Comparative evaluation of phytate and phytase addition on growth performance and nutrient utilization efficiency in broilers and ducks

This study aimed to comparative evaluation of dietary phytate level and phytase addition on growth performance and nutrient utilization efficiency in 21 day-aged broilers and ducks. A total of 540 one-day-old male Arbor-Acres broilers and 540 Cherry Valley ducks were randomly assigned to 9 dietary treatments, with 6 replicates of 10 birds each (60 birds per treatment in total). The dietary treatments included a positive control (PC) containing 0.40% non-phytate phosphorus (nPP) without phytase, and 8 low nPP diets (0.24% nPP) arranged in a 2 × 4 factorial design. The factorial treatment consisted of two phytate-P levels (2.4 and 3.4 g/kg) and four phytase supplementation levels (0, 500, 1000, and 1500 FTU/kg). The results showed that compared with the PC, feeding low-nPP diets significantly impaired the growth performance of both broilers and ducks (P < 0.05). In the absence of phytase, high phytate-P exerted a negative effect on the growth performance in broilers but significantly improved that of ducks (P < 0.05). For broilers, low phytate-P significantly enhenced calcium (Ca) and phosphorus (P) retention, as well as apparent metabolizable energy (AME). In contrast, high phytate-P reduced Ca retention without affecting P retention or AME. For ducks, both phytate-P levels of reduced Ca and P retention, but high phytate-P augured a significant increase in AME (P < 0.05). Under low-nPP diets, plasma P levels decreased in both species; in broilers, plasma P was further reduced by high phytate-P, whereas ducks showed the opposite pattern (P < 0.05). Plasma Ca remained unchanged in broilers but increased with elevated phytate-P in ducks (P < 0.05). Phytase supplementation significantly improved growth performance, nutrient retention, and plasma P levels in both species (P < 0.05). In addition, phytase inclusion increased AME in ducks alon, with no significant effects on AME in broilers or on plasma Ca levels in either species. Collectively, these findings demonstrate species-specific responses of broilers and ducks to dietary phytate and phytase, indicating that phosphorus utilization data derived from broilers cannot be directly extrapolated to ducks. Therefore, species-specific adjustments should be made in feed formulations to optimize nutrient utilization and growth performance in each species.