Maataloustieteellinen A ikakauskirja
Vol. 60: 597—598, 1988

Inheritance of high prolificacy of the Olkuska sheep (preliminary results)

M. J. RADOMSKA 1 , E. MARTYNIUK 1 , J. KLEWIEC 2 and A. KNOTHE 3
' Agricultural University

Rakowiecka 12
02-517 Warsaw, Poland

2 Institute of Genetics and Animal Breeding PAN
Jastrzebiec, 05-551 Mrokow, Poland

3 Agricultural University
Al. Mickiewicza 24
30-059 Cracow, Poland

Abstract. Studies are being conducted on the mode of inheritance of high reproductive
performance of the Olkuska (O) sheep, a local Polish breed. Ten O were used in crosses with
Polish Merino (PM) ewes. The ovulation rate of 60 F, ewes (O x PM) and 129 pure PM ewes
was stated by means of laparoscopy. The prolificacy of female ancestors, full-sisters and progeny
of 3 O rams was extensively analysed.

Index words: Olkuska, Polish Merino, ovulation rate, litter size, inheritance

Introduction

There are five well-known prolific sheep
breeds: Finnsheep, Romanov, D’man, Boo-
roola Merino, Cambridge (1). In Poland,
studies are being conducted on the mode of
inheritance of high reproductive performance
of the Olkuska (O) sheep, a local breed (2).
Ten O rams were used in crosses with Polish
Merino (PM) ewes. The ovulation rate (OR)
of 60 F, ewes (O x PM) and 129 pure PM
ewes was stated by means of laparoscopy. OR
of 19 F, ewes (10 months old) was I—3, of

41 ewes (2 —3 years old) was I—4.1 —4. It was
found that 80 % of PM ewes had 1 corpus
luteum and 20 % had 2 corpora lutea. The
hitherto-obtained results were described by
Radomska et al., (4) and Martyniuk (3).

Experimental and results

In this paper data concerning 3 rams of the
prolific O breed, which were mated to not pro-
lific O ewes and to PM ewes, are presented.
The litter size (LS) of their female ancestors,
their full-sisters and female progeny are list-

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JOURNAL OF AGRICULTURAL SCIENCE IN FINLAND



Table I. Litter size of ram’s female ancestors.

Ram Maximum litter size:

Dam Dam of the sire

7185 4 5
7182 6 5
7179 3 4

ed in Tables I—3. The LS of dams, fullsisters
and pure O daughters was based on data from
at least 3 first lambings at the age of I—31 —3
years.

The lifetime LS records of dams and sire’s
dams are given in Table 1. Not all full-sisters
were prolific (Table 2). The number of daugh-
ters from matings with not prolific O sheep
was small, only one daughter of the ram No.
7182 was prolific (Table 2). The LS of
crossbred daughters received at the experimen-
tal farm of the Institute of Genetics and Ani-
mal Breeding Polish Academii of Science are
listed in Tables 3. The daughters of ram No.
7182 displayed the highest LS, the daughters
of the ram No. 1760 the lowest. The lambing
data confirmed the laparoscopy results. The
greater number of born lambs stated in one

Table 3. Litter size of F, ewes (Olkuska x Polish Me-
rino).

F, ewes Sire:

7185 7182 7179

1. Two years old
(second pregnancy)
Ovulation rate:

number of ewes 3 9 5
ovulations/ewe 1.67 2.44 1.40
maximum ovulations/ewe 2 4 2

Lambing:
number of ewes 3 9 5
mean litter size 1.67 2.33 1.60
maximum litter size 2 3 2

11. Three years old
(third pregnancy)
Ovulation rate:

number of ewes 4 8 5
ovulations/ewe 2.00 2.50 2.00
maximum ovulations/ewe 2 4 3

Lambing:
number of ewes 4 5 3
mean litter size 2.00 2.00 2.00
maximum litter size 2 3 4

case, in comparison to OR rate may be due
to one-egg twins. The OR of the PM ewes at
the same farm was 1.10, the maximum OR be-
ing 2.

Table 2. Number of full-sisters (mean litter size) and daughters with at least one or with no litter size records of
three or more.

Ram Full-sisters Daughters
Total Number with litter size Total Number with litter size

records records
At least one None At least one None

7185 4 3 (2.70) 1 (1.67) 3 3 (1.70)
7182 4 1 (2.25) 3 (1.33) 1 1 (2.75)
7179

References

1. Bindon. B.M. & Piper. L.R. 1986. Genetic Engineer- —260.
ing of Animals ed. V. Evans and A. Hollaender Pie- 3. Martyniuk. E. 1988. 3rd World Congr. Sheep & Beef
num Press, London: 67—93. Cattle Breed. Paris, 2: 688—690.

2. Grabowski, W., Ki.ewiec. J., Knothe, A. & Radoms- 4. Rauomska, M.J., Grabowski, W., Knothe, A. &
ka, M.J. 1987. Animal Genetic Resources. FAO Ki.ewiec, J. 1987. 38th Ann. Meet. EAAP, Lisbon.
Anim. Prod. & Health Paper No. 66, Rome: 259

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