Maataloustieteellinen Aikakauskirja
Voi 60; 505—510, 1988

Breeding and exploitation of prolific breeds in Czechoslovakia

V. JAKUBEC and J. KRIZEK
Research Institute of Animal Production, 104 00 Praha,
10-Uhrineves, Czechoslovakia

Abstract. In the years 1971—1979 many experiments were conducted in order to elucidate
problems ofmeat production increase in sheep. Ewes of native breeds (Mutton Merino = M,
Improved Wallachian = I) were mated to rams of prolific breeds (Finnsheep = F, Romanov
= R), producing FI crossbred females. The crossbred ewes were mated to rams of a third
mutton breed (Texel, Dorset Down, M) to produce meat lambs. In experiments from 1980
to 1987 on the basis of the I and the R and F crossbred combinations were produced to pro-
vide contemporary comparison of purebreds, FI, F 2 and backcrosses, both to I and to F and
R. The purebred and crossbred populations were analysed for the estimation of crossbreeding
parameters necessary for the optimization of the formation of a synthetic dam breed. The
reproduction characters which were analysed were fertility, prolificacy, mortality rate, litter
size (born and weaned) and milk production.From the wool production characters the greasy
wool production, clean wool production and mean fibre diameter were of interest. From the
production characters the following were analysed: birth, weaning and slaughter weights, daily
gain from birth to weaning or slaughter, carcass weight and other carcass value traits.

Index words; Finnsheep, Romanov, Improved Wallachian, Mutton Merino, Tsigaya, crossbreeding, reproduction,
meat production, wool production, milk production, adaptability, fertility, prolificacy, synthetic

Introduction and experimental

in the years 1971—79 extensive experiments
were carried out to elucidate problems of
meat production increase in sheep. Ewes of
native breeds (Mutton Merino = M, Im-
proved Wallachian = I, and Tsigaya = Ts)
were mated to rams of prolific breeds (Finn-
sheep = F, Romanov = R) producing FI
crossbred females. The purebred and

crossbred ewes were mated to rams of a mut-
ton breed (Texel = T, Dorset Down = D, and
M). The experiments were carried out in lo-
calities where the native breeds are kept. M
is kept in lowland regions and Ts and 1 in
mountainous and submountainous regions.
Crossbreeding experiments on the basis of
domestic dam breeds were carried out to
evaluate the adapability of FI dams and
crossbred slaughter lambs to the given en-

505

JOURNAL OF AGRICULTURAL SCIENCE IN FINLAND

https://www.c-info.fi/en/info/?token=mni_YcnFkN2HFAkJ.SCyX4ItwUulKeHU5dq3NAw.eDJDjjILmvkrw93wIQ4mVdbKe8FC_frPUywZREkfAXrVrgijTWlU6zjiO2_mvGJQUtldJuiLqgEVesX8vuE0uOmObkHBdbTCEtLrVoOCxcdN_FE_1gw6QjMkrp-2jLVrxBrbscMtr3zjqGl6hXlOonIqBByM7Y0NveZW8Wem-nxtHVi1670


vironment. The purebred prolific breeds were
kept together with the individuals of M. With
the exception of milk production characters,
heterosis effects are estimated for all charac-
ters in crossbreds on the basis of M and pro-
lific breeds.

The contribution is a survey and summary
of results published in various papers in which
reproduction and production characters were
analysed by the least squares method.

Reproduction

From reproduction characters, conception
rate (CR) and litter size (LS) of 3-yr. old ewes
are given in table 1. CR is expressed by the
number of ewes lambed per 100 ewes mated.
The LS is expressed as lambs born (dead and
alive) per ewe lambing. The impact of sire
breeds on the reproduction characters of all
purebred and crossbred ewes was in all cases
non-significant (2, 3,5). For this reason the
effect of the sire breeds on reproduction
characters was disregarded in the analysis.
Sire-dam crossbred means, dam breed means
across all sire breeds and dam breed means are

presented horizontally; sire-dam crossbred
means, sire breed means across all dam breeds
and sire breed means are presented vertically.

Ts was the best in CR and the worst in LS
of all dam breeds. M was the worst in CR and
I the best in LS. Ts crossbred with prolific
breeds showed the significant highest CR. M
were the worst. In LS were the individual dam
breed means across all sire breeds virtually the
same. In purebreeding, R is a better sire breed
than F both in terms of CR and LS. The
differences between the sire breeds in cross-
breeding in CR and LS are negligible. Differ-
ences in terms of CR did not exist between
crossbred, dam breed and sire breed ewes. The
array of ewes of individual genotypes with re-
spect to LS was:

Purebred dam breeds 1.32; purebred sire
breeds 2.04; crossbreds 1.70.

Wool production

Greasy (GWP) and clean (CWP) wool
production of 2 year old ewes are analysed in
table 2 (1,4, 6). In the mentioned papers fur-
ther wool characters were analysed: wool

Table 1. Conception rate (1) and litter size (2) of 3 year old ewes.

Sire Breed R F Dam breed Dam breed
>. P, means across means

all sire breeds P,

P, \. n % n % n % n %

Dam Breed No. No. No. No.
\y lambs lambs lambs lambs

1 35 77.14 97 82.56 132 79.83 114 77.46
2 57 1.74 109 1.62 166 1.68 93 1.36

1 82 85.53 156 86.45 238 85.99 1572 90.37
2 59 1.68 120 1.71 179 1.70 1310 1.43

1 118 89.70 113 95.25 231 92.47 223 92.65
2 80 1.67 86 1.76 166 1.72 65 1.16

Sire breed
means across 1 235 84.12 366 88.08 601 86.10 1909 86.83
all maternal 2 196 1.70 315 1.70 511 1.70 1469 1.32
breeds

Sire
breed P, 1 94 93.46 42 78.57 136 86.01
means 2 135 2.12 47 1.96 182 2.04

506



yield, percentage of wool fibre, average fibre
diameter and fibre diameter class. I had the
highest GWP and CWP in purebreds and
crossbreds of native breeds. It is a semi-fine
wool breed like Ts, but is even better than M
(fine-wool breed). In Czechoslovakia on the
average, M have a higher GWP than I. The
higher GWP of I was due to the fact that the
experiment on this breed was carried out in
one of the best nucleus flocks in Czechoslo-
vakia. For wool production characters in
purebreeding F is better than R. For wool
production characters in crossbreds both sire
breeds are virtually equal. For both charac-
ters was the following array of genotypes from
the lowest to the highest values: purebred sire
breeds, crossbreds and purebred dam breeds.

Milk production

For randomly chosen groups of 2 and 3 year
old ewes of I, F, R and crossbreds F x I, milk
yield (MY) was studied for 12 weeks after par-
turition (7). This period was divided into two
six-week periods. The MY study was based on
the use of the oxytocin method after Me
Cance (9). The data were analysed by the
least squares method. The effects of LS, lac-
tation order and lamb sex were considered. In
table 3 the genotypes are analysed according
to the amount of milk, fat and protein in kgs.

More than 60 % of the milk is produced
during the first period. Within 12 weeks of lac-
tation the highest MY had 1 and the lowest
R. In the same period the rank of genotypes

Table 2. Greasy (1) and clean (2) wool production.

Sire Breed R F Dam breed Dam breed
P, means across means

N. all sire breeds P,

P; N. n kg a kg n kg n kg
Dam Breed n.

I 2.92 2.85 2.89 3.82
M 2 ' 7 1.75 55 1.70 1.73 62 2.03
I ' 18 3JO 57 3 - 58 75 3 - 44 81 3 - 931 2 ' 8 2.37 2.68 2.53 X 1 2.91
T

'
AO 276 CI 2 ' 72 l« 2 - 74 111 2 ' 972 69 1.73 63 1.66

* 32 1.70 13? 1.93

Sire breed
means across 1 ...

2.99 3.05 ,„ 3.02 3.57
all maternal 2 104 1.95

,77 2.01 281 1.98 28 °

2.29
breeds

Sire
breed P, 1 ~

0.74 1.82 1.28
means 2 0.52 1.18 0.85

Table 3. Yields of milk, fat and protein in the first 12 weeks of lactation.

Breed Milk yield (MY)

n Ist—6th 7th—l2th Ist—l2th Milk Milk
week week week fat protein

kg kg kg kg kg

I 24 75.5 49.2 124.7 8.89 5.16
F 9 64.5 41.9 106.4 7.87 5.50
R 21 58.0 38.5 96.5 7.27 4.86
Fxl 8 67.2 33.3 100.6 6.51 4.37

507



for milk fat production corresponds with the
rank of genotypes for MY with the exception
of R. The highest protein production was
shown by F and the lowest by the crossbred
F x 1.

Meat production

Table 4 contains the results of the meat
production analysis (10, 11). Body weight
(BW) at 60 days, average daily gain (ADG)
from 20 to 40 kg, starch unit intake per 1 kg
gain, eye muscle area and leg proportions are
shown for lambs of pure breeds, single cross-
es and three-way crosses. The highest BW at
60 days was that of lambs whose dams were
M or crossbreds descending from M. The
highest ADG and the lowest values of starch
unit intake per kg gain were shown by T x
M and T X (R X M) genotypes. The R X
I crossbreds and I had the lowest ADG. R
lambs had the highest starch unit intake per
kg gain. All single and three-way crosses with
a share of T genes had the largest eye muscle
area. M had the best leg proportions, cross-
breds F X Ts had the worst.

Heterosis

In table 5 estimates of heterosis effects for
reproduction and production characters are
shown in absolute and relative values. The
data facilitated the estimation of individual
heterosis effects (h,) for wool production
characters and maternal heterosis effects for
reproductive characters.

The following models were used:
Reproduction and wool production charac-

ters

. RM + FM 2M + R + Fh, =‘(m) 2 4
Milk production characters

t F +1h, = FI
2

Fattening and carcass quality characters

, DU R+ Mh. = RM 2

From experiments resulted that positive
values of heterosis effects showed only the
GFW, CWP, BW at 60 days and ADG. The

Table 4. Fattening and carcass quality characters.

Genotype n BW ADG Starch Eye Propor-
at 60 d. from 20 to unit intake muscle tion of

40 kg per 1 kg gain area leg
kg g cm; %

R 19 16.39 199 5.53 12.46 32.49
M 82 17.25 222 3.70 12.22 34.26
I 73 16.43 168 4.57 10.90 32.00
Ts 46 15.43 177 4.35 11.51 32.38
RxM 41 18.16 212 4.21 12.17 33.13
Rxl 33 16.70 166 4.50 11.18 31.94
RxTs 46 14.44 191 4.50 11.49 31.35
FxM 29 18.86 212 3.97 12.01 32.98
Fxl 20 16.53 175 4.44 11.18 31.13
FxTs 39 14.56 204 4.25 11.29 30.52
TxM 38 17.18 284 2.69 13.64 32.47
Txl 42 15.92 203 3.90 13.09 32.36
TxTs 19 14.38 219 3.90 13.22 32.55
Tx(RxM) 25 19.60 256 2.85 13.76 32.47
Tx(Rxl) 22 16.22 223 3.06 13.08 32.42
Tx(RxTs) 20 14.34 198 4.47 11.76 32.60
Tx(FxM) 15 19.65 205 3.69 13.06 32.38
Tx(Fxl) 20 15.96 209 3.82 13.34 31.90
Tx(FxTs) 18 2U 3JX) 31.68

508



heterosis for the ADG was very slow. If we
assume that heterosis is expressed only by
means of positive parameters, then the other
characters did not show heterosis.

Formation of a synthetic breed

The experiments in the seventies had shown
that a two-way crossbreeding system would be
more effective than a three-way one, if a pro-
lific and well adapted synthetic dam popula-
tion would replace the F, prolific dams. In
the eighties a maternal synthetic population
is being formed under farm-scale conditions
in submountaineous regions on the basis of
I. The ewes were mated by R rams and gradu-
ally crossbred generations F,, F 2, B, and B lrec

were produced. Besides these generations also
both parental populations are analysed.
Preliminary results including estimated in-
dividual and maternal heterosis effects were
published by Krizek and Jakubec (8).

In table 6 the main performance dataof the
experiment are shown. The experiment will be
concluded in 1988, the data analysed, the
genetic parameters estimated and a new syn-
thetic population with the optimal gene
proportion of both parental populations pro-
posed. The most important character is the LS

and therefore only the LS results will be dis-
cussed. The difference between both parental
populations was 1.11 lambs. It is obvious that
only in the B, is heterosis realized. This can
be influenced by the maternal heterosis and
the maternal effect of R. This can be also the
reason for the higher LS of F 2 than F,.

Table 5, Maternal heterosis for reproduction characters
and individual heterosis for production charac-
ters.

h,Character

rel. %abs.

Conception rate % 1.91 2.33
Litter size, no. of lambs 0.02 1.17
Greasy wool prod., kg + 0.34 +13.33
Clean wool prod., kg + 0.29 + 20.14
Milk production kg —14.95 —12.90
Milk Fat prod., kg 1.87 —22.30
Milk Protein prod., kg 0.96 —lB.OO
Body weight at 60 days, kg +1.34 + 8.00
Aver.daily gain from 20 to
40 kg, g +1.50 + 0.70
Starch unit intake per
1 kg gain 0.41 8.90

Eye muscle area, cm2 0.17 1.40
Proportion of leg, % 0.25 0.70

Table 6. Generation means for reproduction and wool production characters.

Breed n Number Live weight Greasy wool
of lambs at 60 d. production
per ewe kg kg

P, —I 267 1.36 14.25 3.83
P,—R 26 2.47 15.35 2.18
F,—Rxl 261 1.68 13.80 3.43
F2 —RlxRI 15 1.80 14.39 3.30
B,—lxßl 47 1.87 16.25 3.73
B, rK Rlxl 155 1.47 15.38 3.91

References

I. Jakubec, V. & Lindovsky, R. 1976. Quantitative and
qualitative production of wool of Mutton Merino
breed, prolific breeds and their crossbreds F,.
Scient. Agric. Bohemosl. 8,4: 271 —278.

2. Jakubec, V., Krlzek, J. & SlanA. O. 1977.
Reproduction of Mutton Merino sheep and their
hybrids with prolific breeds. Scient. Agric. Bo-
hemosl., 9,1: 39—46.

509



3. Jakubec, V., Krlzek, J. & Slanä, O. 1978a.
Reprodukce krizenek mezi domäeimi plemeny
(zirne merino, cigäja) a plodnymi plemeny
[Reproduction of crossbreds between native breeds
(Mutton Merino, Tsigai) and prolific breeds]. Zi-
vocisnä vyroba, 23, 3: 191—198.

4. Jakubec, V., Krizek, J., LindovskY, R. & Pindäk, A.
1978b. Kvantitativni a kvalitativni produkce vlny ple-
mene cigäja a jeho krizencu s plodnymi plemeny
(Quantitative and qualitative production of wool of
Tsigai sheep and their crosses with prolific breeds).
Zivocisnä vyroba, 23, 6: 405—414.

5. Jakubec, V., Krlzek, J. & Louda, F. 1979.
Reproduction of Improved Wallachian sheep and
their crossbreds with prolific breeds. Scient. Agric.
Bohemosl. 11, 1: 33—37.

6. Jakubec, V., Krizek, J., LindovskY, R. & Pindäk, A.
1980. Kvantitativni a kvalitativni produkce vlny
zuslechtenych valasek a jejich krizencu s plodnymi
plemeny (Quantitative and qualitative wool produc-
tion of Improved Wallachian sheep and their cross-
es with prolific breeds). Zivocisnä vyroba, 25, 5:
321—327.

7. Krizek, J., Louda, F., Jakubec, V. & Doney, J.M.

1978. Analyza mlecne produkce ovci plemene zus-
lechtenä valaska, plodnych piemen a jejich krizenek
(Analysis of milk production in the Improved Wal-
lachian breed, prolific breeds and their crossbreds).
Zivocisnä vyroba, 23 , 6: 461—470.

8. Krizek, J., Jakubec, V. & Rehäcek, E. 1986. Esti-
mates of crossbred parameters and their exploita-
tion in forming of a synthetic line of sheep. 37th
Ann. Meet. E.A.A.P., Budapest, (Comm. Anim.
Genet, and Sheep & Goat Prod.), Voi. 1: 86—87.

9. Me Cance, 1, 1959. The determination of milk yield
in the Merino sheep. Aust. J. Agric. Res., 10:
839—853.

10. Slanä, O. & Jakubec, V. 1976. Vykrmnost a jatec-
nä hodnota jehnat pri trojplemennen uzitkovem
krizeni ovci. (Fattening capacity and carcass value
of lambs in three-breed commercial crossing). Zivo-
cisnä vyroba, 21, 8: 587—598.

11. Slanä, 0., Jakubec, V., Krlzek, J. & PodebradskY,
Z. 1983. Hodnoceni masne uzitkovosti jehnat pri
hybridizaci ve stanicnich podminkäch. (Evaluation
of meat production of lambs under station condi-
tions). Mezinärodni sympozium o produkci a
kvalite masa, Nitra: 423—429.

510