Role of ascorbic acid in chicks exposed to high environmental temperature

Abstract

This study was conducted to determine if ascorbic acid (AA) 1) increases resistance to high environmental temperature in young chickens and 2) alters heat-induced changes in several physiological responses. Groups of male chicks received either a standard ration containing 1,000 mg/kg (ppm) of AA or the ration without AA. Chicks were brooded for 3 wk and then maintained at 22 +/- 0.8 degrees C. At 4 wk of age, both AA-supplemented and control chicks were exposed to 30 min of heating (43 +/- 0.1 degrees C and 40 +/- 2% rh) on each of 3 consecutive h in an environmentally controlled chamber. Chicks were challenged with sheep erythrocytes (1 ml, 10(5) cells, iv) 12 h postheating. Heating reduced plasma potassium, body weight gain, relative bursa and spleen weights, and anti-sheep erythrocyte levels. Heating increased cloacal temperature, plasma protein, corticosteroid levels, and mortality. AA ameliorated many of these stress-related responses.

Effect of breeder age and lighting regimen on growth performance, organ weights, villus development, and bursa of fabricius histological structure in broiler chickens

“…Spleen is the most important lymphoid organ and combines the innate and adaptive immune response in a uniquely organized way. Pardue et al (1985) and Awadalla (1998) reported lighter spleen weight after chick's exposure to environmental stressors. The results of the present study showed that spleen of CL chicks was significantly heavier than that of SD chicks.…”

Performance and Humoral Immune Response in Heat-Stressed Broilers Fed an Ascorbic Acid Supplemented Diet

“…Despite the difference in the relative size of the bursa, the histologic study suggests that the changes were very limited, consisting of only a mild lymphoid depletion. This apparently contradictory result might be explainedby the protective effect of AA on immunological tissues and cell membranes from the insult of steroids (Pardue et al, 1985b). If this is the case, then the concentration of 500 ppm AA would seem to be adequate for this protection.…”

“…Kafri and Cherry (1984) also reported a greater body weight in 36-day-old heat-stressed broilers fed a diet supplemented with 100 ppm AA. The immunosuppression mediated by heat stress in chickens has been found to be partially ameliorated by AA supplementation (Pardue et al, 1985b). The improvement, as assayed by the increased agglutinin levels to sheep red blood cells, was attributed to the decrease of endogenous adrenocortical hormones (Pardue et al, 1985b) as a result of the inhibition of C-21 and 11-0-hydrowlase in the steroidogenic pathway (Cooper and Rosental, 1962;Kitabchi, 1967).…”

“…The exact mechanisms by which AA alleviates stress are still unknown. A postulated hypothesis is that AA would serve as a regulator of glucocorticoid synthesis, or protect tissues from the cytotoxic effect of adrenal glucocorticoids via its role as an antioxidant, or both (Pardue et al, 1985b).…”

Evaluation of cold water and vitamin C on broiler growth during hot-dry season in sw Nigeria

“…However, efficacy of this practice has not been scientifically proved in Nigeria. Dietary supplementation with vitamin C has been reported to be efficient in reducing effects of heat stress in chickens (Pardue et al, 1985;Pardue and Thaxton, 1986;Sahin, 2003;Mahmoud et al, 2004). Combining chilled water with vitamin C may be more useful.…”