Effects of dietary inclusion of a cocktail NSPase and β-mannanase separately and in combination in low energy diets on broiler performance and processing parameters

Two experiments were conducted to investigate whether an additive effect on performance could be achieved with the inclusion of a β-mannanase and a cocktail NSPase in combination. The design of both experiments included 5 dietary treatments, each containing 8 replicates: positive control (PC), negative control (NC) with a reduction of 132 kcal/kg AME throughout the experiment, NC + β-mannanase, NC + NSPase, and NC + β-mannanase/NSPase. In experiment 1, birds were fed a predetermined amount of feed, while in experiment 2, diets were fed to a certain age. Experiment 1 dietary phases included starter (0.68 kg), grower (1.45 kg.), finisher (1.45 kg), and withdrawal (remaining feed required). In the NC on d 14 and 28, BW was reduced (P < 0.05). Increases (P < 0.05) in BW were observed with NSPase and the combination of β-mannanase/NSPase on d 14 and with all treatments on d 28. The FCR was increased (P < 0.05) through d 28 in the NC. The combination of β-mannanase/NSPase reduced the FCR through d 28 to levels similar to the PC. Experiment 2 dietary phases included starter (d 1 to 14), grower (d 15 to 27), and finisher (d 28 to 41). A reduction in BW was observed (P < 0.05) in the NC diet on d 14, 27, and 35. Increases in d 14 BW were observed with the individual inclusion of the NSPase and the combination of β-mannanase/NSPase. The combination of β-mannanase/NSPase increased (P < 0.05) BW compared to the NC on d 27 and 35. Increases (P < 0.05) were observed in the FCR in the NC for each dietary phase. The inclusion of NSPase reduced the FCR through d 41 compared to the NC. The combination of β-mannanase/NSPase reduced the FCR through d 41 compared to the NC. These data confirm that enzyme supplementation in a low energy diet improves performance and indicates that beneficial effects may be observed from the use of multiple enzymes.