DDGS in the diet of finishing double-muscled Belgian Blue cows

The effect of wheat-based dried distiller grains with solubles (DDGS) on the zootechnical performances of finishing double-muscled Belgian Blue (DMBB) cows was studied. Eighty animals were assigned to one of 4 treatments: 2 control diets with a low (3.3%, LS) or a high (21%, HS) starch content in the concentrate, and 2 diets containing DDGS, either as concentrate ingredient (DC, 63% DDGS on DM basis), or as protein supplement (DS). Diets consisted of concentrate and maize silage (50/50 on DM basis), except DS, where maize silage was supplemented with DDGS (65/35 on DM basis; 34% CP in DDGS) and a mineral-vitamin premix. All diets were fed ad lib. There were no differences in daily total DM intake between the groups (on average 12.4 kg DM/day), although the DM intake of maize silage was higher for DS (P<0.001). The incorporation of DDGS in the diet resulted in a higher crude protein (CP) intake per day (P<0.001) and per kg metabolic weight. The daily CP-intake and daily rumen degradable protein balance (OEB) was highest for DS. Although formulated to be isocaloric, LS and DC diets contained more net energy for fattening (NEF) than HS (8.87 MJ/kg DM and 8.26 MJ/kg DM versus 7.38 MJ/kg DM) resulting in a higher daily NEF intake (P<0.001). NEF of DS was intermediate between HS and DC. Nevertheless there was no difference in NEF/kg weight. Daily gain ranged between 1.10 and 1.32 kg and was highest in LS, but not significantly different from the other groups. There were no differences in carcass weight, dressing percentage and carcass classification. These results indicate that DDGS can be used effectively in finishing diets for DMBB cows, without negative effects on growth performance and carcass characteristics. Supplementation of DDGS in the concentrate did not result in a reduction in concentrate or maize silage uptake. Separate supply of DDGS even resulted in a higher maize silage intake. Depending on its market price, DDGS can be used as an alternative protein supplement.