Genetic parameters of test day records of British Holstein-Friesian heifers

1992 ◽  
Vol 55 (1) ◽  
pp. 11-21 ◽  
Author(s):  
B. L. Pander ◽  
W. G. Hill ◽  
R. Thompson
Keyword(s):  
Maximum Likelihood ◽  
Milk Yield ◽  
Milk Fat ◽  
Genetic Parameters ◽  
Genetic Correlations ◽  
Lactation Performance ◽  
Likelihood Methods ◽  
Holstein Friesian ◽  
Maximum Likelihood Methods ◽  
Heritability Estimates

AbstractEstimates of genetic parameters for test day records of yields of milk, fat and protein and concentrations of fat and protein were obtained on 47 736 British Holstein-Friesian heifers in 7973 herds, progeny of 40 proven (to improve connectedness) and 707 young sires (comprising about one-fifth of the progeny), using multivariate restricted maximum likelihood methods with a sire model.Heritability estimates for lactation yields of milk, fat and protein and concentrations of fat and protein were 0·49, 0·39, 0·43, 0·63 and 0·47, respectively. Estimates for individual test day records of these traits ranged from 0·27 to 0·43, 0·16 to 0·34, 0·22 to 0·33, 0·11 to 0·48 and 0·21 to 0·43, respectively. Generally, heritability estimates for test day records were lowest at start and highest in mid lactation.Estimates of genetic correlations among yields of a trait on different test days ranged from 0·57 to 0·99, and for fat and protein concentrations from 0·34 to 0·99, the correlations being highest for adjacent tests. Phenotypic correlations were lower than genetic correlations. Genetic correlations of test day records with corresponding lactation traits were high (0·76 to 0·99), being highest in mid lactation.Genetic correlations of test day milk yield with test day yields and concentrations of fat and protein throughout the lactation were similar to those for complete lactation.The high heritabilities of test day yields and their high genetic correlations with complete lactation, except for the first 1 or 2 test days, suggest that lactation performance may be predicted from test days in early and mid lactation.

scholarly journals Genetic parameters of production and reproduetive traits in on a farm tested Danish Large White and Landrace swine in Greece

2000 ◽  
Vol 43 (3) ◽  
pp. 287-298
Author(s):  
J. Bizelis ◽  
A. Kominakis ◽  
E. Rogdakis ◽  
F. Georgadopoulou
Keyword(s):  
Maximum Likelihood ◽  
Genetic Correlation ◽  
Genetic Parameters ◽  
Genetic Correlations ◽  
Production Traits ◽  
Likelihood Methods ◽  
Large White ◽  
Reproduction Traits ◽  
Maximum Likelihood Methods ◽  
Genetic And Phenotypic Correlations

Abstract. Production and reproduetive traits in Danish Landrace (LD) and Large White (LW) swine were analysed by restricted maximum likelihood methods to obtain heritabilities as well as genetic and phenotypic correlations. Production traits were: age, backfat thickness (BT), muscle depth (MD) and the ratio BT/MD, adjusted to Standard bodyweight of 85 kg. Reproduction traits were: number of pigs born (NB) and number of pigs weaned (NW) per sow and parity. Heritabilities for age, BT, MD and BT/MD were 0.60, 0.44, 0.51 and 0.42 for LD and 0.36, 0.44, 0.37 and 0.45 for LW, respectively. Genetic correlations between age and BT were −0.22 in LD and – 0.44 in LW. The genetic correlation between age and MD was close to zero in both breeds. Genetic correlation between BT and MD were −0.36 and −0.25 in LD and LW, respectively. Heritabilities for NB were 0.25 in LD and 0.13 in LW while heritabilities for NW were close to zero in both breeds. Genetic correlation between NB and NW was 0.46 and 0.70 in LD and LW, respectively.

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 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

Bias in heritability estimates from genomic restricted maximum likelihood methods under different genotyping strategies

2018 ◽  
Vol 136 (1) ◽  
pp. 40-50 ◽  
Author(s):  
Alberto Cesarani ◽  
Ivan Pocrnic ◽  
Nicolò P. P. Macciotta ◽  
Breno O. Fragomeni ◽  
Ignacy Misztal ◽  
...  
Keyword(s):  
Maximum Likelihood ◽  
Restricted Maximum Likelihood ◽  
Likelihood Methods ◽  
Maximum Likelihood Methods ◽  
Heritability Estimates

Genetic aspects of common health disorders and measures of fertility in Holstein Friesian dairy cattle

1997 ◽  
Vol 65 (3) ◽  
pp. 353-360 ◽  
Author(s):  
J. E. Pryce ◽  
R. F. Veerkamp ◽  
R. Thompson ◽  
W. G. Hill ◽  
G. Simm
Keyword(s):  
Dairy Cows ◽  
Milk Yield ◽  
Genetic Parameters ◽  
Genetic Correlations ◽  
Economic Importance ◽  
Milk Fever ◽  
Holstein Friesian ◽  
Health Disorders ◽  
Selection For ◽  
Fertility Traits

AbstractThe purpose of this study was to estimate genetic parameters for measures offertility and several health disorders in dairy cows. Data consisted of 33732 records, of which 9163 were on heifers, on 305-day milk yield, health disorders and inseminations. Measures offertility were calculated from calving and insemination dates and included calving interval, days to first service and conception to first service. Health disorders included milk fever, mastitis and lameness. Genetic and phenotypic (co)variances were estimated using restricted maximum likelihood. Heritability estimates for both health disorders and fertility traits were low, ranging from 0·003 to 0·080. All genetic correlations between 305-day milk yield and health and fertility traits, in cows and heifers together, were antagonistic implying that selection for milk yield may have caused a deterioration in health and fertility. The unfavourable correlation between milk yield and health and fertility traits, plus the economic importance of the latter, suggests that future breeding goals should be expanded to include some health disorders and fertility.

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.

Genetic and environmental effects on milk yield of Pitangueiras cattle

1984 ◽  
Vol 39 (2) ◽  
pp. 157-163 ◽  
Author(s):  
R. B. Lôbo ◽  
F. A. M. Duarte ◽  
A. A. M. Gonçalves ◽  
J. A. Oliveira ◽  
C. J. Wilcox
Keyword(s):  
Maximum Likelihood ◽  
Least Squares ◽  
Milk Yield ◽  
Environmental Effects ◽  
Intraclass Correlation ◽  
Statistical Analyses ◽  
Likelihood Methods ◽  
Maximum Production ◽  
Lactation Length ◽  
Maximum Likelihood Methods

ABSTRACTData from 5270 lactation records of 1380 cows sired by 132 bulls and recorded from 1962 to 1977 were analysed. Statistical analyses, using least squares and maximum likelihood methods, showed significant effects for genetic group, age of cow, month and year of calving, and lactation length. Overall mean milk yield was 2780 kg (CV = 0·31) with mean lactation length of 281 days. Maximum production occurred in the fifth lactation (104 or 105 months of age at calving) with a yield of 1·3 times that of the first lactation. Repeatability estimated by intraclass correlation was 0·40 (s.e. 0·03). Heritability estimated from paternal half-sib correlation was 0·16 (s.e. 0·06). Overall results were very similar to those obtained from research with European breeds in temperate areas.

Genetic parameters of the duration of fertility in hens

1992 ◽  
Vol 72 (2) ◽  
pp. 193-201 ◽  
Author(s):  
Catherine Beaumont
Keyword(s):  
Maximum Likelihood ◽  
Key Words ◽  
Genetic Parameters ◽  
Control Period ◽  
Genetic Correlations ◽  
The Other ◽  
Selection For ◽  
Heritability Estimates ◽  
Highly Correlated ◽  
Box Cox Transformation

After two successive artificial inseminations (AI) with 125 × 106 spermatozoa, various characteristics of the duration of fertility were observed in 2375 egg-type hens at 33 and 44 wk of age: number of fertile (F) or hatched (H) eggs during a 21-d control period after AI, early, medium or late embryonic mortalities occurring at the same time and efficient (De) and maximum (Dm) duration (i.e. time between AI and the first clear egg or the last fertile egg, respectively). Heritability estimates of F, H, De or Dm ranged from 0.08 to 0.31. All genetic correlations between these variables (measured at the same age) were high (0.45–0.99) as well as those between the same variable measured at different ages (0.30–0.97). Estimates of genetic parameters varied little when estimated by Henderson's method III or REML but with the second method only all estimates were within the parameter space. A Box-Cox transformation of data slightly modified heritability estimates and animal ranking after genetic evaluation. The best criterion of selection for duration of fertility seems to be H as it is economically important, well heritable and highly correlated with the other characteristics of duration of fertility. Key words: Genetic parameters, fertility, poultry, Restricted Maximum Likelihood

scholarly journals Genetic Parameters of Bovine Milk Fatty Acid Profile, Yield, Composition, Total and Differential Somatic Cell Count

Animals ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 2406
Author(s):  
Tania Bobbo ◽  
Mauro Penasa ◽  
Martino Cassandro
Keyword(s):  
Animal Models ◽  
Somatic Cell ◽  
Cell Count ◽  
Milk Yield ◽  
Milk Fat ◽  
Fixed Effects ◽  
Somatic Cell Count ◽  
Genetic Parameters ◽  
Genetic Correlations ◽  
Bovine Milk

The growing interest of consumers for milk and dairy products of high nutritional value has pushed researchers to evaluate the feasibility of including fatty acids (FA) in selection programs to modify milk fat profile and improve its nutritional quality. Therefore, the aim of this study was to estimate genetic parameters of FA profile predicted by mid-infrared spectroscopy, milk yield, composition, and total and differential somatic cell count. Edited data included 35,331 test-day records of 25,407 Italian Holstein cows from 652 herds. Variance components and heritability were estimated using single-trait repeatability animal models, whereas bivariate repeatability animal models were used to estimate genetic and phenotypic correlations between traits, including the fixed effects of stage of lactation, parity, and herd-test-date, and the random effects of additive genetic animal, cow permanent environment and the residual. Heritabilities and genetic correlations obtained in the present study reflected both the origins of FA (extracted from the blood or synthesized de novo by the mammary gland) and their grouping according to saturation or chain length. In addition, correlations among FA groups were in line with correlation among individual FA. Moderate negative genetic correlations between FA and milk yield and moderate to strong positive correlations with fat, protein, and casein percentages suggest that actual selection programs are currently affecting all FA groups, not only the desired ones (e.g., polyunsaturated FA). The absence of association with differential somatic cell count and the weak association with somatic cell score indicate that selection on FA profile would not affect selection on resistance to mastitis and vice versa. In conclusion, our findings suggest that genetic selection on FA content is feasible, as FA are variable and moderately heritable. Nevertheless, in the light of correlations with other milk traits estimated in this study, a clear breeding goal should first be established.

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.

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