Sequestering Phosphatic Solution as a Phosphorus Source for Ruminants1,2

Abstract

A sequestering phosphatic solution (ammonium polyphosphate) was compared to dicalcium phosphate as a phosphorus source for ruminants. These materials were mixed with corn, urea, and limestone as supplements to a phosphorus–deficient ration of molasses–dried beet pulp and corn stover silage. In steer feeding trials, using six lots of seven animals each, the two phosphorus supplements supported performance equally well and considerably better than the nonphosphorus supplemented basal ration (0.62 vs. 0.10kg gain per day, respectively). Serum inorganic phosphorus was normal in the supplemented groups, 7.3–8.4 mg/100ml, compared to 2.9–4.3 mg/100ml in the unsupplemented groups. In a balance and digestion trial using sheep, no differences in digestibility were observed between the basal and supplemented groups, but phosphorus balances were +74, +357, and +474mg per day for the basal and the animals supplemented with dicalcium phosphate and sequestering phosphatic solution, respectively.