scholarly journals Estimation the Genetic Parameters for Milk Yield in Romanian Spotted, Simmental Type Cattle Breed

2021 ◽  
Vol 24 (2) ◽  
pp. 105-121
Author(s):  
Rodica Stefania Pelmuș ◽  
Mircea Cătălin Rotar ◽  
Cristina Lazăr ◽  
Răzvan Alexandru Uță
Keyword(s):  
Animal Model ◽  
Milk Yield ◽  
Genetic Parameters ◽  
Genetic Correlations ◽  
Cattle Breed ◽  
Random Regression ◽  
Breeding Value ◽  
Regression Test ◽  
Fat Yield ◽  
Heritability Estimates

Abstract The aim of this study was to estimate the genetic parameters for test-day traits milk yield and the breeding value in Romanian Spotted, Simmental type cattle. Random regression test-day animal model was used to estimate the genetic parameters. The number of records were 2062 test-day from 302 cows. The data were obtained from Romanian Breeding Association Romanian Spotted, Simmental type. The heritability estimates values for milk yield ranged between 0.377 and 0.417. The heritability for fat test-day yield in our study was low the values ranged between 0.117 and 0.236 and for protein test-day yield was medium, the values ranged between 0.308 and 0.372. The breeding value for the best ten cows for milk yield ranged from 1946.57 to 3250.38 kg, for fat yield were between 64.92 and 98.86 kg and for protein ranged from 67.26 to 102.21 kg. The correlations between test-day milk yields ranging from 0.28 to 1. Genetic correlations between test day fat and protein yields were high.

scholarly journals Genetic parameters for test-day milk yield in tropical Holstein Friesian cattle fitting a multiple-lactation random regression animal model

1970 ◽  
Vol 47 (3) ◽  
pp. 352-361
Author(s):  
S. Meseret ◽  
E. Negussie
Keyword(s):  
Animal Model ◽  
Milk Yield ◽  
Genetic Improvement ◽  
Genetic Parameters ◽  
Genetic Correlations ◽  
Random Regression ◽  
Likelihood Method ◽  
Holstein Friesian ◽  
Heritability Estimates ◽  
Friesian Cattle

Accurate estimates of genetic parameters are essential for genetic improvement of milk yield in dairy cattle and for setting up breeding programmes. Estimates of genetic parameters from test-day models, particularly for Holstein Friesian cattle maintained in tropical environments, are scant in the literature. The objective of this study was therefore to estimate genetic parameters for milk yield by fitting a multiple-lactation random regression animal model (RRM) based on data from Ethiopian Holstein Friesian herds. Data were used from the first three lactations of cows that calved between 1997 and 2013. The data comprised 13 421 test-day milk yield records from 800 cows from two large dairy herds. Variance components were estimated using the average information restricted maximum likelihood method fitting an RRM. Heritability estimates for first, second, and third lactations ranged from 0.20 to 0.26, 0.15 to 0.27, and 0.17 to 0.28, respectively. Heritability estimates ranging from 0.15 to 0.28 indicate that effective genetic improvement should be accompanied by a corresponding improvement of the production environment. Across-lactation genetic correlations between first and second, second and third, and first and third lactations, expressed on a 305-day yield basis, were 0.88, 0.83, and 0.70, respectively. These genetic correlations, less than or equal to 0.88, indicate that different lactations are different traits. For an accurate evaluation of the genetic merit of animals for milk yield, lactations should be treated as different, but correlated traits in a multiple-lactation analysis.Keywords: Genetic correlation, heritability, Legendre polynomial, test-day model

scholarly journals Milk yield genetic parameters estimated using random regression model in Teleorman Black Head Sheep

2021 ◽  
Vol 24 (1) ◽  
pp. 44-52
Author(s):  
Florin Popa ◽  
Horia Grosu ◽  
Mircea-Cătălin Rotar ◽  
Rodica Ștefania Pelmuș ◽  
Cristina Lazăr ◽  
...  
Keyword(s):  
Milk Yield ◽  
Genetic Parameters ◽  
Genetic Correlations ◽  
Random Regression ◽  
Breeding Value ◽  
First Year ◽  
Sheep Population ◽  
Random Regression Model ◽  
Regression Test ◽  
Black Head

Abstract Genetic parameters are important in breeding program of sheep. For the genetic evaluation of sheep was used the random regression test-day animal model. This model was better economic that another models because reduces generation interval and reduces the costs with test-days records. Data consisted of 1050 test-day of 403 ewes in first year (2017), 752 test-day of 374 ewes in second year (2018) and 1164 test-day of 319 ewes in third year (2019). The main goal to achieve the objectives of this research were the estimation of the genetic parameters important in obtaining the breeding value by calculation heritability for test-day milk yields and the correlations between test-days milk yields, for Teleorman Black Head Sheep population from Teleorman county in three different years. The heritability for test-day milk yield ranged from 0.150 to 0.237 in 2017, from 0.212 to 0.600 in 2018 and in 2019 from 0.186 to 0.403. Genetic correlations between sheep test-days milk yield in 2017 were positive and high.

scholarly journals Random regression models to estimate genetic parameters for test-day milk yield and composition in Iranian buffaloes

2013 ◽  
Vol 56 (1) ◽  
pp. 276-284 ◽  
Author(s):  
M. Madad ◽  
N. Ghavi Hossein-Zadeh ◽  
A. A. Shadparvar ◽  
D. Kianzad
Keyword(s):  
Milk Yield ◽  
Milk Fat ◽  
Milk Protein ◽  
Genetic Parameters ◽  
Genetic Correlations ◽  
Random Regression ◽  
Production Traits ◽  
Environmental Correlations ◽  
Protein Percentage ◽  
Heritability Estimates

Abstract. The objective of this study was to estimate genetic parameters for milk yield and milk percentages of fat and protein in Iranian buffaloes. A total of 9,278 test-day production records obtained from 1,501 first lactation buffaloes on 414 herds in Iran between 1993 and 2009 were used for the analysis. Genetic parameters for productive traits were estimated using random regression test-day models. Regression curves were modeled using Legendre polynomials (LPs). Heritability estimates were low to moderate for milk production traits and ranged from 0.09 to 0.33 for milk yield, 0.01 to 0.27 for milk protein percentage and 0.03 to 0.24 for milk fat percentage, respectively. Genetic correlations ranged from −0.24 to 1 for milk yield between different days in milk over the lactation. Genetic correlations of milk yield at different days in milk were often higher than permanent environmental correlations. Genetic correlations for milk protein percentage ranged from −0.89 to 1 between different days in milk. Also, genetic correlations for milk percentage of fat ranged from −0.60 to 1 between different days in milk. The highest estimates of genetic and permanent environmental correlations for milk traits were observed at adjacent test-days. Ignoring heritability estimates for milk yield and milk protein percentage in the first and final days of lactation, these estimates were higher in the 120 days of lactation. Test-day milk yield heritability estimates were moderate in the course of the lactation, suggesting that this trait could be applied as selection criteria in Iranian milking buffaloes.

scholarly journals Genetic parameters for milk production and persistency in the Iranian Holstein population by the multitrait random regression model

2014 ◽  
Vol 57 (1) ◽  
pp. 1-12 ◽  
Author(s):  
Khabat Kheirabadi ◽  
Sadegh Alijani
Keyword(s):  
Milk Yield ◽  
Milk Fat ◽  
Genetic Correlations ◽  
Random Regression ◽  
Genetic Dissection ◽  
Production Traits ◽  
Data Set ◽  
Random Regression Model ◽  
Regression Test ◽  
Fat Yield

Abstract. For genetic dissection of milk, fat, and protein production traits in the Iranian primiparous Holstein dairy cattle, records of these traits were analysed using a multitrait random regression test-day model. Data set included 763 505 test-day records from 88 204 cows calving since 1993. The (co)variance components were estimated by Bayesian method. The obtained results indicated that as in case of genetic correlations within traits, genetic correlations between traits decrease as days in milk (DIM) got further apart. The strength of the correlations decreased with increasing DIM, especially between milk and fat. Heritability estimates for 305-d milk, fat, and protein yields were 0.31, 0.29, and 0.29, respectively. Heritabilities of test-day milk, fat, and protein yields for selected DIM were higher in the end than at the beginning or the middle of lactation. Heritabilities for persistency ranged from 0.02 to 0.24 and were generally highest for protein yield (0.05 to 0.24) and lowest for fat yield (0.02 to 0.17), with milk yield having intermediate values (0.06 to 0.22). Genetic correlations between persistency measures and 305-d production were higher for protein and milk yield than for fat yield. The genetic correlation of the same persistency measures between milk and fat yields averaged 0.76, and between milk and protein yields averaged 0.82.

EFFICIENCY AND COMPARISON OF THE TEST-DAY MODEL AND BLUP METHOD MODIFICATIONS FOR ASSESSING BULLS BREEDING VALUE IN SIMMENTAL CATTLE BREED

2020 ◽  
Author(s):  
А.И. МАМОНТОВА ◽  
С.А. НИКИТИН ◽  
Е.Е. МЕЛЬНИКОВА ◽  
А.А. СЕРМЯГИН
Keyword(s):  
Animal Model ◽  
Milk Yield ◽  
Cattle Breed ◽  
Breeding Value ◽  
Am1 Method ◽  
Production Traits ◽  
Genetic Trend ◽  
Sire Model ◽  
The Russian Federation ◽  
Simmental Cattle

Целью проведенных исследований являлась отработка и адаптация применения методик BLUP AM (Animal Model — модель животного) и TDM (Test-Day Model — модель тестового дня) для прогнозирования племенной ценности быков-производителей и оценки селекционно-генетических параметров на популяции скота симментальской породы четырех регионов РФ. Проведен сравнительный анализ указанных методов с более ранним методом BLUP SM (Sire Model — модель отца). Рассчитана племенная ценность быков и коров симментальской породы по признакам молочной продуктивности: удой за 305 дней, выход молочного жира, выход молочного белка. Анализ полученных средних значений достоверности оценок быков-производителей, рассчитанных на основе сопоставляемых методов, свидетельствует, что достоверность для признака «удой за 305 дней» при переходе от метода SM1 к AM1 увеличивается на 2,4%, а при переходе от SM1 к TDM1 — на 7,8%. Даны варианты генетического тренда по удою с использованием различных уравнений моделей расчета племенной ценности. На основании полученных данных можно сделать вывод о том, что модель тестового дня позволяет не только повысить точность оценок быков, но и более рельефно выявить их ранги, а также несколько уменьшить срок получения достоверных оценок производителей по качеству потомства по продуктивным признакам. The purpose of this research was to develop and adapt the application of BLUP AM (Animal Model) and TDM (Test-Day Model) methods for predicting the sires breeding value and evaluating genetic parameters for Simmental cattle population in four regions of the Russian Federation. A comparative analysis of these methods with the earlier BLUP SM (Sire Model) method is performed. The breeding value for sires and cows of Simmental breed was calculated by milk production traits: milk yield for 305 days; milk fatyield; milk proteinyield. The sires reliability of average breeding value calculated by different methods reveal that milk yield for 305 days when switching from the SM1 to AM1 method increases by 2.4%, and when switching from SM1 to TDM1 — by 7.8%.The variants of the genetic trend for milk yield are given using various equations of BLUP and TDM. Based on the obtained data, it can be concluded that the Test-Day model allows increasing the accuracy of bull’s evaluation and also more clearly identifying their ranks, as well as slightly reducing the time for obtaining reliable estimates of bulls by offspring for production traits.

Genetic analysis of docility score of Australian Angus and Limousin cattle

2018 ◽  
Vol 58 (2) ◽  
pp. 213 ◽  
Author(s):  
S. F. Walkom ◽  
M. G. Jeyaruban ◽  
B. Tier ◽  
D. J. Johnston
Keyword(s):  
Adverse Effect ◽  
Animal Model ◽  
Genetic Analysis ◽  
Genetic Parameters ◽  
Genetic Correlations ◽  
Production Costs ◽  
Breeding Value ◽  
Maternal Behaviour ◽  
Production Traits ◽  
Subjective Score

The temperament of cattle is believed to affect the profitability of the herd through impacting production costs, meat quality, reproduction, maternal behaviour and the welfare of the animals and their handlers. As part of the national beef cattle genetic evaluation in Australia by BREEDPLAN, 50 935 Angus and 50 930 Limousin calves were scored by seedstock producers for temperament using docility score. Docility score is a subjective score of the animal’s response to being restrained and isolated within a crush, at weaning, and is scored on a scale from 1 to 5 with 1 representing the quiet and 5 the extremely nervous or anxious calves. Genetic parameters for docility score were estimated using a threshold animal model with four thresholds (five categories) from a Bayesian analysis carried out using Gibbs sampling in THRGIBBS1F90 with post-Gibbs analysis in POSTGIBBSF90. The heritability of docility score on the observed scale was 0.21 and 0.39 in Angus and Limousin, respectively. Since the release of the docility breeding value to the Australian Limousin population there has been a favourable trend within the national herd towards more docile cattle. Weak but favourable genetic correlations between docility score and the production traits indicates that docility score is largely independent of these traits and that selection to improve temperament can occur without having an adverse effect on growth, fat, muscle and reproduction.

scholarly journals Comparison of models for estimating genetic parameters and predicting breeding values for birth weight and calving ease in Czech Charolais cattle 

2014 ◽  
Vol 59 (No. 7) ◽  
pp. 302-309 ◽  
Author(s):  
L. Vostrý ◽  
Z. Veselá ◽  
A. Svitáková ◽  
H. Vostrá Vydrová
Keyword(s):  
Animal Model ◽  
Birth Weight ◽  
Beef Cattle ◽  
Fixed Effects ◽  
Genetic Parameters ◽  
Genetic Correlations ◽  
Genetic Effects ◽  
Parameters Estimation ◽  
Calving Ease ◽  
Heritability Estimates

The most appropriate model for genetic parameters estimation for calving ease and birth weight in beef cattle was selected. A total of 27 402 field records were available from the Czech Charolais breed. For estimation of genetic parameters for calving ease and body weight, three bivariate models were tested: a linear-linear animal model (L-LM) with calving ease classified into four categories (1 – easy; 2–4 – most difficult), a linear-linear animal model (SC-LM) in which calving ease scores were transformed into Snell scores (Snell 1964) and expressed as percentage of assisted calving (ranging 0–100%), and a bivariate threshold-linear animal model (T-LM) with calving ease classified into four categories (1 – easy, 2–4 – most difficult). All tested models included fixed effects for contemporary group (herd × year × season), age of dam, sex and breed of a calf. Random effects included direct and maternal genetic effects, maternal permanent environmental effect, and residual error. Direct heritability estimates for calving ease and birth weight were, with the use of L-LM, SC-LM, and T-LM, from 0.096 ± 0.013 to 0.226 ± 0.024 and from 0.210 ± 0.024 to 0.225 ± 0.026, respectively. Maternal heritability estimates for calving ease and birth weight were, with the use of L-LM, SC-LM, and T-LM, from 0.060 ± 0.031 to 0.104 ± 0.125 and from 0.074 ± 0.041 to 0.075 ± 0.040, respectively. Genetic correlations of direct calving ease with direct birth weight ranged from 0.46 ± 0.06 to 0.50 ± 0.06 for all tested models; whereas maternal genetic correlations between these two traits ranged from 0.24 ± 0.17 to 0.25 ± 0.53. Correlations between direct and maternal genetic effects within-trait were negative and substantial for all tested models (ranging from –0.574 ± 0.125 to –0.680 ± 0.141 for calving ease and from –0.553 ± 0.122 to –0.558 ± 0.118 for birth weight, respectively), illustrating the importance of including this parameter in calving ease evaluations. Results indicate that any of the tested models could be used to reliably estimate genetic parameters for calving ease for beef cattle in the Czech Republic. However, because of advantages in computation time and practical considerations, genetic analysis using SC-LM (transformed data) is recommended.

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.

scholarly journals Schätzung genetischer Parameter für Testtagsergebnisse der Milchleistung bei ostfriesischen Milchschafen mit Bayes-Methoden für longitudinale Daten

2002 ◽  
Vol 45 (1) ◽  
pp. 61-68
Author(s):  
A. Horstick ◽  
O. Distl
Keyword(s):  
Protein Content ◽  
Milk Yield ◽  
Bayesian Methods ◽  
Regression Models ◽  
Genetic Parameters ◽  
Fat Content ◽  
Random Regression ◽  
Lower Saxony ◽  
Milk Performance ◽  
Heritability Estimates

Abstract. Title of the paper: Estimation of genetic parameters for test day results of milk performance in East Friesian milk sheep using Bayesian methods for longitudinal data The objectives of this study were to estimate genetic parameters of milk performance traits in East Friesian milk sheep by using test day models with random regresssion. The analysis was based on 7545 test day records of 918 East Friesian milk sheep with 1380 lactation records. The data were provided by the sheep breeding organizations of Lower-Saxony, Westphalia, and Bavaria. The milk recordings were collected in the years 1992 to 2000. The average values of the heritability estimates by using random regression models were for the milk yield h2 = 0.25 ± 0.03, for the fat content h2 = 0.46 ± 0.09, and for the protein content h2 = 0.63 ± 0.12. The range of heritability estimates in dependence of the days in milk was for milk yield h2 = 0.03 to 0.70, for fat content h2 = 0.30 to 0.70, and for protein content h2 = 0.44 to 0.92.

Genetic perspective of milk yield persistency in the first three lactations of Iranian buffaloes (Bubalus bubalis)

2017 ◽  
Vol 84 (4) ◽  
pp. 434-439 ◽  
Author(s):  
Navid Ghavi Hossein-Zadeh ◽  
Mohammad Ali Nazari ◽  
Abdol Ahad Shadparvar
Keyword(s):  
Milk Yield ◽  
Genetic Correlations ◽  
Reproductive Traits ◽  
Bubalus Bubalis ◽  
Random Regression ◽  
Genetic Trend ◽  
Breeding Center ◽  
Regression Test ◽  
The Difference ◽  
Estimated Breeding Values

The objectives of this study were to estimate the genetic parameters and genetic trends for different measures of persistency (PM) for milk yield in Iranian buffaloes using a random regression test day model. Test day records of the first three lactations of buffaloes within 715 herds comprising 43 014, 38 941 and 33 937 records, respectively, were obtained from the Animal Breeding Center of Iran during 1992 to 2012. Legendre polynomial functions were chosen to fit the lactation curves in the framework of a random regression test day model for estimating (co)variance components. Three measures of persistency were modified based on the lactation curve conditions of buffaloes: (1) The average of estimated breeding values (EBVs) for test day milk yields from day 226 to day 270 as a deviation from the average of EBVs from day 44 to day 62 (PM1), (2) A summation of contribution for each day from day 53 to day 247 as a deviation from day 248 (PM2), (3) The difference between EBVs for day 257 and day 80 (PM3). The highest heritability estimates were observed for PM2over the first three lactations (0·29, 0·80 and 0·42, respectively). Estimates of genetic correlations between persistency measures and milk yield varied from −0·48 to 0·29 (first lactation), from −0·12 to 0·48 (second lactation), and from −0·62 to 0·63 (third lactation). Estimate of genetic trend for first lactation PM2was negative (−0·0088 ± 0·0043;P< 0·05). It is essential to include milk yield persistency in the breeding goal of Iranian buffaloes along with other important traits such as milk yield or reproductive traits.

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