Effects Of Phytase On Growth Performance In Ducks Diets With High And Low Nutrient Density

The trial was conducted to study the effects of phytase in diets with two different nutrition densities on growth performance, ileal digestibility and tibia quality for ducks. A 2×3 factorial design was used with two nutrients density diets and three kind diets (positive diet with normal dietary Ca and P, negative diet with lower dietary Ca and P, negative diet with addition of phytase. 576 one-day-old Cherry valley ducks were assigned randomly to 6 treatments with 8 replicates per treatment, 12 ducks per replicate. All diets were pellet processed at a commercial feed mill. Trial lasted 42 days. The results were as follows: With the lower nutrient density diet, the body weight at 21 day and 42 day, the body weight gain at different phases were decreased significantly with the significant increase of feed intake and feed to gain ratio. With the addition of phytase, the body weight at 42 day, body weight gain of 22 to 42 days or the whole phase, the content of ash, Ca, and P in tibia were increased significantly that were similar or superior to positive diet with no influence on the body weight at 21 days, body weight gain and feed to gain ratio of 1 to 21 days, feed intake at all phases. The results showed that the addtition of phytase to substitute the dicalcium phosphate at the two nutrient density diets could improve the duck growth performance and tibia quality with the lower dietary dicalcium phosphate level and increase of income.