Differential growth performance and intestinal immune gene expression in diverse genetic lines of growing chickens fed a high concentration of supplemental phytase

摘要

The objective of the current experiment was to determine the effects of high-concentration phytase (5000 FTU/kg) feeding to diverse lines of chickens fed phosphorus (P) adequate maize-soybean meal diets (4.5 g/kg non-phytate P) on the performance and intestinal immune function. Performance was measured for outbred broiler (Ross 308) and inbred Fayoumi lines over 0-21 days, and duodenum and ileum were harvested for the determination of mucin-2, interleukin (IL)-1 beta and IgA mRNA by quantitative reverse transcription polymerase chain reaction. Over the 0-7-day period, there was a significant line x diet interaction, as high phytase supplementation increased broiler average daily gain (ADG), but had no effect on Fayoumi ADG. Treatment of diets with phytase increased expression of the mucin-2 gene in the duodenum mucosa. There were significant interactions between line and age, and line, diet and age on duodenal expression of the IL-1 beta gene as phytase supplementation of the broiler line reduced IL-1 beta in comparison to control fed broilers without change in the Fayoumi line. Overall, the addition of a high concentration of phytase to broilers fed adequate concentrations of non-phytate P resulted in improved growth performance early with a reduction in this effect over time. Mucosal mucin-2 expression was increased with high-concentration phytase feeding across both lines, but IL-1 beta mRNA expression was reduced in the duodenum of broilers fed high concentrations of phytase, suggesting that the increased performance noted might be related to decreased inflammation.