Performance of Finnsheep in South Africa

Reproduction, survival, growth and wool parameters were calculated for an experimental flock of Finnsheep from 1969 until 1986 under semi-intensive conditions. The total number of lambs bom were 1774. Litter size, survival rate at birth and from birth to weaning differed significantly (PcO.Ol) between years. Lambing percentages varied between 56.0 and 90.6% while average litter size varied between 1.97 and 3.1 lambs. Survival rate at birth declined as litter size increased, from 92.2% for singletons to 63.5% for quintuplets, while survival rate from birth to weaning also declined from 74.1% for singletons to 57.0% for quintuplets. For singletons, twins, triplets, quadruplets and quintuplets the least squares means of birth mass was 2.5 ± 0.06; 2.2 ±0.05; 2.0 ±0.05; 1.8 ± 0.06 and 1.7± 0.10, weaning mass was 19.0± 0.47; 16.8 ± 0.37; 16.8 ±0.36; 16.2 ±0.45 and 16.4 ± 0.94, and 12months mass 43.9 ± 1.5; 40.1


Introduction
Attempts to improve economic and biological efficiency in sheep production systems have focussed attention on the vital role of reproduction and consequently on highly fertile sheep breeds of the world. Improvement in the reproduction rate through accelerated lambing and/or higher fecundity of the ewe flock may offer the greatest opportunity for increasing production. The infusion of high fertility genes through crossbreeding has proved to be the most rapid breeding procedure to increase the reproduction rate in sheep flocks and the Finnish Landrace has been used extensively for this purpose (Maijala, 1984). However, with the exception of a few publications (eg. Goot et al., 1979;Maijala and Österberg 1977;Maijala 1984; Aboul-Naga 1988;Baker 1988;Boylan et al. 1988;Valls Ortiz 1988)  After importation the animals were kept under confined veterinary quarantine conditions for three and a half years and standard management practices were followed with one lambing per year. Handmating was practised and mating took place during April and May (Autumn) each year with lambing during September and October (Spring). Three to four days before lambing ewes were penned individually where they lambed under close supervision and where birth details were recorded. Depending on the milk flow of the ewe, lambs were reared by their dams or received additional cow's colostrum for approximately 3 days after birth. Thereafter, depending on litter size and the strength of the lambs, they received additional cow's milk until weaning.
Initially, the animals received a basic diet of milled lucerne hay ad libitum with a daily allowance of about 200 g of a commercially pelleted concentrate. As from 1978 the animals were kept on Pennisetum clandestinum pastures and received a complete pelleted diet during late pregnancy and lactation. From three weeks of age the lambs had free access to the complete pelleted diet and received this diet through weaning at about 100 days of age until about six months of age. Ewe lambs mated at seven months of age were kept on this diet until their lambs were weaned.

Statistical methods
Lambing percentage and survival rate were analysed with a Chi-square procedure (Steel and Torrie, 1980) while fecundity, growth and wool data were analysed with the least squares means and maximum likelihood computer programme of Harvey (1977). Year of birth, type of birth (i.e. singles or multiples), age of dam and sex of lamb were included in the model as fixed effects. Contrasts were used to test for significant differences between effects within a major class.

Reproductive performance and survival
Observations on lambing percentage, fecundity and mortality rate for the flock are indicated in Table 1.
Year had a significant effect (P<0.01) on lambing percentage, fecundity and survival rate. Compared to the results of Maijala and Österberg (1977), the lambing percentage was lower because ewe lambs which were mated at 7 months of age were included in the analyses. Ewes that were mated for the first time at about 7 months of age had an average lambing percentage of 56.8%. This low lambing percentage is probably due to a low body mass of less than 27 kg at time of mating. In 1977 ewe lambs were not mated at 7 months of age which accounted for the 100% lambing percentage recorded for the subsequent breeding season. In 1983 all ewes were artificially inseminated with imported frozen Finnsheep semen which accounted for the 23.4% lambing percentage. In 1984, 1985 and 1986 mature ewes were intra-uterally inseminated, after which ewes that did not conceive were mated to Finn rams. An average fecundity of 239.4% was obtained with a range of 197.6% (1978) to 310% During 1983 all mature ewes were inseminated with frozen semen (a) Lambing from intra-uterine inseminations (b) Excluding 1977Excluding , 1983 and lambing from intra-uterine inseminations Empty cells: Data not available (1986) for handmating. The age of the ewe had a significant effect (P<0.05) on fecundity which increased until 6 years of age (Table 2). The average mass of ewes at lambing was about 53 kg. These fecundity rates agree very well with comparable results in the literature (Maijala and Österberg 1977). About 67% of all lambs were born either as twins or triplets while the rest were singles (11 %) quadruplets (18%) or quintuplets (5%) ( Table 3). Heavier ewes seem to produce more lambs (Table 3). Most of the lambs born as singles were from ewes lambing at 12 months of age.
In general the survival rate of lambs was very poor. Table 1 indicates an average mortality rate of 21% at birth, 38% from birth to weaning at 100 days and 36% from weaning until 12 months of age. During 1975 95% of all lambs born died before one year of age. It appears that there are two major causes of the high mortality rates among Finnsheep: 1. Environmental stress caused by diurnal fluctuations in temperature results in heavy losses in newborn lambs. 2. Finnsheep appear to be more susceptible than local breeds to lung diseases such as Pasteurellosis.
Regular innoculation against this disease was not effective nor did sheep respond to treatment with antibiotics. Survival rate is closely related to litter size (Table   4). As litter size increases, the survival rate at birth and from birth to weaning decreases significantly (P<0.05). Furthermore, notwithstanding the fact that lambs were fed additional milk irrespective of the type of birth, lambs bom from ewes lambing at one year of age were generally weaker and required additional care.

Gestation length
No significant differences were found in gestation length between ewes with different litter sizes (Table 5), but these values (143 days) are lower than the average gestation length recorded for breeds such as the Merino (150.3 days), Karakul (150.7 days) and Romney Marsh (149.6 days) (Hugo, 1966 The first signs of oestrus occurred during March. In April there was a sharp increase which peaked in June. Thereafter it declined until October after which no signs of oestrus were recorded. Ewe lambs showed the first signs of oestrus at an average body mass of 31.8 ± 3.98 kg and at 242 ± 24.4 days of age, with an oestrus every 16.1 ± 1.03 days on average.  Table 7 indicates that as litter size increased, birth mass, weaning mass and 12 months mass decreased. No significant differences were found for wea-ning mass and 12 months mass between triplets, quintuplets and quadruplets, probably because quadruplets and quintuplets received preferential treatment from birth. Age of the ewe had a highly significant effect (P<0.01) on birth mass and 12 months mass (Table  8) but not on weaning mass with a mean of 16.3kg, probably because the effect of milk production was eliminated, since weak lambs received additional milk from birth until weaning. As the age of the ewe increased, birth mass increased to an age of 9 years. The twelve month mass of lambs bom from ewes lambing at about 1 year of age was significantly P<0.01) lighter than lambs born from mature ewes, in spite of the fact that no significant differences were found for weaning mass.
Sex of the lamb also had a significant effect on birth mass, weaning mass and 12 months mass. In all cases ewe lambs were significantly (P<0.01) lighter than ram lambs (Table 9). Wool traits Table 10 indicates the wool characteristics of Finnsheep rams and ewes. Very light fleeces of respectively 2.6 and 2.2 kg were recorded for rams and ewes. However, no significant differences were found between rams and ewes for any wool trait. Visually the fleeces differ greatly from Merino type fleeces but with a fibre diameter of 26.0 and 26.7 micron, and with crimps per 25 mm

Carcass traits
Thirteen ram and 16 ewe lambs were slaughtered at 5 different live masses. Each carcass was dissected into subcutaneous fat (scf), meat and bone and the mass of each component, as a percentage of the total carcass mass are indicated in Table 11.
Although a small numberof lambs is involved, it is clear that as slaughter mass increases, dressing percentage and percentage subcutaneous fat in the carcass also increases while percentage bone decreases in accordance with the general tendency recorded in the literature (Kempster et al., 1982).
Ewe lambs had a higher dressing percentage and more subcutaneous fat than ram lambs at all masses while the percentage lean was about the same. It 101.0 appears that the amount of subcutaneous fat of both sexes is far less than the average amount of subcutaneous fat of 8.5 percent for carcasses of 17.5 kg of all sheep slaughtered in South Africa (Bruwer et al., 1987). These results agree with the findings of Boylan et al. (1976) in Finnsheep crosses, indicating the leanness of this breed.

Conclusions
With very few exceptions no significant role is seen for pure-bred Finnsheep in the local sheep industry. However, through crossbreeding, Hofmeyr (1980), Greeff and Hofmeyr (1988) and Greeff et al, (1990) showed that the high fertility of the Finnsheep can make a valuable contribution in increasing the reproductive efficiency of sheep production under intensive, semi-intensive and extensive conditions in South Africa. Traditionally, the sheep industry has resisted any encouragement to promote multiple births in sheep. The comparatively low value ofindividual animals did not justify the managerial and labour inputs associated with multiple births such as the nursing and fostering of lambs. However, this perception has changed in recent years with the increase in improved pastures and relatively high mutton and lamb prices.
The local market has not been very receptive as far as Finnsheep wool is concerned, but Hofmeyr (1980) indicated that the processing qualities of Finn x Merino wool was closer to Merino wool than that of any other Merino cross produced. As wool production is a major consideration in a country such as South Africa, the Finnsheep could play an important part in the establishment ofa dual purpose white wool composite female line for the industry, especially where nutritional conditions favour intensive lamb production.