Two commercially available acidified fermentation by-products were evaluated in the close-up
period (21 days before expected calving) for their effects on feed intake, postpartum performance,
and cow health. Diets were formulated to contain similar protein and energy values
but differed in dietary cation anion difference and anion source. Treatments were Bio-Chlor,
SoyChlor, and a control. Prepartum feed intake tended to be lower for SoyChlor than for the
control, but postpartum intake did not differ among dietary treatment groups. Likewise, no
significant differences were detected for milk yield between treatments. Protein percentage,
milk urea nitrogen, and lactose percentage were greatest for SoyChlor-treated cows. Therefore,
despite a trend for a negative effect on prepartum feed intake, SoyChlor supported similar productivity
in early lactation.