Lecture 2 Part 1 Flashcards
why do we analyze feed
- need to know what nutrients are present
- test for anti-nutritional factor or toxins
- know more about what we are buying or selling
- want to establish or add value
depending on scale and level of management, how many times may a farmer collect and analyze feed
daily, weekly, monthly, quarterly, annually
what is important when taking samples of feedstuffs (should be)
- collected correctly
- labeled consistently
- stored appropriately (prevent degradation)
round bales
- outside and inside were at different locations when raked and baled
- outside=dry, moldy, ;ess nutrients
how do you take a sample to analyze a square bale
grab samples
silage
- keep sealed
- core sampling
- testing nutrition and fermentation
what kind of testing do you use for silage
core sampling
what kind of testing do you use for grain
grab samples
sampling forages
- Grab sample
- core sample
- sample numbers and composites
what are the two general analytical procedures used in feed analysis
- proximate analysis
- van soest analysis
in a feed analysis, what are the specific analytical procedures
- vitamins
- minerals
- toxins
what are other forms of feed analysis
- near infrared reflectance spectroscopy
- biological models
what is the history behind feed analysis
- 1860
- Weende Analysis/ Weende Experiment Station
proximate analysis
series of procedures used to determine nutrient categories
- quantitative method to determine amount of different macronutrients in feed
what are the 6 fractions of proximate analysis
DM
EE
CF
CP
Ash
NFE
water
dry matter
crude protein
protiens
ether extract
lipids
ash
minerals
crude fiber
carbs
nitrogen free extract
carbs
Key Points to Dry Matter (DM)
- moisture meters
- microwave equipment
- freeze drying
“As fed”
air dried
how do you perform dry matter
weigh sample, dry it, weigh sample again
moisture meters (DM)
- immediate
- depend on electrical conductivity
- precision lower
microwave equipment (DM)
- may not be as accurate
- temp control IMPORTANT
freeze drying (DM)
- best technique
- can only do small sampling at a time
problems with dry matter
fermented feeds
what does crude protein (CP) determine
quantity and measures nitrogen in material
how is the nitrogen expressed as in CP
N times 6.25
What procedure foes with CP
Kjeldahl Procedure
how is CP analyzed
- digest feed in concentrated H2SO4
- mixed with NaOH and titrated with acid
what type of animal is CP not useful in
non-ruminants
fats are not…
water soluble
how do you analyze ether extract
-reflux sample with ether
- measure material left behind
what does ether extract determine (EE)
determines fat content
what is the importance of ether extract figures
energy value
what is possible misinformation for EE
soluble compound not useful to the animal
what is Ash
-residue remaining after a high temp burn
what is left in ash
inorganic compounds
how is crude fiber determined (CF)
- boil an ether extracted sample in dilute acid and then dilute base
- sample burnt in 600 degrees
what is the difference between pre and post burn quantity
CF
misinformation about CF
- excludes some fiber
- contains lignin, cellulose, and hemicellulose
Nitrogen Free Extract (NFE)
- no extraction
- represents the non fibrous carbohydrate fraction
how is NFE calculated
by difference
NFE+100-(water+CP+EE+CF+ASH)
what is the problem with NFE
calculated not measured so there are better methods to measure starch
what type of carbs does NFE look at
soluble carbs
what type of carbs does Crude Fiber look at
fibrous carbs
