This study examined the effect of ambient temperature on energy intake, perceived appetite and gut hormone responses during rest in men. Thirteen men (age 21·5 (sd 1·4) years; BMI 24·7 (sd 2·2) kg/m2) completed three, 5·5 h conditions in different ambient temperatures: (i) cold (10°C), (ii) thermoneutral (20°C) and (iii) hot (30°C). A standardised breakfast was consumed after fasting measures, and an ad libitum lunch provided at 4–4·5 h. Blood samples (analysed for plasma acylated ghrelin, total peptide tyrosine-tyrosine (PYY) and total glucagon-like peptide 1 (GLP-1) concentrations), perceived appetite and thermoregulatory responses were collected throughout. Linear mixed models were used for statistical analyses. Ad libitum energy intake was 1243 (sd 1342) kJ higher in 10°C and 1189 (sd 1219) kJ higher in 20 v. 30°C (P = 0·002). Plasma acylated ghrelin, total PYY and GLP-1 concentrations did not differ significantly between the conditions (P ≥ 0·303). Sensitivity analyses for the 4 h pre-lunch period showed that perceived overall appetite was lower in both 30 and 10°C when compared with 20°C (P ≤ 0·019). In conclusion, acutely resting in a hot compared with a thermoneutral and cold ambient temperature reduced lunchtime ad libitum energy intake in healthy men. Suppressed perceived appetite may have contributed to the reduced energy intake in the hot compared with thermoneutral ambient temperature, whereas gut hormones did not appear to play an important role.

Data on admissions of schizophrenia- and schizoaffective disorder patients to Tel-Aviv’s seven public psychiatric hospitals during 11 consecutive years were obtained along with relevant meteorological information. Mean monthly admission rates were significantly higher during the summer (for schizophrenia patients) and fall (for schizoaffective patients). Schizophrenia patients’ mean monthly admission rates correlated with mean maximal monthly environmental temperature (R =0.35, N =132 months, P <0.001). The present study may indicate that persistent high environmental temperature may be a contributing factor for psychotic exacerbation in schizophrenia patients and their consequent admission to mental hospitals.

Introduction. Olive processing in producing countries, such as Iran, is often not well synchronized with crop harvests due to the number and size of the oil-extraction facilities. After harvest, olives might be piled in heaps and stored at ambient temperatures for up to several weeks and, during this period, the greatest deterioration takes place. Therefore, the green olive processing industry is interested in the use of an alternative to the above pre-processing storage method for fresh olives. Materials and methods. Green olives cvs. Blady, Conservolea Mission and Shengeh were harvested at the mature green stage and stored at (5, 10 and 20) °C for 10–15 weeks to evaluate their postharvest physiology and quality changes. In the second year of the experiment, olives were treated with 1-MCP at concentrations of (0.45, 0.9 and 1.8) µL·L–1 at 20 °C for 24 h and stored at 5 °C. Olive quality was measured periodically for skin color, fresh firmness, mass loss and fruit deterioration. Results and discussion. Generally, storage of olive fruits at (5, 10 and 20) °C caused a decrease in flesh firmness, but fruit softening was faster in fruits stored at (20 and 10) °C than in fruits at 5 °C. Olives stored for 60 d at 5 °C showed no symptoms of chilling injury whatever the cultivar. Olive cultivars retained satisfactory firm flesh above 2 kg for 60 d at 5 °C, 30 d at 10 °C and 15 d at 20 °C. After 60 d of storage, red skin color development did not progress much with fruits stored at 5 °C, but there was a significant difference with the other temperature treatments. However, cv. Shengeh developed red skin color greater and sooner than other cultivars did. In the second year of the experiment, 1-MCP treatment effectively reduced loss of firmness for fruits stored at 5 °C for 15 weeks. Application of (0.9 and 1.8) µL 1-MCP·L-1 was sufficient to delay significantly olive softening and color changes (P < 0.05), compared with control untreated fruits. Conclusion. Conservolea, Mission and Blady olive cvs. can be stored for up to 60 d at 5 °C and this could be extended to 15 weeks when fruits are treated with (0.9 and 1.8) µL 1-MCP·L-1 before storage.

The effects of ante-mortem stressors such as stunning, struggling, environmental temperature and feed withdrawal on the biochemical changes of broiler breast muscle are assessed in relation to post-mortem biochemical changes and the subsequent tenderness of broiler breast meat. The findings of investigations concerned with broiler meat are presented alongside more fundamental studies addressing such aspects as Ca2+ release and sequestration, endocrine changes during periods of stress and the role of fatty acids as regulators of membrane bound channels. An attempt is made to assimilate the pertinent facts associated with this topic and to give directions for future research. It is concluded, however, that, whilst tenderness in meat is often associated with a loss of ATP, glycogen breakdown and lactic acid accumulation within muscles, current data are insufficient to enable a definitive decision to be made as to which have adverse effects on broiler meat tenderness.

Thermal environment and water supply are factors which are supposed to influence the performance and well being of farm-raised mink but conclusive literature data are still very limited. The present series of experiments was conducted in order to quantify effects of thermal environment on water intake and excretion, urinary solute excretion and estimate possible stress reactions. Water intake and excretion, urinary osmolality and urinary excretion of sodium (Na), potassium (K), cortisol and catecholamines were studied in a balanced Latin-square design experiment with six adult male mink, kept at three different ambient temperatures (Ta); (5°C, 20 °C and close to 35 °C) and given three different water supplies (E: extra water in the food; N: normal ad libitum drinking water supply; R: restricted, free access to drinking water twice daily). The experiment comprised nine periods, each of 3 days. Food apparent digestibility, intake of metabolizable energy (ME), metabolic and evaporative water, oxidation of nutrients and ME requirement for maintenance (MEm) were calculated. Water intake was strongly affected by Ta, with dietary water being the major source at 5°C and 20 °C, its importance being profoundly exceeded by drinking water at 35 °C. Water excretion in urine was highest at the lowest Ta and lowest at the highest Ta. Restriction of access to drinking water resulted in lower total water intake, and excretion, mainly by decreased urinary volume, reflected by increased urinary osmolality and increased solute concentration. ME intake decreased as Ta increased but urinary and total water output per kJ ME was not significantly affected by Ta or water supply. Excretion of Na and К per kJ ME mainly monitored urinary water excretion, being highest under conditions when urine production was highest. Metabolic water made up 0·14 to 0·17 of the total water intake and evaporative loss increased from about 50 to 125 g/kg live weight (M)0·75 as Ta increased. MEm was lowest (534 kJ/kg M0·75) at 20 °C, and highest (647 kJ/kg M0·75) at 35 °C. Cortisol excretion generally tended to increase when water supply was restricted, the increase being significant at 35 °C. This, in combination with outer signs of distress in the animals, emphasized that this high temperature in combination with limited access to drinking water exposed the animals to a very stressful situation but rectal temperature remained normal, indicating intact temperature regulation mechanisms.

Quantitative water intake and excretion, urinary osmolality and urinary excretion of Na, K and cortisol were studied in an experiment with nine adult male mink. The experiment comprised four periods each of 3 days, and ambient temperature (Ta) was increased from 5°C to 20 °C (periods 1 to 2) and, after an interval of 1 day, continued at 20°C and then decreased to 5°C (periods 3 to 4). Three different water supplies were given, namely E: extra water in the food, N: normal ad libitum water supply or R: restricted, free access to drinking water twice daily. Intake of metabolizable energy (ME) was calculated, and the water intake and excretion data were related to ME intake. The effect of Ta on quantitative water intake and excretion was evident, with the greatest response recorded when Ta was decreased. Intake of drinking water was highest at 20 °C, as well as the total water balance. The water supply had some, but not a profound, influence on water intake and excretion, with tendencies for reduced drinking water intake and water excretion in urine for R mink. Intake of ME decreased during period 3 at 20 °C and then increased when Ta was decreased to 5°C, which was reflected by an increased 24-h excretion of Na and K as well as an increased osmolality of the urine. Therefore, it was concluded that water intake and excretion were affected by combined effects of Ta and ME intake. Generally, it was shown that the mink responded rapidly to changes in Ta, and within 24 h significant effects of the change could be recorded for several of the traits studied.

The trade-off made by pigs between exposure to a concentration of ammonia gas recorded in commercial piggeries and thermal comfort was observed in two chronic choice tests. In the first experiment, eight pigs which were paired and eight pigs which were held as singles, were forced to choose between compartments of a preference chamber that were polluted with an ammonia gas concentration of 40 p.p.m. and heated with a 750 W radiant heater or compartments that were unpolluted and unheated, for 8 days. The location of the choice options was switched after 4 days to eliminate positional bias. Air temperature ranged from 0·5 °C to 15·0 °C. In the second experiment, eight pigs held as pairs, were free to choose between compartments that were polluted with an ammonia gas concentration of 40 p.p.m. and heated with a 750 W radiant heater, polluted and unheated, unpolluted and heated and unpolluted and unheated, for 14 days. The location of the choice options was switched after 7 days to eliminate positional bias. Air temperature ranged from 4·0 °C to 24·0 °C. All compartments contained food and water ad libitum; wood shavings were used as bedding material. In both experiments, the location of all pigs was scan sampled every 15 min and their behaviour at this time was recorded instantaneously. Location and behaviour were compared against air temperature. In the first, forced choice experiment, the pigs preferred the heated-polluted compartments when air temperature was less than the estimated lower critical temperature (LCT) (P < 0·001). As air temperature approached the estimated LCT, the pigs occupied the unheated-unpolluted compartments more often. Overall each visit made to the heated-polluted compartments lasted significantly longer at 265 min (paired), 208 min (single) than visits to the unheated-unpolluted compartments at 29 min (paired), 31 min (single) (P < 0·001). Although they could have huddled to conserve heat, the paired pigs spent less time, overall, in the unheated-unpolluted compartments (P < 0·001). When air temperatures were lower than the estimated LCT, the pigs huddled together but as air temperature increased, the pigs spent more time resting apart (P < 0·001) in the heated-polluted compartments. It is suggested that the paired pigs were motivated to remain in the heated-polluted compartments for companionship rather than thermal comfort. In the second, free choice experiment, the pigs preferred to remain in the unpolluted compartments, adjusting their occupancy of the heated and unheated compartments as ambient air temperature decreased or increased above the estimated LCT (P < 0·001). The pigs made fewer visits to the polluted compartments and each visit was shorter, at 44 min (P < 0·001). Visits to the unpolluted compartments lasted for 291 min. It is suggested that the delayed aversion shown to ammonia in both experiments was due to a progressive sense of malaise. However, both experiments indicated that this delayed ammonia aversion was weaker than preference for thermal comfort.

The present experiments4 were undertaken to investigate the effects of environmental temperatures on growth, abdominal fat content, rate of muscle protein turnover, and heat production in tube-fed intact male broiler chickens. Plasma concentrations of thyroxine (T4), triiodothyronine (T3), and corticosterone (CTC) were also examined. Chicks (15d old) were kept at different environmental temperatures (16,19,22,25,28,31, and 34°) and given the experimental diet (200g crude protein/kg, 13·;57M/kg metabolizable energy) by tube three times daily throughout the 12d experimental period. In the hot conditions, except for 34°, body-weight gain was significantly higher than in the cold conditions. Thus, food conversion ratios (food: gain ratios) were lower when the birds were exposed to the hot conditions other than 34°. Likewise, abdominal fat content was significantly increased, and heat production was lower in the groups kept under the hot conditions other than 34°. The rate of skeletal muscle protein turnover and plasma concentration of CTC were decreased when the birds were exposed to hot conditions other than 34°. suggesting a role of CTC in the regulation of muscle protein turnover. Plasma concentrations of T4 and T3 were significantly decreased as environmental temperature increased. These results clearly show that plasma concentrations of thyroid hormones and CTC are associated with accelerated muscle protein turnover and heat production.

An experiment involving 18 individually fed barrows weighing about 81 kg was conducted to determine the effects of a high ambient temperature (30°C v. 22°C) and dietary fat supplementation (100 g/kg diet of encapsulated-tallow v. 0 g/kg) on growth performance and carcass fatness of finishing pigs. Digestible energy (DE) intake and growth rates were significantly lower at a high ambient temperature (P < 0·001). Dietary fat supplementation considerably increased DE intakes at a high ambient temperature (40·0 v. 33·8 MJ/day) while slightly increasing it at a thermoneutral temperature (53·1 v. 50·6 MJ/day). Dietary fat supplementation tended to increase growth rates and significantly improved the efficiency of food utilization (P<0·01). Pigs with dietary fat supplementation exhibited greater enhancement in backfat depths, carcass fatness and internal organ fat at a high ambient temperature than at a thermoneutral temperature. Linear correlation between DE intake and crude fat concentration of carcasses was statistically significant at a high ambient temperature (P < 0·01, r = 0·71). Although there appeared to be a positive correlation, it was not statistically significant at a thermoneutral temperature (P > 0·05). Crude fat concentration of the internal organs linearly correlated with DE intake (P < 0·01, r = 0·66). However, fat concentration of the internal organs did not correlate to DE intake at a thermoneutral temperature. The present study indicated that although dietary fat supplementation improved growth performance of pigs over 81 kg live weight initially in hot environments, there was the disadvantage of excessive fat deposition in their bodies.

Ten Holstein bulls, 4 to 5 years old were used to study the effect of cooling the bulls on their semen quality. Five bulls were sprinkled with water for 15 min five times a day throughout a 6-week period of the summer season (hot-dry) in Saudi Arabia, and the other five bulls acted as the control and were not sprinkled with water. Semen quality was improved significantly during the cooling period. This improvement was evident from the significant increase in sperm motility (P < 0·01) and decrease in the percentage of both dead and morphologically abnormal (primary and secondary) spermatozoa per ejaculate of cooled bulls (P < 0·01). The effect of cooling was more marked through the last 3 weeks than during the first 3 weeks of the experimental period. Ejaculate volume, sperm concentration and hence total sperm counts did not differ significantly between the cooled and the non-cooled bulls. Concerning the type of abnormal spermatozoa, the overall secondary abnormality was higher than the primary in both the cooled and the control groups, with higher values for the control (P < 0·01). Only the mid piece showed higher primary defects than the secondary. The pyriform heads, the coiled mid pieces and tails and the bent tails were the main sources of variations (P < 0·01) in the incidence of sperm abnormality between the cooled and the non-cooled bulls. Cooling the bulls during the heat stress period also lowered their rectal temperature and increased blood haemoglobin level without affecting the packed cell volume

Heat production (HP) and the intake and retention of energy and nitrogen were measured in growing broiler fowl kept at 32° and given diets with metabolizable energy contents from 8 to 15 MJ/kg and crude protein (N × 6·25; CP) contents of 130 and 210 g/kg. The temperature of 32° was chosen for comparison with earlier measurements at 20° to minimize heat produced for the maintenance of body temperature. The effects of diet composition were observed when the same birds were taken from 20 to 32°. The tendency for energy intake to increase with dietary energy concentration was less at 32 than at 20°. The lower heat increments measured for the high-fat diets did not, therefore, confer an increased ability to sustain higher energy intake at 32°. HP was about 17% lower at 32 than at 20°; the change in HP between 20 and 32° was not significantly influenced by diet composition. The absence of significant effects of diet composition on HP, combined with the significant trend in energy intake, produced significant differences (related both to dietary energy and dietary protein concentrations) in total energy retention and in the partition of retained energy between protein and fat. As at 20°, variation in energy retention and in the composition of retained energy were the main responses to variation in dietary CP concentration and energy intake; a significantly higher energy cost of unit protein accretion on the low-CP diets was insufficient to produce an elevation in total HP because the higher unit energy cost was balanced by a lower absolute rate of protein accretion.

Cellular sodium transport via the Na+, K+-ATPase contributes significantly to daily energy expenditure. The effect of a meal on leucocyte Na+ transport and intracellular electrolytes was therefore investigated in lean normal subjects at room temperatures of 23° and 33°, to determine if the Na pump responds to the need for thermogenesis. In the fasting state, the ouabain-sensitive efflux rate which reflects active Na+ transport, and the intracellular electrolytes were similar. At 2 h after eating a 4·2 MJ (1000 kcal) meal, the ouabain-sensitive efflux rate constant rose when the room temperature was 23° but not at 33°. The ouabain-sensitive Na+ efflux rate, an index of active Na+ transport, 0rose post-prandially at 23° only. The post-prandial activation of leucocyte active Na efflux in normal subjects was blunted at higher environmental temperatures, when the need for thermogenesis was reduced.