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Title:The Effects of High Environmental Temperature Induced Acid-Base Disturbance on The Utilization of Calcium by The Domestic Hen
Author(s):Odom, Ted William
Department / Program:Animal Science
Discipline:Animal Science
Degree Granting Institution:University of Illinois at Urbana-Champaign
Subject(s):Agriculture, Animal Culture and Nutrition
Abstract:The effects of an acute heat stress (35(DEGREES)C) on respiratory rate, blood pH, blood PCO(,2) and blood HCO(,3)('-) concentration was investigated in SCWL hens. Within one hour after initiation of heat challenge, respiratory rate was significantly (P < .01) elevated which led to blood alkalosis from a reduction (P < .01) in blood PCO(,2). These trends continued for an additional hour when blood pH began declining. Following the heat stress period, blood pH was reduced from initial pH but not significantly. During this time blood PCO(,2) remained low while HCO(,3)('-) concentration dropped 50 percent. Accompanying this pH and HCO(,3)('-) drop was an increase (P < .01) in blood lactate and pyruvate. This suggests that the buffering of these organic acids by blood HCO(,3)('-) brought the blood {HCO(,3)('-)}/{H(,2)CO(,3)} ratio back toward 20:1 by reducing blood HCO(,3)('-) concentration. As a result blood pH was lowered.
Development of alkalosis during thermal panting was studied in conjunction with blood ionized calcium. As before, alkalosis developed shortly after panting started. Concomitant with elevated blood pH was a decline in ionized calcium. Two hours after the start of heat stress blood ionized calcium was reduced by 15 percent. This reduction in blood ionized calcium continued although blood pH was returning. The elevation (P < .01) of lactate and pyruvate was highly correlated (-0.81 and -0.77, respectively) with declining blood ionized calcium, suggesting that they and possibly other organic acids were binding ionized calcium. Further, ionized calcium levels did not return until blood organic acid concentration fell.
A study was initiated in which effects of drinking carbonated water on egg production and egg shell quality could be determined during controlled and natural heat stress episodes. Under controlled heat stress, exposure to 35(DEGREES)C produced a rapid decline in percent egg shell and egg specific gravity. Hens drinking carbonated water had significant (P < .01) relief from this reduction. In addition, critical decline in percent egg shell (<8.5 percent) was one day later for hens drinking carbonated water. Thus, the devastating effect on egg shell quality might be avoided if hens drink carbonated water during short periods of high environmental temperature (1 or 2 days).
Issue Date:1982
Description:137 p.
Thesis (Ph.D.)--University of Illinois at Urbana-Champaign, 1982.
Other Identifier(s):(UMI)AAI8218533
Date Available in IDEALS:2014-12-15
Date Deposited:1982

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