Estimation of genetic parameters of preweaning performance in the French Limousin cattle breed

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Estimation of genetic parameters of preweaning

performance in the French Limousin cattle breed

Mj Shi, D Laloë, F Ménissier, G Renand

To cite this version:

Original

article

Estimation of

_genetic

_parameters

of

_preweaning

_performance

in the

French Limousin cattle breed

MJ Shi

D

Laloë

F

Ménissier, G Renand

Institut National de la Recherche _{Agrono!nique,} Centre de Recherches de _{Jouy-en-Josas,} Station de G6n6tique Quantitative et _Appliquée,

78352 _{Jouy-en-Josas Cedex,} France

(Received

11 June 1992; accepted 7 December

₁₉₉₂₎

Summary - Direct and maternal _genetic and environmental _parameters of _preweaning growth and conformation at _weaning were estimated in the French Limousin beef cattle field _recording program using the tilde-hat _approach of Van Raden and Jung

(1988)

with a sire, maternal _grandsire

_(MGS)

and dam within MGS model. The numerator _relationship

matrix among bulls was included in the estimation. The data available after editing contained 169 391 calves with _{performance records,} from 43 683 dams, 7 265 _sires, 5 664 maternal _grandsires and 1 605 _herds, for the _years 1972-1989. The traits involved were:

birth, 120-d and 210-d

_weights,

_{average daily gains} from birth to _120-d, from 120-d to

210-d,

from birth to _210-d, muscular _development

_(MD)

and skeletal development

(SD)

scores at weaning. Estimates

_ranged

from 0.22 to 0.32 for additive direct heritabilities and from 0.06 to 0.16 for maternal heritabilities. Correlations between direct and maternal genetic effects for these traits were _{negative, ranging} from -0.23 to -0.49. Maternal permanent environmental effects were small for all traits, accounting for 5-9% of the phenotypic variances for _{preweaning growth performance,} and 3% and 4% for MD and SD, respectively.

beef cattle _/ variance _{components / preweaning growth /} conformation score _/ direct and maternal effects _/ field data

Résumé - Paramètres _génétiques des _performances avant sevrage en race bovine

Limousine française. Les _{paramètres génétiques} et environnementaux de la croissance

avant sevrage et de la _conformation au _{sevrage ont} été estimés _pour la race Limousine à partir des données du contrôle de

_performances

_{en ferme.} La méthode d’estimation de ces

paramètres était la méthode tilde-chapeau de Van Raden et _Jung

_(1988),

avec un modèle

père, grand-père maternel et mère intra-grand-père maternel. Les _coefficients de parenté

ont été inclus dans _l’analyse. Les données _analysées comprenaient 169 391 veaux avec *

performances nés entre 1972 et _1989, issus de _{43 68,i mères,} 7 265 _{pères, 5 6!4}

_grand-pères

maternels et 1 605 troupeaux. Les caractères considérés étaient : les _poids à la naissance, à 120 j et à 210 j, les croissances de la naissance à 120 _j, de _{120 j} à _{210 j} et de la naissance à 210 j, les _{développements} musculaire et _{squelettique.} Les héritabilités estimées

se situent entre 0,22 et 0,32 pour les effets directs et entre 0,06 et 0,16 pour les effets

maternels. Les estimées des corrélations _génétiques entre _effets directs et maternels _pour

ces mêmes caractères sont toutes _négatives et se situent entre _-0,23 et _-0,l9. Les _effets

d’environnement permanent maternel sont _faibles pour tous les _caractères, contribuant à la variance _{phércotypique} à hauteur de 5% à 9% pour les caractères de croissance avant sevrage, et de 3% et _l!% pour les développements musculaire et _{squelettique.}

bovins à viande _{/ composantes} de la variance _/ croissance _{avant sevrage /} conforma-tion _/ effets direct et maternel _/ contrôle de _performances en ferme

INTRODUCTION

Knowledge

of the

_magnitude

of the variance and covariance _components is critical for the

_genetic

evaluation of animals and the

_development

of sound

_breeding

programs. For

maternally

influenced _traits, direct as well as maternal effects need

to be

_quantified.

Direct and maternal effects seem to be

correlated,

but the

_sign

and

_magnitude

of this correlation is often a

_topic

of some debate.

For the estimation of

_(co)variance

_components REML

_(Patterson

and

_Thompson,

1971)

is now the method of

_reference,

due to its desirable

_properties,

ie

non-negativity

(Harville,

1977),

ability

to take account of selection

_(Sorensen

and

Kennedy,

1984;

Werf and

_Boer,

_1990).

With

_large

data _sets,

_however,

REML is almost unusable due to the need for inversion of the

_large

coefficient matrix of the mixed model _equations

_{(Henderson, 1973)}

or the inverse of the

complete

covariance matrix of the vector of

observations,

despite

a number of available numerical

techniques

(Meyer,

1990).

Consequently,

less

_expensive

_procedures

with estimators

reasonably

close to REML solutions are desirable.

Among

approximate

REML

procedures

like Henderson’s method IV

(Henderson,

1980),

Schaeffer’s method

(Schaeffer, 1986)

and the tilde-hat

_approach

of Van Raden and

_Jung

_(1988),

the last has been shown to

_yield

estimates closest to

REML

solutions in data without or

with little selection

_(Van

Raden and

_Jung,

_1988;

_Ouweltjes

et

_al,

_1988).

_Moreover,

the tilde-hat

_approach

of Van Raden and

_Jung

₍₁₉₈₈₎

does not

_require

_{any inversion}

of a

large

matrix and is

computationally

_easy even when the numerator

_relationship

matrix and covariances between random effects are included

_(Manfredi,

_1990;

Manfredi et

_al,

_1991).

In the French Limousin

_{breed, genetic}

trends for

_preweaning

traits have been estimated

_by

an animal model

(Lalo6,

personal

communication).

It appears that there has been

_only

limited selection

_practised

in the

_population.

With a small data _set, Shi and Lalo6

(1991)

showed that the tilde-hat

_approach

led

to estimates

_comparable

to those of REML.

The

_objective

of this

_study

was to estimate direct and maternal

_genetic

and

MATERIALS AND METHODS Data

_description

The French Limousin

_Breeding

Association

_(France

Limousin

_Selection)

_provided

an extensive data set for estimation of direct and maternal

_{(co)variances}

for the entire breed in France. Data consisted of 309 530 records collected from 1972 to

1989.

Traits

_analysed

were

_{birth, 120-d,}

210-d

_weights,

_average

_daily

_gain

from birth

to 120-d

_(GO-120),

from 120-d to 210-d

_(G

₁₂₀

_-

₂₁₀

_),

from birth to 210-d

_(GO-210)7

muscular

_development

_(MD)

and skeletal

_development

_(SD)

scores at

_weaning.

The 120-d and 210-d

_weights

were

_{computed by interpolation}

between

_neighbouring

records which were

_measured,

at 3-month

intervals,

by

technicians

_according

to

national rules

_{(FNOCPAB-ITEB,}

₁₉₈₃₎

Some

_weight

records _may be used in

interpolation

for both standard

_weights.

Birth

_weight,

declared

_by

the

breeder,

was not used in this

_{interpolation.}

MD and SD were linear functions of

elementary

scores

_given

by experienced

technicians.

Primary

edits were conducted

_{by eliminating:}

₁₎

calf

_weights

and scores outside

3.5 SDs from the mean values of the

_{corresponding}

traits within each sex;

2)

any calf with a common sire and maternal

_{grandsire (MGS);}

and

₃₎

calves born from

a dam < 23 months or > 16 _y old at

_calving,

or later than the 12th

_parity.

Further

edits were

_performed

to

_{require, sequentially,}

sires to have at least 4 _progeny, dams

to have 2 _progeny and MGS to have sired 2

_dams,

_{respectively.}

Herds were

required

to have a minimum of 8 records. In this _way, the edited data set consisted of 169 391 records. For average

daily

gain traits,

only

168 980 records were left after removal

of records outside 3.5 SDs from mean values

_by

sex. As a

_result,

2 data files were

METHODS

A

_sire,

MGS and dam within MGS model was used for

_estimating

the

(co)variance

components of the assumed

_maternally

influenced traits. The model in matrix notation was:

where:

y = _vector of

observations;

b = _vector of unknown fixed

effects, including herd-year-season,

_sex and

parity;

Ul

, u2 and u3 = _vectors of unknown random effects for sire, MGS and dam within MGS

_effects,

_{respectively;}

e = vector of random residual

effects;

Z, Z

1

,

Z

2

and

Z

3

= known matrices

relating

records _to the fixed and random effects in the model.

Identification and distribution of the number of levels for the fixed effects are

reported

in table II.

The

_expectations

and variance-covariance structure of the effects of the model

or 2,a2, 1 2 !3

and

or2

= variances of

sires,

MGS,

dam within MGS and residual

effects,

respectively;

a

12 = covariance between _sire and MGS

effects;

A = numerator

relationship

matrix among bulls which included both sires and MGS. In

_total,

10 348

_pedigree

bulls over 5

_generations

were

_generated

from 9 400

bulls

_represented

in the data. The

_{relationships}

between dams were

_ignored.

The

_{corresponding}

mixed model

_equations

after

_absorption

of fixed effects were:

The tilde-hat

_approach

of Van Raden and

_Jung

₍₁₉₈₈₎

involves

_quadratics

which

are functions of solutions and

_approximate

solutions for the random effects of the mixed model

_equations

_!l).

The

_approximate

solutions were obtained

by

(Bertrand

and

_Benyshek,

_1987):

where

D

11

,

D

12

,

D

22

and

D

33

are

diagonal

matrices with

diagonal

elements

identical to those of the matrices

_{Z! MZ1}

+

_{A -1 k11, Z! MZ2}

+

A -1 k

12

,

_ZZMZz

+

A -1 k

22

and

_Z§MZ

₃

+

IA;!,

_{respectively.}

In

_fact,

the

_diagonals

of matrix

_{Z! Z2}

were zero due to removal of calves

_having

the same bull as sire and MGS.

_However,

those of

Z[MZ

2

(Z[ 22

after

_absorption

of fixed

_effects)

were not

_equal

to zero.

The

_general

formula for a model with _p

_possibly

correlated random effects is:

where:

_i,

_j,

h and k =

1, 2, ... ,

P, ie the number of random effects in the model. For the model assumed in this

_study,

5

_quadratics

_{(û! A -1 u!, û! A-I U2,}

u2A-l

u

l

,

u2A-

l

u

2

and

_Û!U3)

were used to estimate 4

_(co)variance

_components

(af,

<!i2,

o-

22

,

and

3 .

As more

_quadratics

were available than unknown variance

components the least _squares

_approach

was used.

where:

N = total number of observations in the

analyses;

r(X)

= rank of matrix X.

The tilde-hat

procedure

requires

only

the

_diagonals

of the coefficient matrix in

equations

[1]

for

_(co)variance

estimation.

_{Consequently,}

the mixed model

_equations

were not

_explicitly

_constructed,

and solutions for random effects in

_equations

_[1]

were obtained

_by

the direct iteration

_approach

on data

(Schaeffer

and

Kennedy,

1986;

Mandredi,

1990; Mandredi et

al,

1991).

Thus,

2 levels of nested iterations

were involved for the

analyses.

Solutions for fixed and random effects were first

obtained from the inner iterations. After 15 iterations or when the _convergence

criterion attained

_10-

₇

_,

the outer iteration was then

_implemented

for the estimation of the variance components. Iteration was

finally stopped

after a value of

10-

7

for

convergence was reached. The criterion of _convergence

(0)

was calculated as follows:

where: .

o

i= solutions for fixed and random effects for the inner iteration, and variance

components for the outer

_interation;

k = number of iterations;

n = total levels for fixed and random effects in the inner iteration, and is 5 for the outer iteration.

The

_expectations

of the

_{(co)variances}

estimated from model

_[1]

were as follows:

where:

0’

7t

and

_a

₂

_m

=

genetic

variances of direct and maternal

effects,

respectively;

0’

AM = covariance between direct and maternal

genetic effects;

a c 2

= variance of maternal _permanent environmental

effects;

a

The

_genetic

and environmental _parameters were estimated as:

where u is the total

_phenotypic

_variance,

_hA

is the direct

_{heritability,}

_h2

_m

is the maternal

_heritability

and

_{h 2}

is the

_{total heritability}

as defined

_by

Dickerson

_(194?),

c

2

is the

_proportion

of

_phenotypic

variance

_imputable

_to the maternal _permanent environmental

_effects,

rAM is the correlation

between

direct and maternal additive

genetics effects,

rsMGS is the correlation between sire and maternal

_grandsire

effects.

RESULTS AND DISCUSSION

Table III and table IV show estimates of

_{(co)variances}

and estimates of heritabilities

Direct and maternal _parameters for

_{preweaning growth}

traits

Estimates of direct heritabilities of birth and

weaning

weights

and

preweaning

gain

from birth to

_weaning

_(fi

₅

=

_0.31,

0.26 and

_0.25,

respectively)

_were in close

agreement with the median values of literature surveys

(Petty

and

Cartwright,

1966;

Baker,

1980;

Meyer,

1992;

Renand et

_al,

₁₉₉₂₎

but

_higher

than values

_reported

in the North American Limousin breed

_(0.22

and 0.16 for birth and

_weaning

_weights,

respectively;

Bertrand and

_Benyshek,

_1987).

Maternal

_heritability

estimates in this

_study

were lower than direct heritabilities

of the

_{corresponding}

traits

_(h

_Ã1

=

_{0.08, 0.13}

and

_0.13,

respectively).

Most literature estimates for maternal

_genetic

_{heritability ranged}

from 0.05 to 0.25 for birth

_weight,

and 0.10 to 0.35 for

_{preweaning gain}

or

_weaning

_weight

(Quaas

et

_al,

_1985;

_Bertrand

and

_Benyshek,

_1987;

_Wright

et

_al,

_1987;

Trus and

_{Wilton, 1988;}

Garrick et

_{al, 1989;}

Kriese et

_al,

_1991;

M6nissier and

Frisch, 1992;

Meyer,

1992).

The present estimates

for maternal _genetic effects in French Limousin breed were in the lower tail of the

ranges.

The estimates of the ratio between the maternal _permanent environmental variances and the

_phenotypic

variances were small in the French Limousin

breed,

ranging

from 0.05 to 0.09. These values were in accordance with the _reports

_given

by

Bertrand and

_Benyshek

_(1987),

_Wright

et al

₍₁₉₈₇₎

and

_Meyer

_(1992).

North American Limousin breed

_(r

_AM

= -0.16 and -0.30 for birth and

weaning

weights, respectively;

Bertrand and

_Benyshek,

_1987).

Moreover,

the

_majority

of

reports in the literature indicated

_negative

rAM of similar traits

(M6nissier,

1976;

Quaas

et

_al,

_1985;

Bertrand and

_Benyshek,

_1987;

Cantet et

_al,

_1988; Trus and

Wilton,

1988; Garrick et

al,

1989; Kriese et

al,

1991; M6nissier and

Frisch, 1992;

Meyer,

1992).

These estimates

_{frequently ranged}

from 0 to -0.5

However,

some

positive

direct-maternal

_genetic

correlations were also

reported

(Wright

et

al,

1987;

Northcutt et

_al,

1991;

Trus and

Wilton, 1988;

Meyer,

1992).

As a matter of

fact,

considerable variation exists in the literature estimates of direct and maternal effects and their covariance _components. This can be attributed

to a number of

factors,

_eg methods of estimation, statistical

models,

data resources

(experimental

or field

data,

breeds and

production

systems),

assortive

matings

or

previous

selection. On the other

_hand,

even with the most realistic

model,

the maternal animal

model,

some effects were

_always

assumed to be absent due to

computational

limitation. For _instance, a covariance between maternal and direct environments _{may exist}

_(resulting

from side effects of

_high

nutrition

_during

_rearing

of heifers on their milk

ability; Mangus

and

Brinks,

1971)

and

consequently

may bias the estimation of covariance between direct and maternal

_genetic

effects

_(Koch,

1972; Baker, 1980;

Willham,

1980;

Canter et

_al,

_1988).

Otherwise,

relatively large

sampling

variances of the estimates could exist for

_maternally

influenced traits

(Thompson,

1976;

Foulley

and

_{Lefort, 1978;}

_Cantet,

_1990;

_Meyer,

_1992).

Weaning

weights

of beef calves

_{depend primarily}

upon the

joint expression

of

preweaning

growth potential

of calves and maternal traits

_(primarily

the milk

production)

of their dams. The relative

_importance

of direct and maternal effects

on

_growth

_may be better

_{expressed by}

the estimates for

_preweaning

growth

rate

(Go-120,

G

120

-

210

or 120-d

weight.

The estimates for both direct and maternal

effects of 120-d

_weight

were _very similar to those of 210-d

_weight,

with maternal effects

_{being slightly}

more

_important

for 120-d

_weight

(table IV).

This is realistic

since calves are able to eat

_supplemental

feed at the later _stage of lactation. As shown

_by

Neville

₍₁₉₆₂₎

and Le Neindre et al

_(1976),

milk

_production

was more

important

during

the

_{early period}

of the calf’s

life,

and declined

_slightly

up to

weaning.

A much lower direct

_heritability

was obtained

using

a

_{dam-offspring}

relationship by

Molinuevo and Vissac

₍₁₉₇₂₎

in the same breed. This confirms the

negative

relationship

between direct and maternal effects. The estimates for

GO-120

were _very similar to those of 120-d

_weight

for both heritabilities

for,

and correlation between direct and maternal effects. For the

_{growth period}

from 120 d to 210

_d,

however,

the maternal

_genetic

variation had been

_greatly

reduced

_compared

to the earlier

_period

of

_growth

_(table

III)

and

_consequently

maternal

_heritability

was

lower

_(h

_Ã

₁

=

0.07)

than for

GO-120

(h

m

=

0,15).

It was the

only

trait with different

(lower)

total

_heritability

_(table

_IV).

The maternal influence of 210-d

_weight

was

apparently

a _carry-over effect.

Rutledge

et al

(1971)

reported

that when measures

of milk

_yield

for the first 4 months were in the

model,

inclusion of measures from

the

_remaining

3 months did not lead to a

significant

reduction in the residual sum of squares.

Further,

the

antagonism

between direct and maternal effects was

stronger in the later

_period

of

_growth

_(table

_IV).

This fact

_might

be induced

_by

the inflated

_negative

covariance between maternal and direct environments that is

_always

assumed to be zero in models. As

_{suggested by}

Robison

_(1981),

calves from dams

_producing

less milk are forced to seek

_supplemental

feed earlier which may over-compensate for the extra milk

_{production by}

other dams. Such

over-compensation

is as

_important

as the calf becomes older and concentrate is

_supplied.

Moreover,

especially

for the

_{growth period}

of 120-d to

_210-d,

the estimated ratio between maternal _permanent environmental variances and

_phenotypic

variances

was small

(table IV).

Direct and maternal _parameters for conformation at

_weaning

The results of this

_study

showed that MD and SD were

moderately

heritable and

mainly

controlled

_by

direct

_genetic

effects rather than maternal

_genetic

effects

_(table

IV).

The _present direct heritabilities of MD and SD were similar to the estimates of Lalo6 et al

₍₁₉₈₈₎

in French Limousin cattle. For overall conformation score at

weaning, Petty

and

_Cartwright

₍₁₉₆₆₎

_reported

an _average value of 0.36 of direct

genetic heritability

from 24 estimates. The same value was obtained

by Vesely

and

Robison

₍₁₉₇₁₎

for Hereford cattle.

Due to the

_antagonism

between direct and maternal

_{genetic effects,}

the total heritabilities for both MD and SD were

_slightly

reduced. Moderate heritabilities indicate that direct selection for conformation at

_weaning

should be efficient.

However,

a small

_negative

_response of the maternal

_ability

will

_{result. Muscularity}

is desirable for carcass

quality. However, improved

inuscularity

_may lead to a deterioration of maternal

_{calving ability}

due to the late

_maturing

rate of the

_pelvic

opening

(M6nissier

and

Frisch,

1992).

The estimates of the ratio between the maternal _permanent environmental variances and the

_phenotypic

variances were smaller for both conformation traits

(0.03

to

_0.04)

than for

_weights

or

_{preweaning gain.}

CONCLUSION

The

_preweaning

_growth

_genetic

parameters in this

_study

show that the

_growth

genetic

variability

is different for different

_growth

_stages. Foetal

_growth,

measured

by

birth

_weight,

is

_largely

influenced

by

direct

genetic effects,

with an

_important

foeto-mateinal

regulation

as shown

by

a

_{negative genetic}

correlation between direct

and maternal effects.

_Otherwise,

maternal effects are more

_important

for

_early

growth

after

_birth,

with a still

_negative

but lower

_genetic

correlation between direct

and maternal effects. Close to

_weaning,

maternal influences are smaller for

growth,

and,

similarly,

beef conformation at

_weaning

is

_largely

controlled

_by

direct

_genetic

effects. &dquo;

From a selection

_point

of

view,

weaning

weight

or

growth

to

weaning

is heritable

enough

to allow an efficient selection for direct

_genetic

_effects,

ie for the calf’s

growth

ability.

However,

selection

_solely

for direct

_genetic

effects does not lead to

breeds such as the French Limousin cattle. The maternal

_genetic

_parameters of the

different

_preweaning

_growth

_stages show

_that,

among the

analysed

traits,

120 d

weight

or

growth

from birth to 120 d is a

good

selection criterion for

carrying

out a

_joint

selection on cows’

_{suckling ability}

(maternal

effects)

and calve’s

growth

capacity

(direct effects).

On the other

_hand,

it is essential to have estimates of

_genetic

correlations between traits for both maternal and direct

_effects,

in order to

_optimize

the choice of measurements and selection criteria for

_preweaning

_growth.

ACKNOWLEDGMENT

Support

of this research

_by

a _grant from the INRA is

gratefully acknowledged.

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