|
|
||||||||
Research Reports |
Department of Poultry Science, University of Arkansas, Fayetteville 72701
Correspondence: 3 Corresponding author: waldroup{at}uark.edu
Two experiments were conducted to adapt the results of previous studies from our laboratory on calcium and nonphytate phosphorus (NPP) requirements to feeding intervals more similar to the commercial broiler industry. Feeding periods of 0 to 14, 14 to 35, 35 to 42, and 42 to 56 d were used. In the first experiment, a positive control diet similar to industry levels (0.45% NPP and 1.0% Ca, 0.40% NPP and 0.9% Ca, 0.35% NPP and 0.8% Ca, and 0.30% NPP and 0.8% Ca for the various feeding periods, respectively) was compared with various combinations of Ca and NPP levels, with phytase supplementation used in some diets with low NPP. It was observed that birds fed starter diets with 0.40% NPP followed by 0.30% during the grower phase grew as well with equivalent feed conversion as those fed the positive control diet. Feeding less than 0.30% during the grower period resulted in excessive mortality over the duration of the study. In the second experiment, consisting of 2 consecutive trials in which birds were housed beginning on new softwood shavings, adjustments were made in the NPP and Ca levels used in the first experiment; diets were fed with or without phytase supplementation. At the conclusion of the second trial, samples of litter were evaluated for total and soluble P contents. All of the modified diets supported BW gain, feed conversion, livability, and bone parameters that did not differ significantly from that of birds fed the positive control diets. Total and soluble P contents of the litter were significantly reduced by the modified diets fed with or without phytase. Use of the modified diets resulted in significant savings in dietary costs associated with reduced levels of P supplementation.
Key Words: broiler phosphorus litter eutrophication soluble phosphorus phytase
1 Published with approval of the Director, Arkansas Agricultural Experiment Station, Fayetteville, AR 72701. Mention of a trade name, proprietary product, or specific equipment does not constitute a guarantee or warranty by the University of Arkansas and does not imply its approval to the exclusion of other products that may be suitable.
2 Present address: Cobb-Vantress Inc., Siloam Springs, AR 72761.
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |