Effect of phytase and xylanase enzymes on growth performance and Mucin2 gene expression in broiler chickens.

Abstract

Development of exogenous enzymes is one of the most important discoveries in animal nutrition. The supplementation of exogenous enzymes in broiler diets allows for supplying nutrient deficiencies and to decrease endogenous losses. The effects of phytase (Hostazym and Phyzyme) and xylanase (Ronozyme) enzymes were investigated on growth performance and Mucin2 gene expression in broilers. A completely randomized design was applied, including 7 treatments, 4 replicates and 25 birds per replicates. A total of 700 male Ross (308) broiler chickens were fed with similar diets supplemented by Hostazym and Phyzyme (500 and 1000FTU/kg) and Ronozyme (100 and 200EXU/kg). Weight gain (WG), feed intake (FI) and feed conversion ratio (FCR) were determined for three phases and entire rearing period. On 42 days of age, four birds per replicate were slaughtered. Total RNA was extracted from jejunum samples, and Mucin2 gene expression was measured by real-time PCR. Phytase and xylanase enzymes had a significant effect (p<0.05) on traits (WG and FCR) in grower and finisher phases and whole rearing period, but FI was not affected by enzymes (p>0.05). Carcass (74.13g) and breast (27.76g) weights by Hostazym (1000FTU/kg) were higher than other treatments (p<0.05). Weight of liver, bursa and spleen were significantly influenced by enzymes (p<0.05). Likewise, bursa and spleen weights in Hostazym (1000FTU/kg feed) and Ronozyme (200EXU/kg feed) were significantly higher than other treatments (p<0.05). Mucin2 gene expression was affected by enzymes in whole treatments. The lowest amount of Mucin2 gene expression belonged to Ronozyme (200 and 100EXU/kg), and the highest was belonging to Hostazym (1000 FTU/kg). Phytase enzymes have higher effect on broiler performance and Mucin2 gene expression compared to xylanase. High doses of Hostazym (1000FTU/kg feed) could be supplemented in broiler chicken diets to improve optimum growth and feed efficiency.