Effect of Corticosterone Administration on Small Intestinal Weight and Expression of Small Intestinal Nutrient Transporter mRNA of Broiler Chickens

Abstract

The effects of corticosterone (CORT) administration on the weight of small intestine and the expression of nutrient transporter mRNA in the small intestine of broiler chickens (Gallus gallus domesticus) were investigated. One hundred and eight seven-day-old birds were randomly divided into two equal groups comprising a control group (CTRL) and an experimental group (CORT). CTRL birds were fed a basal diet and the CORT birds were fed a basal diet containing 30 mg corticosterone/kg from d 8 to 21. At 21 d of age, average daily feed intake (ADFI), serum corticosterone level, small intestinal absolute wet weight and relative weight, and relative abundance of SGLT1, CaBP-D28k, PepTl mRNA in the duodenum and L-FABP mRNA in the jejunum were determined. The results showed that serum corticosterone level, liver weight and small intestinal relative weight (small intestinal wet weight/body weight) of CORT chickens were about 30.15%, 26.72% and 42.20% higher, respectively, than in the CTRL group (p<0.05). CORT birds had relative mRNA abundance of CaBP-D28k and PepT1 in the duodenum, and L-FABP in the jejunum which was 1.77, 1.37 and 1.94 fold higher, respectively, than in the CTRL group (p<0.05); the relative abundance of SGLT1 was 1.67 fold higher than in the CTRL group (p = 0.097). ADFI, small intestinal wet weight and length in CORT-treated broiler chickens was about 29.11%, 31.12% and 12.35% lower, respectively, than in the CTRL group (p<0.05). In conclusion, corticosterone administration lowered the wet weight but increased the relative weight of the small intestine and the expression of intestinal nutrient transporter mRNA of broiler chickens.