Histopathological Alterations of Ceca in Broiler Chickens (Gallus gallus) Exposed to Chronic Heat Stress.

Abstract

Heat stress has been found to cause adverse effects on small intestinal microstructure, but little is known about its impact on chicken's cecum. In this research, the histopathological alterations of broiler chicken's cecum following chronic heat stress were evaluated. 20 broiler chickens were randomly divided into control group and treatment group containing 10 replicates, respectively. Both groups were reared under standard conditions until 21 days of age. From day 22 to day 42, the control group was kept at 24-28⁰C as well as relative humidity of 40-55%, while the treatment group was exposed to high temperature of 36-40⁰C and relative humidity of 45-65% for eight hours per day. At the end of the period, proximal part of each chicken's cecum was collected and made into histopathological slides with Hematoxylin and Eosin staining. Villus height, villus width, crypt depth, villus surface area, and villus height to crypt depth ratio were examined from 10 villi per replicate. Results analysis revealed that chronic heat stress profoundly (P<0.05) reduced the crypt depth. Insignificant (P>0.05) changes of the villus despite the longterm heat exposure might imply that the damage is at its early phase. In conclusion, chronic heat stress can produce morphological alterations in the ceca of broiler chickens, though requiring longer duration due to cecum's durability.

Effects of Eimeria tenella Infection on Key Parameters for Feed Efficiency in Broiler Chickens

“…This possibly reduced concentration of VFA and modulated VFA production in ceca content by affecting microbiome of the broiler chickens. Ceca only have villi at the entrance of the ceca to filter large particles away and to act as an immunological detector of cecal contents [ 34 , 35 ], and middle and distal parts of the ceca only have smooth mucous membrane without villi [ 36 ]. Thereby, another possible reason for increased CD in broilers infected with E. tenella would be that birds increased CD to let crypts function like villi as a defensive mechanism in the proximal ceca because E. tenella infected ceca are vulnerable for further infections (e.g., bacterial infection).…”

Morphology, microbiota, and metabolome along the intestinal tract of female turkeys

“…For instance, the present study confirmed the large surface area in the small intestine for rapid water and nutrient absorption ( Svihus, 2014 ; Bindari and Gerber, 2022 ) and relatively shallow crypts associated with a low epithelial turnover ( Iji et al, 2001 ). Ceca were confirmed to possess a smaller surface area, associated with a slower ingesta transit time and time-consuming microbial fermentation processes ( Adji et al, 2019 ). Additionally, their deeper crypts indicate a higher enterocyte replacement rate ( Iji et al, 2001 ).…”

“…EXP 3 was affected by an unusual cold-period in the third and fourth week, during which the birds had a reduced weekly body weight gain. Both cold and heat stress can alter intestinal morphology by causing villus stunting and reduced VSA ( Adji et al, 2019 ). In our study, histomorphometric samples were only collected after the birds had regained their weight in wk 7–10.…”

“…The gut epithelium is continuously renewed by enterocyte proliferation in crypts and migration to villi tips ( Iji et al, 2001 ). Infectious and noninfectious causes may lead to mucosal damage with villus shortening, followed by crypt hyperplasia where enterocyte turnover is increased ( Iji et al, 2001 ; Adji et al, 2019 ). Villus stunting can negatively influence absorption processes in the gut, impairing weight gain in affected animals ( Awad et al, 2008 ).…”