Journal articles: 'Blackface sheep'

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Dwyer, C. M., and A. B. Lawrence. "EFFECTS OF MATERNAL GENOTYPE AND BEHAVIOUR ON THE BEHAVIOURAL DEVELOPMENT OF THEIR OFFSPRING IN SHEEP." Behaviour 137, no. 12 (2000): 1629–54. http://dx.doi.org/10.1163/156853900502754.

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AbstractSignificant breed differences in grazing, activity, social and other affiliative behaviours are known to exist in sheep. The roles of maternal and offspring genotype in determining the development of breed-specific behavioural differences in lambs were investigated using embryo-transfer. Two breeds of sheep (Suffolk and Scottish Blackface) were chosen as they differ markedly in social and affiliative behaviours. Sixty ewe-lamb pairs (15 each of the four combinations of ewe and lamb) were observed over the first 3 days after lambing, then when the lambs were aged between 2-5 months old and during the first 6 weeks after weaning. Lamb breed was the main factor affecting lamb activity at birth and play behaviour over the first postnatal days, with Blackface lambs being significantly more active than Suffolk lambs. Lamb sucking behaviour during this period, however, was significantly affected by ewe breed with a higher frequency of sucking interactions observed with Suffolk ewes. When out at grass the two breeds of ewe differed in their use of the field, with Blackface ewes using upland areas whilst Suffolk ewes were found almost exclusively in the lowland parts. Ewes also differed in their spatial relationship to their lamb, with Blackface ewes maintaining a closer relationship to their lamb than Suffolk ewes, regardless of lamb breed. Blackface ewes were also more active than Suffolk ewes and were more frequently observed grazing. The breed of their mother significantly influenced the behaviour of the lambs, and their spatial relationships to other sheep, both before and after weaning. Lambs with Blackface mothers were more active than lambs with Suffolk mothers and this difference persisted after weaning. Blackface-reared lambs also had a shorter nearest neighbour distance after weaning, aggregated into smaller subgroups and were significantly more likely to be in upland areas of the field, regardless of lamb breed, than lambs reared by Suffolk ewes. Maternal influence, therefore, plays an important role in shaping the behaviour of their offspring in sheep, although neonatal lamb activity is not affected by maternal behaviour.

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Annett, R. W., A. F. Carson, L. E. R. Dawson, D. Irwin, and D. J. Kilpatrick. "Lifetime performance of crossbred ewes in the hill sheep sector." Proceedings of the British Society of Animal Science 2009 (April 2009): 72. http://dx.doi.org/10.1017/s1752756200029112.

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Hill sheep flocks in the UK are dominated by purebred ewe genotypes, with the Scottish Blackface being the most common. However a long term decline in economic returns, combined with recent changes to the Common Agricultural Policy, has lead many hill sheep producers to consider keeping crossbred ewes to exploit the benefits of hybrid vigour for lamb survival and to introduce beneficial traits for prolificacy, ease of lambing and carcass quality. In 2001, a major on-farm research programme was initiated to evaluate the performance of a range of crossbred ewe genotypes for the Northern Ireland hill sheep sector. Provisional data has already identified that retaining Lleyn X Blackface and Texel X Blackface ewes can improve lamb output at weaning by up to 10% relative to purebred Blackface ewes (Speijerset al., 2007). However, ewe longevity is a major issue for hill flocks, where the annual replacement rate often exceeds 20%. Therefore it is inappropriate to evaluate crossbred ewe genotypes based on average annual performance alone, and the aims of this study were to investigate the lifetime performance of a range of crossbred genotypes under hill conditions.

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Sveistiene, Ruta, and Miika Tapio. "SNPs in Sheep: Characterization of Lithuanian Sheep Populations." Animals 11, no. 9 (2021): 2651. http://dx.doi.org/10.3390/ani11092651.

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In Lithuania, there are two recognised native sheep breeds: old native Lithuanian Coarsewooled and Lithuanian Blackface. In addition, in 2005, primitive Heidschnucke-type Skudde sheep were imported to Lithuania and were argued to possibly represent a lost Lithuanian sheep type. The aim of the study was to investigate the genetic variation in the two Lithuanian native sheep breeds, compare them with the imported Skudde sheep and establish the historical patterns of admixture and the genetic relatedness of Lithuanian sheep to British, Central European and Nordic sheep breeds included in the SheepHapMap study. In total, 72 individuals, representing two Lithuanian native and imported Skudde sheep breeds, were genotyped using a Neogen 12K Illumina Infinium chip. The population analysis was carried out by model-based clustering, principal component analysis and neighbour net analysis, and showed similar patterns for the Lithuanian sheep populations. Lithuanian Coarsewooled and Skudde in Lithuania have unique divergence and possibly some shared ancestry, while the Lithuanian Blackface conforms to a modern synthetic breed. The study clearly showed that the Coarsewooled and the Skudde breeds are distinct from each other. Historical data strongly suggest that the Coarsewooled breed represents a local breed, while the Skudde origin is less directly linked to the geographical area of modern-day Lithuania. Within the modern-day Lithuanian context, the Lithuanian Coarsewooled sheep is very important historical sheep type for conservation.

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AL-NAKIB, F. M. S., N. BATEMAN, R. H. FINDLAY, C. SMITH, and R. THOMPSON. "Comparative performance of British hill sheep breeds and crosses." Journal of Agricultural Science 128, no. 2 (1997): 199–206. http://dx.doi.org/10.1017/s0021859696003991.

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Five British hill sheep breeds and their crosses were compared on a hill farm in a common environmental and husbandry system in 1974 in Peeblesshire, Scotland. A home-bred Scottish Blackface stock was maintained, and ewes were crossed with rams of each of the five hill breeds, North Country Cheviot, Derbyshire Gritstone, Exmoor Horn, Swaledale and Scottish Blackface. The crossbred female progeny were then mated half to homebred Blackface rams and half to rams of the paternal breed. This was reversed in later generations to form a continuous criss-crossing system. The performances of the crossbred ewes and of the crossbred lambs were compared, and the effects of the breeds and the average heterosis were estimated. A total of 5579 ewe and 6516 lamb records were available for comparison over an 8-year period from 1977 to 1984. Some 20 rams per breed were used over this period. The Swaledale crosses had substantially higher output and efficiency than any of the other crosses, while the Derbyshire Gritstone and Exmoor Horn crosses were generally inferior. There was appreciable heterosis for most traits, that for fleece weight and for litter weight at weaning being the highest. The heterosis for output per ewe exposed and efficiency of lamb production are positive and significant. The results support greater use of the Swaledale and of a crossbreeding system with Blackface to exploit heterosis in harsh hill farm conditions.

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Murphy, A., and J. Conington. "A genetic analysis of wool and lamb production traits in Scottish Blackface Sheep." Proceedings of the British Society of Animal Science 2002 (2002): 21. http://dx.doi.org/10.1017/s1752756200006773.

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Scottish Blackface sheep have a multi-purpose role in the UK to produce breeding females and lambs for meat consumption. Over the last fifty years, wool has accounted for a very low proportion of economical return from hill sheep production in the UK. In recent years, the ratio of the value of lamb meat to wool clip has altered, with wool becoming relatively more important in particular for hill breeds. The consequence of direct selection for improved carcass traits in these breeds on wool quality is unknown. With other sheep breeds such as Merino, selection for improved wool traits has largely been undertaken with little regard to the impact on meat production. The objectives of this study are to quantify wool quality traits and examine genetic relationships between wool quality and carcass traits in Scottish Blackface sheep.

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Gunn, R. G. "A note on the comparative reproductive performance of Friesland × North Country Cheviot and North Country Cheviot ewes on two levels of pasture prior to mating." Animal Science 42, no. 2 (1986): 287–89. http://dx.doi.org/10.1017/s0003356100018018.

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The Friesland or East Friesian breed of sheep is a heavy-milking type with a high level of prolificacy. The progeny of the cross with the Scottish Blackface female sheep (ewe) have been shown to have larger, heavier litters in a good lowland environment compared with crossbreds derived from other crossing sires (Boaz, Jones and Smith, 1980; British Friesland Sheep Society, 1983) and to have a higher twinning rate than Scottish Blackface ewes when mated on improved pasture on a hill farm (Doney, Peart, Smith and Sim, 1983). Information is required on the performance of crossbred ewes derived from Friesland sires on other hill breeds and run in less favourable environments such as are common in the hills and uplands.

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Stevenson, Heather, Cici Corbett, Katrina Henderson, Colin Mason, and Peter Richards‐Rios. "Lymph node aplasia in Scottish blackface sheep." Veterinary Record 192, no. 12 (2023): 489–90. http://dx.doi.org/10.1002/vetr.3200.

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CARSON, A. F., D. IRWIN, and D. J. KILPATRICK. "A comparison of Scottish Blackface and Cheviot ewes and five sire breeds in terms of lamb output at weaning in hill sheep systems." Journal of Agricultural Science 137, no. 2 (2001): 221–33. http://dx.doi.org/10.1017/s0021859601001277.

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A study was carried out on six hill farms in Northern Ireland over 2 years (1996–1998) to investigate the effect of ewe and ram breed on ewe prolificacy, lamb viability and weaned lamb output. On each farm, groups of 40 Scottish Blackface ewes (mature weight of 53·8 kg) were mated to Scottish Blackface, Blue-Faced Leicester and Texel rams. Similarly, groups of 40 Wicklow Cheviot ewes (mature weight 63·7 kg) were mated to Cheviot, Suffolk and Texel rams. All ewe×ram breed combinations were present on each farm. Overall, ewe prolificacy was similar in Blackface and Cheviot ewes (1·52 and 1·55 (S.E. 0·026) lambs born/ewe lambed). However, there was a farm×ewe breed interaction (P < 0·001) indicating that, whilst prolificacy was similar in Blackface and Cheviot ewes on the majority of farms (4 out of 6), on one farm prolificacy was higher in Blackface and on another lower, compared with Cheviot ewes. There were no farm×breed interactions for any of the other main production traits. The proportion of ewes lambing without assistance was higher in Cheviot compared with Blackface ewes when crossed with Texel sires (P < 0·001). Cheviot ewes produced heavier Texel-sired lambs compared with Blackface ewes (4·76 versus 4·51 (S.E. 0·076) kg; P < 0·05). Mortality levels were similar in lambs produced from Blackface and Cheviot ewes. The weight of lamb weaned per ewe was higher in Cheviot compared with Blackface ewes (41·5 versus 38·8 (S.E. 1·01) kg/ewe lambed; P < 0·05). However, the weight of lamb weaned per kg of ewe metabolic weight did not differ significantly between the breeds.With Blackface ewes, the proportion of ewes lambing without assistance was lower for Blue-Faced Leicester compared with Blackface sires (P < 0·001). In addition, the proportion of ewes lambing without assistance was lower (P < 0·001) for Texel compared with both Blackface and Blue-Faced Leicester-sired lambs. Lamb birth weights were higher in Blue-Faced Leicester (P < 0·05) and Texel (P < 0·001) compared with Blackface-sired lambs (4·38, 4·51 and 4·09 (S.E. 0·076) kg, respectively). Similarly, the weight of lamb weaned per ewe lambed was higher (P < 0·001) with Blue-Faced Leicester and Texel compared with Blackface sires (39·8, 38·8 and 33·8 (S.E. 1·01) kg, respectively). The carcass weight of the male lambs 3 weeks post-weaning was significantly higher (P < 0·001) in Blue-Faced Leicester and Texel compared with Blackface-sired lambs (12·5, 12·0 and 10·2 (S.E. 0·20) kg, respectively). Carcass conformation classification was higher in Texel compared with Blue-Faced Leicester and Blackface-sired lambs (P < 0·001). Fat classification was higher in Texel (P < 0·01) and Blue-Faced Leicester (P < 0·05) compared with Blackface-sired lambs. With Cheviot ewes, a greater number of ewes lambed unaided (P < 0·05) with Cheviot and Texel compared with Suffolk-sired lambs. The number of lambs born dead was higher (P < 0·01) with Suffolk compared with Cheviot and Texel-sired lambs (0·14, 0·08 and 0·07 (S.E. 0·016) lambs born dead/ewe lambed, respectively). Growth rates were higher in Suffolk compared with Cheviot-sired lambs (P < 0·05). Overall, Suffolk (P = 0·06) and Texel (P < 0·001) sires produced a greater weight of lamb at weaning compared with Cheviot sires (40·0, 41·5 and 36·9 (S.E. 1·01) kg, respectively). Carcass weight of lambs 3 weeks post-weaning was higher for Suffolk (P < 0·05) and Texel (P < 0·01) compared with Cheviot-sired male lambs. Carcass conformation classification was higher in Texel and Suffolk compared with Cheviot-sired (P < 0·001) lambs. Fat classification was also higher in Texel compared with Cheviot-sired lambs (P < 0·05). Carcass chemical composition was not significantly affected by lamb genotype.

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9

Sawalha, R. M., J. Conington, S. Brotherstone, and B. Villanueva. "Analyses of lamb survival of Scottish Blackface sheep." Animal 1, no. 1 (2007): 151–57. http://dx.doi.org/10.1017/s1751731107340056.

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Bishop, S. C., N. D. Cameron, B. K. Speake, J. Bracken, I. A. J. Ratchford, and R. C. Noble. "Responses in adipocyte dimensions to divergent selection for predicted carcass lean content in sheep." Animal Science 60, no. 2 (1995): 215–21. http://dx.doi.org/10.1017/s1357729800008377.

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AbstractAdipocyte dimensions of subcutaneous fat, sampled by biopsy at the 13th rib, were measured in 20-week-old rams from lines of Texel-Oxford and Scottish Blackface sheep, both divergently selected for carcass lean content. A total of 163 animals were measured, with close to equal numbers per breed-line combination. In both breeds, the high (lean) selection line had significantly lower backfat depths (0·71 mm in the Texel-Oxford and 0·83 mm in the Scottish Blackface, s.e.d. = 0·14 and 0·13 mm, respectively), but body weight did not differ between the lines. The ultrasonic fat depth differences between the Texel-Oxford selected lines were accompanied by increases in adipocyte diameter, area, diameter standard deviation within each sample and implied cell number, calculated as the ratio of ultrasonic fat depth to average adipocyte diameter. In the Scottish Blackface sheep there were no selection line differences in adipocyte dimensions, but there was an increase in implied cell number in the line selected for increased fatness. Across breeds, ultrasonic fat depth was correlated with both adipocyte diameter and implied adipocyte number (r = 0·58 and 0·75, respectively), but these latter two measurements were uncorrelated with each other.

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Al-Nakib, F. M. S., R. H. Findlay, and C. Smith. "Performance of different Scottish Blackface stocks and their crosses." Journal of Agricultural Science 107, no. 1 (1986): 119–23. http://dx.doi.org/10.1017/s0021859600066867.

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SUMMARYThe performance of different stocks of Scottish Blackface sheep and their crosses was compared on a harsh Scottish hill experimental farm. The strains were the Stanhope farm stock (a control flock, closed for 30 years), stock from local Breeders, and first crosses and back-crosses of Stanhope stock with stocks represented by rams purchased at Lanark market. Some 3892 ewe records were available with 1837 lamb performance records. Estimated effects for the three types of stock and of heterosis in the Stanhope and Lanark cross were derived statistically. The local Breeders' stock had the heaviest lambs at weaning and the Stanhope stock the lightest. The local Breeders' stock also had the heaviest ewes and higher litter size but had lower fertility and lower lamb survival. Output expressed relative to ewe weight was highest for the cross-bred stock. Heterosis was positive for all traits studied except survival but was statistically significant only for ewe weight and lamb birth weight. If the Stanhope stock was representative of Scottish Blackface sheep of 30 years ago, breeding by Scottish Blackface breeders has led to an estimated improvement of 9% in the output per ewe exposed, and 5% in efficiency of production.

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Wiener, G., J. A. Woolliams, Carol Woolliams, and A. C. Field. "Genetic selection to produce lines of sheep differing in plasma copper concentrations." Animal Science 40, no. 3 (1985): 465–73. http://dx.doi.org/10.1017/s0003356100040150.

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ABSTRACTMale lambs were selected annually at 18 and 24 weeks of age for high or low concentrations of copper in plasma to produce two closed lines. The difference between the high and low lines increased to approx. 0·5 mg/1 after 5 years when the experiment ended, indicating appreciable additive genetic variation for the concentration of Cu in plasma. The selection lines were derived from a population of Scottish Blackface × Welsh Mountain crosses which had been interbred for many generations. The two parental breeds contributing to the cross normally differ in a number of aspects of Cu status with that of the Welsh higher than that of the Blackface. Both pure breeds were kept as controls. In the final year, Cu concentrations of the high selection line exceeded the values of the Welsh and the low selection line had values below those of the Blackface. Differences between the selection lines persisted at all ages.There were indications of changes in the frequency of the Hb alleles, associated with the selection for Cu concentrations, but there were no correlated changes in body weight, reproductive performance or lamb mortality during the 5-year selection period when dietary supplies of Cu were not particularly restrictive.

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Doney, J. M., A. D. M. Smith, and D. A. Sim. "Growth rate and carcase composition of Border Leicester x Scottish Blackface, East Frlesland x Blackface and East Friesland x North Country Cheviot Lambs." Proceedings of the British Society of Animal Production (1972) 1987 (March 1987): 82. http://dx.doi.org/10.1017/s0308229600035170.

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The East Friesland breed, developed as a dairy sheep, has a potentially useful role as a sire of first-cross breeding ewes from hill breeds of sheep. Advantages have been shown in terms of reproductive and lactation performance (Doney et al, 1983, Gunn, 1986) but the carcase conformation may reduce the acceptability of first-cross castrated male (wether) lambs. The characteristics of lambs derived from dairy-type breeds may be suitable for the heavy, lean carcase market (Butler-Hogg et al, 1985). The present study was undertaken as a pilot investigation of the potential growth rate and carcase composition of wether lambs over a range of live weights. East Friesland X Blackface (EFB) wethers were compared with a similar group of Border Leicester X Blackface (BLB) and a smaller group of East Friesland X North Country Cheviot (EFC) wethers.

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Hyslop, J. J., F. A. Kennedy, H. F. Adamson, and R. Keatinge. "Voluntary herbage intake and diet selection in Scottish-Blackface ewes suckling twin lambs and grazing perennial ryegrass/white clover swards with or without protein supplementation." Proceedings of the British Society of Animal Science 2003 (2003): 192. http://dx.doi.org/10.1017/s175275620001351x.

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Mixed perennial ryegrass and white clover swards are often used as the basis of upland sheep grazing systems. This study’s objective was to examine voluntary herbage intake and diet selection in 30 lactating Scottish-Blackface ewes grazing mixed perennial ryegrass (PRG) and white clover (WC) swards supplemented with or without protein. The work was part of a wider study of nutrition and parasitology in organic sheep systems.

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Bari, F., M. Khalid, W. Haresign, B. Merrell, A. Murray, and R. I. W. Richards. "An evaluation of the success of MOET in two breeds of hill sheep maintained under normal systems of hill flock management." Animal Science 69, no. 2 (1999): 367–76. http://dx.doi.org/10.1017/s1357729800050931.

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AbstractThis study was undertaken to investigate factors affecting the success of multiple ovulation and embryo transfer (MOET) in Scottish Blackface (no. = 120) and Welsh Mountain (no. = 120) ewes, over a period of 2 years using a laparoscopic procedure for both embryo recovery and transfer. Superovulation was induced with ovine FSH, with 98 to 100% of ewes of both the breeds responding to the treatment. The overall mean superovulatory responses were 15⋅0 (s.e. 0⋅8) and 12⋅5 (s.e. 0⋅7) for Scottish Blackface and 15⋅3 (s.e. 0⋅9) and 12·8 (s.e. 0⋅8) for Welsh Mountain ewes in years 1 and 2, respectively. However, there was a wide degree of variation in superovulatory responses within each breed, with a range of 3 to 29 in Scottish Blackface and 1 to 40 in Welsh Mountain ewes. The mean embryo recovery rate was 71⋅9 (s.e. 3⋅5) % and 69⋅6 (s.e. 3⋅4) % for Scottish Blackface and 57⋅5 (s.e. 4⋅1) % and 60⋅6 (s.e. 3⋅6) % for Welsh Mountain ewes in years 1 and 2, respectively. The mean number of embryos recovered from Welsh Mountain ewes was significantly (P < 0⋅05) lower than that from Scottish Blackface ewes in both years. The lower mean number of embryos recovered in year 2 for both breeds was entirely a reflexion of the lower superovulatory responses in year 2. A significant (P < 0⋅001) relationship was observed between superovulatory response and the number of embryos recovered for both breeds. Some 77% and 72% of Scottish Blackface ewes and 65% and 73% of Welsh Mountain ewes yielded four or more transferable embryos in years 1 and 2, respectively. Neither the mean number nor the mean percentage of transferable embryos per donor ewe differed between breeds or years. A significant (P < 0⋅001) negative relationship was observed between the time of onset of oestrus and both superovulatory response and number of embryos recovered in Scottish Blackface ewes only. Embryo quality was affected by the time of onset of oestrus. In both breeds, the highest proportion of grade 1+2 embryos and the lowest proportion of unfertilized/degenerate embryos occurred in the middle range time, with a reduction in the proportion of grade 1+2 embryos in ewes that came into oestrus either early <19 h) or late (>30 h) after sponge removal. Only one embryo was transferred to each recipient and the embryo survival rates were 76⋅8% and 74⋅6% (Scottish Blackface), and 69⋅6% and 87⋅3% (Welsh Mountain) for years 1 and 2, respectively. Overall the results of this study suggest that MOET is as successful in hill ewes as has been reported for lowland breeds, even without making any major concessions to their hill status.

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Ilska, J., J. Conington, and N. Lambe. "Genetic aspects of lambing difficulty in Scottish Blackface sheep." Advances in Animal Biosciences 1, no. 1 (2010): 301. http://dx.doi.org/10.1017/s2040470010004449.

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Al-Nakib, F. M. S., and G. Simm. "A selection Index for hill sheep." Proceedings of the British Society of Animal Production (1972) 1989 (March 1989): 18. http://dx.doi.org/10.1017/s0308229600010199.

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Apart from the MLC indices for hill sheep (MLC, 1986) and Atkins’ (1984) study for Scottish Blackface sheep, little attention has been directed towards the general implementation of selection indices in hill sheep production, despite the fact that hill sheep constitute the backbone of the British sheep industry (eg. the genetic contribution of hill sheep to lamb carcass meat was estimated at 33 per cent, to total lambs slaughtered 36 per cent, and to dams of the lambs slaughtered 56 per cent - see MLC, 1988)The purpose of this paper is to try to define appropriate breeding objectives for hill sheep that could be incorporated in a selection index, in order to improve output and efficiency of sheep production in such a limiting environment.

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Karamichou, E., G. R. Nute, R. I. Richardson, K. McLean, and S. C. Bishop. "Identifying QTL for meat quality and carcass composition traits in Blackface sheep." Proceedings of the British Society of Animal Science 2005 (2005): 45. http://dx.doi.org/10.1017/s175275620000956x.

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The development of genetic markers and their application to farm animals has progressed rapidly, opening new prospects for identifying chromosomal regions that control quantitative traits (quantitative trait loci or QTL). However, there is less activity in QTL identification in sheep than in other livestock species. Surprisingly few QTL have been published for traits of direct relevance to sheep meat production, apart from studies of individual major genes such as the callipyge locus (Freking et al, 2002). This suggests there may be more QTL effects still to be found in sheep. Hence, this study aims to identify QTL for carcass composition and meat quality traits. This will provide a basis for targeting genomic regions to verify QTL in independent sheep populations.

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Fisher, G. E. J., and A. MacPherson. "Effects of cobalt deficiency in the pregnant ewe on neonatal lamb survival." BSAP Occasional Publication 15 (1992): 169–71. http://dx.doi.org/10.1017/s0263967x00004201.

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It has been suggested (Mills, 1981) that there was a lack of research on the effects of cobalt (Co) deficiency on the reproductive performance of sheep. Duncan, Morrison and Garton (1981) reported that clinically Co-deficient ewes produced fewer lambs with a higher incidence of stillbirths and neonatal mortalities than Co-sufficient animals. Garton, Duncan and Fell (1981) related these findings to the vitamin B12 and methylmalonic acid status of dams. However, their investigations used few animals and were therefore inconclusive. The objectives of this work were to investigate the effects of subclinical Co deficiency in pregnant hill sheep on reproductive performance and neonatal lamb viability.Experiment 1 (1985/86) comprised 60 Scottish Blackface × Swaledale ewes, while experiment 2 (1986/87) included 30 of these animals plus 30 pure Scottish Blackface sheep. In both experiments the ewes were housed and bedded on sawdust and a Co-deficient diet of timothy hay, micronized maize, maize gluten, dibasic calcium phosphate and sodium chloride was offered. Skimmed milk powder was introduced to the diet during lactation. The Co content of the diet was 0.06 mg Co per kg dry matter.

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Dawson, L. E. R., A. F. Carson, and B. W. Moss. "Effects of crossbred ewe genotype and ram genotype on lamb meat quality from the lowland sheep flock." Proceedings of the British Society of Animal Science 2002 (2002): 52. http://dx.doi.org/10.1017/s1752756200007080.

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Ewe and ram genotype have been shown to have a significant effect on carcass quality. For example, Dawson and Carson (2001) demonstrated that lambs from Bluefaced Leicester X Blackface ewes were of poorer conformation than lambs from the Texel X Blackface, Suffolk X Cheviot or Texel Cheviot ewes while high lean growth index sired lambs had an improved conformation compared with lambs sired by non-recorded rams. Recent work has shown that genotype can have significant effects on the meat quality of lambs from hill sheep systems (Carson et al. 2001). Therefore the aim of the current study was to investigate the effect of ewe and ram genotype from the lowland sector on meat quality.

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Martin, Simon J., Chris Newcombe, Andrea Raab, and Jörg Feldmann. "Arsenosugar Metabolism Not Unique to the Sheep of North Ronaldsay." Environmental Chemistry 2, no. 3 (2005): 190. http://dx.doi.org/10.1071/en05053.

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Environmental Context. Seaweed is enjoying a revival in farming practice, in particular by organic farmers. However, seaweed accumulates arsenic, and these arsenic compounds can enter the food chain. It is known that the arsenic is present mainly as arsenosugars, but the metabolism of these compounds by ruminants needs clarification. Abstract. Here we describe a feeding trial with Blackface sheep conducted on an organic farm in Kintyre (Scotland), which aims to prove that the metabolism of arsenic, acquired from the consumption of seaweed, is not unique to the North Ronaldsay sheep, which are adapted to a seaweed diet. Results show that the trial sheep supplemented their diet with, on average, 20 ± 9% Laminaria digitata when given the choice. The daily arsenic intake varied greatly from sheep to sheep but on average, the sheep consumed 65 μg kg−1 b.w. Total arsenic concentrations in urine, as measured by inductively coupled plasma-mass spectrometry (ICP-MS) (m/z 75) also show significant differences between the trial and control group (P < 0.0001). HPLC coupled with ICP-MS in parallel with electrospray ionization-mass spectrometry (ES-MS) for detection was used for the identification of arsenic metabolites in urine samples. Dimethylarsinic acid (DMAV) is the main metabolite in the control group as well as in the trial group. In addition, arsenic metabolites previously only found in the urine of North Ronaldsay sheep were successfully identified in the urine of the trial group of the seaweed-eating Blackface sheep: dimethylarsinoyl acetic acid (DMAA) and its thio-analogue dimethylarsinothioyl acetic acid (DMAAS) as well as the monosulfide of DMAV, DMAS. However, the poor chromatographic recovery indicates that the urine contains arsenic species, which do not elute under the conditions tested.

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Hurst, Emma, Katrina Henderson, Heather Stevenson, et al. "Rickets in Scottish blackface lambs on five South West Scotland farms." Veterinary Record Case Reports 8, no. 1 (2020): e001008. http://dx.doi.org/10.1136/vetreccr-2019-001008.

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Vitamin D plays a critical role in the regulation of calcium and phosphate homeostasis and in the development and maintenance of skeletal health. Sheep can obtain vitamin D via either cutaneous production following exposure to UV radiation or consumption of vitamin D containing foodstuffs. In northern Europe, sheep are often unable to cutaneously generate vitamin D in late winter due to the lack of UV radiation. Consequently, they are heavily reliant on dietary sources of vitamin D, which, if insufficient, can lead to rickets in growing lambs. Here, we report the diagnosis of rickets in Scottish blackface lambs on five farms in South West Scotland. Cases were diagnosed based on classical skeletal clinical signs alongside extremely low concentrations of 25 hydroxyvitamin D, the major circulating metabolite of vitamin D, which is widely used to assess vitamin D status. This report demonstrates that rickets can be a major health problem in hill sheep.

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Hoste, S., and C. Smith. "The evaluation of selection in a crossing ram breed to improve litter size in sheep." Proceedings of the British Society of Animal Production (1972) 1986 (March 1986): 27. http://dx.doi.org/10.1017/s0308229600015385.

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Five genotypes were compared as sires of crossbred ewes from Scottish Blackface dams. These included Border Leicester (BL), New Zealand Romney (R) (from two group breeding schemes where selection had emphasized litter size), and three lines from the composite A.B.R.O. Damline (DL). Selection of the male and female lambs in the purebred DL flock was: a)for an average of 5.5 years on a Ewe Index of eight week litter weight (Martin and Smith, 1980).b)for an average of 3.5 years on a Testis index, combining testis size (adjusted for body weight) and Ewe Index of eight week litter weight both components receiving approximately equal weight andc)a random bred control.These five genotypes (two rams per genotype per year for five years) were group mated (sires of individual ewes were not known) with Scottish Blackface ewes on an upland farm in Ayrshire.

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Lawrence, A. B., and D. G. M. Wood-Gush. "Home-Range Behaviour and Social Organization of Scottish Blackface Sheep." Journal of Applied Ecology 25, no. 1 (1988): 25. http://dx.doi.org/10.2307/2403607.

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Bishop, S. C. "Selection for predicted carcass lean content in Scottish Blackface sheep." Animal Science 56, no. 3 (1993): 379–86. http://dx.doi.org/10.1017/s0003356100006425.

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AbstractScottish Blackface sheep have been selected for either increased or decreased predicted carcass lean content at 20 weeks of age, using an index combining ultrasonic backfat depth and body weight. The index was designed to alter carcass lean content without changing body weight. After 4 years there have been large responses in the index and fat depth, the proportional difference between the divergent lines in fat depth is 0·28, but body weight and ultrasonic muscle depth have not changed between the lines. The realized heritability for the index is 0·45. Heritabilities for the index, ultrasonic fat depth, body weight and ultrasonic muscle depth, calculated using multivariate restricted maximum likelihood, are 0·47 (s.e. = 0·14), 0·39 (s.e. 0·13), 0·23 (s.e. 0·12) and 0·36 (s.e. 0·14), respectively. The selected lines will be used to investigate relationships between carcass lean content, viability and maternal performance under the harsh environmental conditions encountered in the Scottish hill environment.

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Ashworth, C. J., C. M. Dwyer, K. McIlvaney, M. Werkman, and J. A. Rooke. "Breed differences in fetal and placental development and feto-maternal amino acid status following nutrient restriction during early and mid pregnancy in Scottish Blackface and Suffolk sheep." Reproduction, Fertility and Development 23, no. 8 (2011): 1024. http://dx.doi.org/10.1071/rd10290.

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This study assessed the effect of feeding 0.75 energy requirements between Days 1 and 90 of pregnancy on placental development and feto-placental amino acid status on Day 125 of pregnancy in Scottish Blackface and Suffolk ewes carrying a single fetus. Such moderate nutrient restriction did not affect placental size, placentome number or the distribution of placentome types. Although fetal weight was unaffected by maternal nutrition, fetuses carried by nutrient restricted mothers had relatively lighter brains and gastrocnemius muscles. Suffolk fetuses were heavier and longer with a greater abdominal circumference, relatively lighter brains, hearts and kidneys, but heavier spleens, livers and gastrocnemius muscles than Blackface fetuses. Total placentome weight was greater in Suffolk than Blackface ewes. Ewe breed had a greater effect on amino acid concentrations than nutrition. Ratios of maternal to fetal amino acid concentrations were greater in Suffolk ewes than Blackface ewes, particularly for some essential amino acids. The heavier liver and muscles in Suffolk fetuses may suggest increased amino acid transport across the Suffolk placenta in the absence of breed differences in gross placental efficiency. These data provide evidence of differences in nutrient handling and partitioning between the maternal body and the fetus in the two breeds studied.

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O'Connor, C. E., and A. B. Lawrence. "Relationships between lamb vigour and maternal behaviour on sucking success at parturition." Proceedings of the British Society of Animal Production (1972) 1990 (March 1990): 36. http://dx.doi.org/10.1017/s0308229600018183.

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High perinatal mortality in sheep flocks worldwide remains a major economic and welfare issue. Maternal behaviour and lamb vigour are both considered major variables affecting lamb survival, but there is little data to describe their relative importance. The aim of this study was to investigate the relationships between lamb vigour and maternal behaviour at parturition. With the increase in hill ewes being crossed to longwool breeds there is an interest in the relative survivability of these lambs. This study compared the behaviour of Mule [Bluefaced Leicester x Blackface] lambs with purebred Scottish Blackface lambs.Data on 32 third parity single and twin-bearing Blackface ewes lambing indoors were collected by focal animal observations on the ewe's grooming behaviour. These observations included details of the time spent grooming specific areas of the lamb's body and also general activity and udder-seeking behaviour of the lambs. Observations lasted 10 minutes and were made at parturition and then at 30 and 90 minute intervals. The data was transformed by arcsin. for proportions, or log, for frequencies, and analysed by Analysis of Variance,

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Pickup, H. E., and C. M. Dwyer. "Breed differences in the expression of maternal care at parturition persist throughout the lactation period in sheep." Proceedings of the British Society of Animal Science 2002 (2002): 70. http://dx.doi.org/10.1017/s1752756200007262.

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In the ewe maternal care begins at parturition with grooming of the neonate and cooperation with early sucking attempts (e.g. Shillito-Walser 1978). Subsequently maternal care is expressed through sucking interactions, a close ewe-lamb association and a tendency to seek absent lambs (e.g. Hinch et al 1987). The ewe increasingly controls sucking interactions using a ‘head-up’ posture to signal when the lamb may approach and suck (Lawrence 1984).Two breeds of sheep, Suffolk and Scottish Blackface, are known to differ in their initial maternal behaviour. Blackface ewes spend longer grooming their lambs, show more cooperation with sucking attempts and less negative behaviour such as aggression and rejection, when compared to Suffolk ewes (Dwyer & Lawrence 1998). The aim of this study was to examine whether these breed differences in the expression of maternal care persist throughout the lactation period.

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McCloskey, E. P., J. H. McAdam, and A. F. Carson. "Spatial distribution of Scottish Blackface ewes in comparison to other crossbreds on a hill environment." Proceedings of the British Society of Animal Science 2009 (April 2009): 96. http://dx.doi.org/10.1017/s1752756200029355.

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Domestic sheep have a strong social tendency (Dwyer and Lawrence, 1999). Sheep recognise members of their own flock, and social bonds can determine grazing distribution. The distribution and distance between grazing ewes can vary widely depending on availability and quality of vegetation. However it tends to be a characteristic of breed (Sibbald and Hooper, 2003). Hill sheep breeds are known to have a higher flexibility than lowland breeds (Dwyer and Lawrence, 1999) and tend to have less need to be close to other animals in free ranging environments. The aim of this study was to monitor the behaviour and grazing patterns of a traditional upland breed, Scottish Blackface ewes in comparison to a range of other crossbred ewes.

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Dwyer, C. M., and A. B. Lawrence. "Interactions between ewe and lamb genotype and sucking success in neonatal lambs." Proceedings of the British Society of Animal Science 1998 (1998): 105. http://dx.doi.org/10.1017/s1752756200597579.

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Perinatal lamb mortality remains a major economic and welfare concern in sheep farming with 80-90% of pre-weaning lamb losses occur in the immediate postnatal period (Haughey, 1993). One of the predominant factors in the death of neonatal lambs is failure of ewe-lamb bonding leading to delay or lack of sucking. Successful sucking requires the co-ordinated expression of appropriate behaviour from both the ewe and lamb. Previously we have demonstrated an interaction between ewe and lamb breed in the rate of successful sucking (Dwyer et al., 1996) with Blackface lambs having a higher rate than Suffolk lambs but also a higher rate with Suffolk ewes than with Blackface ewes. In the present study we investigated the role of ewe responses to lamb sucking attempts in determining the sucking success of neonatal lambs.

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Sharples, T. J., and J. Dumelow. "Prediction of body dimensions of Mule and Scottish Blackface ewes from measurement of body weight." Animal Science 50, no. 3 (1990): 491–95. http://dx.doi.org/10.1017/s0003356100004979.

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ABSTRACTThe body dimensions and live weight of 126 Mule (Bluefaced Leicester × Scottish Blackface) and Scottish Blackface ewes were measured during the 1986/87 housing season. Body dimensions included: head and neck length, body length, diagonal body length, height to withers, height to rump, girth at widest point, heart girth, width at widest point and width at shoulders. It was found that most body dimensions varied greatly with body weight. However, some body dimensions such as head length were found to be independent of weight within the weight range studied. Prediction equations are presented for each body dimensions for unshorn sheep.These predictions can be used as a basis for the design of sheep housing, for example, trough space allowances, design of feeders or as a biological basis for space allowance.

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Dwyer, C. M., and A. B. Lawrence. "Interactions between ewe and lamb genotype and sucking success in neonatal lambs." Proceedings of the British Society of Animal Science 1998 (1998): 105. http://dx.doi.org/10.1017/s0308229600033183.

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Perinatal lamb mortality remains a major economic and welfare concern in sheep farming with 80-90% of pre-weaning lamb losses occur in the immediate postnatal period (Haughey, 1993). One of the predominant factors in the death of neonatal lambs is failure of ewe-lamb bonding leading to delay or lack of sucking. Successful sucking requires the co-ordinated expression of appropriate behaviour from both the ewe and lamb. Previously we have demonstrated an interaction between ewe and lamb breed in the rate of successful sucking (Dwyer et al., 1996) with Blackface lambs having a higher rate than Suffolk lambs but also a higher rate with Suffolk ewes than with Blackface ewes. In the present study we investigated the role of ewe responses to lamb sucking attempts in determining the sucking success of neonatal lambs.

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Davies, G., M. J. Stear, M. Benothman, et al. "Quantitative trait loci associated with parasitic infection in Scottish blackface sheep." Heredity 96, no. 3 (2006): 252–58. http://dx.doi.org/10.1038/sj.hdy.6800788.

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Lambe, N. R., J. Conington, S. C. Bishop, A. Waterhouse, and G. Simm. "A genetic analysis of maternal behaviour score in Scottish Blackface sheep." Animal Science 72, no. 2 (2001): 415–25. http://dx.doi.org/10.1017/s1357729800055922.

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AbstractUnder field conditions, ewe behaviour was quantified by maternal behaviour score (MBS)-a six-point scale which assesses ewe flight distance when lambs are handled for the first time, within 24 h of birth (adapted from O’Connor et al., 1985). MBS was measured on 847 Scottish Blackface ewes on two experimental hill farms, over a maximum of four parities. Live weights of lambs born to these ewes were measured at birth, marking (average age of 42 days) and weaning (average age of 120 days).MBS was significantly higher ( P < 0·05) for ewes with more lambing experience (multiparous ewes), for older ewes and for twin-bearing ewes compared with ewes with single lambs. MBS was under genetic control ( h2 = 0·13, permanent environmental effect = 0·19, when analysed as the same trait across parities) and the repeatability was 0·32.MBS had no significant effects on weight gain of lambs. However, a moderate, positive genetic correlation was estimated between MBS and the average weight gained by lambs from birth to marking ( rg = 0·4, s.e. 0·22), although the genetic correlation estimated between MBS and weight gained to weaning was close to zero ( rg = 0·02, s.e. 0·16). Ewes with a MBS of 1 (ewe flees and does not return to her lambs) had significantly more lambs dying before marking and weaning than ewes with a higher maternal behaviour score. Selection to reduce the proportion of ewes in this category may therefore be beneficial.

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35

Friggens, N. C., T. H. McClelland, I. Kyriazakis, and M. Shanks. "An Assessment of Growth Potential in Small Sized British Sheep Breeds." Proceedings of the British Society of Animal Production (1972) 1993 (March 1993): 108. http://dx.doi.org/10.1017/s030822960002434x.

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Lamb producers in the Less Favoured Areas (LFAs) of the European Community appear, for different reasons, to be constrained by the economic value of the indigenous small-sized sheep breeds. The trial reported here forms part of a collaborative project whose overall aim is to improve the quality and marketability of sheep meat produced in the LFAs. The objective of this trial was to assess the growth potential of nine small sized sheep breeds, across three centres, providing a basis for subsequent production work. The three collaborating centres in Greece (paper no. 112), Spain (paper no. 26) and Scotland used indigenous breeds appropriate to their LFAs. The three British breeds studied were Scottish Blackface (SB), Welsh Mountain (WM), and Shetland (SH).

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Davies, G., M. J. Stear, and S. C. Bishop. "Quantitative trait loci associated with parasitic infection in sheep." Proceedings of the British Society of Animal Science 2005 (2005): 50. http://dx.doi.org/10.1017/s1752756200009613.

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Gastrointestinal nematodes cause major losses to the UK sheep industry. As anthelmintic resistance is becoming a widespread problem alternative control methods are now sought. Breeding for improved parasite resistance is a possible control method (Woolaston and Windon, 2001). As genetic markers are now widely available there is considerable potential for application to livestock breeding through quantitative trait loci (QTL) detection and subsequent marker-assisted selection schemes. Although much work is underway, there are few published studies that identify QTL associated with parasite resistance. Therefore this study aims to identify QTL associated with parasitic nematode infection in a population of Scottish Blackface lambs using faecal egg count and Immunoglobulin A activity.

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Dunne, L. D., J. J. Robinson, P. J. Broadbent, T. G. McEvoy, and D. F. Dolman. "Response to superovulation in Scottish Blackface ewes during seasonal anoestrus." Proceedings of the British Society of Animal Science 1996 (March 1996): 187. http://dx.doi.org/10.1017/s175275620059382x.

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A major limitation to the success of genetic improvement programmes using multiple ovulation and embryo transfer is the failure to generate sufficient viable embryos per donor ewe to maintain selection intensities and sustain a low generation interval. Seasonal anoestrus imposes a biological constraint on embryo production in many breeds of sheep. The objective of this study was to investigate the response to superovulation during seasonal anoestrus (April - May) in Scottish Blackface ewes.

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Dunne, L. D., J. J. Robinson, P. J. Broadbent, T. G. McEvoy, and D. F. Dolman. "Response to superovulation in Scottish Blackface ewes during seasonal anoestrus." Proceedings of the British Society of Animal Science 1996 (March 1996): 187. http://dx.doi.org/10.1017/s0308229600031536.

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A major limitation to the success of genetic improvement programmes using multiple ovulation and embryo transfer is the failure to generate sufficient viable embryos per donor ewe to maintain selection intensities and sustain a low generation interval. Seasonal anoestrus imposes a biological constraint on embryo production in many breeds of sheep. The objective of this study was to investigate the response to superovulation during seasonal anoestrus (April - May) in Scottish Blackface ewes.

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Waterhouse, A., and T. H. McClelland. "Supplementation of Scottish Blackface Gimmers During Mating and Mid-pregnancy." Proceedings of the British Society of Animal Production (1972) 1987 (March 1987): 40. http://dx.doi.org/10.1017/s0308229600034784.

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Lamb output in terms of both reproductive performance and lamb growth during lactationof hill gimmers (18 months old at first mating) is typically well below that of their multiparous contemporaries. This paper reports an attempt to evaluate the effects of supplementary feeding during the mating period and mid-pregnancy on gimmer performance.Three hundred and ninety three Scottish Blackface gimmers from two hirsels (flocks of sheep from contiguous areas of land) of Auchtertyre Farm in west Perthshire were split according to the following design.

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Conington, J., S. Watts, K. McLean, N. Lambe, and L. Bünger. "Using computed tomography (CT) to quantify bone properties in Scottish Blackface ewes." Proceedings of the British Society of Animal Science 2005 (2005): 123. http://dx.doi.org/10.1017/s1752756200010346.

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Good bone quality in breeding ewes is important for the mineralisation of foetal skeletons and to sustain maternal dentition, as tooth loss is the main reason for culling sheep in the UK. Among other functions, bone is a storage depot for calcium and other key minerals that are mobilised to meet major demands such as during lactation. As other studies in humans and poultry have shown, there is substantial genetic variation (h2 between 0.5 and 0.8) for bone properties, suggesting a similar situation in ewes. These properties, e.g. bone density, are key to successful production and nurturing of healthy lambs, which can be used in selective breeding strategies to extend breeding ewes’ productive lives. CT has been shown to be a useful method of assessing bone properties in sheep (Rubin et al., 2001). This study quantifies the main bone types in Scottish Blackface ewes and investigates environmental factors affecting bone quality.

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Curran, M. K. "Practical breeding developments and future prospects." BSAP Occasional Publication 14 (January 1990): 13–22. http://dx.doi.org/10.1017/s0263967x00002019.

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AbstractThis paper is a review of practical sheep breeding improvement schemes and techniques in the UK. Recent breed population changes in each of the broad categories of hill, longwool/crossing, longwool ewe, terminal sire and shortwool ewe breeds are outlined. Current or planned improvement programmes are reported for Welsh Mountain, Beulah, Scottish Blackface, Border Leicester, Cambridge, Friesland, Romney, Texel, Suffolk, Lleyn and Merino breeds. The techniques of genetic improvement currently available are discussed including some costs and likely genetic gains; techniques include group breeding schemes, artificial insemination, multiple ovulation and embryo transplant, best linear unbiased prediction and transgenic methods. The application of these techniques and contribution they could make to future sheep improvement are assessed.

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Thompson, R., and K. D. Atkins. "Sources of information for estimating heritability from selection experiments." Genetical Research 63, no. 1 (1994): 49–55. http://dx.doi.org/10.1017/s0016672300032079.

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SummaryMaximum likelihood estimation methods with an individual animal model were used to analyse a bi-directional selection experiment, with control, for cannon bone length in Scottish Blackface sheep. A method is described for partitioning the likelihood to allow within- and between-line estimates of genetic variance. It is concluded that both sources of information made substantial contributions to the precision of the base population heritability estimate. The implications for different experimental designs and varying heritability are discussed.

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SPEAKE, B. K., R. C. NOBLE, J. BRACKEN, and S. C. BISHOP. "Responses in plasma free fatty acid composition to divergent selection for predicted carcass lean content in sheep." Journal of Agricultural Science 129, no. 2 (1997): 193–98. http://dx.doi.org/10.1017/s0021859697004607.

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The fatty acid composition of the plasma free fatty acid and adipose tissue triacylglycerol fractions was determined in lean and fat selection lines of Texel-Oxford and Scottish Blackface sheep at the 6th year of divergent selection. The mean proportion of 18[ratio ]2n-6 in the triacylglycerol of subcutaneous backfat was 1·3-fold higher in the phenotypically fatter sheep in the fat lines than in the phenotypically leaner sheep in the lean lines. Regression analysis indicated a positive relationship between this fatty acid and backfat depth whereas the proportion of 18[ratio ]1n-9 in the tissue triacylglycerol was negatively related to fatness. The proportions of 18[ratio ]2n-6 and of other polyunsaturated fatty acids in the plasma free fatty acid fraction were much higher than in adipose triacylglycerol. For the Scottish Blackface sheep in the fed state, the mean proportion of 18[ratio ]2n-6 in plasma free fatty acid (measured on all sheep) was 1·4-fold greater in the fat line than in the lean line. Regression analysis indicated a positive relationship between the plasma content of this fatty acid and backfat thickness whereas the proportion of 18[ratio ]1n-9 in plasma free fatty acid showed a negative relationship with fatness. The relationship between the plasma proportion of 18[ratio ]2n-6 and fatness was not observed after 48 h of fasting; instead, the plasma proportion of 18[ratio ]0 was found to be positively related to fatness in the fasted state. In summary, this paper shows how plasma and adipose tissue fatty acid profiles differ, and it quantifies the effects of selection on the plasma profiles. Possible reasons for the difference in fatty acid profiles between adipose tissue and plasma are discussed in the paper. It is suggested that plasma 18[ratio ]2n-6 levels during the early post-weaning growth period should be investigated as indicators of future fatness.

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Haresign, W., B. Merrell, and R. I. W. A. Richards. "Multiple Ovulation and Embryo Transfer in Hill Ewes." Proceedings of the British Society of Animal Production (1972) 1994 (March 1994): 88. http://dx.doi.org/10.1017/s0308229600026350.

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A breed improvement programme has been initiated at both ADAS Redesdale (Scottish Blackface) and ADAS Pwllpeiran (Welsh Mountain) to improve carcass conformation of hill ewes. From a base population of 1100 Welsh Mountain and 1600 Scottish Blackface ewes, nucleus flocks of 60 ewes have been established. Selection of ewes into the nucleus flock at each site has been based on their ability to consistently produce wether lambs crops with good conformation and above average carcass weights when selected for slaughter at a fat class 2/3L. The next objective is to replicate these ewes through multiple ovulation and embryo transfer (MOET) since theoretical studies (Smith, 1986) indicate that this can substantially increase the rates of genetic improvement through the female line. However, to date little work has been conducted to determine whether this technology can be successfully applied to hill sheep maintained in harsh hill environments in the UK, and this formed the basis of the current study.

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45

Duncan, A. J., B. Roncin, and D. A. Elston. "Effect of blood glutathione status on the susceptibility of sheep to haemolytic anaemia induced by the brassica anti-metabolite, dimethyl disulphide." Animal Science 60, no. 1 (1995): 93–98. http://dx.doi.org/10.1017/s1357729800008183.

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AbstractThe effect of erythrocyte glutathione status and breed on the susceptibility of adult female sheep to the haemolytic anaemia caused by the brassica anti-metabolite dimethyl disulphide (DMDS) was determined in a factorial experiment. Within each breed (Scottish Blackface or Finnish Landrace), six sheep of low glutathione status (<30 mg/100 ml red blood cells (RBC)) and six sheep of high glutathione status (>70 mg/100 ml RBC) were dosed twice daily with DMDS for 35 days (25 mmol per head per day). All sheep developed a classic haemolytic anaemia within 2 weeks of the start of DMDS dosing. Weekly haemoglobin concentrations and packed cell volume values were not affected by breed or glutathione status. Heinz body numbers rose to a higher maximum in low glutathione animals but were not affected by breed. The results call into question the relationship between total erythrocyte glutathione concentration and the resistance of erythrocytes to oxidative damage.

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Hadjipavlou, G., and S. C. Bishop. "Age-dependent quantitative trait loci affecting growth traits in Scottish Blackface sheep." Animal Genetics 40, no. 2 (2009): 165–75. http://dx.doi.org/10.1111/j.1365-2052.2008.01814.x.

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Ryder, M. L. "25—CROSS-BREEDING STUDIES WITH SELECTED FLEECE LINES OF SCOTTISH BLACKFACE SHEEP." Journal of The Textile Institute 76, no. 5 (1985): 362–76. http://dx.doi.org/10.1080/00405008508658946.

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Bünger, L., E. A. Navajas, L. Stevenson, et al. "Muscle fibre characteristics of two contrasting sheep breeds: Scottish Blackface and Texel." Meat Science 81, no. 2 (2009): 372–81. http://dx.doi.org/10.1016/j.meatsci.2008.08.017.

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Bishop, S. C. "Genetic relationships between predicted and dissected carcass composition in Scottish Blackface sheep." Animal Science 59, no. 3 (1994): 421–27. http://dx.doi.org/10.1017/s0003356100007947.

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Carcass composition was measured on 133 Blackface ram lambs from a flock divergently selected for predicted carcass lean proportion. Prediction equations for different carcass components were developed using combinations of live weight and ultrasonic backfat and muscle depth. Both carcass lean and carcass fat proportion were best predicted using only live weight and fat depth, and a genetic transformation of the equation predicting carcass lean proportion was highly correlated (genetic correlation = 0·97) with the index on which the sheep were selected. Weights of carcass tissues were more accurately predicted than proportions. Lean weight was best predicted using live weight and muscle depth, and the weights of different fat components were best estimated using live weight, muscle depth and fat depth.The equations predicting carcass lean proportion, carcass fat proportion, lean mass and fat mass had heritabilities of 0·29, 0·27 0·20 and 0·23, respectively. Heritabilities for carcass lean and carcass fat proportions, and the subcutaneous and intermuscular fat components were 0·43, 0·48, 0·24 and 0·49, respectively. Genetic correlations of the equation predicting carcass lean proportion with lean and fat proportions were 0·52 (s.e. 0·21) and –0·45 (s.e. 0·22), respectively. The same correlations for the equation predicting carcass fat proportion were –0·47 (s.e. 0·22) and 0·57 (s.e. 0·21). The equations predicting carcass lean and fat proportions were strongly correlated with subcutaneous fat proportion but weakly genetically correlated with intermuscular fat proportion.

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Sharpe, A., M. McElroy, H. Bassett, and T. Sweeney. "Clinical and pathological features of experimental scrapie in Irish Blackface Mountain sheep." Research in Veterinary Science 80, no. 1 (2006): 71–78. http://dx.doi.org/10.1016/j.rvsc.2005.04.005.

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Journal articles on the topic 'Blackface sheep'

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