Phytase Effect on Broiler Performance and Gene Expression

Many results already show how phytase increases nutrient digestion in chickens and pigs, but nothing related if phytase could change gene expression. Two experiments were conducted beginning with a commercial 1-d-old Ross 708 broiler line and a heritage line from the University of Illinois. The chicks were weighed and randomly assigned in a factorial schedule (2x3), with two lineage and three phytase levels (0, 500 and 1500 phytase units/kg). On days 14, 21 and 41, the animals and the feed were weighed for the performance, and one bird/replicate was euthanized by cervical dislocation to collect the following tissues: duodenum (+content), jejunum (+content), ileum (+content), liver, spleen, colon, caeca, breast muscle, kidney and the right tibia. The tissue and the contents were immediately frozen in liquid nitrogen and then stored at -80 ºC. All the tissue samples will be used for RNA-sequence. The contents will be used to do bacterial DNA expression. For the performance results, we detected in ross birds at 21 days of age that phytase can improve the weight gain and feed intake when we offer them a feed with low nutrients concentration plus 1500 FTU of phytase when compared to birds that receive the correct nutrient concentrations without phytase. We didn´t find the same performance results for the Illinois birds. For the birds that were fed 1500 FTU of phytase, gene expression data indicated lower levels of mineral transporters in liver tissue.