Evaluation of live performance and carcass characteristics of broiler chickens fed corn-soy diets supplemented with phytase and xylanase

NSPase enzymes have become an integral part of commercial poultry feed for enhancing the efficiency of nutrient utilization by the birds, thereby reducing the cost of production and improving growth performance. The supplementation of phytase in broiler diets is also standard practice due to its proven performance and relatively low cost.

Few studies have reported the contribution of xylanase in diets containing phytase. This study's primary objective was evaluating the efficacy of 66.7 g/MT inclusion of Xylamax, a thermostable xylanase, supplemented to corn-soy broiler diets containing phytase and formulated to four levels of metabolizable energy (ME).

1840 male Cobb 500 broiler chicks were randomly assigned to 1 of 8 dietary treatments, with ten replicate cages per treatment, and 23 birds per cage. Birds were reared for 42 days on re-used wood shavings litter and fed corn-soy diets containing phytase ad libitum. The eight dietary treatments were arranged in a 4 x 2 factorial with four levels of ME, each with or without 65 g/MT supplemental xylanase (Xylamax). Diet energy was adjusted using soybean oil. The crude protein inclusion rate was 22.5% and 20% in the starter (0-21 days), and grower/finisher (22-42 days), respectively.

Key parameters evaluated were:

At each level of dietary energy, Xylamax supplementation reduced 42-day FCR compared to the un-supplemented controls. Across energy levels, Xylamax numerically increased 42-day body weight gain (by +33 g) and significantly improved 42-day FCR by an average of 3 points (1.57 vs. 1.54). The most pronounced FCR improvement by adding Xylamax was seen during the grower/finisher phase and at the lower ME levels during that phase (5-point improvement at 3000 kcal/kg ME and 7-point improvement at 3075 kcal/kg ME). Xylamax supplementation also significantly improved absolute carcass weight (by +71 g), thighs and legs weight (by +23 g), and weight of wings (by +7 g).

Xylmax Provides Strong FCR Improvement in Grower/Finisher Phase

Across energy levels adding 66.7 g/MT Xylamax improved FCR and carcass characteristics compared to unsupplemented control diets. Based on FCR, Xylamax was most effective during the grower/finisher phase when feed intake is highest. These data indicate that Xylamax consistently improves broiler performance in typical corn-soy broiler diets containing phytase.