Enzymatic association in the diets of laying hens raised in an alternative cage-free system

Abstract: The objective of this work was to evaluate the use of enzyme combinations in diets, with different nutritional uplift matrices, for hens raised in an alternative cage-free system. The experiment was carried out with 800 Isa Brown laying hens aged 24-30 weeks, distributed in a 2x2 factorial arrangement, with two combinations of enzymes (phytase and xylanase) and two nutritional matrices (conventional and overvalued uplifts). The treatments were: T1, phytase (450 FTU per kilogram) + xylanase (12,000 BXU per kilogram), using matrix I (100 Kcal kg-1 apparent metabolizable energy, 0.16% calcium, 0.15% available phosphorus, 0.03 sodium, and 0.02% digestible lysine); T2, phytase (1,500 FTU per kilogram) and matrix I; T3, phytase (450 FTU per kilogram) + xylanase (12,000 BXU per kilogram), using matrix II (120 Kcal kg-1 apparent metabolizable energy, 0.22% calcium, 0.20% available phosphorus, 0.04% sodium, and 0.05% digestible lysine); and T4, phytase (1,500 FTU per kilogram) and matrix II. Productive performance variables and external and internal egg quality were analyzed. The use of phytase or of the phytase + xylanase combination, independently of the nutritional matrix used, met the nutrient requirements of the animals and maintained their productive performance. However, the combination phytase + xylanase and the adoption of matrix I was more efficient.