Manipulating Characteristics of High Straw Dry Cow Diets to Improve Consistency in Intake Across the Transition Period
The aim of this thesis research was to determine if reducing the length of wheat straw and water addition to high straw dry cow diets could improve intake, reduce feed sorting, and improve metabolic health and production of dairy cows across the transition period. In 2 studies, Holstein cows were assigned to a dietary treatment at dry off and fed the same lactating diet for 28 d post-calving. In study 1, cows were fed a diet that had straw chopped with either a 2.54-cm screen, or a 10.16-cm screen. In study 2, cows were fed a diet that either had water added or had no water. The diet with straw chopped with a 2.54-cm screen and the diet with added water resulted in improved intake during the dry period and in the week leading up to calving. Cows sorted less against the long particles when fed the shorter chopped straw and the diet with added water. Lastly, cows fed the shorter chopped straw and cows fed the diet with added water, had improved rumen health in the week following calving. The results of these studies suggest that reducing the chop length of wheat straw and adding water can improve intake, reduce feed sorting, and promote both metabolic and rumen health.