Estimates of genetic parameters were obtained from two samples of weights and heights of mature cows provided by the American Angus Association. The first sample consisted of 23,658 records for mature weight (MWT) and 13,012 for mature height (MHT) and the second sample consisted of 23,698 records for MWT and 13,310 for MHT. The four-generation pedigree file included 43,105 animals for the first sample and 44,141 animals for the second sample. Range in ages when cows were weighed was 2 to 11 years at the time of measurement. Variance components were estimated using the MTDFREML programs. Univariate and bivariate analyses were used to estimate genetic parameters for MWT, MHT, and the corresponding genetic correlation. The model included fixed effects of cow age and random cow permanent environmental, contemporary group (herd and year) and residual effects. Heritability estimates (SE) within contemporary group were 0.45 (0.012) for MWT and 0.64 (0.018) for MHT for sample 1 and 0.48 (0.011) for MWT and 0.62 (0.018) for MHT for sample 2. Estimates of repeatability were 0.64 and 0.77 for MWT and MHT, respectively for sample 1 and 0.66 and 0.70 for MWT and MHT, respectively for sample 2. The genetic and permanent environmental correlations between MWT and MHT were 0.80 and 0.75, respectively for sample 1 and 0.83 and 0.69 for sample 2. The estimates of genetic parameters will be used to estimate genetic changes in MWT and MHT from the complete data file

Dib, M.G.

Spangler, Matthew L

Van Vleck, L. D.

English

UNL | Libraries

University of Nebraska - Lincoln 
DigitalCommons@University of Nebraska - Lincoln 
Faculty Papers and Publications in Animal 
Science Animal Science Department 
2009 
Genetic Parameters For Cow Weight And Height Using A 
Repeatability Model In American Angus Cattle 
M.G. Dib 
University of Nebraska-Lincoln 
L. D. Van Vleck 
USDA-ARS, Lincoln 
Matthew L. Spangler 
University of Nebraska-Lincoln, mspangler2@unl.edu 
Follow this and additional works at: https://digitalcommons.unl.edu/animalscifacpub 
Dib, M.G.; Van Vleck, L. D.; and Spangler, Matthew L., "Genetic Parameters For Cow Weight And Height 
Using A Repeatability Model In American Angus Cattle" (2009). Faculty Papers and Publications in Animal 
Science. 802. 
https://digitalcommons.unl.edu/animalscifacpub/802 
This Article is brought to you for free and open access by the Animal Science Department at 
DigitalCommons@University of Nebraska - Lincoln. It has been accepted for inclusion in Faculty Papers and 
Publications in Animal Science by an authorized administrator of DigitalCommons@University of Nebraska - Lincoln. 
Proceedings, Western Section, American Society of Animal Science 
Vol. 60, 2009 
GENETIC PARAMETERS FOR COW WEIGHT AND HEIGHT USING A REPEATABILITY MODEL IN 
AMERICAN ANGUS CATTLE 
M.G. Dib1, L. D. Van Vleck1,2 and M. L. Spangler1 
 
1University of Nebraska, Lincoln, NE, 2ARS-USDA Lincoln, NE 
 
 
ABSTRACT: Estimates of genetic parameters were 
obtained from two samples of weights and heights of 
mature cows provided by the American Angus Association. 
The first sample consisted of 23,658 records for mature 
weight (MWT) and 13,012 for mature height (MHT) and 
the second sample consisted of 23,698 records for MWT 
and 13,310 for MHT. The four-generation pedigree file 
included 43,105 animals for the first sample and 44,141 
animals for the second sample. Range in ages when cows 
were weighed was 2 to 11 years at the time of 
measurement. Variance components were estimated using 
the MTDFREML programs. Univariate and bivariate 
analyses were used to estimate genetic parameters for 
MWT, MHT, and the corresponding genetic correlation. 
The model included fixed effects of cow age and random 
cow permanent environmental, contemporary group (herd 
and year) and residual effects. Heritability estimates (SE) 
within contemporary group were 0.45 (0.012) for MWT and 
0.64 (0.018) for MHT for sample 1 and 0.48 (0.011) for 
MWT and 0.62 (0.018) for MHT for sample 2. Estimates of 
repeatability were 0.64 and 0.77 for MWT and MHT, 
respectively for sample 1 and 0.66 and 0.70 for MWT and 
MHT, respectively for sample 2. The genetic and 
permanent environmental correlations between MWT and 
MHT were 0.80 and 0.75, respectively for sample 1 and  
0.83 and 0.69 for sample 2. The estimates of genetic 
parameters will be used to estimate genetic changes in 
MWT and MHT from the complete data file. 
 
Key Words: Angus,  Cow Height,  Cow Weight, 
Heritability 
 
 
Introduction 
 
Cow weights and cow heights have been used to estimate 
lifetime growth curves (Johnson et al., 1990), influence of 
body size on efficiency (Morris and Wilton, 1976),  
production  including maintenance requirements (Morris 
and Wilton, 1986), cow-calf profitability, reproduction 
(Olson et al., 1994), and cull cow value. Mature size can 
potentially impact the profitability of beef enterprises and 
thus should be considered in selection programs. Previous 
direct heritability estimates have been generally moderate 
to high using various models (Northcutt and Wilson, 1993; 
Kaps et al., 1999; Rumph et al., 2002). 
 
The objective of the current study was to estimate genetic 
parameters and (co) variance components for mature weight 
and mature height of Angus cows using a repeatability 
model as a first step to estimate genetic trends. 
Materials and Methods 
The cow weights and heights data and pedigree files used 
were supplied by the American Angus Association. Two 
samples were obtained from the complete data file based on 
the last digit of the herd code. The first sample contained 
23,658 MWT and 13,012 MHT records (Table.1). The 
second sample contained 23,698 MWT and 13,310 MHT 
records. The four-generation pedigree files included 43,105 
and 44,141 animals for samples 1 and 2, respectively. The 
records were from cows born between 1983 and 2006. The 
range in ages when cows were weighed was 2 to 11 years 
with the majority (80%) of records coming from cows 
between 2 and 6 years of age. Cows on average had 1.7 
records for MWT. 
Animal Model 
In matrix notation, the linear model equation for the vector 
of observations, y, is:  
y = Xb + Z + Q + W + e, 
 
where y is the vector of observed records, b is a vector of 
fixed effects of age when measured; a is a vector of random 
additive genetic effects; c is a vector of random 
contemporary group effects; W is a vector of random 
permanent environmental effects of the cows; X, Z, and Q 
and W are incidence matrices relating Xb, Q, Z, and W to 
y; and e is a vector of random residual effects. Univariate 
and bivariate analyses were used to estimate genetic 
parameters for MWT and MHT, with Henderson’s (1977,  
1984) augmented mixed model equations and the inverse of 
the four generation relationship matrix (Henderson, 1976; 
Quaas, 1976). Estimates were obtained using the 
MTDFREML programs (BOLDMAN  et al., 1995). 
Results and Discussion 
Estimates of variance and covariance components, 
heritability and repeatability for samples 1 and 2 are 
reported in Tables 2 and 3. Estimates of heritability for 
MWT were similar to those from previous reports. Johnson 
et al. (1990) estimated heritability to be 0.38 but it was 
associated with a large standard error (0.30).  Kaps et al. 
(1999) reported an estimate of 0.59 using a two-trait animal 
model with adjusted weaning weight and repeated mature 
weights, with fixed effects of weaning and cow 
contemporary groups, and direct genetic, maternal genetic 
and maternal permanent environment as random effects. 
Rumph et al. (2002) obtained heritability estimates ranging 
between 0.53 and 0.69 using 6 different models with the 
most optimal model being the full model that included 
direct and maternal genetic, direct permanent environment 
and maternal permanent environment as random effects.  
For  mature weight, Northcutt and Wilson (1993) reported 
estimates of heritability of  0.45 (0.10) and 0.48 (0.10) for 
weights adjusted for body condition score and unadjusted 
for body condition score, respectively, using a two-trait 
model for mature weight and mature height.. For mature 
height, Northcutt and Wilson (1993) reported estimates of 
heritability of 0.83 (0.11) using the same model. Estimates 
of variance components and heritability reported by 
Northcutt and Wilson (1993) for the two-trait model were 
similar to those from the single trait analyses in the present 
study. Estimates of repeatability were 0.64 and 0.65 for cow 
weight for samples 1 and 2 and were 0.77 and 0.70 for cow 
height. Contemporary groups accounted for about 50% of 
phenotypic variance for both MWT and MHT.  
Genetic correlations between weight and height were strong 
and positive (table 4).  Previous studies have reported 
similar results, as shown by Northcutt and Wilson (1993) 
who estimated the Spearmen rank correlation between 
weight and height to be 0.94. The permanent environmental 
correlations were also high, ranging from 0.69 to 0.75. In 
comparison with previous studies it may be important to 
note that in the present study, the number of animals with 
records and in the pedigree file were larger. Some of the 
small differences in estimates also may be caused by 
differences in models or statistical methods used in the 
analyses.  
Implications 
Results from the current study, as expected, show that both 
MWT and MHT would respond favorably to selection and 
that changing one would lead to correlated response in the 
other. Selection would be more accurate for MHT than for 
MWT because heritability is greater and because less 
variation is due to permanent environmental effects. These 
results also show that selection for the total animal effect 
(genetic plus permanent environmental values) would be 
considerably more accurate than selection for breeding 
value especially for MWT. The similarity of estimates of 
variance components for the two samples show that the data 
can be pooled in the second step of this project using the 
complete data file to determine if selection has been to 
increase or decrease MWT and MHT. 
 
Literature Cited 
Boldman, K.G., L. A. Kriese, L. D. Van Vleck, C. P. Van 
Tassell, and S. D. Kachman, (1995) ”A manual for 
the use of MTDFREML”.ARS, USDA, Clay Center, 
NE, USA. 
Henderson, C. R. 1976. A simple method for computing the 
inverse of a numerator relationship matrix used for 
prediction of breeding values. Biometrics 32:69-83. 
Henderson, C. R. 1977. Best linear unbiased prediction of 
breeding values not in the model for records. J. 
Dairy Sci. 60:783. 
Henderson, C. R. 1984. Applications of linear models in 
animal breeding. University of Guelph. Ont., 
Canada. ISBN 0-88955-030-1. 
Johnson, Z. B., C. J. Brown, and A. H. Brown, Jr. 1990. 
Evaluation of growth patterns of beef cows. 
Arkansas Agric. Exp. Sta. Bull. 623, Fayetteville. 
Kaps, M., W. O. Herring, and W. R. Lamberson. 1999. 
Genetic and environmental parameters for mature 
weight in Angus cattle. J. Anim. Sci. 77:569–574. 
Morris, C. A,, and J. W. Wilton. 1976. Influence of body 
size on the biological efficiency of cows: A review. 
Can. J. Anim. Sci. 56: 613. 
McMorris, M. R., and J. W. Wilton. 1986. Breeding system, 
cow weight, and milk yield effects on various 
biological variables in beef production. J. Anim. Sci. 
63:1361–1372. 
Northcutt, S. L., and D. E. Wilson. 1993. Genetic parameter 
estimates and expected progeny differences for 
mature size in Angus cattle. J. Anim. Sci. 71:1148–
1153. 
Olson, T. A. 1994. The effect of cow size on reproduction. 
In: M. J. Fields and R. S. Sand (ed.). Factors 
Affecting Calf Crop. pp 243– 249. CRC Press, Ann 
Arbor, MI. 
Quaas, R.L. 1976. Computing the diagonal elements and 
inverse of a large numerator relationship matrix. 
Biometrics 32:949-953. 
Rumph, J.M., R.M. Koch, K.E. Gregory, L.V. Cundiff, and 
L.D. Van Vleck.  2002. Comparison of models for 
estimation of genetic parameters for mature weight 
of Hereford cattle.  J. Anim. Sci. 80:583-590. 
 
 
 
 
 
 


Genetic Parameters For Cow Weight And Height Using A Repeatability Model In
American Angus Cattle

DigitalCommons@University of Nebraska

University of Nebraska - Lincoln DigitalCommons@University of Nebraska - Lincoln Faculty Papers and Publications in Animal Science Animal Science Department 2009 Genetic Parameters For Cow Weight And Height Using A Repeatability Model In American Angus Cattle M.G. Dib University of Nebraska-Lincoln L. D. Van Vleck USDA-ARS, Lincoln Matthew L. Spangler University of Nebraska-Lincoln, mspangler2@unl.edu Follow this and additional works at: https://digitalcommons.unl.edu/animalscifacpub Dib, M.G.; Van Vleck, L. D.; and Spangler, Matthew L., "Genetic Parameters For Cow Weight And Height Using A Repeatability Model In American Angus Cattle" (2009). Faculty Papers and Publications in Animal Science. 802. https://digitalcommons.unl.edu/animalscifacpub/802 This Article is brought to you for free and open access by the Animal Science Department at DigitalCommons@University of Nebraska - Lincoln. It has been accepted for inclusion in Faculty Papers and Publications in Animal Science by an authorized administrator of DigitalCommons@University of Nebraska - Lincoln. Proceedings, Western Section, American Society of Animal Science Vol. 60, 2009 GENETIC PARAMETERS FOR COW WEIGHT AND HEIGHT USING A REPEATABILITY MODEL IN AMERICAN ANGUS CATTLE M.G. Dib1, L. D. Van Vleck1,2 and M. L. Spangler1  1University of Nebraska, Lincoln, NE, 2ARS-USDA Lincoln, NE   ABSTRACT: Estimates of genetic parameters were obtained from two samples of weights and heights of mature cows provided by the American Angus Association. The first sample consisted of 23,658 records for mature weight (MWT) and 13,012 for mature height (MHT) and the second sample consisted of 23,698 records for MWT and 13,310 for MHT. The four-generation pedigree file included 43,105 animals for the first sample and 44,141 animals for the second sample. Range in ages when cows were weighed was 2 to 11 years at the time of measurement. Variance components were estimated using the MTDFREML programs. Univariate and bivariate analyses were used to estimate genetic parameters for MWT, MHT, and the corresponding genetic correlation. The model included fixed effects of cow age and random cow permanent environmental, contemporary group (herd and year) and residual effects. Heritability estimates (SE) within contemporary group were 0.45 (0.012) for MWT and 0.64 (0.018) for MHT for sample 1 and 0.48 (0.011) for MWT and 0.62 (0.018) for MHT for sample 2. Estimates of repeatability were 0.64 and 0.77 for MWT and MHT, respectively for sample 1 and 0.66 and 0.70 for MWT and MHT, respectively for sample 2. The genetic and permanent environmental correlations between MWT and MHT were 0.80 and 0.75, respectively for sample 1 and  0.83 and 0.69 for sample 2. The estimates of genetic parameters will be used to estimate genetic changes in MWT and MHT from the complete data file.  Key Words: Angus,  Cow Height,  Cow Weight, Heritability   Introduction  Cow weights and cow heights have been used to estimate lifetime growth curves (Johnson et al., 1990), influence of body size on efficiency (Morris and Wilton, 1976),  production  including maintenance requirements (Morris and Wilton, 1986), cow-calf profitability, reproduction (Olson et al., 1994), and cull cow value. Mature size can potentially impact the profitability of beef enterprises and thus should be considered in selection programs. Previous direct heritability estimates have been generally moderate to high using various models (Northcutt and Wilson, 1993; Kaps et al., 1999; Rumph et al., 2002).  The objective of the current study was to estimate genetic parameters and (co) variance components for mature weight and mature height of Angus cows using a repeatability model as a first step to estimate genetic trends. Materials and Methods The cow weights and heights data and pedigree files used were supplied by the American Angus Association. Two samples were obtained from the complete data file based on the last digit of the herd code. The first sample contained 23,658 MWT and 13,012 MHT records (Table.1). The second sample contained 23,698 MWT and 13,310 MHT records. The four-generation pedigree files included 43,105 and 44,141 animals for samples 1 and 2, respectively. The records were from cows born between 1983 and 2006. The range in ages when cows were weighed was 2 to 11 years with the majority (80%) of records coming from cows between 2 and 6 years of age. Cows on average had 1.7 records for MWT. Animal Model In matrix notation, the linear model equation for the vector of observations, y, is:  y = Xb + Z + Q + W + e,  where y is the vector of observed records, b is a vector of fixed effects of age when measured; a is a vector of random additive genetic effects; c is a vector of random contemporary group effects; W is a vector of random permanent environmental effects of the cows; X, Z, and Q and W are incidence matrices relating Xb, Q, Z, and W to y; and e is a vector of random residual effects. Univariate and bivariate analyses were used to estimate genetic parameters for MWT and MHT, with Henderson’s (1977,  1984) augmented mixed model equations and the inverse of the four generation relationship matrix (Henderson, 1976; Quaas, 1976). Estimates were obtained using the MTDFREML programs (BOLDMAN  et al., 1995). Results and Discussion Estimates of variance and covariance components, heritability and repeatability for samples 1 and 2 are reported in Tables 2 and 3. Estimates of heritability for MWT were similar to those from previous reports. Johnson et al. (1990) estimated heritability to be 0.38 but it was associated with a large standard error (0.30).  Kaps et al. (1999) reported an estimate of 0.59 using a two-trait animal model with adjusted weaning weight and repeated mature weights, with fixed effects of weaning and cow contemporary groups, and direct genetic, maternal genetic and maternal permanent environment as random effects. Rumph et al. (2002) obtained heritability estimates ranging between 0.53 and 0.69 using 6 different models with the most optimal model being the full model that included direct and maternal genetic, direct permanent environment and maternal permanent environment as random effects.  For  mature weight, Northcutt and Wilson (1993) reported estimates of heritability of  0.45 (0.10) and 0.48 (0.10) for weights adjusted for body condition score and unadjusted for body condition score, respectively, using a two-trait model for mature weight and mature height.. For mature height, Northcutt and Wilson (1993) reported estimates of heritability of 0.83 (0.11) using the same model. Estimates of variance components and heritability reported by Northcutt and Wilson (1993) for the two-trait model were similar to those from the single trait analyses in the present study. Estimates of repeatability were 0.64 and 0.65 for cow weight for samples 1 and 2 and were 0.77 and 0.70 for cow height. Contemporary groups accounted for about 50% of phenotypic variance for both MWT and MHT.  Genetic correlations between weight and height were strong and positive (table 4).  Previous studies have reported similar results, as shown by Northcutt and Wilson (1993) who estimated the Spearmen rank correlation between weight and height to be 0.94. The permanent environmental correlations were also high, ranging from 0.69 to 0.75. In comparison with previous studies it may be important to note that in the present study, the number of animals with records and in the pedigree file were larger. Some of the small differences in estimates also may be caused by differences in models or statistical methods used in the analyses.  Implications Results from the current study, as expected, show that both MWT and MHT would respond favorably to selection and that changing one would lead to correlated response in the other. Selection would be more accurate for MHT than for MWT because heritability is greater and because less variation is due to permanent environmental effects. These results also show that selection for the total animal effect (genetic plus permanent environmental values) would be considerably more accurate than selection for breeding value especially for MWT. The similarity of estimates of variance components for the two samples show that the data can be pooled in the second step of this project using the complete data file to determine if selection has been to increase or decrease MWT and MHT.  Literature Cited Boldman, K.G., L. A. Kriese, L. D. Van Vleck, C. P. Van Tassell, and S. D. Kachman, (1995) ”A manual for the use of MTDFREML”.ARS, USDA, Clay Center, NE, USA. Henderson, C. R. 1976. A simple method for computing the inverse of a numerator relationship matrix used for prediction of breeding values. Biometrics 32:69-83. Henderson, C. R. 1977. Best linear unbiased prediction of breeding values not in the model for records. J. Dairy Sci. 60:783. Henderson, C. R. 1984. Applications of linear models in animal breeding. University of Guelph. Ont., Canada. ISBN 0-88955-030-1. Johnson, Z. B., C. J. Brown, and A. H. Brown, Jr. 1990. Evaluation of growth patterns of beef cows. Arkansas Agric. Exp. Sta. Bull. 623, Fayetteville. Kaps, M., W. O. Herring, and W. R. Lamberson. 1999. Genetic and environmental parameters for mature weight in Angus cattle. J. Anim. Sci. 77:569–574. Morris, C. A,, and J. W. Wilton. 1976. Influence of body size on the biological efficiency of cows: A review. Can. J. Anim. Sci. 56: 613. McMorris, M. R., and J. W. Wilton. 1986. Breeding system, cow weight, and milk yield effects on various biological variables in beef production. J. Anim. Sci. 63:1361–1372. Northcutt, S. L., and D. E. Wilson. 1993. Genetic parameter estimates and expected progeny differences for mature size in Angus cattle. J. Anim. Sci. 71:1148–1153. Olson, T. A. 1994. The effect of cow size on reproduction. In: M. J. Fields and R. S. Sand (ed.). Factors Affecting Calf Crop. pp 243– 249. CRC Press, Ann Arbor, MI. Quaas, R.L. 1976. Computing the diagonal elements and inverse of a large numerator relationship matrix. Biometrics 32:949-953. Rumph, J.M., R.M. Koch, K.E. Gregory, L.V. Cundiff, and L.D. Van Vleck.  2002. Comparison of models for estimation of genetic parameters for mature weight of Hereford cattle.  J. Anim. Sci. 80:583-590.       

https://digitalcommons.unl.edu/cgi/viewcontent.cgi?article=1814&amp;context=animalscifacpub

Genetic Parameters For Cow Weight And Height Using A Repeatability Model In American Angus Cattle

Abstract

Similar works

Full text

Available Versions

UNL | Libraries

DigitalCommons@University of Nebraska