Project Number: 3070-31630-008-005-S
Project Type: Non-Assistance Cooperative Agreement
Start Date: Aug 1, 2022
End Date: Jul 31, 2023
To identify ruminal microbial communities in managed beef cattle grazing systems. Specifically, evaluate ruminal microbial communities from weaning through the stocker phase of beef calves grazing small grain forages and small grain-legume forage mixtures, and when beef cows graze native grassland pastures season-long or in rotation with introduced perennial cool-season forage pastures.
Rumen, blood, and fecal samples are collected at timed intervals throughout the stockering phase from weaned beef calves grazing pasture that includes: 1) winter wheat forage pastures (control), and 2) winter small grain forages and small grain-legumes mixtures. All pastures are grazed mid-November to mid-April each year. In a second study, rumen, blood, and fecal samples will be collected at strategic times from beef cows managed with: 1) continuous stocking on native grassland pastures yearlong and supplemented with forage-based cubes during winter (November through March), or 2) rotational stocking on native grassland pastures (April through October) and combined with grazing pastures of stockpiled introduced perennial cool-season grass pasture during November through March. These warm-season native grassland pastures are managed with prescribed burning on a four-year schedule. All rumen samples will be evaluated for microbiome bacterial and archea (methane producing) communities and metabolomes. In addition, blood samples will be evaluated for metabolomes and related to the rumen bacterial community. Rumen metagenomic analysis of community structure and functional potential will be conducted utilizing whole genome shotgun sequencing of rumen sample extracted an Illumina HiSeq 3000 platform. Untargeted metabolomics will be used to determine the metabolome (may include water soluble and insoluble metabolites such as amino acids, sugars, alcohols, organic acids, amines, Krebs Cycle intermediates and short-chain fatty acids) of rumen fluid contents and blood plasma. Fecal samples will be evaluated using NIRS to determine crude protein and digestible organic matter in the diet of these animals. Information should provide relationships of performance, nutrient use, and methane production potential in pasture-based weaned calf stocker systems and managed beef cow production systems.