Submitted to: Poultry Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 11/8/2019
Publication Date: 5/1/2019
Citation: Miska, K.B., Fetterer, R.H. 2019. Expression of amino acid and sugar transporters, aminopeptidase, and the di- and tri-peptide transporter PepT1, between modern fast growing broilers and broilers not selected for rapid growth. Poultry Science. 98:2272-2280. https://doi.org/10.3382/ps/pey583.
Interpretive Summary: Over the course of last 60 years the genetics of chickens used for meat consumption (broilers) has changed to produce birds that weigh five or more pounds in as little time as 40 days. In the past, broiler chickens were raised for more than a 100 days and were half the weight of the modern broiler. Therefore the modern broiler chicken is very efficient at converting nutrients into lean muscle that is sought after by today’s consumers. The purpose of the current study was to compare the production parameters of slow and fast growing broilers as well as studying the differences and similarities in factors that are important for processing and uptake of nutrients. Because the small intestine is the major site of nutrient uptake the current study was carried on these tissues. We found that the slow growing chicks generally expressed greater number of nutrient transport molecules which are present at the lumen of the gut (which is in direct contact with ingested matter), while not as many differences were found between nutrient transport molecules located on the gut surfaces which is responsible transporting nutrients to the rest of the organism. We also found that the molecules that transport sugars in and out of gut cells is at times much higher in the fast growing birds, which may suggest that these molecules play an important role in rapid growth. The results from this study help us identify factors that are important in rapid growth of broiler chicken. This information could be used in the future of poultry production as today’s chickens become better efficient in converting feed to mass.
Technical Abstract: Within the last 60 years genetics of broilers have changed to produce rapid growing birds that achieve market weight in 6 weeks or less. To investigate the differences in factors that play a role in nutrient processing and uptake between modern fast growing (Ross) and slow growing broilers not selected for growth (ACRBC), a study was carried comparing the expression of 13 genes that encode amino acid transporters (ASCT1, ATBo,+, BoAT, bo,+AT, CAT1, CAT2, EAAT3, '+LAT1, and LAT1) and sugar transporters (GLUT2 and GLUT5), as well as aminopeptidase (APN) and the di- and tri- peptide transporter PepT1. The growth rate of Ross birds was approximately 4 times greater than that of ACRBCs, and the feed conversion ratio (FCR) was greater in ACRBCs at all time points measured. Gene expression in the duodenum, jejunum, and ileum was measured at 1, 3, 5, 10 and 14 days post hatch (PH). The expression of genes that encode proteins (particularly ASCT1, ATBo,+, and BoAT located at the brush border of the gut epithelium was generally higher in ACRBCs especially at earlier time points. The expression of genes that encode proteins located at the basolateral surface of the gut epithelium was less affected. The expression of GLUT2 and GLUT5 was significantly decreased in ACRBCs at most time points and gut segments. Based on the present data we conclude that expression of brush border and sugar transporters in the small intestine can be correlated with growth. Presented increases the identification of the factors that influence growth and will assist future studies of the function of these molecules.