Microbial feed phytase supplementation of full-fat rice bran-based diets for ducks
1996
Martin, E.A. | Farrell, D.J. (Central Luzon State Univ., Munoz, Nueva Ecija (Philippines). Dept. of Animal Science)
A microbial feed phytase was added (1000 units/kg) to fuel-fat rice bran-based (FFRB) starter diets (0-400 g/kg with an inorganic phosphorus supplement, P sub i, of 1 or 3 g/kg) and grower diets (0-600 g FFRB/kg with 0.90 g P sub i supplement/kg) with the aim of facilitating hydrolysis of phytate and improving nutrient utilization and performance of ducklings (2-19 d of age) and growing-finishing ducks (19-40 d of age). Growth of ducklings fed on a diet containing 400 g FFRB/kg supplement with feed phytase in conjunction with 1 g P sub i/kg, but not with 3 g P sub i/kg, was comparable with the growth of ducklings fed on a diet without FFRB (+ phytase). Feed phytase improved bodyweight gain and feed conversion ration (FCR) of growing-finishing ducks. The responses to the enzyme were attributed generally to an increase in dietary phosphorus (P) availability (judged from the P retention and tibia ash parameters). However, an increase in the availability of some nutrients was also observed. Apparent metabolizable energy (AME) was increase due to feed phytase addition to the grower diets with 0 g FFRB/kg and 600 g FFRB/kg. In ducklings, the positive effect of the enzyme on AME was observed on the diet with 200 g FFRB/kg + 3 g P sub i/kg. Calcium (Ca) retention was increased due to phytase in ducklings fed on diets with 200 g FFRB/kg + 1 g P sub i/kg. The amounts of Ca and magnesium (Mg) in the tibia ash of ducklings fed on 200 g FFRB/kg + 3 g P sub i/kg were increased by the feed phytase; positive effect of the enzyme on Mg content of tibia ash of ducklings fed on 400 g FFRB/kg + 3 g P sub i/kg was also observed
显示更多 [+] 显示较少 [-]