Files
Abstract
The objective of this research was to determine differences in the gastrointestinal microbiota of Angus heifers that were selected for divergent feed efficiency and how changes in diet impacted these microbes and host animal feed efficiency. The first experiment evaluated animal performance and ultrasound carcass characteristics of heifers during a high-grain diet and a high-forage diet, to determine if heifer feed efficiency was dependent on diet or genetic selection and how their interaction affected ultrasound carcass characteristics. The second experiment evaluated the rumen and fecal microbiome in terms of heifer feed efficiency on grain versus hay to determine how the microbiota changed with different diets within efficiency group. The third experiment evaluated the rumen and fecal microbiome in terms of ultrasound carcass characteristics to determine how the microbiota impacted growing heifer carcass traits.