COMPARISON OF DISTILLERS GRAINS WITH SOLUBLES FROM RYE AND CORN IN PRODUCTION AND DIGESTIBILITY TRIALS WITH LACTATING COWS AND SHEEP
Dehydrated rye distillers grains with solubles or corn distillers grains with solubles were incorporated into dairy concentrate mixes at the level of 15%. These concentrates were then fed along with alfalfa cubes in a 50/50 mix (as-fed basis) to 18 lactating dairy cows in a two 6-wk period change over design. Feed intake, milk yield, milk composition and body weight change data indicated no difference between types of distillers grains. Total collection digestibility studies conducted during the last week of each period with six animals per treatment indicated no difference between the type of distillers grains in dry matter, protein or fiber digestion. Total collection digestibility studies using six mature ewes per treatment indicated no differences in dry matter, organic matter or protein digestibility when determined for the concentrates containing rye distillers grains (RDG) or corn distillers grains (CDG) fed in the dairy production trial. Acid detergent fiber digestibility was significantly lower (P < 0.01) on the RDG diet. Digestibility by difference was used to compare RDG and CDG when they made up 70% of the diet. RDG had significantly lower (P < 0.01) digestibilities of dry matter, energy (12.2 vs. 17.1 MJ digestible energy kg−1 dry matter), protein and fiber. The influence of the lower digestibility of RDG was masked in the concentrate mix and complete diet fed to the lactating cows due to dilution from other ration components. Rye distillers grains plus solubles can replace corn distillers grains in dairy concentrates at the level of 15% with no effects on dairy cow production. Key words: Rye distillers grains, sheep, dairy cattle