* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Download UBC Dairy Education and Research Centre
Citric acid cycle wikipedia , lookup
Gene expression wikipedia , lookup
Microbial metabolism wikipedia , lookup
Ribosomally synthesized and post-translationally modified peptides wikipedia , lookup
G protein–coupled receptor wikipedia , lookup
Genetic code wikipedia , lookup
Ancestral sequence reconstruction wikipedia , lookup
Expression vector wikipedia , lookup
Magnesium transporter wikipedia , lookup
Point mutation wikipedia , lookup
Evolution of metal ions in biological systems wikipedia , lookup
Interactome wikipedia , lookup
Amino acid synthesis wikipedia , lookup
Biosynthesis wikipedia , lookup
Western blot wikipedia , lookup
Protein purification wikipedia , lookup
Nuclear magnetic resonance spectroscopy of proteins wikipedia , lookup
Plant nutrition wikipedia , lookup
Protein–protein interaction wikipedia , lookup
Biochemistry wikipedia , lookup
Nitrogen dioxide poisoning wikipedia , lookup
Protein structure prediction wikipedia , lookup
Two-hybrid screening wikipedia , lookup
Metalloprotein wikipedia , lookup
About myself… 3rd year Graduate Student at UBC working towards a Master of Science Degree Program: Ruminant nutrition Department: Animal Science Faculty: Agricultural Sciences Where I work… -UBC Dairy Education and Research Centre -Pacific Agri-Food Research Centre (PARC) Agassiz, BC 225 lactating cows 200 cow replacement herd In the dairy barn Free stall design 12 cow groups Parallel double 12 milking parlour My Research: Study the effects of nitrogen (N) fertilization on protein quality of forage grass Nitrogen forms N2: nitrogen gas NO3-: nitrate NO2-: nitrite NH3: ammonia Amino Acid H H O N-C-C H R An amino acid OH Proteins 2 amino acids together: dipeptide 3 or more amino acids together: polypeptide Polypeptide chain(s): protein Plant nitrogen 80% of the atmosphere composed of N2 This N is unavailable for plant nutrition Ammonia (NH3 ) is the only form of nitrogen that can be utilized by the plant Nitrogen fixation and oxidation Nitrogen fixation: convert N2 to NH3 Rhizobium and other types of bacteria have enzymes that fix nitrogen Nitrogen oxidation: convert N2 to NO3 Lightning oxidizes nitrogen Nitrate converted to ammonia Plants and bacteria have enzymes that are capable of converting NO3- to NO2 - Plants and bacteria also have enzymes that are capable of converting NO2 – to NH3 Ammonia to amino acids, etc. Ammonia is converted via metabolic pathways into amino acids, nucleotides, and other nitrogen containing molecules. The nitrogen cycle N2 NO3- NO2 - NH3 amino acids, nucleotides, etc. Nitrogen fertilizers Ammonia, nitrates Urea, urea formaldehyde Urease required for breakdown Organic wastes Slow release Cows are ruminants rumen omasum Ruminants “Four chambered stomach”: Reticulum sorts feed Rumen is full of microbes that ferment feed Largest compartment (fits up to 200lbs of feed) Omasum filters and absorbs Abomasum is comparable to our stomach Cows ruminate Cows are ruminants rumen omasum Nutrition Made Simple Cows (like us) are a moving clump of matter Cows need both building material and energy (to build and move) in diet Building material comes from protein Energy comes from carbohydrates Ruminant nutrition protein terms… Crude protein: % nitrogen in a sample x 6.25 “Typical” protein molecule is 1/16 nitrogen 1/16 = 0.0625 Problem: not all nitrogen in food is in protein form Non Protein Nitrogen and True Protein: Crude protein is made up of non-protein nitrogen (NPN) and true protein (TP) Non-protein nitrogen (NPN): nitrogen not in protein molecules (free peptides, free aa, nitrates, ammonia, etc) True protein (TP): nitrogen in the form of proteins (peptides linked together) Protein: Rumen degradable protein (RDP): nonprotein nitrogen (NPN) and true protein (TP) that is degraded into non-protein nitrogen in the rumen. Rumen undegradable protein (RUP): true protein (TP) that is not degraded in the rumen. Protein in Feed Protein Digestion ammonia Carbohydrate digestion Energy metabolism in humans cell glucose Pyruvic acid O2 Acetyl CoA ADP Citric acid cycle CO2 mitochondria ATP H2O nucleus The three VFAs used for energy: Acetate Butyrate Propionate VFA metabolism in cows Butyrate cell Acetate Propionate Ketone bodies Acetyl CoA ADP O2 Citric acid cycle CO2 mitochondria ATP H2O nucleus Human vs. Cattle fat production Humans: Excess glucose used to make fat Cattle: Unable to make fat directly from glucose Excess acetate used for fat production My Research: RUP from Forage Grass Problems: Lactating dairy cows need a lot of protein in their diet A lot of dairy cow diets have too much RDP and too little RUP Environmental concerns Both NO3- and NH4+ are water soluble NO3- is also readily leached out of the soil NH4+ associates with soil colloid particles and resists leaching Plant Nitrogen usage nitrates, ammonia etc. converted into plant proteins nitrates, ammonia etc. taken up by plants nitrates, ammonia etc. from ground Possible Solution Increase the RUP content of forages: Reduce N fertilization Alter harvest schedules Identify genetics that give more RUP What we are doing We are growing three types of grass in 56 plots Each plot is either given 0, 200, or 400 kgs of N fertilizer a year Plots are cut several times a year and grass is allowed to dry to between 25-35% DM The Haldrup Logster Harvester Harvesting the plots Harvest Grass is chopped and put into mini silos Samples are taken before and after ensiling and analyzed for CP, TP and fibre Drying oven Rumen Degradabilities Silage is incubated in the rumens of cannulated cows: Incubated silage analyzed for CP Know N percentage before and after Assess RDP and RUP The cannulated cow barn What We Have Found: Reducing N fertilizer levels decreases the content of non-protein nitrogen (NPN) in grass Less non-protein nitrogen = more true protein in grass More true protein = more rumen undegradable protein Consider a Career in Agricultural Science Agricultural community/ farm background Education in rural setting Good job prospects