Effects of Acidifying XXXX Diets on Emissions of Ammonia, Methane, and Sulfur from Slurry during Storage.

@entity1707 @entity5155 @entity4889
UNASSIGNED: Ammonia ( @entity5155 ) volatilization from intensive livestock production is a threat to natural ecosystems. This study investigated @entity1707 diet manipulation by 1% (w/w) benzoic acid (BA) amendment and lowering of dietary electrolyte balance through substituting 1.4% (w/w) CaCO with 2.0% (w/w) CaCl. Urine and feces were collected separately from 24 @entity1707 fed one of four diets (Control, +BA, +CaCl, +BA+CaCl) in metabolic cages and mixed as slurry. During 103 d of storage, all acidifying diets consistently reduced pH in the slurry by 0.4 to 0.6 units. There was a strong relationship between slurry pH and @entity5155 emissions, which were considerably reduced by the three acidifying diets. The +BA diet decreased @entity5155 emission by 28%, the +CaCl diet by 37%, and the combined +BA and +CaCl diet by 40%. Acidifying diets had no effect on S cycling or emission of @entity4889 compounds under the prevailing conditions of restricted S feeding. Methane (CH) emissions were increased by 73% in diets with CaCl. An initial delay in CH emissions was investigated in a separate experiment with manipulation of pH (5.4, 6.7, or 8.8) and inoculation with adapted @entity1707 slurry (0, 4, 11, or 19%), which showed that methanogenic potential, rather than inhibitory effects of the chemical environment, caused the delay. In conclusion, @entity5155 emissions from slurry could be reduced by addition of BA to @entity1707 diets or by controlling the dietary electrolyte balance, but there was no additive effect of combining the two strategies. However, CH emissions from slurry may increase with acidifying diets.
