Influence of distillers dried grains with solubles (Starprot) in dairy cow feeding

Abstract

The objective of this study was to investigate the suitability of distillers dried grains with solubles (DDGS) from two grain species (wheat, corn) as a protein supplement for the feeding of dairy cows. The feedstuffs produced by an Austrian distillery were incubated in the rumen of four fistulated steers. Values for the effective degradability (ED) of dry matter (DM) at assumed ruminal passage rates of 2, 5, and 8 % h-1 averaged 73.1, 62.0 and 56.1 % respectively. The mean potential degradability (a + b) of DM was 88.3 % and the mean degradation rate of the DDGS was 4.75 % h-1. Based on an in vivo digestibility trial with wethers energy contents (NEL) of 6.93 MJ kg-1 DM for DDGS from wheat and 8.18 MJ kg-1 DM for DDGS of corn were calculated. A feeding trial using 15 lactating dairy cows showed neither significant differences in dry matter intake (DMI) nor in milk yield and composition between the DDGS treatments and the control diet, which contained a mixture of rapeseed cake and soybean meal as protein supplement. The mean DM intake in all groups was 20.9 kg d-1 with a milk yield of 26.2 kg d-1 and concentrations of 4.46 % fat and 3.35 % protein in the milk. Due to the slow degradability of the DDGS and therefore high values for undegraded dietary protein (UDP) as well as the similar milk production results we conclude that the DDGS used in this study can be considered as alternative protein sources to the traditional supply with soybean meal.