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Pharmacological interventions for treating posttraumatic stress disorder in Canadian Armed Forces (CAF) members and Veterans often achieve modest results. The field of pharmacogenetics, or the study of how genes influence an individual’s response to different medications, offers insight into how prior knowledge of gene-drug interactions may potentially improve the trial-and-error process of drug selection in pharmacotherapy, thereby improving treatment effects and remission rates. Given the relative recency of pharmacogenetics testing and sparse research in military samples, we used pharmacogenetics testing in a small pilot group (n=23) of CAF members and Veterans who were already engaged in pharmacotherapy for a service-related mental health condition to better understand the associated opportunities and challenges of pharmacogenetics testing in this population. Our preliminary evaluation involved: (1) reporting the prevalence of pharmacogenetics testing ‘bin’ status according to participants’ reports (‘green’, ‘yellow’ or ‘red’; intending to signal ‘go’, ‘caution’ or ‘stop’, regarding the potential for gene-drug interactions); (2) calculating the percentage of currently prescribed psychotropic medications that were assessed and included in the reports; (3) evaluating whether prescribers used pharmacogenetics testing information according to clinical notes and (4) collecting informal feedback from participating psychiatrists. While pharmacogenetics testing appeared to provide valuable information for a number of clients, a major limitation was the number of commonly prescribed medications not included in the reports.

Biosolids (processed human sewage sludge), which contain low individual concentrations of an array of contaminants including heavy metals and organic pollutants such as polycyclic aromatic hydrocarbons (PAH), polychlorinated biphenyls (PCB), and polychlorinated dibenzodioxins/polychlorinated dibenzofurans known to cause physiological disturbances, are increasingly being used as an agricultural fertilizer. This could pose a health threat to both humans and domestic and wild animal species. This review summarizes results of a unique model, used to determine the effects of exposure to mixtures of environmentally relevant concentrations of pollutants, in sheep grazed on biosolids-treated pastures. Pasture treatment results in nonsignificant increases in environmental chemical (EC) concentrations in soil. Whereas EC concentrations were increased in some tissues of both ewes and their fetuses, concentrations were low and variable and deemed to pose little risk to consumer health. Investigation of the effects of gestational EC exposure on fetal development has highlighted a number of issues. The results indicate that gestational EC exposure can adversely affect gonadal development (males and females) and that these effects can impact testicular morphology, ovarian follicle numbers and health, and the transcriptome and proteome in adult animals. In addition, EC exposure can be associated with altered expression of GnRH, GnRH receptors, galanin receptors, and kisspeptin mRNA within the hypothalamus and pituitary gland, gonadotroph populations within the pituitary gland, and regional aberrations in thyroid morphology. In most cases, these anatomical and functional differences do not result in altered peripheral hormone concentrations or reproductive function (e.g., lambing rate), indicating physiological compensation under the conditions tested. Physiological compensation is also suggested from studies that indicate that EC effects may be greater when exposure occurs either before or during gestation compared with EC exposure throughout life. With regard to human and animal health, this body of work questions the concept of safe individual concentration of EC when EC exposure typically occurs as complex mixtures. It suggests that developmental EC exposure may affect many different physiological systems, with some sex-specific differences in EC sensitivity, and that EC effects may be masked under favorable physiological conditions.

The liver is a major metabolic and endocrine organ of critical importance in the regulation of growth and metabolism. Its function is determined by a complex interaction of nutritionally regulated counter-regulatory hormones. The extent to which hepatic endocrine sensitivity can be programed in uteroand whether the resultant adaptations persist into adulthood is unknown and was therefore the subject of this study. Young adult male sheep born to mothers that were fed either a control diet (i.e.100% of total live weight-maintenance requirements) throughout gestation or 50% of that intake (i.e. nutrient restricted (NR)) from 0 to 95 days gestation and thereafter 100% of requirements (taking into account increasing fetal mass) were entered into the study. All mothers gave birth normally at term, the singleton offspring were weaned at 16 weeks, and then reared at pasture until 3 years of age when their livers were sampled. NR offspring were of similar birth and body weights at 3 years of age when they had disproportionately smaller livers than controls. The abundance of mRNA for GH, prolactin, and IGF-II receptors, plus hepatocyte growth factor and suppressor of cytokine signaling-3 were all lower in livers of NR offspring. In contrast, the abundance of the mitochondrial protein voltage-dependent anion channel and the pro-apoptotic factor Bax were up regulated relative to controls. In conclusion, maternal nutrient restriction in early gestation results in adult offspring with smaller livers. This may be mediated by alterations in both hepatic mitogenic and apoptotic factors.

Two cashmere goat breed lines were selected, over a 5-year period, for increased mean cashmere weight (Value line; V) or reduced mean cashmere diameter (Fine line; F) and were compared with a group bred randomly (Control; C). The mean staple length of V animals increased from 42.2 to 52.0mm (P < 0.001) between Years 1 and 5 and by Year 5 it was longer than that of F (43.9; P < 0.001) and C animals (45.2; P < 0.05). Between Years 1 and 5, the mean maximum drawn length of the V and F cashmere increased, from 50.9 to 63.1mm (P < 0.001) and from 45.0 to 52.8mm (P < 0.001), respectively. The mean minimum length for the V line increased from 32.5 to 49.6mm (P < 0.001). This was attributable to an increase in cashmere length in both males (P < 0.001) and females (P < 0.001). The mean minimum length for the F line increased (P < 0.001) primarily because of an increase in the mean minimum cashmere length of the females (P < 0.05). It is concluded that although the selection program resulted in an increase in cashmere production in the V line and no reduction in the F line animals, the associated increase in length and/or the changes in the relative length of the cashmere and guard hairs were likely to result in a reduction in fleece quality and value, particularly in the V animals.

Nutritional feedback provided by systemic hormones, such as insulin and leptin, influences reproductive neuroendocrine output within the hypothalamus, yet the mechanisms and their interaction with photoperiodic cues remain unresolved in seasonal species. Here, peripheral glucose (G) infusion was used to increase endogenous concentrations of insulin and leptin in food-restricted sheep kept in either long-day (LD) or short-day (SD) photoperiod, and responses were examined in terms of pulsatile luteinising hormone (LH) (gonadotrophin-releasing hormone by inference) output and hypothalamic gene expression for nutritionally sensitive neuropeptides and receptors. We addressed the hypothesis that these hypothalamic responses were correlated and influenced by photoperiod. Oestradiol-implanted, castrated male sheep were kept 16 weeks in SD (8 h light/day) or LD (16 h light/day) and then transferred to the opposite photoperiods for 8 weeks, during which food was restricted to 90% requirement to maintain body weight (maintenance). For the final 6 days, food was reduced to 75% maintenance, and sheep in both photoperiods were infused intravenously with G (60 mM/h) or saline (S) (n=8/group). G-infused sheep had higher mean plasma concentrations of G, insulin and leptin than S-infused sheep, with no effect of photoperiod. In LD, but not in SD, G infusion increased LH pulse frequency and pulse amplitude. In LD, but not in SD, gene expression in the hypothalamic arcuate nucleus was lower in G- than S-infused sheep for neuropeptide Y (NPY) and agouti-related peptide (AGRP) and was higher in G- than S-infused sheep for pro-opiomelanocortin (POMC). Gene expression for leptin and insulin receptors was not affected by photoperiod or infusion. These results are consistent with the involvement of NPY, AGRP and POMC in mediating the reproductive neuroendocrine response to increased systemic nutritional feedback, and they support the hypothesis that hypothalamic responses to nutritional feedback are influenced by photoperiod in sheep.

To characterize the immune response associated with Lawsonia intracellularis infection, twenty-eight, 7-week-old pigs were dosed orally with a pure culture of L. intracellularis. Animals were killed 3, 7, 14, 21, 28, 35, and 42 days postinfection. Light microscopic studies were undertaken to immunophenotype the immunologic response using specific antibodies to T-cell subsets (CD3, CD4, and CD8), B cells, major histocompatibility complex class II, cadherin, and macrophages over the course of time. The results indicate that there is a direct association between the presence of L. intracellularis and reduced T-cell and B-cell numbers. For the first time, this provides evidence of the presence of an immunosuppressive mechanism operating in this disease. Furthermore, macrophage marker studies indicated that macrophages may play a more complex and significant role in the disease process than has been previously reported, with activated macrophages accumulating in infected hyperplastic crypts.

Manipulations of thyroid hormone secretion and function can be used to cure thyroidal deficiencies or overactivity and as a tool to investigate their physiological roles and identify potential protocols for enhancing animal performance. An essential approach to the investigation of thyroid hormone action involves the induction of hypothyroidal states. Methods of inducing hypothyroidal states in ruminants include thyroidectomy and treatment with thionamides. There are few data concerning the induction of an optimal degree of hypothyroidism for the study of thyroid function in ruminants, unlike the situation in rodents. The effects of hypothyroidism on the physiology of ruminants, and the relative merits of thyroidectomy or of treatment with thionamides to manipulate thyroid hormone profiles in them, are reviewed and discussed. Thyroidectomy in ruminants induces an acute, irreversible, hypothyroidal state. It also has indirect, predominantly adverse, effects on many physiological processes and impairs health. Thus, thyroidectomised (THX) animals cannot be sustained for long-term studies without thyroid hormone replacement. Antithyroid drugs of the thionamide class, on the other hand, have been used with success to induce varying degrees of hypothyroidism, predominantly less severe than those induced by thyroidectomy. The changes induced by drugs are reversible upon withdrawal of treatment. However, treatment may require daily administration of the drug for several weeks before stable plasma concentrations of thyroid hormone are achieved. Furthermore, at high doses, these drugs can have toxic side effects. It is concluded that the treatment regime of choice will depend on the objectives of the individual study. Knowledge of the activities of thyroid hormone metabolising, deiodinase enzymes in the target tissues is also required if the actions of some of these drugs, their physiological roles in modulation of the thyroid hormones, and, crucially, their potential effects on animal health and production are to be properly understood and exploited.

Body size and growth data were gathered on 387 wild brush-tailed phascogales captured between 1992–1997 in south-western Australia. This marsupial has not previously been studied in Western Australia. Compared with Victorian phascogales, those in the south-west (single region) are typically 20–30% smaller in mass, smaller in skeletal measurements, and sexual size dimorphism is less. Habitat quality was correlated with body size and the largest phascogales were found in swamp/gully systems. These findings suggest food is a normally limiting resource for this species in the south-west environment. Additionally, a significant decrease in growth and size occurred during a drought year (1994), and growth of young seemed restricted during dependency. Maternal mortality appeared high during late lactation as orphaned, unweaned young were encountered in nest boxes. In 1995 adult males were 25% less in mass than usual; females 15% less. Population decline followed and by 1996 capture rates were 1/3 of that typically found for the time of year. Recovery was not apparent until two years after drought (early 1997). In this food-limited environment phascogale populations appear particularly vulnerable to annual fluctuations in rainfall.

Reproduction and population demographics were examined among wild brush-tailed phascogales in southern Western Australia. Data were gathered in a single region during 1992–97 from 387 individuals, 139 of whom were monitored by radio-telemetry. In contrast to Victorian phascogales, which all have eight teats, the Western Australian population contained females with six (30%), seven (21%), and eight (49%) teats (n = 72). Teat numbers varied between mothers and daughters/sisters, which appears unprecedented among dasyurids. The data strongly suggest that females try to raise as many young as they have teats. Population changes are as described for Victorian phascogales: complete male die-off occurs in July; some females survive to breed in a second year; and there is long-distance male dispersal and high philopatry by female offspring. Births occur from July to September, somewhat later and also less synchronised than among Victoria phascogales. Late breeding by females in one year suggests that sperm storage may be extensive in this species. Strong associations between the physical condition of females and rainfall suggest that these may influence between-year variation in birth times and sex-ratio bias in litters. Similarly, poor physical condition of young during drought may have underpinned atypical dispersal behaviour in males. Decreased teat numbers and smaller litter sizes indicate that phascogales from south-western Western Australia are reproductively adapted to relatively low food availability. However, this species experiences difficulty successfully breeding and rearing young under drought conditions.

CD1 molecules are a family of cell surface-associated glycoproteins now recognized as having a role in antigen presentation. These glycoproteins are distinct from yet have some similarities to classical major histocompatibility complex class I and class II molecules. The role of these molecules has been studied in detail over recent years, with an explosion of interest following the demonstration that they can present nonprotein antigens to certain subpopulations of T cells. The purpose of this paper is to provide an overview of current knowledge of the function of the CD1 family with specific emphasis on the potential role in the pathogenesis of certain diseases. Although much of the current research in this field has inevitably concentrated on mice and humans, this work also has potential significance for veterinary species.

ABSTRACTThe role of wildlife species in the epidemiology of paratuberculosis has been the subject of increased research efforts following the discovery of natural paratuberculosis in free-living rabbits from farms in east Scotland. This paper describes the experimental inoculation of young calves with an isolate ofMycobacterium aviumsubsp. paratuberculosisrecovered from a free-living rabbit. After a 6-month incubation period, all eight calves inoculated with the rabbit isolate had developed histopathological and/or microbiological evidence of M. aviumsubsp. paratuberculosisinfection. Similar results were obtained from a group of calves infected with a bovine isolate of M. aviumsubsp. paratuberculosis. The virulence of the rabbit isolate for calves demonstrated in this study suggests that rabbits are capable of passing paratuberculosis to domestic ruminants and that wildlife reservoirs of M. aviumsubsp. paratuberculosisshould therefore be considered when formulating control plans for the disease.

The brush-tailed phascogale (Phascogale tapoatafa) is considered locally rare and vulnerable, despite being found in all mainland states of Australia. It is rarely detected in faunal surveys and the two most immediate conservation requirements are a determination of its current range and clarification of its taxonomic status. Measures of genetic differentiation amongst Phascogale tapoatafa populations in eastern, western and northern Australia were estimated using a partial (348 bp) sequence of mitochondrial DNA (cytochrome b gene). Observed sequence divergence within P. tapoatafa was substantial, with an average of 13% separating the allopatric populations in south-eastern, south-western and northern Australia. In comparison, an average of 16% sequence divergence separated the two currently recognised Phascogale species (P. tapoatafa andP. calura). Thus, Phascogale comprises four highly divergent lineages, suggesting that the genus is more diverse than previously thought. These data indicate that further taxonomic research is warranted.

This study details morphometric variation among the marsupial brush-tailed phascogale, Phascogale tapoatafa. The validity of phascogales from south-western and south-eastern Australia being classified as the single subspecies P. t. tapoatafa was questioned because of the substantial isolation of the south-west population; the northern Australian subspecies P. t. pirata was included in the inquiry. Discriminant function analysis performed on 18 skull characteristics (n = 50 skulls) produced separation between P. t. pirata, south-western P. t. tapoatafa, and south-eastern P. t. tapoatafa. Separation was also achieved between female phascogales from Victoria and those from New South Wales and southern Queensland, but not between the males of these two populations. Univariate tests identified significant size differences between the groups. Field data gathered on wild P. t. tapoatafa illustrate large size differences between phascogales of Victoria and south-western Australia. Phascogales from south-western Australia also exhibit a polymorphism in teat number (6, 7 or 8 teats; n = 72) that is not observed in other phascogales. This isolated population may represent a distinct taxon.

ABSTRACTRecent reports of natural paratuberculosis (or Johne's disease) in rabbits, foxes, and stoats has focused debate on the presence and importance of wildlife reservoirs in the epidemiology of this disease. This paper describes an extensive study investigating 18 nonruminant wildlife species for evidence of paratuberculosis. Using both culture and histopathological analysis, fox, stoat, weasel, crow, rook, jackdaw, rat, wood mouse, hare, and badger were found to harborMycobacterium aviumsubsp. paratuberculosis, the causative organism of paratuberculosis, suggesting that the epidemiology of this disease is more complex than previously realized.

Lawsonia intracellularis is a recently identified bacterial pathogen which causes disease in a broad range of animals. Invasion of intestinal epithelial cells and the resultant hyperplasia of infected cells are central processes in disease pathogenesis. In this study, we aimed to establish whether immunocompetent mice were susceptible to infection and whether gamma interferon (IFN-gamma) contributed to the pathogenesis of infection. Wild-type 129-Sv-Ev mice (129 mice) and IFN-gamma receptor knockout mice based on the 129 background (IFN-gammaR(-)) were challenged orally with approximately 5.5 x 10(7) L. intracellularis cells. Both 129 and IFN-gammaR(-) mice became infected, although the extent of infection (as determined by the proportion of infected crypts) was substantially lower in 129 mice than in IFN-gammaR(-) mice. Despite these differences, infected crypts showed characteristics typical of proliferative enteropathies of other animals, i.e., intracellular colonization of epithelial cells by L. intracellularis with resultant epithelial hyperplasia. Infection in 129 mice was cleared between days 21 and 28 postchallenge, whereas infection in IFN-gammaR(-) mice was evident in 100% of animals from day 21 onward. Additionally, in IFN-gammaR(-) mice the infection was so extensive that fatalities resulted. IFN-gamma therefore plays a significant role in limiting intracellular infection and increased cellular proliferation associated with L. intracellularis. L. intracellularis infection is generally associated with modest cellular infiltration; therefore, further comparative examinations will be necessary to determine pathogenicity factors and define the role of IFN-gamma in controlling this infection.

The effect of an 18.5-week infantry training program on health status was studied in 23 male military personnel (aged 22.0 +/- 0.5 years, mean +/- SE). Aerobic power, body composition, and immune function (including natural killer cell activity, mitogen-stimulated lymphocyte proliferation, in vivo cell-mediated immunity, and secretory immunoglobulin A levels) were measured in subjects at the beginning and end of the course. Subjects self-reported their symptoms of sickness in health logs using a precoded checklist. Data from this study indicate that subjects became leaner and maintained, but did not increase, their aerobic fitness by the end of the course. Cell function was enhanced significantly; however, in vivo cell-mediated immunity remained the same, and levels of secretory immunoglobulin A were lower by the end of the course. The incidence of infection remained stable throughout the course. These results indicate that the current pattern of infantry training does not have an adverse effect on the health status of recruits.

A middle‐aged golden retriever presenting with exercise intolerance and multifocal cutaneous nodules was diagnosed as having non‐epitheliotropic cutaneous lymphoma with concurrent myasthenia gravis. Treatment with corticosteroids induced short‐term remission of the lymphoma and alleviation of myasthenic signs.

Five groups of 8 adult male castrated goats were used in an 8-month study. For a 6-month period commencing in November, goats of one group were dosed with propylthiouracil (PTU), a drug which reduces the rate of conversion of thyroxine (T4) to triiodothyronine (T3) in peripheral tissues. Animals of a second group were treated with bromocriptine (Br), a drug which reduces the circulating concentrations of prolactin. Animals of other groups were treated with PTU + Br, PTU + triiodothyronine (PTU + T3), or vehicle only (control). The mean date of moult onset was later in animals of the PTU + T3 (P &lt; 0.05), PTU + Br (P &lt; 0.05), and Br (P &lt; 0.01) groups than in control animals. PTU + T3 , PTU + Br, and Br animals also exhibited lower minimum levels of primary follicle activity than control animals (P &lt; 0.01). On the basis of a periodic function applied to the data, there was a trend towards a later nadir of both primary and secondary follicle activity. There were no significant effects of treatment on profiles of thyroxine (T4), triiodothyronine (T3), growth hormone (GH), insulin-like growth factor-1, or insulin but a significant (P &lt; 0.001) seasonal increase in mean concentration occurred between November and March–April in all except GH profiles. It is concluded that PTU and Br did not act additively or synergistically on follicle activity or moult. Nevertheless, it is further concluded that the mechanisms of action of the thyroid hormones and prolactin are not independent and that future studies of their effects on follicle function should address their interactions with other hormones and changes in thyroid hormone receptor activity within the follicles.

This paper describes the clinical features, and diagnostic findings of a chronic respiratory condition in 29 West Highland white terriers. Typically, the dogs were coughing chronically, had dyspnoea and tachypnoea of varying severity, and had deteriorated progressively over months to year. The mean (sem) survival time in months from the clinical signs being first noted by the owners was 17.9 (2.3). Most cases had a combination of respiratory signs, but coughing was the predominant sign in 18 cases. Inspiratory crackles were audible on chest auscultation in 28 cases, 10 of which were also wheezing. Rhonchi were the predominant sound in the remaining case. The main radiographic changes were mild to severe increased interstitial markings in all cases, with additional bronchial markings in 14 of the dogs. Right‐sided cardiomegaly (cor pulmonale) was recorded in 15. Bronchoscopic findings in 17 of the dogs were either normal or involved a mild airway mucoid reaction in eight. Chronic mucosal changes were observed in eight, but in two this finding was equivocal. Dynamic changes to the lumen of the airway were present in seven cases. No significant haematological or biochemical changes could be detected in 20 cases, but four cases were hypercholestrolaemic. A histopathological assessment of four cases revealed alveolar septal fibrosis to be the predominant change. Prednisolone, with or without bronchodilators, was the most commonly used therapy, and the response was variable. The condition appears to be associated with significant pulmonary interstitial fibrosis of unknown aetiology and has clinical similarities to idiopathic pulmonary fibrosis (cryptogenic fibrosing alveolitis) in human beings.

Radiographic evidence of chronic interstitial lung changes, usually believed to be attributable to lung fibrosis, is readily recognised in canine practice. Furthermore, there is a body of anecdotal evidence suggesting that a specific clinical entity consistent with chronic lung fibrosis occurs in specific breeds of terrier dogs. However, there is little pathological data to confirm these radiographic and clinical findings and, therefore, chronic interstitial lung disease of dogs is poorly characterised. In this report, a case of chronic pulmonary fibrosis is described in which histopathological confirmation was possible, and suggested that the condition might be analogous to idiopathic pulmonary fibrosis (cryptogenic fibrosing alveolitis) in humans.

Summary.Mature Suffolk ewes were either actively or passively immunized against the synthetic fragment of porcine inhibin alpha, pIα(1-30), to determine the effects on gonadotrophin secretion and ovulation rate. Thirteen control ewes were immunized against human serum albumin, 12 ewes were actively immunized against pIα(1-30) and 36 ewes were passively immunized with pIα(1-30) antiserum. Blood samples were collected at 4-h intervals for 72 h from oestrus-synchronized ewes following the withdrawal of the progestagen pessaries. Mean gonadotrophin concentrations measured during the oestrous cycle of control ewes, ewes actively immunized against pIα(1-30) and ewes passively immunized against pIα(1-30) were similar, but their secretory profiles differed. Serum concentrations of follicle-stimulating hormone (FSH) were highest in ewes which had received antiserum at the time of pessary withdrawal; FSH concentrations did not decrease during the follicular phase of the oestrous cycle in ewes given antiserum 24 h after pessary withdrawal. Subtle but significant increments in serum FSH concentrations were observed in all passively immunized ewes in which sampling commenced at the time of treatment. The amplitude of the preovulatory luteinizing hormone (LH) peak, but not of the FSH peak, and the postovulatory secondary rise in FSH were lower (P< 0·05) in actively immunized ewes than in control ewes. The mean (±s.e.) ovulation rate for actively immunized ewes (6·6 ± 1·0) was 3 times higher (P< 0·05) than that for control ewes (2·0 ± 0·2), but was unaffected by passive immunization (range, 1·8–2·3). The divergent results involving serum gonadotrophins and ovulation rate following active or passive immunization to the same pIα(1-30) immunogen suggest that changes in circulating gonadotrophins alone may not account for the increased ovulation rate in immunized Suffolk ewes.Keywords:inhibin; fecundity; LH; FSH; immunization; sheep

Antibodies were prepared in sheep against purified plasma membranes from pig adipocytes. Western (immuno) blotting revealed reactions of the antisera with a large number of proteins in adipocyte plasma membranes but remarkably few in plasma membranes from muscle, kidney, liver, lung, brain, spleen, and erythrocytes. This illustrated the high degree of specificity the serum had for adipose tissue. When injected into localized subcutaneous sites such antisera were able to cause considerable adipocyte destruction, which resulted in complete loss of adipose tissue from the site for ≥ 14 wk. This cell destruction was probably mediated in part by lymphocytic infiltration. Subcutaneous injections were of limited use because of the localized nature of the effects, but, when treatment was administered intraperitoneally, systemic effects were produced that resulted in a 30% reduction in backfat thickness in the region of the last rib and a 25% reduction in fat content of fore- and hind-loin joints that resulted in a significant increase in the percentage of lean tissue. Total feed intake, live weight gain, hot carcass weights, and dressing percentage were unaffected. These results demonstrate the potential for producing long-term reductions in body fat in pigs by an immunization technique that may also provide the unexpected, potential benefit of increased lean deposition. This suggests that fat deposition per se exerts a restrictive influence on lean carcass development.

Ovarian follicle development in response to FSH infusion was investigated in Scottish Blackface ewes with high and low body condition scores in which endogenous gonadotrophin secretion and follicle development to ≥ 2.5 mm diameter was suppressed using subcutaneous implants containing a GnRH agonist. In two experiments conducted during the normal breeding season, groups of 20 (Expt 1) and 15 (Expt 2) ewes were fed to achieve body condition scores ≥2·75 (high; H) or ≤1·75 (low; L). In both experiments GnRH agonist implants were inserted four weeks before FSH was infused for 72 h at 7 μg h−1to group H animals or at 5 μg h−1to group L animals; the infusion rates were designed to ensure similar circulating FSH concentrations in animals of both groups. In Expt 2, additional subcutaneous implants containing oestradiol were inserted 21 days after insertion of GnRH agonist implants and 7 days before the FSH infusion began. In both experiments, FSH infusion was associated with an increase in circulatory concentrations of LH (P< 0.01) and FSH (P< 0·001), but there was no difference with body condition in mean circulating gonadotrophin concentrations, the numbers of ovarian follicles ≥ 2.5 mm diameter, the proportion of these follicles that were oestrogenic or the mean rate of oestradiol secretion in vitro. It is concluded that differences in body condition of ewes do not affect the responsiveness of the ovary to FSH, in the presence or absence of oestradiol, as measured by the number, size and steroidogenic capacity of ovarian follicles present following FSH infusion.

Abstract:  The anti-CD1 monoclonal antibodies IAH-CC14 and SBU-T6 were used to immunopurify CD1 antigens from sheep thymocytes. The amino-terminal sequence of IAH-CC14 yielded 13 amino acids, and 29 amino acids were obtained from the SBU-T6 antigen. The sequence of the IAH-CC14 antigen was 100% identical to the predicted sequence of the sheep CD1B clone, SCD1B-42. The 29 amino acid sequence of the SBU-T6 antigen did not match identically with the derived amino acid sequence of any of the previously reported sheep CD1 genes but had closest similarity to the derived sequence of human CD1E. Degenerate polymerase chain reaction primers based on this sequence identified a group 2 sheep CD1 gene. The predicted amino acid sequence of this gene shows that it is not identical to the SBU-T6 peptide, indicating that a different, CD1D-like gene was cloned.

Summary.Plasma prolactin concentrations during the first 2 months after lambing, at oestrus, and during early pregnancy were investigated in 2 experiments in which Finn × Dorset Horn ewes were mated at an induced oestrus approximately 9 weeks after lambing.Mean prolactin concentrations between lambing and mating were dependent on season, being >260 ng/ml plasma in lactating ewes mated in July and <150 ng/ml in those mated in October. Within 8 days of weaning of the lambs at 50 days post partumvalues declined to 122 and 30 ng/ml respectively. Plane of nutrition had little effect on prolactin levels. Higher prolactin values were recorded during oestrus in ewes mated in March or July, the normal period of anoestrus, than in December, the normal breeding season, mean values being approximately 200 ng/ml and 35 ng/ml respectively. The mean increases in the concentrations of prolactin during oestrus were smaller in lactating than non-lactating ewes.It is suggested that these differences in prolactin levels may be responsible for the effects of season and lactation on ewe fertility.

Summary.Finnish Landrace × Dorset Horn ewes of two flocks comprising 47 and 51 animals were mated to Suffolk rams at a synchronized oestrus on 9 December (Flock D) and 8 April (Flock A) after treatment with 500 i.u. PMSG. The ewes were slaughtered between 50 and 145 days of pregnancy. The mean ± s.e.m. ovulation rates were 4·5 ± 0·24 (Flock D) and 5·0 ± 0·32 (Flock A) for ewes which conceived to the induced oestrus and the corresponding litter sizes were 2·8 ± 0·15 and 2·8 ± 0·18. Mean concentrations of progesterone in the peripheral plasma during pregnancy were higher for Flock D than for Flock A ewes both in early (P< 0·001) and late (P< 0·05) pregnancy. An increase in ovulation rate, up to 4 or 5, was associated with an increase in mean litter size. There was evidence that higher ovulation rates were counterproductive.

Summary.Two experiments were designed to determine the effects of duration of lactation and plane of nutrition on the reproductive performance of Finn × Dorset Horn ewes mated at a hormonally induced oestrus 9 weeks after lambing. In Exp. 1, ewes were mated on 4 December or 19 March and lactation was terminated at 35 or 15 days before mating or 7 or 35 days after mating. The fertility of ewes lactating at the time of mating was reduced, particularly in ewes mated in March. This was not attributable to differences between lactating and non-lactating ewes for the incidence of oestrus, ovulation rate, litter size or the pattern of LH production. Indirect evidence based on progesterone profiles and returns to service suggest that reproductive failure was due to failure of fertilization and to embryonic death.In Exp. 2 ewes were mated on 1 July or 15 October. Lactation was terminated 15 days before or 7 days after mating and the ewes in each group were subjected to a high or low plane of nutrition. Lactation depressed fertility in ewes mated in July but not in those mated in October. While the fertility of non-lactating ewes was independent of nutritional treatment, lactating ewes on a low plane and mated in July had a higher lambing rate than those on a high plane of nutrition. Nutritional effects on fertility appeared to be mediated through changes in milk production and reproductive failures were attributed to failure of fertilization and embryonic death. Seasonal and treatment effects on the incidence of oestrus and on ovulation rates, litter sizes and LH production were small and of little importance.

The effect of level of food intake on LH and FSH profiles and pituitary sensitivity to gonadotrophin-releasing hormone (GnRH) was investigated in two groups of 12 ovariectomized ewes. Ewes with a high intake (group H) had a mean daily intake (± s.e.m.) of 1·99 ± 0·075 kg dry matter (DM)/head per day while ewes with a moderate intake (group M) consumed a mean of 1·02 ± 0·021 kg DM/head per day. Ovaries were surgically removed from six ewes of each group on day 11 of the luteal phase and from the remainder 30 h after an injection of 100 μg prostaglandin analogue given on day 11 to induce luteolysis. During both the luteal phase and the follicular phase, mean LH and FSH concentrations and LH pulse frequencies and amplitudes were unaffected by the level of intake but mean plasma prolactin concentrations were higher (P< 0·05) in group H than in group M ewes in the follicular phase. Mean LH and FSH concentrations at day 2 after ovariectomy were unaffected by treatment while mean prolactin concentrations were higher (P< 0·05) in group H than in group M ewes. At day 7 after ovariectomy, mean LH and FSH concentrations were lower (P< 0·05) in group H than in group M ewes although mean LH pulse frequencies and pulse amplitudes were not significantly affected by the level of intake at either time.The level of food intake and the stage of the oestrous cycle at the time of ovariectomy did not affect the amount of LH released in response to a bolus injection of GnRH (10 μg, i.v.) but the FSH response was significantly (P< 0·05) greater in group M than in group H ewes.It is concluded that the pituitary glands of ovariectomized ewes with moderate levels of intake are more responsive to GnRH than those of ewes with a high intake and that hypothalamic activity and GnRH secretion are not affected by the level of food intake.Journal of Endocrinology(1989) 121,325–330

The effects of body fat content (body condition) of ewes on hypothalamic activity and gonadotrophin-releasing hormone (GnRH) secretion and on pituitary sensitivity to GnRH were investigated using Scottish Blackface ewes. Two groups of 12 ewes were fed so that they achieved either a high body condition score (2·98, s.e.m.= 0·046; approximately 27% of empty body weight as fat) or a low body condition score (1·94, s.e.m.= 0·031; approximately 19% of empty body weight as fat) by 4 weeks before the period of study. Thereafter, they were differentially fed so that the difference in mean condition score was maintained. Oestrus was synchronized, and on day 11 of the subsequent cycle half of the ewes of each group were ovariectomized. On day 12, the remaining ewes were injected (i.m.) with 100 μg prostaglandin F2αanalogue and ovariectomized 30 h later. Numbers of large ovarian follicles and corpora lutea present at ovariectomy were recorded. Blood samples were collected at 15-min intervals for 12 h on day 10 of the cycle (luteal phase) and at 10-min intervals from 24 to 30 h after prostaglandin injection (follicular phase). At days 2 and 7 after ovariectomy, samples were collected at 15-min intervals for 8 h and ewes were then injected with 10 μg GnRH and samples were collected for a further 3 h. Samples were assayed for LH and FSH. Ewes in high body condition had more more large follicles than ewes in low body condition during the luteal phase (15·3 vs 6·5; P< 0·05) and follicular phase (11·5 vs 7·0; NS) and a slightly higher mean ovulation rate (1·50 vs 1·20; NS). However, during the luteal and follicular phases of the cycle before ovariectomy there was no effect of condition score on mean LH or FSH concentrations or mean LH pulse frequency or pulse amplitude. Two days after ovariectomy, ewes of high body condition had a higher mean LH pulse frequency than ewes of low body condition (P< 0·05) and higher mean FSH concentrations (P< 0·05). Mean LH concentration and pulse amplitude were not affected. LH and FSH profiles were not affected by body condition on day 7. GnRH-induced increases in LH and FSH concentrations on days 2 and 7 were not affected by body condition. At day 7, but not day 2, ewes ovariectomized during the luteal phase of the cycle had a significantly (P< 0·05) greater GnRH-induced LH release compared with ewes ovariectomized during the follicular phase. It is concluded that body condition directly affects hypothalamic activity and GnRH secretion, but not pituitary sensitivity to GnRH, and that effects on reproductive performance are also mediated through changes in ovarian hormones or in hypothalamo-pituitary sensitivity to ovarian hormones.Journal of Endocrinology(1989) 120,497–502

Abstract. The effect of body condition on ovarian follicular development was investigated in Scottish Blackface ewes in high and low body condition. Follicles were dissected from ovaries on days 11 and 12 of the luteal phase and 24 h after prostaglandin-induced luteal regression. Ewes in low body condition had a lower ovulation rate (low: 0.9; high: 1.8 P< 0.05) and lower mean plasma levels of FSH during both the luteal (low: 54; high: 72 μg/l) and follicular (low: 34; high: 43 μg/l) phases of the cycle. Low body condition was associated with a reduced number of large (⩾ 4 mm) follicles in both the luteal and follicular phases, and in low condition a lower proportion of these follicles was oestrogenic and potentially ovulatory as assessed by follicular fluid levels of oestradiol. However, within the different oestrogenic classifications of these large follicles there were no significant differences in the steroidogenic capacity as assessed by the concentrations of either oestradiol or testosterone in follicular fluid, basal and hCG-stimulated testosterone production, thecal 125I hCG binding or basal and testosterone-stimulated oestradiol production by granulosa cells in relation to body condition. These results suggest that body condition influences ovulation rate by altering the concentration of FSH in blood, which in turn affects the number of potentially ovulatory follicles growing beyond 4 mm.

An 18‐month‐old, entire male German shepherd dog was presented with signs indicative of a caudal abdominal space‐occupying mass. A needle‐core biopsy of this mass failed to establish a definitive diagnosis, but identified a prominent round‐cell component. The dog's condition worsened and euthanasia was performed on humane grounds. Histopathology of the mass revealed a mesenchymal chondrosarcoma.

Summary.In the first 11 days of pregnancy, progesterone and prolactin levels were significantly correlated (P< 0·05), positively in December-mated animals (r= 0·889) and negatively in those mated in March (r= −0·865).

Massive open online courses (MOOCs) are freely available online courses open to anyone who registers and typically are associated with thousands or hundreds of thousands of participants. Using an established online platform, the authors created and delivered a five-week MOOC aimed primarily at prospective veterinary students, but open to anyone with an interest in finding out more about the veterinary profession in general. 11,911 people signed up for the course, and of these, 8137 interacted in some way with the course and 1716 received a certificate of completion. The majority of participants (84 per cent) were female, and there was a wide age range (under 18 to over 65). Most participants were from North America or the UK. 65 per cent of those completing the entry survey were hoping or intending to work in the vet profession in the future, while 33 per cent were not. Qualitative data indicated that the course was helpful in aiding those undecided as to whether they wanted to be a veterinarian or not to decide one way or another whether they want to pursue veterinary medicine as a career. Furthermore, the course was seen as being a useful introduction to the veterinary profession even for those who had no intention of working in the field.