Feeding value of condensed distillers solubles for growing-finishing pigs

The aim of this experiment was to determine the apparent ileal and fecal digestibility of condensed distillers solubles’ (CDS) nutrients and the variability between CDS from different origin.
Five CDS from different origin were tested. Apparent fecal and ileal digestibility was estimated by comparing nutrient digestibility of the test diets including 30% (dry matter) CDS, with the nutrient digestibility of the basal diet. Each diet was tested with six pigs.
The average apparent fecal digestibility coefficient (AFDC) of gross energy was 83.0±5.6% (mean±SD), with 76.6±2.3% for the least digestible and 88.8±1.6% for the best digestible CDS. The AFDC of crude protein varied between 71.9±4.3% and 83.8±1.0% (overall average 76.4±9.9%). The AFDC of ether extract varied between 75.2±5.9% and 87.9±7.8% (overall average 83.4±8.6%). The AFDC for gross energy was significantly (P<0.05) correlated with the AFDC of crude protein (r=0.91), organic matter (r=0.98) and NSP (r=0.70). The net energy content (MJ/kg dry matter) of CDS from different sources varied between 7.7±0.3 and 9.7±0.6 (overall average 8.9±0.9).
The apparent ileal digestibility coefficients (AIDC) of crude protein varied between sources from 57.7±18.8% to 80.6±19.0%, with an overall average of 74.8±14.7%. The AIDC of lysine varied from 61.3±15.1% to 93.8±5.1%, with an overall average of 74.8±16.6%. The AIDC of the individual amino acids was well correlated with the AIDC of crude protein, with r>0.85, except for lysine (r=0.71). Aspartic acid showed the lowest AIDC (64.5±20.3), while arginine showed the highest AIDC value (85.3±10.5).
It is clear that the digestibility coefficients and net energy content varied widely between CDS sources and source dependent matrix values will be necessary for accurate feed formulation.