correlations between production traits, selected linear type traits, and somatic cell score were estimated. The results could be useful for breeding programs involving Czech Holstein dairy cows or other populations. A series of bivariate analyses was applied whereby (co)variance components were estimated using average information (AI-REML) implemented via the DMU statistical package. Chosen phenotypic data included average somatic cell score per a 305-day standard first lactation as well as the production traits milk yield, fat yield, protein yield, fat percentage, and protein percentage per the standard first lactation. Fifteen classified linear type traits were added, as they were measured at first lactation in the Czech Holstein population. All phenotypic data were collected within the progeny testing program of the Czech-Moravian Breeders Corporation from 2005 to 2009. The number of animals for each linear type trait was 59&nbsp;454, except for locomotion, for which 53 424 animals were recorded. The numbers of animals with records of&nbsp;milk production data were 43 992 for milk yield, fat percentage, protein percentage, and fat-to-protein percentage ratio and 43 978 for fat yield and protein yield. In total, 27 098 somatic cell score records were available. The strongest positive genetic correlation between production traits and linear type traits was estimated between udder width and fat yield (0.51 &plusmn; 0.04), while the strongest negative correlation estimated was between body condition score and fat yield (&minus;0.45 &plusmn; 0.03). Other estimated correlations were between those two extremes but generally they were close to zero or positive. The strongest negative phenotypic correlations were estimated between udder depth and milk yield and protein yield (both &minus;0.17), while the strongest positive phenotypic correlations were estimated between milk yield, protein yield, and udder width (both 0.32). &nbsp;

Multiple-trait selection in jack pine

1991 ◽  
Vol 21 (4) ◽  
pp. 439-445 ◽  
Author(s):  
G. W. Adams ◽  
E. K. Morgenstern
Keyword(s):  
Genetic Relationships ◽  
Selection Index ◽  
Genetic Correlations ◽  
Jack Pine ◽  
Height Growth ◽  
Quality Traits ◽  
Multiple Trait ◽  
Growing Seasons ◽  
Stem Straightness ◽  
Variance And Covariance Components

Open-pollinated jack pine (Pinusbanksiana Lamb.) families were evaluated at four sites in New Brunswick after seven growing seasons for height growth, crown quality, stem straightness, branch angle, and relative branch diameter. Variance and covariance components were estimated to determine heritability of traits and genetic correlations between traits. Results indicated that there is a negative genetic correlation between height growth and all other traits. Selection based on height growth alone would result in degradation of quality traits of secondary economic importance at this age. A restricted selection index approach was examined for family roguing in seedling seed orchards because of the adverse genetic relationships between traits. Such an approach may be used to hold secondary quality traits constant, although some loss in maximum potential genetic gain in height at 7 years is incurred.

Genetic analyses of profit for Australian dairy cattle

1995 ◽  
Vol 61 (1) ◽  
pp. 9-18 ◽  
Author(s):  
P. M. Visscher ◽  
M. E. Goddard
Keyword(s):  
Dairy Cattle ◽  
Milk Yield ◽  
Selection Index ◽  
Genetic Correlations ◽  
Net Income ◽  
For Profit ◽  
Holstein Friesian ◽  
Yield Trait ◽  
Dairy Bulls ◽  
Selection Of

AbstractDirect genetic evaluation of profit was investigated as an alternative to a selection index. PROFk was defined as (net income)/(food requirement) until the start of the kth lactation, for k = 2 to 6. Genetic parameters such as heritabilities and genetic correlations were estimated for profit traits for Australian Holstein-Friesian and jersey dairy cattle. Heritabilities for profit until the start of a given lactation were moderate, ranging from 0·12 (for profit until the start of the second lactation in Holsteins) to 0·31 (profit until the start of the third lactation in Jerseys). Genetic correlations between profit traits were very high, and approached unity for most pairs of traits, so that profit early and late in herd life were nearly the same trait. Genetic correlations between profit traits and stayabilities until a given lactation were high, ranging from 0·71 to 0·97. Genetic correlations between profit traits and first lactation milk yield traits were approximately 0·80 for Holsteins and 0·90 for Jerseys. A single analysis urns carried out for lifetime profit using all data, including cows that were still in the herd at the time of data collection. Heritabilities were 0·13 for Holsteins and 0·19 for Jerseys. Genetic correlations between lifetime profit and first lactation yields were high. For the selection of dairy bulls, a multivariate analysis on a milk yield trait (e.g. protein yield) and profit until the last known lactation of bulls' progeny was suggested.

scholarly journals Genetic and phenotypic trends for age at first calving and milk yield and compositions in Holstein dairy cows

2011 ◽  
Vol 54 (4) ◽  
pp. 338-347
Author(s):  
N. G. Hossein-Zadeh
Keyword(s):  
Milk Yield ◽  
The Other ◽  
Protein Yield ◽  
Fat Percentage ◽  
Milk Traits ◽  
Age At First Calving ◽  
Other Hand ◽  
Fat Yield ◽  
Over Time ◽  
Genetic Trends

Abstract. Calving records from the Animal Breeding Center of Iran collected from January 1990 to December 2007 and comprising 207 106 first calving events of Holsteins from 2 506 herds were analysed using linear sire models to estimate genetic trends for age at first calving (AFC) and milk traits. Genetic trends were obtained by regressing yearly mean estimates of breeding values on year of birth. In general, there were decreasing genetic trends for AFC, fat percentage and protein percentage over the years but there were increasing genetic trends for milk yield, mature-equivalent milk yield, fat yield, mature-equivalent fat yield, protein yield and mature-equivalent protein yield over the years. On the other hand, there was a decreasing phenotypic trend for AFC but estimates of phenotypic trends were positive for milk yield and compositions over the years. It seems that the decline in calving age in this study over time resulted primarily from increased turnover rate and increased culling of heifers that failed to get pregnant. On the other hand, increasing trend for yield traits over time in this study indicated that Iranian dairy producers were successful in choosing progressively better semen and sires from imported and local sources over the years.

scholarly journals Schätzung genetischer Parameter für Testtagsergebnisse von Milchleistungsmerkmalen bei Bunten Deutschen Edelziegen

2004 ◽  
Vol 47 (2) ◽  
pp. 193-202
Author(s):  
D. Bömkes ◽  
H. Hamann ◽  
O. Distl
Keyword(s):  
Protein Content ◽  
Milk Yield ◽  
Milk Fat ◽  
Genetic Parameters ◽  
Genetic Correlations ◽  
Protein Yield ◽  
Lower Saxony ◽  
Genetic Progress ◽  
Performance Traits ◽  
Milk Performance

Abstract. Title of the paper: Estimation of genetic parameters for test day records of milk performance traits in German Improved Fawn The objectives of this study were to estimate genetic parameters for milk performance traits of German Improved Fawn by using univariate und multivariate animal models. The analysis was based on 27,778 test day records of 1,848 German Improved Fawn with 3,574 lactation records distributed over 229 flocks in Lower Saxony, Saxony and Baden-Wuerttemberg. Milk records were sampled between 1988 and 2002. The animals in our analysis were the progeny of 455 sires and 1.148 does. Heritabilities estimated with a multivariate test day model with fixed regression were h2 = 0.19, 0.16 and 0.15 for milk, fat and protein yield. For fat and protein content and Somatic Cell Score (SCS) heritabilities were h2 = 0.17, 0.14 and 0.16, respectively. The additive genetic correlations between milk yield and fat as well as protein yield of German Improved Fawn were very high and positive (rg = 0.84 and rg = 0.77). Milk yield and milk contents were genetically negative correlated with rg = −0.28 for fat and rg = −0.22 for protein content. A moderate additive genetic correlation (rg = 0.48) between fat and protein content was estimated. There were no considerable additive genetic correlations between fat yield and protein content as well as between fat content and protein yield (rg = 0.05 and rg = 0.09). Additive genetic correlations between milk, fat or protein yield and SCS were high and negative, whereas additive genetic correlations between fat or protein content and SCS were low and positive. The genetic parameters estimated from field test records allow to achieve genetic progress in milk performance traits of German Improved Fawn.

scholarly journals Genetic parameters between somatic cell score and production traits for Holstein cattle in Southern Brazil

2020 ◽  
Vol 33 (1) ◽  
pp. 60-70
Author(s):  
Gabrieli S Romano ◽  
Luis Fernando B Pinto ◽  
Altair A Valloto ◽  
José-Augusto Horst ◽  
Victor B Pedrosa
Keyword(s):  
Somatic Cell ◽  
Milk Yield ◽  
Variance Components ◽  
Genetic Parameters ◽  
Genetic Correlations ◽  
Milk Quality ◽  
Somatic Cell Score ◽  
Fat Percentage ◽  
Fat Yield ◽  
Selection For

Background: Somatic cell score is an important parameter to predict milk quality and health of cows. However, in countries like Brazil, this trait is still not selected on a large scale, and no genetic parameters are reported in the literature. Objective: To estimate the variance components and genetic parameters for somatic cell score, milk yield, fat yield, protein yield, fat percentage, and protein percentage in Holstein cows. Methods: Records from 56,718 animals were used to estimate variance components, heritability, and genetic correlations using a multi-trait animal model by the REML method. Results: The heritability estimates were 0.19 for somatic cell score, 0.22 for milk yield, 0.26 for fat yield, 0.18 for protein yield, 0.61 for fat percentage, and 0.65 for protein percentage. The estimates of genetic correlations among analyzed traits ranged from -0.50 to 0.82. Conclusion: The low heritability observed for somatic cell score indicates that selection for this trait should result in benefits related to animal health and milk quality, but only in the long term. The low correlation between productive traits and somatic cell score indicates that inclusion of somatic cell score in animal breeding programs does not interfere negatively with the genetic selection for milk yield or solids.Keywords: Holstein; genetic correlation; genetic parameters; heritability; mastitis; milk quality; milk yield; multi-trait model; somatic cell score; variance components.  Resumen Antecedentes: El conteo de células somáticas es un parámetro importante para predecir la calidad de la leche y la salud de las vacas. Sin embargo, en países como Brasil, esta característica aún no se selecciona a gran escala y no se reportan parámetros genéticos en la literatura. Objetivo: Estimar los componentes de varianza y parámetros genéticos para el conteo de células somáticas, producción de leche, producción de grasa, producción de proteína, porcentaje de grasa y porcentaje de proteína en vacas de la raza Holstein. Métodos: Se usaron registros de 56.718 animales para estimar los componentes de la varianza, heredabilidad y correlaciones genéticas usando un modelo animal multicaracterístico por medio del método REML. Resultados: Las estimaciones de heredabilidad fueron 0,19 para el conteo de células somáticas, 0,22 para la producción de leche, 0,26 para la producción de grasa, 0,18 para producción de proteína, 0,61 para el porcentaje de grasa y 0,65 para el porcentaje de proteína. Las estimaciones de correlación genética entre las características analizadas variaron entre -0,50 a 0,82. Conclusión: La baja heredabilidad encontrada para conteo de células somáticas demostró que la selección para esta característica podría resultar en beneficios para la salud animal y calidad de la leche, pero sólo a largo plazo. La baja correlación genética existente entre las características productivas y el conteo de células somáticas indica que la inclusión del conteo de células somáticas en programas de selección no interfiere negativamente en la selección genética para la producción de leche o sólidos.Palabras clave: calidad de leche; correlación genética; conteo de células somáticas; componentes de varianza; heredabilidad; Holstein; mastitis; modelo multicaracteristico; parametros geneticos; producción de leche; selección genetica. Resumo Antecedentes: O escore de células somáticas é um parâmetro importante para a predição da qualidade do leite, bem como para a saúde das vacas. No entanto, em alguns países como o Brasil, essa característica não é selecionada em larga escala e não há parâmetros genéticos disponíveis na literatura. Objetivo: Estimar os componentes de variância e parâmetros genéticos para o escore de células somáticas, produção de leite, produção de gordura, produção de proteína, porcentagem de gordura e porcentagem de proteína em vacas da raça Holandesa. Métodos: Foi utilizado um total de 56.718 animais para estimar os componentes de variância, herdabilidade e correlações genéticas, considerando-se o modelo animal multicaracterística por meio do método REML. Resultados: As estimativas de herdabilidade foram de 0,19 para o escore de células somáticas, 0,22 para a produção de leite, 0,26 para a produção de gordura, 0,18 para produção de proteína, 0,61 para a porcentagem de gordura e 0,65 para a porcentagem de proteína. As estimativas de correlação genética entre as características analisadas variaram entre -0,50 a 0,82. Conclusão: A baixa herdabilidade encontrada para o escore de células somáticas demonstrou que a seleção para esta característica poderá resultar em benefícios para a saúde animal e qualidade do leite, porém, somente a longo prazo. A baixa correlação genética existente entre as características produtivas e o escore de células somáticas demonstrou que a inclusão do escore de células somáticas em programas de seleção não causa interferência negativa na seleção genética para a produção de leite ou sólidos.Palavras-chave: componentes de variância; correlação genéticas; escore de células somáticas; herdabilidade; mastite; modelo multicaracterística; parâmetros genéticos; produção de leite; qualidade do leite; raça Holandesa; seleção genética.

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