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

## TL;DR

This study compares how adding phytate and phytase affects the growth and nutrient use in broilers and ducks, showing species-specific differences.

## Contribution

The study reveals distinct responses of broilers and ducks to dietary phytate and phytase, highlighting the need for species-specific feed formulations.

## Key findings

- Low-nPP diets impaired growth in both broilers and ducks, but ducks showed improved growth with high phytate-P.
- Phytase supplementation improved growth performance and nutrient retention in both species.
- Ducks showed increased AME with phytase, while broilers did not, emphasizing species-specific differences.

## Abstract

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.