10 Maataloustieteellinen Aikakauskirja Vol. 60: 591—596, 1988 Breeding possibilities of Booroola Merino in East-Europe L. VERESS 1, F. HOREK 2 , T. KOMLOSP, A. JAVOR 1 and K. MAGYAR 1 'University of Agriculture, Debrecen, Hungary 2University of Agriculture, Brno, Czechoslovakia Abslracl. Booroola Merino (BM) rams and ewes were imported from New Zealand to Hungary and Czechoslovakia in the 1980’s. Part of the imported animals were proved to be homozygous for the F gene. Frozen semen of these has been used for spreading this gene to Hungarian (HM) and Czechish (CM) Merinos. The crossbred lambs were 4—7 % lighter at birth and at 30 d., 6—24 % lighter at 100 d. and s—lo % lighter at 1-yr than HM. The 1-yr weight was 10—22 % lighter than that of CM. Greasy fleece weights were s—lo % higher, staple lengths 7—ll % longer than in HM or CM, while fibres were finer. The litter size of BM x HM ewes at Ist lambing was 1.42, at 2nd 1.52 and at 3rd 1.69, while the last figure for HM ewes was 1.15. The % of twins born to the BM xHM ewes was ca. 35 %, when HM ewes had 12 %. The corresponding figures for triplets were 9 and 0.2 %. The BMxHM crosses had shorter anestrus periods after lambing than HM ewes, except after the first lambing. The BM x HM ewes produced 2.4 lambs/yr. in a continuous lambing system, while HM ewes gave 1.9 lambs. Index words: Booroola, Merino, Hungarian Merino, Czechish Merino, crossbreeding, live weight, fleece weight, lit- ter size, lambing interval Introduction By breeding strains viz. Elektoral in Ger- many, Negretti in Bohemia and in Hungary, and Mazajevi in Russia, these countries played a significant role in Merino (M) breeding in the third part of the 19th century in Europe. Nowadays, most Ms in the East-European countries are bred in Germany and the G.D.R., Hungary and in the Soviet Union, where primarily meat, meat + fleece and fleece + meat producing strains, respectively, are kept, while in other countries such as Czechoslovakia, Poland, Rumania and Bul- garia fleece + meat producing strains are dom- inant. In Hungary, Rumania and Bulgaria some of the Ms are milked as well. Since 1968, accelerated lambing has shown a rapid in- crease in Hungary (14). For the past decades an increase in mature body weight has become general in almost ev- ery strain of M. Although the direct and com- 591 JOURNAL OF AGRICULTURAL SCIENCE IN FINLAND https://www.c-info.fi/en/info/?token=kRiJvectKEQz00sK.nKruTwTGX5KJFrqTh6EOjQ.1g7uD4EZqkwG3KTMlTnDmEf5x4GV5o0_sdmqKwt3DWTQ0-D8ezk9jj6G4YvIEEAYhK2lv8ywZLXXmlhVZNVwSqL2zBzN9pKxmSL7tw1tf83_YnE4iuO_D0gU0TgNcWMTPyudyh7kErjNWX38JHPG7nBKZCO-fOJLfqPvAlOGIe_MSAXrI-xeugL_vH8uG14HhnYzGam407mq1rpNkPD_oPQGgZ1RGTE 592 binative crossing for production of M has yielded promising results (5, 9), it has failed to become prevalent in large-scale sheep farm- ing. In England, for the last decades, pure breeding has been reduced to the indispensa- ble reproductional ratio, giving way to a wide range of combinative productional crossing. In comparison with the pure breeding of meat producing strains, this sort of crossing has proved to be far more productive and eco- nomical (16). Booroola Merino (BM) is likely to prove an excellent partner for crossing in those regions of East Europe that are suitable for breeding M (13, 15). Therefore we wish to highlight here some of our plans pertaining to the utili- zation of this breed. Subject and method In response to our recommendation, 20 rams and 3 ewes were brought from Haldon Station, New-Zealand (N.Z.), in the years of 1980, 1982 and 1986, to enlarge the available experimental stock. In 1985, Czechoslovakia bought 7 rams from the same source. This stock was the offspring of 19 rams altogether which descended from 9 original rams import- ed from Robertson’s stock in Australia. While still in N.Z., four of them were qualified as homozygotes on the F gene, five other sires were either not assessed or were labelled as heterozygotes. Our intention is to promote F- gene homozygote populations in several breeding stocks, which could then subsequent- ly be developed into nucleus. Besides focusing on producing F-gene homozygous stocks, we endeavour to improve maternal traits (i.e. oestrus aseasonality, per- fect conceiving and lamb rearing capability) as well as the parameters of fleece producing capacity (i.e. clean-fleece yield, ratio of fine and long staples). For the purpose of achieving this, the sperm of the best imported rams has been frozen so that »post mortem» fertilization could be car- ried out. The sperm of heterozygous rams is going to be used only when a sufficient num- ber of homozygous ewes are available so that homozygous lines could be obtained from them, as it is done in N.Z. and France as well (4, 8). Mating heterozygous partners is also preferable because, on the one hand, 1/4 of the offspring is homozygous, and their pheno- type is closer to that of Hungarian M (HM), on the other hand, the gene frequency of the breed is extended as well. The deep-frozen sperm is introduced into the uterine horn by means of an endoscope. The fertility rate, however, has not exceeded the 30—40 percent level and it is still far from the results of 60 % reported by Salamon et al. (11). Parallel with new-breed crossing three- breed crossing has also been initiated where partner A is HM on Czech M and partner B is a BM, an the terminal partner is a Suffolk which, owing to its high growth capacity, compensates for the lower growth rate of the BM, and moreover it contributes to improv- ing meat ratio and feed conversion. There is no doubt, that ewes obtained from this crossing are smaller in weight, but this is not considered to be a shortcoming. Their phenotype, however, is the same as that of HM, their relative fleece production is more favourable. Moreover, this sort of fleece can be marketed at a 20 °7o higher price as it is finer, longer stapled and cleaner as well (15). Achieved results The body weight of the imported rams al- ternated between 50—70 kg. Due to indoor breeding it has increased by 30 %, the fibre diameter has become 3 microns coarser, sta- ple length and rendement have remained con- stant while clean fleece yield has increased by 5 % (7). The lambs of imported BM rams weigh 4—7 % less, at the age of 30 days they lag be- hind by 5—7 % and when they were 100 days old they weighed 6—24 % less than the HM (15). When they were one year old, their weight decreased by s—lo5—10 % in Hungary and by 10—22 °7o in Czechoslovakia in compari- son with pure bred control animals. Grease fleece yield decreased by I—lß Wo in Hungary and by 10—22 % in Czechoslovakia. Grease fleece production in relation to the control group increased by s—lo % together with the increase of staple length (7—11 %), whilst fur became finer and the rendement im- proved (6, 14). The influence of BM crossings on decreasing growth and mature body weight has been pointed out by several authors (4). It has also been reported that this effect is of the same degree in both F-gene-bearing homozygous and heterozygous rams (11). This is true in respect of slaughtering and fleece production characteristics as well (6). We are firmly convinced that the variance in mature body weight is partly of phenotyp- ic origin which is caused, on one hand, by prenatal and postnatal state of nourishment and, on the other hand, by the age when the animals are used for breeding. Our observa- tions indicate that the BM can be classified as a slowly developing and growing type. Despite this fact a bigger genotype could be produced, if it were so desired. Sperms from 15 homozygous and 4 presum- ably heterozygous rams originating from 6 lines have been frozen so far. We have to store sperm of 10 rams from two further lines. Fecundity results seem to be satisfactory, though, 3 of the rams that could be appraised so far are merely heterozygous carriers of the F gene. The first lambings happened when the ewes were on the average of 21—22 months old (15), but in spite of this the rate of twin- nings amounted to 30—37 %, the frequency of litters with 3 lambs alternated between 3 and 13 %. In the course of the second and third lambings this rate grew by an addition- al 10 %. In comparison with AM ewes with repeated lambings, the rate of productivity was 54 % better. Ewes are lambing continually on the farm from which these data are obtained. Thus it Table 1. Progeny test of 4 rams for their daughters’ prolificacy. Rams lambing lambing ... ,twins triplets and morerate —! n It n % n % first 502/78 162 145,0 61 37,6 6 3,0 62/80 119 140,0 39 32,8 6 5,0 51/80 222 138,0 74 33,3 6 2,7 183/80 15 206,6 5 30,0 2 13,3 Ix, orx 518 142,0 179 34,5 20 3,86 second 502/78 147 158,0 57 38,7 13 8,0 62/80 95 168,0 38 40,0 13 13,8 51/80 191 153,0 57 29,8 22 11,4 183/80 Ix, or x 433 152,0 152 35,1 48 11,0 third 502/78 71 163,0 30 42,2 7 9,4 62/80 51 182,0 16 31,1 13 25,5 51/80 111 166,0 38 34,2 17 16,2 183/80 Ix, or x 233 169,0 84 36,0 37 15,8 Hungarian Merino 451 114,5 56 12,4 1 0,2 (control) 593 has become possible to compare the abilities to accelereted lambing of HM and BM cross- ings (Table 1).The anoestrus period of the BM is a bit shorter than that of the HM as it is referred to in previous studies (1, 2). Signifi- cant difference was found between the aver- age interval of the second and third lambing of BM crossings as far as the main season is concerned (P < 1 °7o), and in the pre-and post- seasons as well as out-of-season (P