Hill Sheep Research Articles

Initial responses to selection for fibre value and fibre diameter in cashmere goats

The production of cashmere from goats is one of the most promising options for hill sheep farmers wishing to diversify. Not only is cashmere, the down from the secondary hair follicles, a valuable commodity but goats’ grazing preferences can benefit pasture management and ecology. Because no economically viable breeds of cashmere bearing goats are indigenous to the UK, goats were imported from Iceland, Siberia, Tasmania and New Zealand and an extensive crossbreeding programme involving these genotypes and native feral goats was undertaken to produce genotypes suitable to Scottish conditions (Bishop and Russel, 1994). At the completion of this crossbreeding programme the best means of continued improvement of the existing cashmere goat population was considered to be selection for genetic merit, based on an index combining traits of economic importance. This paper summarises responses to the first two years of this selection.

Parasite control in transhumant situations

Transhumance is defined as ‘seasonal moving of livestock to regions of different climate’. It is an integral part of livestock production in many parts of the world and takes several forms including moving of livestock from lowland to mountainous pastures or from dry to humid areas. The impact of transhumance on parasite populations of livestock and on parasite control is described, mainly using examples from Europe. The epidemiology of trichostrongylidosis of cattle, mainly caused by Ostertagia ostertagi and Cooperia oncophora, is characterised by prolonged survival of overwintered infective larvae until the end of June. Cattle moved to such contaminated pastures in a transhumant grazing system are exposed to these larvae and may be protected, during the second half of the grazing season until autumn, by a late application (June/July) of an intraruminal drug-release device. Community pastures used in a transhumant system with mixed grazing of young cattle originating from various farms may enhance transmission of dictyocaulosis. Therefore, specific prophylactic measures are required. Hill sheep nematode populations may differ from those in lowland sheep in the Haemonchus contortus generally plays a minor role in hill sheep in which Ostertagia circumcincta and Nematodirus spp. predominate. Infections with Fasciola hepatica and Dicrocoelium dendriticum can be acquired on mountainous pastures by cattle, sheep and other livestock grazing in a transhumant system as intermediate hosts of these parasites may find suitable habitats in these regions. There is evidence that in the prealpine and alpine area both parasites are mainly transmitted in two-season cycles. Further examples for the impact of transhumance on parasite-host inter-relationships include cysticercosis in cattle, echinococcosis, psoroptic mange in sheep, tick-borne fever of cattle, and hypodermosis in cattle. These are described and discussed.

Multiple Ovulation and Embryo Transfer in Hill Ewes

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.

The effects of shepherding and nutritional inputs in an extensive hill sheep system

There is increasing pressure on hill farmers to reduce stock numbers on the hills. With such a reduction in sheep numbers, farmers would have the option of either maintaining or reducing management and physical inputs. In general, current extensive hill sheep farming systems are characterised by low stocking densities, low inputs and high lamb mortality.The trial was conducted as part of a work programme studying extensive systems. Compared to a system with very low inputs this trial examined the effects of increasing inputs, in terms of supplementary feeding in late pregnancy and shepherding at lambing.Within an extensive hill fanning system (0.66 ewes/ha) two hundred ewes were allocated to one of two nutritional treatments in late pregnancy together with the provision or absence of shepherding at lambing in a 2x2 factorial design. All the ewes were of the Scottish Blackface breed and were mated on the open hill without access to improved grazing. Ewes remained on the hill until mid-pregnancy at which stage they were assigned to either Group H (supplementation with feedblocks, low forage availability) or Group L (minimal supplementation, high forage availability). Group L continued to graze on the open hill whilst Group H were confined to a hill park (approximately 45 ha).

Opportunities for genetic improvement of sheep and cattle in the hills and uplands

AbstractThe principles of genetic improvement apply to hill sheep and cattle in just the same way as they apply to other livestock species. However, the breeding goals often differ, and will continue to change in the light of new economic and political circumstances. Also, there are particular problems of implementing breeding programmes in some of these areas, which do not apply to other livestock species. In this paper we aim to review or discuss (i) the current structure of the livestock industry in the hills and uplands, (ii) strategies for genetic improvement, (iii) the results of relevant selection experiments and industry breeding schemes, (iv) some of the difficulties of implementing breeding programmes and possible solutions, and (v) new opportunities for the genetic improvement of animals in the hills and uplands.

Potential of different sheep breeds to improve wool production on UK hill and upland sheep farms

Ninety-four sets of data on wool characteristics and mature live weight of more than 50 sheep breeds and crosses were studied to examine the potential for increased financial returns from wool on hill and upland farms in the UK. Within each of the four main breed groups (Australian Merino, European Merino, UK breeds and Australian Merino-UK breed crosses), annual clean wool weight per unit metabolic live weight was positively related to mean fibre diameter, indicating a negative relationship between wool quantity and quality. However, each breed group had different productivity characteristics, with the Australian Merinos having a high annual production (135–230 g/kg BW 0.75) of 19–27 μm diameter wool. British breeds grew only 30–130 g/kg BW 0.75 of 25–46 μm wool. Crosses between these two groups were intermediate in wool quality and quantity. European Merinos grew 55–135 g/kg BW 0.75 of 20–34 μm wool. Although wool prices are subject to large variations, the general relationship between price and quality is such that at fibre diameters greater than 20–22 μ, increased financial returns are achieved through increased fleece weight, whereas at fibre diameters of less than 20–22 μm increased returns stem from improved quality. The data suggest that crossing the finest of Australian and British breeds, i.e., the Saxon or Tasmanian fine-wool Merino and Shetland, could significantly increase financial returns from wool on UK hill and upland farms. This is supported by preliminary results from wool samples taken from such crossbred sheep.

Superovulatory responses of hill ewes

There is a clear need to improve financial returns from hill sheep to help maintain rural populations in hill/upland areas while at the same time reducing the reliance of hill sheep farmers on social/production type subsidies. Particular problems with hill sheep are their small carcass size and poor conformation, which result in reduced values for both draft ewes and wether lambs. These poor carcass attributes are also passed down to the lowland producer through the production of poor conformation halfbred ewes out of hill ewes. With the increasing pressures being placed on the lowland sector to improve carcass quality, many producers are beginning to look at the possibility of breeding their own replacement top-cross ewes. Any widespread adaption of this practice will further undermine the profitability of sheep production in the hill and upland sectors.

Environmental and genetic influences on hill lamb performance

Fat reserves are often perceived as essential to the hill ewe, so that they may be mobilised in adverse conditions to meet energy deficits. However, deer and some primitive breeds of sheep are remarkably lean animals which survive and thrive/reproduce in such conditions. The consequence of using genetically lean sheep in hill environments to meet the ultimate goal of reducing carcass fat is largely unknown. It is possible that the ewes' maternal ability, performance and welfare are in some way compromised. An SAC/IAPGR Hill Sheep Project was instigated: (1) to investigate if selection for differing fat levels under intensive concentrate feeding has any effect on progeny reared in extensive situations; (2) to determine the relationships between growth, carcass, reproduction, wool and survival traits, and to investigate which traits would be useful in an index of overall merit; and (3) to investigate if selection for improved carcass and growth characteristics affect maternal performance and survivability.

Strategies to avoid parasitic gastro-enteritis in an intensive organic hill sheep system

In hill sheep systems, a major concern for health and welfare is for lambs grazing improved land at higher stocking rates and succumbing to parasitic gastro-enteritis. With only a small amount of improved land available, there is little or no scope for ‘clean grazing’ systems as access to this better land is crucial on an annual basis to achieve better performance from the flock. Access at lambing and at ewe mating is of particular value. There may however be some scope for reduced parasitic challenge to lambs during the summer grazing period because of the differential in stocking densities between the hill and the improved grazings.

Potential systems for increasing income from wool in hill and upland sheep flocks in the UK

A study was undertaken to examine the probable outcome of attempts to improve the financial returns from UK hill and upland sheep enterprises by increasing the quantity of higher quality, i.e. finer, wool produced through the use of the Merino, either as a purebred or in crosses with native breeds. Six hill and seven upland systems of sheep production based on a wide range of costs and prices were considered. The results show that the use of Australian fine-wool Merinos or Merino-crossbreds within the traditional stratified UK lamb production systems is unlikely to have any marked financial benefits. On hill farms intensively managed purebred Australian Merinos and an extensively managed fixed cross between Australian Merinos and the hardy native Shetland breed could be expected to increase gross margins by 9% and 6%, respectively. On upland farms the use of European Merino rams could improve gross margins by 6%. The greatest probable increase in gross margin of 33% could come from an intensively managed purebred Australian fine-wool Merino flock, but fixed costs in terms of housing and labour are also likely to be high. The development of a synthetic breed based on a cross between a native breed with the finest wool and Australian Merinos could produce wool of a quality sufficient to attract a substantial premium and without any significant increase in costs. The pursuit of such a development for hill farms is advocated.

Reducing lamb mortality in hill sheep

Lamb mortality is high in hill farming systems. This is not a new phenomenon. Orr and Fraser (1932) reported losses of lambs between birth and weaning of over 30% and indeed an annual ewe death rate of up to 24%.Poor nutrition, of both macro- and micro-nutrients, is a prime cause of this problem exaggerated by difficult environmental conditions at the time of birth. Improved nutrition during late pregnancy was believed to be the most important (Wallace, 1948) and nutrition during mid pregnancy received scant attention. However, applied experiments with mid-pregnancy feeding of hill ewes (Milne, 1984; Waterhouse and McClelland, 1987) showed very significant effects of better nutrition during this period. The present paper summarizes the implementation of improved mid-pregnancy nutrition in a monitored systems study, associated with changes in management in late pregnancy made possible by assessment of foetal numbers from ultrasound pregnancy scanning.

The effects of increased prolificacy on lamb and ewe mortality in an intensive hill sheep system

Increased prolificacy is often believed to increase the incidence of both lamb and ewe mortality especially in harsher environments. Fecundin® (Coopers Pittman Moore) is a vaccine which leads to immunization against androstenedione and a resulting increase in prolificacy (Rhind, 1987). The use of this drug gives a method of manipulating prolificacy without confounding any effects with improved nutrition, the most usual means of modifying reproductive success.A programme was commenced in 1985 in which half the ewes in a flock of Scottish Blackface ewes was vaccinated with Fecundin (F), the remainder left unvaccinated (N). In subsequent years ewes were maintained on the same treatment. The data presented here are an analysis of a single age group of ewes completing a full lifetime on each treatment. Eighty-five ewes were allocated at random to each treatment. These were vaccinated in autumn 1985, given a booster vaccination 4 weeks pre-ram joining in 1986, 1987 and 1988 and sold as ‘cast for age’ after lamb weaning in 1989. With the exception of injection with Fecundin, at all times management was independent of treatment.

Effects of cobalt deficiency in the pregnant ewe on neonatal lamb survival

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.

Britain's Declining Heather Moorlands

Heather moorland is a valuable resource in the hills of Britain. It is of high conservation value, can be an important source of winter fodder for hill sheep and is essential for the maintenance of grouse populations. There is evidence, however, that over the last 40 years the amount of heather moorland has been declining not just because of the expansion of plantation forestry and the increase in improved land but also because of changes in land management practices. These changes have been brought about by the changing economic climate and can only be reversed by the use of public money targeted with this problem in mind. Any such schemes will have to include incentives to land managers to set acceptable stocking rates and to manage stock in a way that does not damage heather. As an aid to determining such management systems on a farm-specific basis, a computer model has been built at the Macaulay Land Use Research Institute. The model is currently being improved and has the potential to be used as an integral part of any incentive scheme.

Valuations of Scottish hill sheep stocks before 1946

Valuations of Scottish hill sheep stocks before 1946

Mother-daughter and peer relationships of Scottish hill sheep

Observations were made on the behaviour of juvenile ewes in a home-range group of Scottish hill sheep, Ovis aries. The group, including the juvenile ewes, remained on the hill throughout the year. In contrast to previous studies of hill sheep, whilst the juveniles remained in their natal group, their associations with their mothers declined from about 6 months of age onwards. There was no indication of any recovery in the mother-daughter bond by the end of the study. In this respect the present study concurs with other work on populations of feral and wild sheep. Whilst associations with mothers declined, the preference for peers increased in autumn and strengthened considerably in winter, as the juveniles formed peer groups that moved independently of older ewes. Peer associations declined the following summer as the juvenile ewes again became integrated into the larger group. Although juveniles did not associated with their mothers, cluster analysis of movement patterns showed that at 1 year old they tended to develop summer ranging behaviour similar to their mothers. It is suggested that separation from the mother and the development of relationships with peers have arisen in sheep as these social processes facilitate the formation and cohesion of large home range groups with the benefits that larger group sizes confer.

Serum vitamin B 12 and methylmalonic acid determinations in the diagnosis of cobalt deficiency in pregnant ewes

Serum vitamin B 12 and methylmalonic acid (MMA) concentrations were used to monitor the development of cobalt (Co) deficiency and repletion from the deficient state in housed pregnant hill sheep. Serum MMA concentrations were less variable and provided a more accurate diagnosis of Co deficiency than serum vitamin B 12. This was particularly the case for subclinical disease. However, unlike serum MMA, concentrations of the vitamin in serum could be used prognostically. The most precise diagnosis was provided by serum vitamin B 12 and MMA data used in conjunction, but where one technique is to be used, serum MMA determinations are preferred.

A selection Index for hill sheep

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.

Reproductive and kid performance of a newly established feral goat herd being graded up for cashmere production

Interest in farming goats for cashmere production has recently arisen, both as a means of farm diversification and, through goats grazing preferences, to utilise previously under exploited resources on hill farms.A herd of 160 feral does of Irish and Scottish origin was established at the West of Scotland College's Kirkton Unit in June 1987 to investigate the potential for cashmere production from goats on a hill sheep farm. The Irish goats are of mixed ancestry with obvious dairy crossbreds in addition to many of more feral phenotype. The Scottish feral does came as an established group but proved excitable and difficult to handle. Whenever goats were grouped together for handling or at feeding points there was considerable fighting and other agonistic behaviour. A year later the level of this has reduced.One hundred and fifty eight does were divided into four groups and oestrus synchronised (goats sponges 45 mg progesterone supplied by Intervet). These were then artificially inseminated by laparoscope in two, two day sessions a week apart (21/10, 22/10, 29/10 and 30/10).

Suckling in intensively housed lowland sheep compared to extensive hill sheep

Suckling in hill sheep (Swaledale/Scottish Blackface) grazed extensively (15-40 ewes ha-i) was compared with that in lowland sheep (Mule/Texel/Suffolk) penned indoors (0.5 ewe m-~). Individual ewes and their lamb(s) were observed within the flock for 2.5 h continuously at 2 and 5 weeks of age. Lambs reared extensively very rarely sucked at any ewe other than their mother. In contrast, 20% of suckling attempts on ewes raising single lambs indoors were by alien lambs. Most of these intrusions by aliens achieved little successful suckling, but a significant number were sustained and they frequently disrupted ongoing suckling of the ewe's own lambs. Other causes of suckling termination in intensive conditions that were rare outdoors included aggression towards lambs and interference by other ewes. Furthermore, the tendency for the suckling of twin lambs outdoors to be synchronized was disturbed, with a lower proportion of the total suckling time involving the simultaneous presence of both lambs. As a consequence of these disturbances of suckling indoors, a lower proportion of suckling periods initiated were sustained and a higher proportion of initiations failed to achieve any successful suckling. However, the frequency of initiation of suckling periods was slightly higher indoors and those sucklings that were not disturbed tended to last longer. As a result, the total suckling time was greater in intensive than in extensive conditions. Though possible breed differences in lactational physiology preclude an unequivocal conclusion, this suggests that the various disturbances of suckling that occur in intensive conditions may be compensated for by more frequent initiations and more sustained suckling periods when they are not disturbed.