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High Environmental Temperatures (high + environmental_temperature)

Distribution by Scientific Domains

Life Sciences	66%
Medical Sciences	33%

Selected Abstracts

ORIGINAL ARTICLE: Ileal endogenous amino acid flow of broiler chickens under high ambient temperature

JOURNAL OF ANIMAL PHYSIOLOGY AND NUTRITION, Issue 5 2010
A. F. Soleimani
Summary High environmental temperature has detrimental effects on the gastrointestinal tract of poultry. An experiment was conducted to determine the effect of acute heat stress on endogenous amino acid (EAA) flow in broiler chickens. A total of 90, day-old broiler chicks were housed in battery cages in an environmentally controlled chamber. Chicks were fed a nitrogen-free diet on day 42 following either no heat exposure (no-heat) or 2 weeks exposure to 35 ± 1 °C for 3 h from days 28 to 42 (2-week heat) or 1 week exposure to 35 ± 1 °C for 3 h from days 35 to 42 (1 week heat). The most abundant amino acid in the ileal flow was glutamic acid, followed by aspartic acid, serine and threonine in non-heat stressed group. The EAA flow in 1-week heat and 2-week heat birds were significantly (p < 0.05) higher than those under no heat exposure (14682, 11161 and 9597 mg/kg of dry matter intake respectively). Moreover, the EAA flow of 2-week heat group was less than 1-week heat group by approximately 36%. These observations suggest that the effect of heat stress on EAA flow is mostly quantitative; however, heat stress may also alter the content of EAA flow qualitatively. [source]

Effect of high environmental temperatures on ascorbic acid, sulfhydryl residue and oxidized lipid concentrations in plasma of dairy cows

ANIMAL SCIENCE JOURNAL, Issue 3 2007
Masahito TANAKA
ABSTRACT Information on oxidative stress under hot conditions from the levels of cells to organs and the whole body has accumulated in the last decades. Although a hot climate decreased dairy performance, changes of oxidative stress markers under hot conditions have remained obscure. Therefore, the effect of high environmental temperature on ascorbic acid, sulfhydryl (SH) residue and oxidized lipids concentrations in plasma from a total of 128 dairy cows was investigated. The monthly average maximum day temperature varied from 9.2°C in January to 32°C in August of 2004 in this institute. High ambient temperatures increased the rectal temperature of dairy cows up to 39.3°C in August. One of the reducing equivalents in plasma, SH residue concentration, decreased in July compared with December (P < 0.05). Another antiradical molecule, ascorbic acid concentration in plasma, also decreased in July (P < 0.01). The oxidative stress index, thiobarbituric acid reactive substance (TBARS), which was produced from the oxidation of polyunsaturated fatty acids under oxidative conditions, increased in summer (P < 0.05). A significant positive relationship of SH residue and ascorbic acid concentrations in the hot season was observed (P < 0.01). A negative correlation between rectal temperatures and ascorbic acid concentrations in the hot season was obtained (P < 0.01). However, TBARS concentration varied independently of the SH residue and ascorbic acid concentration. These results suggest that the response of oxidative stress markers of SH residue, ascorbic acid and TBARS concentration to oxidative stress under hot conditions were not shown to be the same, and that oxidative stress in dairy cows in the hot season increased. [source]

Factors influencing testicular volume in young men: results of a community-based survey

BJU INTERNATIONAL, Issue 4 2002
J.H. Ku
Objective,To investigate the factors influencing testicular volume in young men in the community. Subjects and methods,Between May and November 2001, 2700 men aged 20 years and dwelling in the community were randomly selected at a 10% sampling fraction after a sampling process by census district; 2080 men agreed to participate in the study. All volunteers underwent a standard evaluation, including a detailed medical history and physical examination. After excluding those with testicular diseases the study comprised 1792 men. Results,There were significant but weak correlations between testicular volumes and height, body weight and body mass index. In a multivariate model, high environmental temperature was associated with a decreased likelihood (odds ratio, OR, 0.42; 95% confidence interval, CI, 0.29,0.60; P < 0.001) of a paired testicular volume being below the 25th percentile of all participants. The likelihood of a low paired testicular volume varied by area, with a 1.6-fold greater risk in men dwelling in large rural areas than in those in major towns. Increasing height was associated with a decreased likelihood (OR 0.60; 95% CI 0.38,0.96; P = 0.032) and low body weight with an increased likelihood of a low paired testicular volume (OR 2.54; 95% CI 1.57,4.12; P < 0.001). Conclusion,These results establish that demographic and environmental factors have an effect on testicular size and suggest that body size may be important in determining testicular size in late adolescents. [source]

Nursing management of fever in children: A systematic review

INTERNATIONAL JOURNAL OF NURSING PRACTICE, Issue 1 2003
FRCNA, Robin Watts RN
ABSTRACT Objectives:, The aim of the present review was to determine whether the best available evidence supports the types and timing of the various nursing interventions that are commonly used to reduce fever in non-critically-ill children, and to what extent the outcomes are influenced by these nursing actions. Methods:, Studies included were randomised or quasi-randomised controlled trials that involved non-critically-ill children with a fever aged between 3 months and 16 years. ,,The search strategy sought to identify both published and unpublished research reports in the English language and covered all major databases up to 1998. ,,The methodological quality of each study was assessed by two independent reviewers using a piloted critical appraisal checklist. ,,Despite all studies being randomised, heterogeneity precluded conduction of a meta-analysis; therefore, evidence was synthesised using narrative summaries. Results: Ten studies were assessed as being of sufficient quality to be included in the review. These studies addressed two of the intervention categories identified in the protocol: (i) administration of antipyretics (paracetamol); and (ii) direct cooling measures on the outcome measure (reduction of or prevention of increase in fever). The review found little benefit from sponging in temperate climates and usually at the expense of the child's comfort. There may be situations in high environmental temperatures and high humidity, or where there is a need for immediate temperature reduction, in which sponging may be warranted. Risks were identified when paracetamol was administered on a sustained basis over even a short period of time and above a relatively low total daily dosage. There was a lack of evidence to support the administration of antipyretics to reduce the incidence of febrile convulsions. There is a need for parental education that focuses on knowledge of the body's protective physiological responses and how to support these responses. Conclusion: The primary purpose for intervening when a child has a fever is to increase the child's comfort. This consideration should be weighed against any harm that might result from intervening. There was a lack of evidence to support the routine use of sponging. The administration of paracetamol should be used selectively and with caution. In summary, care needs to be individualised, based on current knowledge of the effectiveness and risks of interventions. [source]

Effect of polyphenols extracted from Tamarind (Tamarindus indica L.) seed coat on physiological changes, heterophil/lymphocyte ratio, oxidative stress and body weight of broilers (Gallus domesticus) under chronic heat stress

ANIMAL SCIENCE JOURNAL, Issue 2 2010
Worapol AENGWANICH
ABSTRACT The aim of this experiment was to determine the effect of polyphenols extracted from tamarind (Tamarindus indica L.) seed coat on physiological changes, oxidative stress and production of male broilers maintained at high environmental temperatures. The results found that body temperature and respiratory rate of broilers maintained at 38 ± 2°C was higher than broilers maintained at 26 ± 2°C (P < 0.05). On day 1, the heterophil/ lymphocyte ratio of broilers maintained at 38 ± 2°C and received polyphenols at 300 and 400 mg/kg in diets was lower than broilers that received polyphenols at 0 and 200 mg/kg in diets (P < 0.05). At week 1, the malondialdehyde of the broilers maintained at 38 ± 2°C who received polyphenols at 400 mg/ kg in their diet was lower than broilers that received polyphenols at 100 and 200 mg/kg in diets (P < 0.05). At week 1, the body weights of broilers that were maintained at 38 ± 2°C who received polyphenols at 100,500 mg/ kg in diets, and broilers maintained at 26 ± 2°C were higher than that of the control group which had not been treated with a polyphenol diet (P < 0.05). This study indicated that polyphenols could reduce heat stress, oxidative stress and improve the growth rate of heat-stressed broilers. [source]