Sleep has been shown to impact on both physical and mental health, and sleep problems present a considerable burden for individuals and society. There appears to be a complex bidirectional relationship between sleep disturbance and psychiatric symptoms, each potentially influencing the other. In particular, sleep disorders have been associated with more severe symptoms and are predictive of relapse in those with psychotic disorders. This article discusses the relationship between psychosis and insomnia, sleep apnoea, nightmares, circadian rhythm abnormalities and the impact of medications on these relationships. We also discuss the clinical implications of the relationship between sleep disturbance and psychotic disorders along with potential targets for intervention.

A detailed survey was undertaken to assess the rate of production and current management practices on Irish sheep farms and quantify their associations with flock size and ewe breed type. A total of 39 questions relating to the farm production system and farm management practices were devised, including: producer age, location, farm size, livestock numbers and type, in addition to flock management data such as flock breeding policy, lamb finishing strategy, flock health, lambing date, winter housing and feeding practices. A total of 717 sheep producers were surveyed across 45 different discussion groups. The surveyed respondents were sub-divided into four groups depending on flock size (very small, small, medium and large) and into three groups depending on ewe breed type (maternal, terminal and hill). The average survey respondent was 48 years old, with a flock size of 150 breeding ewes on a farm size of 58 ha. The average stocking rates were 6·55 and 3·14 ewes/ha and weaning rates were 1·44 and 1·02 lambs per ewe joined to the ram for the lowland and hill flocks, respectively. Relative to very small flocks (<62 ewes), larger flocks (>190 ewes) had higher stocking rates (6·98 v. 5·66 ewes/ha) and ewe to ram ratios (40 v. 30), and tended to lamb later in the year. The rate of technology adoption such as faecal egg sampling and pregnancy scanning was greater on larger flocks compared with smaller flocks. Flocks with maternal ewe breeds had higher scanning and weaning rates, and drafted a greater proportion of lambs off grass compared with flocks with terminal and hill ewe breeds. Flocks with maternal and terminal ewe breed types were more likely to winter house ewes, lamb indoors, test silage quality and have a handling unit compared with flocks with hill-type ewe breeds. Results from the present study provide a bank of knowledge on current Irish sheep industry performance and show that flock size and ewe breed type have a significant impact on key flock performance variables.

An experiment was conducted to determine: (1) the effect of excess maternal I supplementation on the thyroid hormone status of the ewe and her progeny; (2) potential mechanisms underpinning the failure of passive transfer associated with excess I and (3) the growing lambs’ response to natural gastrointestinal infection. Twin-bearing ewes received one of two treatments (n 32/treatment group): basal diet (C) or C plus 26·6 mg of iodine/ewe per d (I), supplied as calcium iodate. Ewes were individually fed from day 119 of gestation to parturition. Progeny of I ewes had lower (P<0·01) serum IgG concentrations from 24 h to 28 d postpartum but higher serum IgG concentrations at day 70 postpartum (P<0·05). I supplementation increased the relative expression of Fc receptor, IgA, IgM high affinity and polymeric Ig receptor in the ileum of the lamb at 24 h postpartum; however, thyroid hormone receptor-β (THRB) and β-2-microglobulin (B2M) expression declined (P<0·05). Progeny of I ewes had higher growth rates to weaning (P<0·05) and lower faecal egg count (FEC) for Nematodirus battus (P<0·05) between weeks 6 and 10 postpartum. In conclusion, excess maternal I supplementation negatively affected the thyroid hormone status, serum IgG concentration, ileal morphology and the gene expression of THRB and B2M in the ileum and ras-related protein (RAB) RAB25 and the mucin gene (MUC) MUC1 in the duodenum of the lamb postpartum. These effects were followed by an enhancement of average daily gain and lower N. battus FEC in the pre-weaning period of I-supplemented lambs.

Three hog genotypes are simulated to determine how producer profits, economically optimal slaughter weights, and carcass component weights change under three pricing models. Live weight pricing pays more for the fatter barrows whereas a three component (separate payments for fat, lean, and byproducts) and six component (separate payments for major primal cuts, other lean, fat, and byproducts) pricing system pay more for the leaner gilts. Implications for selection of genetic stock and pricing system are presented.

The Orlock Bridge Fault separates the Ordovician and Silurian turbidite sequences within the Southern Uplands thrust belt. A large biostratigraphical break and the 1 km wide sinistral Slieve Glah Shear Zone associated with the fault in northern Ireland led to previous interpretation as a major regional structure, possibly a terrane boundary. In Scotland, however, the stratigraphical break is much less and an association with inliers of the Moffat Shale Group suggests that the fault is essentially similar to the other tract-bounding faults which originated as syn-D1 thrusts within the imbricate stack. Localized sinistral deformation apparent along the trace of the Orlock Bridge Fault in southwestern Scotland, associated with post-1 reactivation, is comparable to that seen at Slieve Glah. Further east, a broad zone (up to 8 km) of sinistral ductile deformation, the Moniaive Shear Zone, is recognized adjacent to the Orlock Bridge Fault over a strike length of about 100 km. However, this zone differs from the Slieve Glah Shear Zone in its width and its location relative to the fault, suggesting that it is not simply related to the fault but represents a more regional deformation. Sinistral reactivation of the Orlock Bridge Fault was possibly initiated in the Wenlock during the peak of sinistral shear at the thrust front, although it may have developed over a long time contemporaneously with, but locally post-dating, the Moniaive Shear Zone. The latter deforms porphyroblasts with the thermal aureole of the c. 392 Ma Cairnsmore of Fleet granite pluton, which was emplaced into and largely post-dates the shear zone, but is deformed by the Orlock Bridge Fault. Major dip-slip reactivation of the fault post-dates the Moniaive Shear Zone and regional metamorphism and probably occurred in the Carboniferous or Permian. There is some evidence for a deep crustal feature coincident with the Orlock Bridge Fault, possibly the boundary between different crustal blocks in the collage of terrane fragments accreted during the final closure of Iapetus, which may explain the unusual extent of the reactivation of the Orlock Bridge Fault within the allochthonous Southern Uplands thrust stack. However, the situation of the fault within the Southern Uplands terrane and, in Scotland, the biostratigraphical evidence of no major stratigraphical break across the fault and the lack of any clear relationship between the Orlock Bridge Fault and the Moniaive Shear Zone indicate that the fault should not be regarded as a terrane boundary.

Efforts have been made to control the oestrous cycle of ewes so that breeding can be induced at most times of the year (Gordon, 1963, 1975; Cognie, Hernandez-Barreto & Saumande, 1975; Smith, Boland & Gordon, 1981). Despite a high oestrous response, conception rates have generally been low in lactating anoestrous ewes (Hunter, 1968; Land & McClelland, 1971; Cognie et al. 1975; Shevah, Black & Land, 1975). The ability to achieve conception in post-partum ewes appears to be related to season, breed and lactational status (Cognie et al. 1975; Evans & Robinson, 1980; Rhind et al. 1980). Early research has shown that conception rates of 90% can be achieved in Finnish Landrace × Dorset Horn ewes using exogenous hormones, early weaning and artificial lighting (Robinson, Fraser & McHattie, 1975). Subsequent studies have shown that similar results can be obtained under natural daylight conditions provided that each ewe received pregnant mare serum gonadotrophin (PMSG) at the time of sponge withdrawal (Fraser el al. 1976). Some breeds of sheep may be induced to lamb at 6-month intervals, when maintained under ideal conditions including artificial lighting (Evans & Robinson, 1980). There seems to be some conflict in the literature as to factors affecting conception rate in ewes. Kann & Martinet (1975) have shown that it is the problem of suckling rather than lactation that is responsible for the delay in return to normal reproductive activity. It has been shown that luteinizing hormone (LH) release is quantitatively less in lactating than in cyclic ewes (Cognie & Pelletier, 1976; Evans, 1980). Also the pattern of LH production has been shown to differ in ewes conceiving and those which fail to conceive (Rhind et al. 1980). Cognie & Pelletier (1976) have suggested that in lactating ewes, a proportion of eggs are shed abnormally late in relation to the LH surge and may not be fertilized. The purpose of the present experiment was to investigate some of the factors which may influence the induction of pregnancy in nursing ewes in the non-breeding season.

It has been shown (Gordon, 1975) that certain progestagens administered intravaginally can be highly effective in the control of oestrus, ovulation and fertility in ewes. Prostaglandin (PGF2α) when infused into the uterine vein ipsilateral to the ovary containing the corpus luteum has been shown to result in luetolysis and a return to oestrus in a high proportion of ewes (Hearnshaw, Restall & Gleeson, 1973). Synthetic analogues of PGF2α have also been shown to have a marked luteolytic effect in ewes (Baird & Scaramuzzi, 1975). Variable fertility has been reported following the use of prostaglandin or its analogue for oestrous synchronization (Jennings, 1975; Haresign, 1976; Fairnie, Cumming & Martin, 1976; Lightfoot, Croker & Marshall, 1976; Trounson, Willadsen & Moor, 1976). Low fertilization has been reported after the use of a prostaglandin analogue and artificial insemination at a predetermined time in ewes (Boland, Gordon & Kelleher, 1978). The purpose of the present experiment was to extend these observations, using a ram in natural service after employing a double prostaglandin injection regime or an intravaginal progestagen treatment for the control of oestrus in cyclic sheep.

In the first of two experiments 45 ewes were treated on day 141 of gestation with either prostaglandin F2a or saline. Doses of 10, 15, 20 or 25 mg PGF2a failed to induce lambing earlier than in control animals. A further 50 ewes were similarly treated on day 144; neither dose level of PGF2a nor day of administration had any effect on the interval from injection to lambing compared with controls. In a second experiment 159 ewes were randomly assigned to one of four treatment groups as follows: (1) 20 mg oestradiol benzoate (ODB); (2) 16 mg dexamethasone; (3) 15 mg PGF2a; (4) 2 ml saline. Ewes were injected on either day 143 or 144 of gestation and on each of those days animals were injected either in the morning or evening. The mean times to induction of lambing were 38·6 ± 20·8; 44·2 ± 18·1; 83·5 ± 39·8 and 82·9 ± 43·1 h for the four treatments respectively. Neither day nor time of treatment had any significant effect on the interval to lambing. Both ODB and dexamethasone induced parturition earlier than PGF2a or saline (P < 005).

In exploiting to the full the possible advantages of a synchronized oestrus in ewes, the mating management of the ram requires special attention. Previous recommendations (Gordon, 1963) on ram management stated that progestagen-PMSG synchronized ewes should be run with rams at a ram to ewe ratio of 1:10 in the days following treatment. Preliminary work from this laboratory has shown that delaying the introduction of rams until 48 h following sponge withdrawal could improve conception rates significantly (Joyce, 1972). The purpose of the present experiment was to investigate further the effect of time of ram introduction on ewe fertility following oestrous synchronization.

Quantitative information concerning preejaculation sexual preparation of bulls was published some years ago by Collins, Bratton & Henderson (1951), who concluded that about 40% more motile sperm could be obtained by imposing one false mount before ejaculation. It had been suggested that one false mount in bulls is essentially as efficient as two such attempts in terms of sperm output (Branton, D'Arensbourg & Johnston, 1952). More recently Hafs, Knisely & Desjardins (1962) have shown that bulls given a planned 5 min sexual preparation yielded 30% more sperm than those given no preparation. Similarly 10 min preparation resulted in a 12% increase in sperm output when compared with a 5 min preparation. These authors also showed that zero, one, two or three false mounts significantly affected motile sperm output.

It is now possible to synchronize the cycle of ewes at all times of the year (Gordon, 1975). Conception rates approaching those obtained following natural service have been reported following double (Colas & Brice, 1970; Colas et al. 1973; Barlow, Pryce-Jones & Reed, 1974; Gordon, 1975) or single (Smith, Boland & Gordon, 1978) set-time inseminations. In France, synchronization of ewes' oestrous cycle is based on the use of a Cronolone pessary (Colas, 1975), while field trials conducted in Britain have used the 60 mg Medroxy progesterone acetate (MAP) sponge (Barlow et al. 1974). Robinson et al. (1967) in an evaluation of different progestagen treatments found MAP to be less predictable than Cronolone. The purpose of the present experiment therefore was to evaluate the use of a 30 mg Cronolone or a 60 mg MAP intravaginal treatment when used in conjunction with fixed-time inseminations. In addition, two dose levels of pregnant mare serum gonadotrophin (PMSG) were compared.

Research has shown that it is now possible to control the oestrous cycle of ewes with a high degree of precision (Robinson et al. 1967; Gordon, 1975; Boland, Kelleher & Gordon, 1978). There is general agreement that a high concentration of progestagen, followed by rapid withdrawal and adequate ovarian stimulation is necessary for acceptable fertility (Robinson et al. 1967; Gordon, 1975; Colas, 1975). Application of artificial insemination in France has involved the use of a 40–45 mg Cronolone sponge (Cognie, Mariana & Thimonier, 1970; Colas et al. 1973) while controlled breeding in sheep in Ireland has been used in conjunction with a 30 mg Cronolone pessary (Gordon, 1975; Smith, Boland & Gordon, 1978, 1981). The present experiment was designed to compare the relative effectiveness of two doses of Cronolone (30 or 45 mg) when administered in conjunction with two quantities(375 or 750 i.u.) of pregnant mare serum gonadotrophin (PMSG), given by intramuscular injection.

With the development of effective methods of oestrus synchronization (Gordon, 1975), it is now possible to breed ewes at most times of the year. Encouraging conception rates have been reported following insemination (Colas & Brice, 1970; Colas et al. 1973; Gordon, 1975). A major disadvantage with the technique is the need to inseminate ewes twice at 10–14 h intervals. Because of the anatomy of the ovine cervix, it is not possible to deposit semen in the uterus as in the bovine. The present experiment was designed to compare a single or double insemination with natural service. Two types of inseminating gun were employed in an effort to deposit semen deep in the cervical folds.

Oestrus and ovulation was controlled by progestagen-impregnated sponges in 279 adult dry ewes in late anoestrus: at pessary withdrawal, ewes received doses of 0, 250, 500 or 750 i.u. pregnant mare serum gonadotrophin (PMSG). Rams were introduced to half the number of ewes which did not receive PMSG at the time of sponge withdrawal and to the remainder 48 h later. A significantly lower (P < 0·05) oestrous response was observed in ewes which did not receive PMSG but were introduced to rams at 48 h, when compared with ewes introduced to rams at time of sponge withdrawal. With iams introduced at 48 h a greater precision of synchronization was achieved by the use of PMSG (P < 0·05). Differences in conception rates were not evident between the various treatment groups, but a significantly higher (P < 0·05) litter size followed the use of the 750 i.u. PMSG dose.