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War of the inner world. Where creatures lurk…. …with delicious terror yet form and function so sublime …. …creatures beyond our wildest imagining…. Welcome to: The world of animal science…. …an inner world of war…. ..dwelling within the humble ruminant.
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…an inner world of war…
Ruminant digestion: the most advanced in the solar system Four compartments to ruminants stomach • Rumen (pH 7)-fermentation vat - host to microbes • Reticulum - mixes, filters large particles • Omasum - removes water • Abomasum (true stomach) - pH 2 - same as human stomach
Rumen function: Mutualism • Bugs supply VFA and microbial protein • Byproducts: CO2, CH4 and NH4+ • Animal supplies 5 star accommodation
Rumen bacteria • World population = 6.5 billion = 6.5 x 109 = 6 500 000 000 • Bacteria in 1 drop of rumen fluid = 1 x 1011 = 100 000 000 000
Rumen bacteria • Cellulolytic - digest cellulose • Amylolytic - digest starch • Proteolytic - digest protein • Acid utilising
The big issues of animal production Methane production Antibiotics in feed
Methane protozoan methanogen
Methane inhibition • Defaunation (sweeping protozoa) • Ionophoric antibiotics • Vaccine • Fish-oil, tannins
How much antibiotics do we use? • Total use: 700 Tonnes per year • Humans: 250 Tonnes per year • Veterinary: 50 Tonnes per year • Stock feed: 400 Tonnes per year JETACAR report, 1999
Gram + Gram - Peptidoglycan Peptidoglycan Membrane Membrane Periplasm Lipopolysacharide & protein
Antibiotics as growth promoters • Voluntary European ban in 2005 • USA & Australia expected to follow • Need to find safe alternatives
Reduce pollution Reduce antibiotic dependency Less methane Less ammonia Improve product quality Altered rumen fermentation Australian plants Bloat control Acidosis control Improved welfare & production Conserve biodiversity
Is Australian flora antimicrobial on selected species of bacteria?
Where the research is at 1. Screening Australian plants in vitro 2. Inhibition on pure cultures 3. Molecular quantification -DGGE, Real-time PCR 4. In vivo feed trial
Questions for the modern scientist Can we; • Improve rumen efficiency? • Reduce environmental pollutants? • Reduce dependence on antibiotics? • Maintain consumer-safe production?
Can we understand the war of the inner world? • Bioenergetics of animal production • Microbiology • Underlying chemistry • Molecular quantification • Application of science • Careers in animal production
Why are bugs important in animal production? • Rumen fermentation • Manufacturing of dairy products • Soil Health • Disease • Silage • Bioremediaton of farm waste
Bioremediation of farm waste • Recycling animal excreta & crop residues • Agriculture provides 15% of land photosynthetic biomass • Animal excreta 1.5 billion T/yr (USA)