Intestinal amino acid and peptide transporters in broiler are modulated by dietary amino acids and protein.

This study evaluated the effect of three levels of digestible amino acids (DAA; 100, 107 and 114% of Cobb recommendations) on mRNA abundance of peptide (PepT1) and amino acid (AA) transporters in 480-day-old broilers during prestarter period. Jejunal mRNA levels of the PepT1 and b0,+AT increased as DAA level increased from 100 to 114%. The expression of CAT1 mRNA in the jejunum was higher in birds fed 100% DAA diet. The transport systems B0AT and y+LAT1 were not affected by the dietary treatments. These results demonstrated that dietary content of protein and DAA differentially affected the expression of intestinal peptide and AA transporters to modulate absorption of peptide and AA in broilers.

Impact of mash and crumble diets on intestinal amino acids transporters, intestinal morphology and pancreatic enzyme activity of broilers.

The objective of this study was to evaluate effects of mash and crumble pre-starter diets on pancreatic enzyme activity, intestinal morphology, gene expression of intestinal peptide and amino acid (AA) transporters of broilers. Broilers in battery cages were assigned to different feed forms of pre-starter diet from 1 to 10 days of age. Significantly increased body weight gain (BWG), feed intake (FI) and lowered FCR were observed in birds fed crumble pre-starter diet (CPD, p < 0.05). Feed forms had no effect on whole and small intestine length, but relative intestinal length and relative small intestinal length significantly increased in the broilers fed a mash pre-starter diet (MPD, p < 0.05). Feeding CPD increased the weight of pancreas (p < 0.05), but relative weight of the pancreas was not influenced by treatments. Pancreatic protease and amylase activities significantly increased in the broilers fed CPD (p < 0.05) but the activity of lipase was not influenced. Crypt depth (CD) and villus height (VH) were higher in broilers fed CPD (p < 0.05) but villus width (VW), villus surface area (VSA) and villus height-to-crypt depth ratio (VCR) were not influenced by treatments. mRNA levels for peptide transporter 1 (PepT1), Na+ -independent cationic AA transporter1 (CAT1), Na+ -independent cationic and Na+ -dependent neutral AA transporter 1 (y+ LAT1) and Na+ -dependent neutral AA transporter (B0 AT) were lower in birds fed CPD (p < 0.05). There were no differences in mRNA abundance of Na+ -independent cationic and zwitterionic AA transporter (b0,+ AT) among treatments. Overall, the present data showed that feeding crumble diet during first 10 days of age, through higher FI, enhanced intestinal histomorphology, increased digestive enzyme activity is beneficial to growth performance of broilers. Indeed, dietary form can be an important factor in the expression of jejunal transporters.