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

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

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