The effect of short heat stress upon leucocyte count, plasma corticosterone level, plasma and leucocyte ascorbic acid content

Db, Nathan; Ed, Heller; Perek, M.

doi:10.1080/00071667608416303

Cited by 65 publications

(26 citation statements)

References 16 publications

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“…In hens, changes of leukocytes in response to stress have been found to be less variable and thus a more reliable indicator than plasma corticosterone values (Gross and Siegel 1983;McFarlane and Curtis 1989). Heat stress has been found to decrease lymphocyte numbers and increase plasma corticosterone concentrations in cockerels (Ben Nathan et al 1976). Altan et al (2000) reported that after a 2 h heat stress, broiler chickens exhibited significantly reduced lymphocyte and raised heterophil ratios.…”

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Impact of Vitamins C and E Dietary Supplementation on Leukocyte Profile of Layer Hens Exposed to High Ambient Temperature and Humidity

2010

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A 30-day experiment involving 720 White Leghorn layer hens was carried out to evaluate the effects of vitamins C and E on leukocyte and heterophil/lymphocytes ratios of the layer hens during the natural summer conditions. The birds were divided into 4 groups, one control with basal diet and three experimental with diet supplemented with vitamin C, vitamin E, or combination of both vitamins. Each group was divided into 4 subgroups. Exposure of layer hens to 31 ± 3 °C and 33 ± 0 °C ambient temperature and 84.6% and 81.5% relative humidity during the experiment caused an increase in the value of temperature humidity index of 15.5 above the threshold value of 70 established for this species. Total white blood cells, lymphocytes, and eosinophil levels were significantly (p < 0.001) higher in all treated groups compared to control. Similarly, heterophil/lymphocyte ratios of 0.51, 0.52, and 0.50 for groups with diet supplemented with vitamin C, vitamin E and vitamins C + E, respectively, were significantly (p < 0.001) lower compared to 0.59 recorded in the control group. However, heterophil, basophil and monocyte values were significantly (p < 0.001) higher in the control group compared to all treated groups. The results of the present study showed that dietary supplementation of vitamins C and E, or their combination, reduces the harmful effect of high ambient temperature and humidity on the leukocyte indicators of exposed layer hens, thereby alleviating the stress imposed on their thermoregulatory mechanism and physiological status. Heat stress, antioxidant vitamins, white blood cells, laying birdsAll over the world, farmers have to solve a problem of heat stress in poultry during the summer period. Global warming as a result of increased industrialization and environmental degradation has led to continuous increase in ambient temperature, thereby making heat stress a major problem of livestock farming, particularly in the poultry sector (Daghir 2009). This is because poultry are particularly sensitive to high ambient temperature (AT), more than to cold. Heat stress interferes with the birds' comfort and suppresses production efficiency. In birds, high ambient temperature leads to increased endogenous heat production, since convective transfer of heat is the major thermoregulatory mechanism of birds and depends on air movement by natural or fan-powered ventilation (Shane 2005). As a response, birds have to make major thermo-regulatory adaptations to prevent death from heat exhaustion. As a result, the genetic potential of layer hens is often compromised (Holik 2009). The responses of poultry to high ambient temperatures have been studied several times, but the effect of relative humidity (RH) on intensifying or modifying these responses has received little attention. Relative humidity is rarely included as an experimental variable or measured for information purposes. Such information is important because in poultry-producing regions high temperature can often be accompanied by a range of RH, which can marked...

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Impact of Vitamins C and E Dietary Supplementation on Leukocyte Profile of Layer Hens Exposed to High Ambient Temperature and Humidity

2010

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“…Heat treatment did not impair the in vivo clearance of carbon particles and it was concluded that a high environmental temperature depresses the ability of chickens to express humoral immune responses (Thaxton and Siegel, 1970;Thaxton and Briggs, 1972;Thaxton and Siegel, 1973;Seto, 1972). In a previous publication (Ben Nathan et al, 1976) it was found that heat caused a significant decrease in leukocyte counts and an increase in corticosteroid and ascorbic acid in plasma. The object of this research was to determine the effect of short heat stress on the primary antibody response, number of splenic plaque forming cells (PFC) and phagocytotic activity in young birds.…”

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Short heat stress as an immunostimulant in chicks

Perek

1979

Avian Pathology

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SUMMARYThe effect of 1 hour exposure of seven 1-week-old chicks to heat stress (41.5-42.5°) on their antibody titre after antigenic stimulation with E.coli bacteria was assessed.Exposure to heat 24 or 96 hours after immunisation resulted in a significant increase in antibody titres while heat treatment 42 or 72 hours after vaccination caused a non-significant increase in antibody titres. Heat exposure for 2 hours, 24, 48, 72 or 96 hours after immunisation either with E. coli or sheep red cells (SRBC) resulted in significantly increased antibody titres. When a number of antibody forming cells (against SRBC) in the spleens were tested, heat treated chicks showed no significant increase compared with the non-treated group. Heat-exposed chicks phagocytised Staphylococcus aureus bacteria (as measured by their disappearance from the blood) more rapidly than the non-treated group.

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“…McFarlane and Curtis (1989) reported that exposing 7-d-old chickens to environmental heat stress for 7 d did not increase CS levels. On the contrary, Ben-Nathan et al (1976) found an increased level of CS in chickens exposed to constant chronic heat stress (32.2°C) compared with control (21°C). These contradictory observations might be associated with the age or genetic background of chickens involved in the study.…”

Section: Discussionmentioning

confidence: 61%

Effects of genetic group × ambient temperature interactions on performance and physiological responses of Naked-neck chickens and their F<sub>1</sub> crosses with Lohmann White and New Hampshire laying hens

Melesse

Maak²,

Lengerken³

2011

J. Anim. Feed Sci.

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The objective of this study was to evaluate the effects of genotype x temperature interactions on hormonal heat stress indicators and performance traits. Two-hundred forty female oneday-old chicks were randomly assigned to a completely randomized design in a 5×2 factorial arrangement with 5 genotypes (Naked-neck, Na, from Ethiopia; New Hampshire, NH; Lohmann White, LW and F 1 crosses of Na with NH and LW) and 2 ambient temperatures (thermo-neutral, 18-20 o C; heat stress, 30-32 o C). Blood samples were taken from 12 randomly selected birds per genotype and ambient temperature at 22, 38, 51 and 65 weeks of age. Levels of corticosterone (CS) and 3,5,3′-triiodothyronine (T 3 ) were determined in blood plasma. Heat stress effects on egg production traits were most severe in LW and NH, least severe in Na and Na × LW, intermediate in Na × NH. Plasma T 3 level was significantly reduced by 27.9% in heat stressed genotypes. Plasma CS increased by 12.6% in heat exposed genotypes. However, inconsistent responses of CS and T 3 levels were observed at different ages. The Na and their F 1 crosses demonstrated relatively better thermotolerance than LW and NH hens. Levels of plasma T 3 hormone might be considered as indicator of long-term heat stress in hens. HEAT STRESS -LAYING PERFORMANCE

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The effect of short heat stress upon leucocyte count, plasma corticosterone level, plasma and leucocyte ascorbic acid content

Cited by 65 publications

References 16 publications

Impact of Vitamins C and E Dietary Supplementation on Leukocyte Profile of Layer Hens Exposed to High Ambient Temperature and Humidity

Impact of Vitamins C and E Dietary Supplementation on Leukocyte Profile of Layer Hens Exposed to High Ambient Temperature and Humidity

Short heat stress as an immunostimulant in chicks

Effects of genetic group × ambient temperature interactions on performance and physiological responses of Naked-neck chickens and their F<sub>1</sub> crosses with Lohmann White and New Hampshire laying hens

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