about myself…

About myself…

33rdrd year Graduate Student at UBC year Graduate Student at UBC working towards a Master of Science working towards a Master of Science

DegreeDegree Program: Ruminant nutritionProgram: Ruminant nutrition Department: Animal ScienceDepartment: Animal Science Faculty: Agricultural SciencesFaculty: Agricultural Sciences

Where I work…

-UBC Dairy Education and Research Centre -UBC Dairy Education and Research Centre

-Pacific Agri-Food Research Centre (PARC) -Pacific Agri-Food Research Centre (PARC)

Agassiz, BCAgassiz, 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) Study the effects of nitrogen (N) fertilization on protein quality of forage fertilization on protein quality of forage grassgrass

Nitrogen forms

NN22: nitrogen gas: nitrogen gas

NONO33--: nitrate: nitrate

NONO22--: nitrite: nitrite

NHNH33: ammonia: ammonia

Amino Acid

N-C-C

H H O

H R OH

An amino acid

Proteins

2 amino acids together: dipeptide2 amino acids together: dipeptide 3 or more amino acids together: polypeptide3 or more amino acids together: polypeptide Polypeptide chain(s): proteinPolypeptide chain(s): protein

Plant nitrogen

80% of the atmosphere composed of N80% of the atmosphere composed of N22

This N is unavailable for plant nutritionThis N is unavailable for plant nutrition Ammonia (NHAmmonia (NH33 ) is the only form of ) is the only form of

nitrogen that can be utilized by the plant nitrogen that can be utilized by the plant

Nitrogen fixation and oxidation

Nitrogen fixation: convert NNitrogen fixation: convert N2 2 to NHto NH33

Rhizobium Rhizobium and other types of bacteria and other types of bacteria have enzymes that fix nitrogenhave enzymes that fix nitrogen

Nitrogen oxidation: convert NNitrogen oxidation: convert N2 2 to NOto NO33--

Lightning oxidizes nitrogenLightning oxidizes nitrogen

Nitrate converted to ammonia

Plants and bacteria have enzymes that are Plants and bacteria have enzymes that are capable of converting NOcapable of converting NO33

-- to NO to NO2 2 --

Plants and bacteria also have enzymes that Plants and bacteria also have enzymes that are capable of convertingare capable of converting NONO2 2

– – to NH to NH33

Ammonia to amino acids, etc.

Ammonia is converted via metabolic Ammonia is converted via metabolic pathways into amino acids, nucleotides, and pathways into amino acids, nucleotides, and other nitrogen containing molecules.other nitrogen containing molecules.

The nitrogen cycle

NN22

NONO33-- NO NO2 2

- - NHNH3 3 amino acids, amino acids,

nucleotides, nucleotides, etc. etc.

Nitrogen fertilizers

Ammonia, nitratesAmmonia, nitrates Urea, urea formaldehydeUrea, urea formaldehyde

Urease required for breakdownUrease required for breakdown Organic wastesOrganic wastes

Slow releaseSlow release

Cows are ruminants

abomasum

rumen

omasum

reticulum

Ruminants

““Four chambered stomach”:Four chambered stomach”: Reticulum sorts feed Reticulum sorts feed Rumen is full of microbes that ferment feed Rumen is full of microbes that ferment feed

Largest compartment (fits up to 200lbs of Largest compartment (fits up to 200lbs of feed) feed)

Omasum filters and absorbsOmasum filters and absorbs Abomasum is comparable to our stomachAbomasum is comparable to our stomach Cows ruminateCows ruminate

Cows are ruminants

abomasum

rumen

omasum

reticulum

Nutrition Made Simple

Cows (like us) are a moving clump of Cows (like us) are a moving clump of mattermatter

Cows need both building material and Cows need both building material and energy (to build and move) in diet energy (to build and move) in diet

Building material comes from proteinBuilding material comes from protein Energy comes from carbohydratesEnergy comes from carbohydrates

Ruminant nutrition protein terms… Crude protein: % nitrogen in a sample x Crude protein: % nitrogen in a sample x

6.256.25 ““Typical” protein molecule is 1/16 Typical” protein molecule is 1/16

nitrogen nitrogen 1/16 = 0.06251/16 = 0.0625

Problem: not all nitrogen in food is in Problem: not all nitrogen in food is in protein formprotein form

Non Protein Nitrogen and True Protein: Crude protein is made up of non-protein Crude protein is made up of non-protein

nitrogen (NPN) and true protein (TP)nitrogen (NPN) and true protein (TP) Non-protein nitrogen (NPN): nitrogen not Non-protein nitrogen (NPN): nitrogen not

in protein molecules (free peptides, free aa, in protein molecules (free peptides, free aa, nitrates, ammonia, etc)nitrates, ammonia, etc)

True protein (TP): nitrogen in the form of True protein (TP): nitrogen in the form of proteins (peptides linked together)proteins (peptides linked together)

Protein:

Rumen degradable protein (RDP): non-Rumen degradable protein (RDP): non-protein nitrogen (NPN) and true protein protein nitrogen (NPN) and true protein (TP) that is degraded into non-protein (TP) that is degraded into non-protein nitrogen in the rumen.nitrogen in the rumen.

Rumen undegradable protein (RUP): true Rumen undegradable protein (RUP): true protein (TP) that is not degraded in the protein (TP) that is not degraded in the rumen.rumen.

Protein in Feed

Protein Digestion

ammonia

Carbohydrate digestion

Energy metabolism in humans

nucleusmitochondria

cell

glucose Pyruvic acid

Acetyl CoA

Citric acid cycle

O2

CO2

ATPH2O

ADP

The three VFAs used for energy:

AcetateAcetate ButyrateButyrate PropionatePropionate

VFA metabolism in cows

nucleusmitochondria

cellButyrate

Ketone bodies

Acetyl CoA

Citric acid cycle

O2

CO2

ATPH2O

ADP

Acetate

Propionate

Human vs. Cattle fat production

Humans:Humans:

Excess glucose Excess glucose used to make fatused to make fat

Cattle:Cattle:

Unable to make fat Unable to make fat directly from directly from glucoseglucose

Excess acetate used Excess acetate used for fat productionfor fat production

My Research: RUP from Forage GrassProblems: Problems:

Lactating dairy cows need a lot of protein in Lactating dairy cows need a lot of protein in their diettheir diet

A lot of dairy cow diets have too much A lot of dairy cow diets have too much RDP and too little RUPRDP and too little RUP

Environmental concerns

Both NOBoth NO33- - and NHand NH44

++ are water soluble are water soluble

NONO33- - is also readily leached out of the soilis also readily leached out of the soil

NHNH44++ associates with soil colloid particles associates with soil colloid particles

and resists leachingand resists leaching

Plant Nitrogen usage

nitrates, ammonia etc. taken up by plants

nitrates, ammonia etc. from ground

nitrates, ammonia etc. converted into plant proteins

Possible Solution

Increase the RUP content of forages:Increase the RUP content of forages:

Reduce N fertilizationReduce N fertilization Alter harvest schedulesAlter harvest schedules Identify genetics that give more RUP Identify genetics that give more RUP

What we are doing

We are growing three types of grass in 56 We are growing three types of grass in 56 plotsplots

Each plot is either given 0, 200, or 400 kgs Each plot is either given 0, 200, or 400 kgs of N fertilizer a yearof N fertilizer a year

Plots are cut several times a year and grass Plots are cut several times a year and grass is allowed to dry to between 25-35% DMis allowed to dry to between 25-35% DM

The Haldrup Logster Harvester

Harvesting the plots

Harvest

Grass is chopped and put into mini silosGrass is chopped and put into mini silos

Samples are taken before and after ensiling Samples are taken before and after ensiling and analyzed for CP, TP and fibreand analyzed for CP, TP and fibre

Drying oven

Rumen Degradabilities

Silage is incubated in the rumens of Silage is incubated in the rumens of cannulated cows:cannulated cows:

Incubated silage analyzed for CPIncubated silage analyzed for CP Know N percentage before and afterKnow N percentage before and after Assess RDP and RUPAssess RDP and RUP

The cannulated cow barn

What We Have Found:

Reducing N fertilizer levels decreases the content Reducing N fertilizer levels decreases the content of non-protein nitrogen (NPN) in grass of non-protein nitrogen (NPN) in grass

Less non-protein nitrogen = more true protein in Less non-protein nitrogen = more true protein in grassgrass

More true protein = more rumen undegradable More true protein = more rumen undegradable proteinprotein

Consider a Career in Agricultural Science

Agricultural community/ farm backgroundAgricultural community/ farm background

Education in rural settingEducation in rural setting

Good job prospectsGood job prospects