Innate immune responses to metabolic stress can be detected in rumen fluids
ABSTRACT
Many production diseases of dairy cows are related to digestive troubles. The rumen subacute acidosis is the most relevant one, albeit not easily recognized. Recent studies suggest that forestomachs can perform regulatory actions at both regional and systemic levels since forestomach walls express immune receptors and cytokines, and the rumen liquor is infiltrated by leukocytes. Therefore, the rumen fluid could be conveniently collected for investigating metabolic production diseases. Thus, we investigated the origin of the leukocytes of the rumen fluid and demonstrated that they partly derive from saliva. Next, we carried out a field survey of innate immunity in rumen fluids of 128 cows from 12 dairy farms, along with clinical inspections, assessment of milk yield, rumen pH, volatile fatty acids (VFA) and major inflammo-metabolic parameters. Significant statistical correlations were found between immune markers in rumen fluids and biochemical parameters. A significant negative correlation was found in rumen between CD45 gene expression (leukocyte infiltration) and pH level. B cells were the most frequent mononuclear leukocyte population in the rumen liquor and their infiltration was negatively affected by low ruminal pH and high concentrations of VFA. Moreover, total Ig and IgM in rumen fluids were negatively correlated with ruminal pH and positively correlated with uremia. Our data suggest that forestomach immune responses could be directed to “dangers” arising within the forestomach environment. The immune markers could integrate consolidated diagnostic parameters (e.g. rumen pH) and contribute to robust, early diagnosis of tricky digestive troubles of cattle.
Keywords: Dairy cow, Forestomach, Immune response, Metabolic stress, Rumen fluid, Production disease.
This abstract was originally published in Research in Veterinary Science 117 (2018) 65–73. https://doi.org/10.1016/j.rvsc.2017.11.008.
As we go along should Feed Efficiency Genomics Algarythemes be looking at Rumen PH, Rumen Microbiome and certain saliva enzymes to best breed a cow best capable to handle high roughage diets and/or handle high concentrate diets when land and or soil fertility is limited. This revelation could and should take out a lot of fluff and spur better direction of real working enzyme blends and buffers as well as nutritional heat abatement strategies.
I am way out of my Wheel House when I suggest this, but I find it hard to think natural anti-cortisol levels can antagonize feed efficiencies. I believe DNA and DNA editing today and in the future will be the fastest way to address livestock emissions and efficiencies. More latter if not
asked to leave!
I am interested to know how representative sample of rumen liquor can be drawn from cows.
A difficult issue faced by the farmers without much more knowledge is tried to solve. The solution is understandable but needs much more to further verify and to enable the farmers to be benefitted. Congratulations to authors, as scientists mostly avoid to do research on difficult issues.
