Effectiveness of poll stunning water buffalo with captive bolt guns.

Practical experience has indicated that shooting water buffalo with a captive bolt gun in the front of the head does not always produce an effective stun. Slaughtermen have been claiming that the poll position is more reliable, but under present EU regulations this shooting position is not allowed for domesticated bovines. This study examined the effectiveness of shooting water buffalo with captive bolt guns in the poll region. The depth of concussion was assessed in 30 water buffalo from physical collapse, presence or absence of corneal and palpebral reflexes, normal rhythmic breathing, eyeball rotation, nystagmus and whether the animal was re-shot. All except one animal collapsed immediately. The one animal that failed to collapse was not breathing. The prevalence of a shallow depth of concussion in the poll shot animals was 53%. Two had been shot through the spinal cord, and with the exception of those plus one other in which the bolt did not penetrate the brain, the other animals were considered to be adequately stunned. Post mortem examination of the brain showed that 79% of the under thirty month old animals were shot in the midbrain or brain stem, but these regions had to be avoided in over thirty month old animals because of the risk of damaging the brain stem sample needed for BSE testing. In addition, three water buffalo were shot in the crown position and one in the front of the head. The frontal position was ineffective as the animal did not collapse, and all animals shot in the crown position resumed breathing shortly after shooting, indicating a shallow depth of concussion. It is concluded that poll shooting can be effective in water buffalo, but it produces a shallow depth of concussion compared with frontal shooting in cattle. It requires accurate placement of the gun to ensure that buffalo are not shot through the spinal cord instead of the brain. Vigilance is needed in ensuring that the animals are stuck promptly so that none recover consciousness.

Noise levels in lairages for cattle, sheep and pigs in abattoirs in England and Wales.

Levels of sound intensity were measured over periods of 24 hours in 34 abattoir lairages in England and Wales. The mean integrated range in 12 cattle lairages was 52 to 79 dB(A), in 11 sheep lairages, 45 to 76 dB(A) and in 11 pig lairages, 46 to 87 dB(A). In general, the pig lairages were the noisiest, with spot peak recordings of up to 110 dB(A). Typically, the sound intensities in all the lairages were 10 to 20 dB(A) higher during the working day than at night. In many sheep lairages, high intensities of sound were recorded frequently throughout the night, but others were very quiet, below 40 dB(A). Vocalisations were the major sources of noise in the pig and cattle lairages, but there were variations between them. There were high intensities of sound from handling systems (80 to 90 dB[A]), and ventilating fans (70 to 80 dB[A]).

Effect of scrapie incubation on the concentrations of plasma amino acids and L-lactate in infected lambs.

Three groups of two weeks old growing lambs differing in PrP genotype were orally inoculated with scrapie and maintained under defined conditions until disease endpoint. Plasma concentrations of free alanine and serine, but not L-lactate increased during the final 6 months of the disease. At the same time, plasma concentrations of several essential and non-essential free amino acids decreased linearly, indicating reduced feed intake and are consistent with, but occurring before establishment, of cachexia. These observations are consistent with those reported previously from studies on cattle infected with BSE and with the hypothesis that scrapie may effect peripheral tissue metabolism.

Scrapie infection alters the distribution of plasma metabolites in diseased Cheviot sheep indicating a change in energy metabolism.

Nuclear magnetic resonance (NMR) spectroscopy has been used to profile the metabolic status of plasma from; sheep showing clinical signs of scrapie, those known to be infected with scrapie but yet to show clinical signs, and control animals. The NMR measurements have shown that energy metabolism in scrapie infected animals is altered before the onset of clinical symptoms. These metabolic changes may provide the foundation for a pre-clinical diagnostic test for scrapie in sheep.

Smoking cessation advice for patients with chronic periodontitis.

BACKGROUND: There are limited data on the utility of dental professionals in providing smoking cessation counselling in the UK. OBJECTIVES: The purpose of this study was to determine quit rates for smokers with chronic periodontitis who were referred to a dental hospital for treatment. MATERIALS AND METHODS: Forty-nine subjects with chronic periodontitis who smoked cigarettes were recruited. All subjects received periodontal treatment and smoking cessation advice as part of an individual, patient-based programme provided by dental hygienists trained in smoking cessation counselling. Smoking cessation interventions included counselling (all patients), and some patients also received nicotine replacement therapy (NRT) and/or Zyban medication. Smoking cessation advice was given at each visit at which periodontal treatment was undertaken (typically four to six visits) over a period of 10-12 weeks. Smoking cessation advice was also given monthly during the programme of supportive periodontal care over the following nine months. Smoking status was recorded at three, six and 12 months and was confirmed with carbon monoxide (CO) monitors and salivary cotinine assays. RESULTS: Forty-one per cent, 33%, 29% and 25% of patients had stopped smoking at week four, months three, six and 12, respectively. Gender, age, the presence of another smoker in the household, and baseline smoking status (determined using subject-reported pack years of smoking) were not significant predictors of quit success (P < 0.05). Baseline CO levels were significantly associated with quit success, however, and were significantly higher in those subjects who continued to smoke compared to those subjects who were quitters at week four, month three and month six (P < 0.05). CONCLUSION: Success rates in quitting smoking following smoking cessation advice given as part of a periodontal treatment compared very favourably to national quit rates achieved in specialist smoking cessation clinics. The dental profession has a crucial role to play in smoking cessation counselling, particularly for patients with chronic periodontitis.

Smoking cessation as a dental intervention--views of the profession.

OBJECTIVE: To undertake a questionnaire-based survey to determine the attitudes and activities of dental professionals in primary care in the Northern Deanery of the UK in relation to providing smoking cessation advice. METHODS: Questionnaires for dentists, hygienists and dental nurses were sent to hygienists to distribute to other members of the team. The information collected included: smoking status of the professionals and the practice; roles of the dental team in giving smoking cessation advice; levels of training received; and potential barriers to giving this brief intervention. RESULTS: Over 90% of practices were smoke-free environments and significantly more dental nurses (23%) were smokers compared to dentists (10%) and hygienists (7%) (p<0.01). The majority of dentists and hygienists enquired about smoking status of their patients and all three groups believed that hygienists and dentists should offer brief smoking cessation advice. Potential barriers to delivering smoking cessation advice were identified: lack of remuneration; lack of time; and lack of training. CONCLUSION: Dental teams in primary care are aware of the importance of offering smoking cessation advice and, with further training and appropriate remuneration, could guide many of their patients who smoke to successful quit attempts.

Assessing adherence with toothbrushing instructions using a data logger toothbrush.

OBJECTIVES: To evaluate patient compliance with toothbrushing instructions using a data logger and a brushing diary. METHODS: Dental patients were provided with powered toothbrushes modified to carry electronic data loggers. Demonstration of the most effective way to use the toothbrush was provided with instructions to brush for 2 minutes morning and evening. Data logger brushes were supplied for two episodes of 8 weeks. Brushing time was also recorded in a diary during episode 1. RESULTS: Data from 14 brushes (2,287 recordings) were used to evaluate compliance in episode 1 Nine brushes (1,526 recordings) were used in episode 2 A total of 2,333 brushing events were reported manually in the diaries. Data logger records during episode 1 showed that only 34% of events were compliant with the instruction of a 2 minute brushing time, 20% were partially compliant (within +/-30s of 2 minutes), and 46% of events were non-compliant (>30s from 2 minutes). The respective proportions for episode 2 were 24%, 24% and 52%. Diary data reported 58% of events as compliant with 42% non-compliant. CONCLUSIONS: Manually completed brushing diaries do not provide an accurate reflection of subjects' compliance with toothbrushing instructions.

Influence of maternal dexamethasone administration on thermoregulation in lambs delivered by caesarean section.

We have previously shown that lambs delivered by caesarean section 1 week prematurely become hypothermic due to reduced brown adipose tissue function in conjunction with low plasma concentrations of cortisol and thyroid hormones. The present study therefore aimed to determine whether maternal dexamethasone (a synthetic corticosteroid) administration could improve thermoregulation in premature lambs to the extent that they become similar to term lambs. Lambs were either delivered by caesarean section into a warm (30 degrees C; WD) or cool (15 degrees C; CD) ambient temperature at 140 days of gestation, 2 days after maternal dexamethasone treatment, or at 146 days for controls. During the first 30 min of life the decline in colonic temperature was greater in dexamethasone treated lambs compared with controls delivered into the same ambient temperature. All lambs then restored colonic temperature although this adaptation took longest in dexamethasone treated lambs CD but these subsequently attained highest plateau colonic temperatures. Oxygen consumption, breathing frequency and plasma free fatty acid concentrations were highest in dexamethasone treated lambs CD. There were no differences in plasma thyroid hormones between groups, but cortisol concentrations were lower in dexamethasone treated lambs irrespective of delivery temperature. Analysis of brown adipose tissue samples at 6 h of life demonstrated that dexamethasone treated lambs WD had more uncoupling protein and, in both dexamethasone treated and control lambs, uncoupling protein content was higher in lambs CD compared with those WD. An effect of ambient temperature on thermogenic activity was only observed in the dexamethasone treated group. It is concluded that maternal dexamethasone treatment can significantly improve thermoregulation after birth following premature delivery by caesarean section. As a consequence, dexamethasone treated lambs delivered 1 week prematurely do not remain hypothermic and have higher or similar colonic temperatures compared with untreated lambs born 1-2 days before term.

Effect of maternal dexamethasone treatment and ambient temperature on prolactin receptor abundance in Brown adipose and hepatic tissue in the foetus and new-born lamb.

We investigated the influence of maternal dexamethasone treatment and ambient temperature on prolactin receptor (PRLR) abundance in brown adipose tissue (BAT) and hepatic tissue from foetuses and 6-h-old lambs delivered by caesarean section. Lambs were either delivered into a warm (30 degrees C; WD) or cool (15 degrees C; CD) ambient temperature at 140 days gestation, 2 days after dexamethasone treatment, or at 146 days gestation for controls. Uncoupling protein-1 (UCP1) content of BAT was higher in dexamethasone-treated groups compared to controls. A range of tissue-specific PRLR isoforms was detected. For the long form of PRLR in BAT these isoforms had molecular weights of 66, 54, 34 and 19 kD compared with 88, 76, 66, 58, 54 and 48 kD in liver. In BAT, isoforms of the short form of PRLR had molecular weights of 66, 62, 54, 48, 33 and 31 kD compared with 82, 66, 56, 54, 48, 40 and 33 kD in liver. Dexamethasone treatment in CD lambs resulted in higher abundance of the 54 kD isoform of the short form of PRLR in liver, whilst in BAT dexamethasone resulted in a greater abundance of the 48 kD isoform of the short form, and lower abundance of the 66 kD isoform of the long form of PRLR, compared to controls. A negative correlation (r2 = 0.52) was observed between abundance of 66 kD isoform for the long form of PRLR and UCP1, compared with positive correlations (r2 = 0.58-0.60) for the abundance of the 54 and 48 kD isoforms for the short form of PRLR and UCP1. In conclusion, maternal dexamethasone treatment 1 week before term alters the abundance of PRLR isoforms in a tissue-specific manner. This response is dependent on ambient temperature after birth and may provide a critical endocrine signal for maximising non-shivering thermogenesis.

Plasma prolactin concentrations after caesarean section or vaginal delivery.

The umbilical venous plasma prolactin concentrations of three groups of term infants were compared immediately after birth. Samples were taken following seven vaginal deliveries, eight emergency caesarean sections performed during labour, and 12 elective caesarean sections before labour. Mean concentrations of prolactin were significantly lower in the elective caesarean section group compared with the labour groups. This result indicates that the fetal hypothalamic-pituitary axis is stimulated during labour which could explain the increase in plasma prolactin concentrations at birth.

Influence of relative size at birth on growth and glucose homeostasis in twin lambs during juvenile life.

The effect of differences in size at birth on growth and glucose homeostasis between female twin lambs during juvenile life was examined. Twenty-six sets of twins were entered into the study, of which ten were used for organ sampling at birth and 16 were studied over the first year of life. Eleven sets were defined as being mismatched for birthweight as the weight difference between twins was >25%, with light lambs weighing 4.1 +/- 0.3 kg and heavy lambs weighing 5.1 +/- 0.1 kg. All remaining twins were matched in bodyweight, weighing 4.6 +/- 0.5 kg. During the rapid period of juvenile growth (i.e. one, three and six months of age) and following stabilization of bodyweight (i.e. 12 months of age) glucose tolerance tests were performed by intravenously injecting 0.8 mg kg(-1) bodyweight glucose. This was followed the next day with an insulin tolerance test, performed by intravenously injecting 0.08 units kg(-1) bodyweight insulin. At birth there were no differences in organ weight as a fraction of total bodyweight between matched and mismatched twins, but the ratio of liver to brain weight was lower in light compared with heavy twins. Light lambs remained lighter than their twins up to six months of age, and crown-rump length was also shorter. At one and three months of age there were no differences in basal plasma glucose concentrations between the groups, but glucose tolerance was greater in light compared with heavy lambs at one and six months of age. Insulin tolerance was greater in light compared with matched lambs at one and six months of age. In conclusion, it has been shown that size at birth of one twin in relation to its co-twin is one factor determining glucose regulation during postnatal life. This not only affects glucose and insulin tolerance but also growth over the first six months of age.

Maternal nutrient restriction during early to mid gestation alters the relationship between insulin-like growth factor I and bodyweight at term in fetal sheep.

The present study was designed to determine whether altered placental size, as a consequence of maternal nutrient restriction in sheep between 28 and 77 days gestation, is associated with a modified relationship between fetal weight or dimensions and plasma insulin-like growth factor (IGF) I concentration or abundance of hepatic IGF-I and IGF-II mRNA close to term. Singleton-bearing ewes consumed either 1.2x (controls, n = 19) or 0.5x (nutrient restricted, n = 28) their metabolizable energy (ME) requirements from 28 to 77 days gestation, after which all ewes were fed in order to fully meet their ME requirements for maintenance and pregnancy. Close to term (145 +/- 1 days) plasma IGF-I concentration in cord blood was similar between groups, but only significantly correlated with fetal bodyweight, thoracic circumference, crown-rump length and lean body mass in lambs born to control (r2 0.38, 0.76, 0.33, 0.42; P<0.001), and not to nutrient-restricted (r2 = 0.01, 0.11, 0.01, 0.02) ewes. There were no differences in fetal hepatic expression of IGF-I and IGF-II mRNA between groups close to term. In conclusion, maternal nutrient restriction in early to mid gestation followed by feeding to requirements up to term alters the relationship between fetal IGF-I, bodyweight and length. Increasing maternal nutrition in later gestation after a prolonged period of nutrient restriction may stimulate fetal nutrient supply such that fetal growth is enhanced without an increase in plasma IGF-I. As a result, there is a loss of the relationship between fetal weight and plasma IGF-I concentration observed in fetuses whose mothers are fed adequately throughout gestation.

Studies of embryo transfer from cattle clinically affected by bovine spongiform encephalopathy (BSE).

Semen from 13 bulls, eight with clinical bovine spongiform encephalopathy (BSE), was used to artificially inseminate (AI) 167 cows with clinical BSE, and their resultant embryos were collected non-surgically seven days after AI. The viable and non-viable embryos with intact zonae pellucidae were washed 10 times (as recommended by the International Embryo Transfer Society) then frozen. Later, 587 of the viable embryos were transferred singly into 347 recipient heifers imported from New Zealand, and 266 live offspring were born of which 54.1 per cent had a BSE-positive sire and a BSE-positive dam. The recipients were monitored for clinical signs of BSE for seven years after the transfer, and the offspring were monitored for seven years after birth. Twenty-seven of the recipients and 20 offspring died while being monitored but none showed signs of BSE. Their brains, and the brains of the recipients and offspring killed after seven years, were examined for BSE by histopathology, PrP immunohistochemistry, and by electron microscopy for scrapie-associated fibrils. They were all negative. In addition, 1020 non-viable embryos were sonicated and injected intracerebrally into susceptible mice (20 embryos per mouse) which were monitored for up to 700 days, after which their brains were examined for spongiform lesions. They were all negative. It is concluded that embryos are unlikely to carry BSE infectivity even if they have been collected at the end-stage of the disease, when the risk of maternal transmission is believed to be highest.

A comparative study of two powered toothbrushes and one manual toothbrush in young adults.

The aim of this 3-group, 3-treatment, single-blind, parallel group study was to evaluate and compare the efficacies of the Philips/Jordan HP735 powered toothbrush, the Braun/Oral-B D7 powered toothbrush, and the Oral-B Advantage B35 manual toothbrush in young adults (18-25 years). Full mouth mean (SD) modified Turesky Plaque Index (PI) and the Löe & Silness Gingival Index (GI) were recorded at baseline. After 24 hours abstinence from oral hygiene, the PI was recorded and each subject was given one of the test brushes with detailed instructions for use. Each subject then brushed under supervision for 90 seconds, during which time mean (SD) toothbrushing forces (TBF) were recorded. PIs were recorded immediately after brushing, and the subjects were then discharged for 6 weeks to use the allocated toothbrush at home. After 6 weeks, PI, GI and TBF were again recorded. There were no significant differences (ANOVA) for PI and GI between groups at baseline, or for PI following brushing at 24 hours. After 6 weeks, the powered brushes produced lower mean PI (SD) scores than the manual brushes, but the differences were significant only at interproximal sites. Mean GI scores for the HP735 group were similar at baseline and at 6 weeks, although for the other brushes the GI scores actually increased over this period. Mean (SD) TBF (grams/force) at baseline and 6 weeks, respectively, for the brushes were; HP735 233 (205), D7 159 (58), B35 279 (122) (p = 0.026): HP735 194 (86), D7 141 (57), B35 297 (113) (p = 0.0001). The within-group variability for the HP735 TBF reduced considerably over 6 weeks, which is possibly because of the click-force threshold feature of this brush.

The effect of smoking on periodontal treatment response: a review of clinical evidence.

BACKGROUND: Smoking has been identified as a significant risk factor for periodontal diseases and is regarded as being responsible for incomplete or delayed healing in patients following treatment. AIM AND METHOD: The aim of this conventional review was to review, collate and tabulate the relative effectiveness of treatments of chronic periodontitis in smokers, non-smokers and ex-smokers. OBSERVATIONS: The majority of clinical trials show significantly greater reductions in probing depths and bleeding on probing, and significantly greater gain of clinical attachment following non-surgical and surgical treatments in non-smokers compared with smokers. This benefit is also seen at class I and II furcation sites and in patients prescribed systemic or local antimicrobial treatments. CONCLUSIONS: Data from epidemiological, cross-sectional and case-control studies strongly suggest that quitting smoking is beneficial to patients following periodontal treatments. The periodontal status of ex-smokers following treatment suggests that quitting the habit is beneficial although there are only limited data from long-term longitudinal clinical trials to demonstrate unequivocally the periodontal benefit of quitting smoking.

The effect of quitting smoking on chronic periodontitis.

OBJECTIVES: To evaluate longitudinally the effect of smoking cessation on clinical and radiographic outcomes following non-surgical treatment in smokers with chronic periodontitis. MATERIAL AND METHODS: Forty-nine smokers with chronic periodontitis who wished to quit smoking were recruited. Full-mouth probing depths, bleeding and plaque data were recorded at baseline, 3, 6 and 12 months. Clinical attachment levels were recorded at target sites and subtraction radiography was used to assess bone density changes. Patients received non-surgical periodontal therapy during the first 3 months and supportive periodontal care over the remainder of the study. Smoking cessation counselling was provided according to individual need. RESULTS: After 12 months, of patients with complete data, 10 had continuously quit smoking (20% of the original population), 10 continued smoking and six were oscillators (those patients who quit and then relapsed). There were no differences between the groups following treatment with respect to mean clinical or radiographic parameters. Analysis of probing depth reductions between baseline and month 12, however, and comparing quitters with the other two groups combined, demonstrated a significant difference in favour of quitters (p<0.05). Furthermore, quitters were significantly more likely to demonstrate probing depth reductions > or =2 and > or =3 mm than non-quitters and oscillators (p<0.05). CONCLUSION: Quitting smoking has an additional beneficial effect in reducing probing depths following non-surgical treatment over a 12-month period.

The crossover design to evaluate the efficacy of plaque removal in tooth-brushing studies.

OBJECTIVES: To evaluate the crossover clinical trial design to assess plaque removal efficacy of the Sonicare Elite. MATERIAL AND METHODS: A single-cohort, 12-week, two-treatment, single-blind, crossover clinical trial recruited 45 subjects. Plaque was recorded using the modified Quigley and Hein index plaque index (PI). After screening, subjects used the toothbrush for 2 weeks and were reminded to abstain from tooth cleaning 12-18 h prior to appointments. At visit two, subjects were randomized to 2 or 2(1/2) min. brushing time. PIs was recorded pre- and post-brushing. Subjects brushed for the allocated time for a further 2 weeks. At visit 3, PIs were recorded pre- and post-brushing. Two weeks later, at visit 4, the subjects crossed over and the protocol was repeated. RESULTS: There was no evidence of a learning effect within each arm of the crossover. A significant period effect was detected; however, no significant treatment by period effect was found. 2(1/2) min. brushing removed more plaque at full mouth (p=0.037), smooth (p=0.012) and lingual (p=0.002) sites compared with 2 min. CONCLUSION: The crossover design is a valid model for assessing plaque removal efficacy in tooth-brushing studies where no carry-over effect is clinically plausible.

Influence of thyrotropin-releasing hormone administration at birth on thermoregulation in lambs delivered by cesarean.

OBJECTIVE: We examined the hypothesis that exogenous stimulation with thyrotropin-releasing hormone immediately before umbilical cord clamping can improve thermoregulation in near-term lambs delivered by cesarean. STUDY DESIGN: Twin lambs were injected with either saline solution alone (control, n = 12) or thyrotropin-releasing hormone in saline solution (n = 16) and were immediately placed in a warm (30 degrees C; n = 14) or cool (15 degrees C; n = 14) ambient temperature. In vivo measurements of temperature control (colonic temperature, oxygen consumption, and incidence of shivering) were then performed during the first 6 hours after birth, in conjunction with plasma thyroid hormone measurements. Brown adipose tissue was then sampled for measurement of uncoupling protein 1 abundance. RESULTS: Plasma triiodothyronine concentrations were significantly higher in lambs treated with thyrotropin-releasing hormone than in control lambs between 3 and 6 hours after birth, as were plasma thyroxine concentrations 1 and 5 hours after birth. Delivery temperature had no effect on plasma thyroid hormone concentrations. At 6 hours after birth the abundance of uncoupling protein 1 was higher in lambs treated with thyrotropin-releasing hormone than in control lambs. Lambs treated with thyrotropin-releasing hormone exhibited a lower incidence of shivering than did control lambs between 5 and 6 hours after birth, and an effect of ambient temperature on the incidence of shivering was observed only in the control group. From 3 to 6 hours after birth colonic temperature was significantly higher in cool-delivered lambs treated with thyrotropin-releasing hormone than in the control group. Oxygen consumption was higher in cool-delivered lambs than warm-delivered lambs, but this was not influenced by thyrotropin-releasing hormone. Irrespective of delivery temperature, lambs treated with thyrotropin-releasing hormone possessed more pericardial adipose tissue and hepatic glycogen than did control lambs. CONCLUSION: Thyrotropin-releasing hormone treatment stimulated thyroid hormone secretion in the neonatal lamb and improved thermoregulation during the first 6 hours after birth in near-term lambs delivered by cesarean under cool conditions.

Influence of route of delivery and ambient temperature on thermoregulation in newborn lambs.

We examined the effect of route of delivery on brown adipose tissue (BAT) function and thermoregulation in lambs born either vaginally at term or by cesarean section close to term. Immediately after birth, lambs were placed in a warm (30 degrees C; WD) or cool (15 degrees C; CD) ambient temperature, and measurements of colonic temperature, plus heat production (i.e., oxygen consumption and carbon dioxide production), were recorded for 6 h. Over the first 30 min of life, colonic temperature remained constant in vaginally delivered lambs and was lower in the WD group. Following cesarean section delivery, colonic temperature declined rapidly, a response that was greater in the CD group. Cesarean section-delivered lambs had an increased reliance on shivering thermogenesis and restored colonic temperature after 2 h, and by 6 h these parameters were higher than in lambs born vaginally. Irrespective of delivery, temperature, plasma thyroid hormone concentrations and norepinephrine content of BAT were lower in lambs born by cesarean section compared with those born vaginally. Plasma cortisol concentrations and epinephrine content of BAT were greater in lambs born by cesarean section. The amount of uncoupling protein and level of guanosine 5'-diphosphate binding in BAT were higher in vaginally delivered than in cesarean section-delivered lambs, and for each group mean values were greater for CD than WD lambs. Cesarean section delivery results in altered thyroidal, adrenal, and sympathetic activity, which appears to have a marked influence on BAT function, thereby contributing to distinct differences in thermoregulation compared with lambs born vaginally.

Influence of feeding and ambient temperature on thermoregulation in newborn lambs.

This study examined the effect of ambient temperature and feeding on brown adipose tissue (BAT) function and thermoregulation in lambs born either vaginally at term or by Caesarean section close to term. Immediately after birth lambs were placed in a warm (30 degrees C) or cool (15 degrees C) ambient temperature and measurements of colonic temperature and heat production recorded for 6 h. Lambs were fed 50 ml of colostrum when 5 h old. The amount of uncoupling protein and level of guanosine 5'diphosphate (GDP) binding in BAT was higher in vaginally delivered lambs than in lambs delivered by Caesarean section. For each delivery group, GDP binding was greater in lambs maintained at 30 degrees C than in lambs maintained at 15 degrees C. O2 consumption, CO2 production and colonic temperature only increased after feeding in lambs born by Caesarean section and maintained at 30 degrees C, a response that was accompanied by a decreased incidence of shivering. Irrespective of delivery temperature, plasma thyroid hormone concentrations and noradrenaline content of BAT were lower in lambs born by Caesarean section than in those born vaginally. Plasma cortisol concentrations were higher in lambs delivered by Caesarean section, as was adrenaline content of BAT in these lambs maintained at 30 degrees C. It is concluded that the thermoregulatory response to feeding in terms of changes in both recruitment of shivering and colonic temperature were observed only in lambs delivered by Caesarean section.