Evaluation of normal yellow dent corn and high available phosphorus corn in combination with reduced dietary phosphorus and phytase supplementation for broilers grown to market weights in litter pens

Abstract

A study was conducted to determine the extent fecal P levels could be reduced while maintaining performance. Various strategies were employed including the use of a high available phosphorus hybrid of corn (HAPC), supplementation with phytase enzyme, and reduced dietary P levels. The use of HAPC resulted in a 50% reduction in phytate-bound dietary P as compared with a normal yellow dent corn (YDC) diet. Dietary nonphytate P was maintained at either NRC (1994) recommendations for appropriate age periods or reduced by 0.075 or 0.15%. Portions of the diets were supplemented with 1,000 units of phytase/kg. Male chicks of a commercial strain were grown to 56 d on the test diets. Broilers fed diets with HAPC had BW, feed conversion, livability, and tibia ash that were equal to or superior to those fed diets with YDC with considerably reduced fecal P content at any dietary level of nonphytate P. Phytase supplementation enabled birds to maintain live performance at lower levels of nonphytate P, further reducing the fecal P output. One of the greatest contributions of phytase was a reduction in mortality at the lower levels of nonphytate P. Dietary P levels could be reduced by 0.075% under NRC (1994) recommendations without adversely affecting live performance; a reduction of 0.15% in conjunction with phytase supplementation maintained BW, feed conversion, and livability but reduced tibia ash. The extent to which dietary P levels can be reduced over the entire feeding program is subject to further research.

The effects of phytase supplementation and dietary phosphorus level on performance and on tibia ash and phosphorus contents in broilers fed maize-soyabased diets

“…This result corroborates the findings of and Yan et al (2000), who reported the reduction of excreta P output by approximately 25% to 28%, respectively, when broiler diets were supplemented with phytase. Reported values for P level in broiler excreta vary widely, and can average even 2.1%, with a range of 1.3% to 3.4% .…”

Phosphorus digestibility in low-phytate barley fed to finishing pigs

“…Earlier work with low-phytate corn was also successful in improving phosphorus utilization for pigs (Veum et al 2001) and broilers (Li et al 2000;Yan et al 2000;Waldroup et al 2000).…”

Prospects for the use of genetically modified crops with improved nutritional properties as feed materials in poultry nutrition

“…The authors concluded that HAP maize contained more available P for layers than conventional maize and that only a small quantity of supplemental inorganic P was needed in order to maintain optimal laying performance (Snow et al, 2003). Corresponding results were obtained in studies with broilers, where it was demonstrated that the P in HAP maize was more available than in conventional maize and that diets based on HAP maize, with low levels of supplemental inorganic phosphates, allowed optimal production indices to be supported, while significantly decreasing the concentration of P in excreta (Li et al, 2000;Waldroup et al, 2000;Yan et al, 2000).…”