Feeding high proportions of low-fat dried distillers grain solubles (DDGS) increases dry matter intake with no risk of fat depression, and adding rumen-inert fat increases fat-corrected milk production.
University of Nebraska researchers reported that finding after comparing the effects of feeding conventional and low-fat DDGS. They fed a control diet with no DDGS, a second with 30% DDGS, a third with 30% low-fat DDGS and one with 30% low-fat DDGS plus rumen-inert fat. Twenty Holstein cows consumed each diet for 21 days.
All diets with DDGS resulted in higher dry matter intakes compared with the control ration. Milk production was similar across treatments, averaging 73 lbs/day. Fat-corrected milk production was similar for the first three treatments, but higher – 77 lbs/day – for the diet containing low-fat DDGS plus rumen-inert fat.
Milkfat percentage was reduced when cows consumed the 30% DDGS diet, but not when they were fed the other rations.