Maataloustieteellinen A ikakauskirja VoL 60: 500—504, 1988 Finnsheep and their utilization in crosses with the Merino under range conditions of South-Africa J. C. GREEFF and J. H. HOFMEYR Animal and Dairy Science Research Institute, Irene, RSA Abstract. Two field trials were performed at two localities in a semiarid region to evalu- ate the performance of Finn (F) x Merino (M) crossbred females. The trials involved 781 F x M ewes and 657 M ewes. Ile de France, S.A. Mutton Merino, Dohne Merino, M, and F x M rams were used for matings. The F x M ewes were superior to M ewes in lambing-%, especially after mating as lambs, and the fecundities were 187 and 107 %, resp. Multiple lambs of F x M ewes had better survival rates than those of M ewes. Lambs born from F x M ewes grew faster, had a larger weaning mass, over 10 % longer stables, ca. 2 mm thicker fibres, 30 % lower clean fleece weights, and a little less crimps/25 mm than those born from M ewes. Thus, F x M seemed to provide a suitable and acceptable compositeshowing remarkable adapt- ability to harsh environmental conditions. The results from the F x M wool and its special qualities can be regarded as useful attributes. Establishment of a composite F x M female line appeared well-founded. Index words: Finnsheep, S.A. Mutton Merino, crossbreeding, mutton production, wool production, reproduction, daily gain, synthetic Introduction Improvement in the reproductive rate through accelerated lambing and/or higher fecundity rate of the ewe flock offers the greatest single opportunity for increasing the biological efficiency of lamb as well as mut- ton and wool production. The infusion of high fertility genes through crossbreeding has proved to be the most rapid breeding proce- dure to bring about such biological efficien- cy and for this reason Finnsheep (F) has been introduced into the sheep flocks of many countries. Numerous trials have been conduct- ed in recent years to evaluate its suitability in crossbreeding with local breeds and different environmental conditions. F were imported into the RSA in 1968 and have been used in several crossbreeding experi- ments (3, 4). A small nucleus experimental flock is also maintained to observe the per- formance of pure-breds under local condi- tions. This short paper covers the preliminary 500 JOURNAL OF AGRICULTURAL SCIENCE IN FINLAND results of two field trials set up at two localities in a semi-arid region to evaluate the perfor- mance of F x Merino (M) crossbred females. As is so often the case it is not always possi- ble to plan and conduct field trials as well as in formal experiments, but in spite of certain limitations useful results do accrue. M con- trols were included in both trials. Both trials were launched during an extend- ed drought period which lasted from the previ- ous winter season till last year (1987 July), and the performance of the animals, particularly in the first trial initiated in 1983, suffered seri- ously as a result of poor nutritional condi- tions. Animals in the second trial were supported by irrigated pastures and were not notably af- fected by the drought conditions. Experimental First trial. This trial involved 600 F X M crossbred ewes and 600 M ewes, subdivided into groups and inseminated with semen from lie de France (IdF), South African Mutton Merino (SAMM) and Dohne Merino (DM) rams. This was followed by group mating of the M and F x M ewes with M and F x M rams. Owing to deteriorating environmental conditions, these latter groups were treated slightly better during the last three weeks of gestation. Second trial. In the second trial 181 M X M and 57 M ewes were involved in a compara- tive performance evaluation. Results Trial I Reproduction: Owing to environmental conditions, lambing percentages for natural mating following AI were poor in both groups but clearly in favour of the F X M with 61 % vs. M 48 °7o. Fecundity was 118 % for F x M and 102 % for M. Survival rate of lambs: No significant differences of survival rate occurred between groups in the case of single born lambs, but the survival rate from birth to weaning was significantly (P < 0,05) better for lambs born as multiples to F X M ewes (Table 1). Growth: Lambs from F x M ewes had sig- nificantly (P < 0,01) higher growth rates from birth to five weeks of age and significantly (P < 0,01) higher weaning masses than lambs born from M ewes at 100 days of age (Table 2). The differences between sire-breed groups were not significant except for the Dohne Merino. Woo! at 9 months of age: Except for the Mutton Merino X M, Dohne Merino X M and He de France x M, although not signifi- cant, had on average slightly lighter fleeces than their related crosses born from F x M ewes (Table 3). As expected the M and M off- spring produced the finest fibres while F X M offspring produced longer wool staples. Trial 2 Reproduction: Of the 181 Fx M ewes ex- posed to rams (F X M) between 4— lo months of age, 65 % lambed before 12 months of age with a fecundity rate of 136 % (Table 4). None of the M ewes lambed. F x M ewes lambed within a period of 38 days. All ewes (both groups) were again exposed to rams (F x M) at 18 months of age after some culling on wool faults had been applied (Table 5). Significant differences were found between; lambing % (92 vs. 75 % in favour of F x M); and fecundity (187 vs. 107 % also in favour of F x M). Survival rate of lambs: The first group of offspring of the F x M ewes had a survival rate of 77 % (Table 4) at weaning (100-days) and the second group, 98,9 % vs. the M’s 80,6 % (Table 5). Growth: Lambs of the F x M ewes were significantly (P < 0,01) heavier at weaning (100-days) than lambs born from M ewes (19,2 vs. 14,9 kg). 501 502 Table 1. Survival rate ( °/o) of lambs at different stages from birth to weaning (Trial 1). Ewe breed Finn x Merino Merino Type of birth* Type of birth* 12 3 12 3 Number of lambs born 349 220 39 424 134 21 Survival rate (%) at birth 99,1 98,6 100 99,1 98,5 95,2 birth 5 weeks 89,9 82,8 66,0 90,7 50,0 55,0 s—lo weeks 92,7 88,2 76,9 91,8 85,1 63,6 10 weeks weaning 94,8 97,3 80,0 95,4 92,5 100 (100 days) Total survival rate 79,4 65,9 40,0 78,3 55,2 33,3 * 1 = Singleton; 2 = Twins; 3 = Triplets Table 2. Average daily gain (ADG) from birth to 5 weeks of age and weaning mass of crossbred lambs (g/day) 2 (Trial 1). Ram breed Ewe breed n Finn x Merino n Merino ADG (birth 5 weeks of age: g) (x±S.E.) (x±S.E.) Ile de France 147 299+ 9,3" 171 277+ 2,4» Dohne Merino 24 269±38,6" 95 266121,5 b SA Mutton Merino 108 290± 6,2» 89 276+ 8,6" Merino 1 83 295 ± 16,5» 37 274±16,3» Finn x Merino 1 98 292± 3,1" 44 274± 6,7" Weaning mass at 100 days (kg) He de France 98 18,8 + 0,59» 127 16,710,13= Dohne Merino 9 16,213,79» 66 16,1 + 1,34» SA Mutton Merino 79 18,5±0,35» 54 16,7 + 0,59» Merino 1 61 18,8±0,95» 19 14,3 + 1,35'' Finn x Merino' 71 18,2 + 0,19» 30 15,110,42" 1 Lambs born from Merino and Finn x Merino rams received slightly different treatments. See text. 2 Means with different superscripts in the same column differ significantly from each other. Table 3. Wool characteristics of crossbred lambs shorn at 9 months of age in 1987. 1 (Trial 1). Breed/Genotype2 n Clean fleece (kg) Staple length (mm) Fibre Crimps Crimp deviation 3diameter per (micron) 25 mm Lambs Merino 21 1,40b 88,3» 15,7“ 13,3ac 1,24» 100,5 d 16,4» 13,6“- 1,45b 101,8d 17,2b 12,5» 1,24» 106,9» 17,7b 12,8» 79“ 83“»F/M X M M x F/M 25 50 84“» F/M x F/M IdFxM 37 87 b 1,38blii 91,1' 18,2b 16,01 99“ IdFxF/M 125 1,42b 96,9 f 19,9- 14,4' 103' SAMMXF/M SAMM x M DM x F/M 128 1,26“ 93,4“ 18,2b 1,31“ 80,5 b 16,8“b 1,38b 103,3d 18,2b 14,2bt 94' 61 14,3bc 87 b 16 13,0“b 91 b DM x M 59 1,33ab 80,2b 16,4» 13,2ab 82» 1 Means with the same superscript in the same column do not differ significantly from each other. 2 Ram breed mentioned first. 3 Duerden standard = 100. Wool: Ewes were shorn at 11 months of age (Table 6). As in Trial 1 the M produced sig- nificantly (P < 0,01) more clean wool than the F x M crossbreds, the latter producing an amount equivalent to 71 % of the M. Conclusion/Remarks In a country such as South Africa, where both lamb and wool production are impor- tant, environmental circumstances dictate the relative emphasis placed on the two commodi- ties. In general, extensive range conditions favour wool production and here the M is like- ly to remain the dominant breed in produc- tion systems. This breed consitutes approxi- mately 65 % of the current sheep population of 35 million (1). The M is, however, not suita- ble for intensive lamb and wool production systems (2, 4) and with growing emphasis on more intensive production systems, particu- larly in areas of higher potential it is obvious that a more suitable genotype is required. Results obtained from a comprehensive crossbreeding experiment and several field tri- als, including the two reported on in this paper, have led to the conclusion that the halfbred F X M provides a suitable and ac- ceptable composite showing remarkable adaptability to even comparatively harsh en- vironmental conditions. The favourable results obtained from the crossbred (F x M) wool and its special quali- ties (low felting and low creasing features) are regarded as useful attributes. There appears to be sufficient evidence available now to support the establihment of a composite Fx M female line for deploy- ment in the industry, certainly under condi- tions where favourable nutritional conditions exist. Table 4. Reproduction of Finn x Merino and Merino ewes exposed to rams from 4 —lo months of age (Trial 2). Ewe breed Finn x Merino Merino Number of ewes available 181 57 Lambing (%) 65,7 Fecundity (%) 136,1 Survival rate of weaningl (%) 77,1 Mass at conception (kg) 29,4—30,9 (27,8—28,6) 2 1 Lambs weaned per total number of lambs born. 2 Mass range concurrent with Finn x Merino conception. Table 5. Reproduction of F x M and M ewes mated at 18 months of age and survival rates of their lambs (Trial 2). Ewe breed Finn x Merino Merino 37Number of ewes available 157 Ewe mass at mating 47,8±0,33 43,2 ±0,68 92,4 75,5 kg±S.E. Lambing (%) Fecundity (%) 186,9 107,1 99,3 86,6Survival rate at birth 1 (%) 99,3 Survival rate from birth to weaning 2 ( n /o) 98,9 80,6 Lambs born alive per total number of lambs born. Lambs weaned per number of lambs born alive. Table 6. Wool characteristics of the F x M and M (Trial 2) measured at 11 months of age. Genotype Finn x Merino Merino Number of ewes shorn (n) 168 Mass at shearing (kg) 38 55 38,7 33,3 3,4 4,8Greasy fleece mass (kg) Clean yield (%) 69,6 71,7 2,4 3,4 114,7 106,8 8,9 9,0 21,3 19,9 8692 Clean fleece mass (kg) Staple length (mm) Crimps per 25 mm Fibre diameter (micron) Crimp deviation 503 References I. Abstract Of Agricultural Statistics. 1988. Direc- torate of Agricultural Economics and Marketing. Pretoria. ISBN 0621114235. 2. Bonsma, F.N., 1939. Factors influencing the growth and development of lambs with special reference to crossbreeding of Merino sheep for fat lamb produc- tion in South Africa. Univ. Pretoria Pubi., Sec. 1., NO. 48, Rep. South Africa. 3. Hofmeyr, J.H., Ueckermann, L., Kuhn, G.P. & Roux, C.Z., 1974. Intensive sheep production: Preliminary observations on the effect of crossbreed- ing as exhibited by the production qualities of cer- tain Merino crosses. Proc. of sth Congress. S. Afr. Genet. Soc., Stellenbosch Univ. February, 1974. 140—144. 4. 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