Performing Department
(N/A)
Non Technical Summary
Our proposed research will advance the knowledge of gut health in dairy cattle. Gut health is a hot topic in the industry and may have large effects on animal health, productivity and efficiency but we do not have a thorough knowledge of the dairy cows rumen tissue or its resident immune cells. Especially, we do not know how the diet fed to the cow may affect these tissues or these cells. Building our understanding of how diet can affect the rumen tissue and rumen immune cells will provide strategies to feed cows in a way that improve the health of their gastrointestinal tract which will improve animal welfare, health, and sustainability.We are going to feed dairy cows rations with different types of grain and different amounts of those grains. Then, we will collect rumen tissue from these cows and measure the immune cells present in the tissue. This will allow us to determine how diet may affect the rumen tissue and the immune cells within it.Our ultimate goal from this research is that we can use diets, feed additives, or different strategies to improve the gut health of animals. To reach that goal we must continually grow our knowledge of how the rumen and ruminal immune cells may change under various conditions. Once we do this, we will steadily be able to improve animal health and welfare.
Animal Health Component
25%
Research Effort Categories
Basic
75%
Applied
25%
Developmental
(N/A)
Goals / Objectives
The main goal of this project is to improve our understanding of how dietary formulations, especially the fermentability of a diet, affects the health of the gastrointestinal tract in dairy cattle.Specifically, our primary objectives are as follows:Observe how source of starch affects ruminal immune cell phenotypesIdentify how diet starch concentration affects ruminal immune cell phenotypesWe will also determine how starch concentration and source affects diet digestibility, ruminal pH, fecal pH, and plasma markers for inflammation and metabolism.
Project Methods
The experiment will be a 6 × 6 Latin square design with 6 ruminally cannulated cows and six 28-d periods. Treatments will be laid out in a 3 × 2 factorial arrangement. The factors will be starch concentration and grain source; starch concentrations will be 24%, 30%, or 36% of the diet dry matter with dry ground corn or dry ground barley as the primary grain source.Cows will be housed in tie stalls, fed once daily, and milked twice daily. On the final day of each period, 3 rumen papillae subsamples will be collected, as described previously. One subsample from each site will be used for immunohistochemical staining, one processed for flow cytometry. Rumen fluid, fecal, and blood samples will be collected every 9 h over the final 3 d of each period. Rumen fluid samples will be collected as described by Krogstad et al. (2021a).Flow cytometry and immunohistochemistry will be conducted on rumen tissue to investigate the ruminal immune cell populations. Rumen fluid will be analyzed for volatile fatty acids (Erwin et al., 1961) and ammonia (Chaney and Marbach, 1962). Ruminal and fecal LPS will be determined by the chromogenic limulus amoebocyte lysate (LAL) assay (Charles River, Reading, UK). Plasma samples will be analyzed for glucose (kit #997-03001; Fujifilm, Osaka, Japan), insulin (no. 10-1201-01; Mercodia AB, Uppsala, Sweden), haptoglobin, serum amyloid A, and D-lactate.Data will be analyzed using PROC GLIMMIX (SAS 9.4; Cary, NC). The model will include fixed effects of starch concentration, source, and their interaction, as well as random effects of period and cow. Significance will be declared at P ≤ 0.05 and tendencies at P ≤ 0.10.