Nutrient excretion, phosphorus characterization, and phosphorus solubility in excreta from broiler checks fed diets containing graded levels of wheat distillers grains with solubles
Increased interest in ethanol production
in North America has led to increased production of
distillers dried grains with solubles (DDGS), the majority
of which are fed to livestock. To determine the
impact of including wheat DDGS in broiler diets on
nutrient excretion and P characterization and solubility,
125 one-day-old male broiler chicks were fed wheat and
soybean meal-based diets containing 0, 5, 10, 15,
or 20% wheat DDGS. There were 5 replicate pens per
treatment, with 5 birds per pen arranged in a randomized
block design. Apparent retention of both N and
P were determined by using the indicator method.
Nutrients excreted per kilogram of DM intake were
also calculated. Characterization of excreta P was determined
by 31P-solution nuclear magnetic resonance
spectroscopy, and water-soluble P (WSP) was determined
by extraction of excreta with deionized water.
The apparent retention of both N (P < 0.001) and P
(P < 0.008) decreased linearly with increasing inclusion
rates of DDGS from 0 to 20%. The nutrient output per
kilogram of DM intake increased linearly with increased
DDGS inclusion rate for N (P < 0.04), P (P < 0.0001),
and WSP (P < 0.0003). As the inclusion rate of DDGS
increased, the P concentration in excreta increased (P
< 0.008), whereas excreta phytate P concentrations decreased
(P < 0.01), which led to an increase in WSP
and the fraction of total P that was soluble. Because
the inclusion of DDGS in poultry diets increased N and
P output, as well as the solubility of P excreted, care
should be taken when including high levels of DDGS in
poultry diets, because increases in N and P excretion
are a concern from an environmental standpoint
