What is the single most important factor affecting feed quality?
stage of maturity at harvest
What are some post-harvest feed sampling considerations when analyzing feed? (5)
- storage conditions/ how it was stored
- silage acids
- particle size
What is the typical dry matter of baled hay?
- large bales should be 90% so the inside doesn't mold
- small bales might be around 87%
Describe the fermentation of silage.
- when silage first undergoes fermentation, it’s an aerobic fermentation, and the aerobic organisms use up the oxygen
- it’s important to get compaction so we have very little oxygen present, we want the aerobic organisms to die so the anaerobic organisms take over, produce lactic acid, pickle the feed, and drop the pH
- eventually it gets so low that the anaerobic organisms even die off
What is the best way to sample bunker silage?
- sample it as it's going into the bunker after harvest
- if you sample after storage, sample it as it is coming out of the bunker to be fed (you don't want to sample the face that has been drying out since the last feeding)
How do you sample a round bale versus a small bale of hay?
- probe round bales from the round end; 12 core samples
- probe small based from the butt end; 15-20 core samples
You should sub-sample ________ but not ________.
Fiber is a(n) __________.
structural carb (cellulose, hemicellulose)
What is a consequence of silage being too dry?
What is a consequence of hay being too dry?
- shatter- leaves falling off, crumbling in the field as its baled
- (this is more of a problem for legumes than grasses; grasses don't have leaves)
What are consequences of hay being too wet?
too much oxygen--> aerobic organisms thrive, generate heat--> molding, in extreme cases fire ignites
What is the proper DM% of hay?
- if hay is only 75-80%, add a preservative (proprionate)
What is the proper DM% of silage?
- Ideally 32-45%
- OK anywhere b/w 30-50%
- corn silage should be 32-35%, haylage should be 40-45%
What is a consequence of silage being too wet?
clostridial fermentation or seepage
What are the 4 rations delivered to the cow?
- ration on paper
- ration in the bunk
- ration consumed by the cow
- ration absorbed in the bloodstream
Every pound of dry matter intake correlates to _________.
What is the equation for DMI? Calculate DMI for a 635kg cow producing 36kg milk with 3.5% fat.
- DMI (kg/day)= (0.0968 x BW0.75) + (0.372 x kg FCM)
- FCM= (0.4 x kg milk) + (15 x kg fat)
- FCM= (0.4 x 36) + (15 x 36 x 0.035)= 32.8
- DMI= (0.0968 x 6350.75) + (0.372 x 32.8)= 24.7kg/day DMI
What percent of a corn silage sample should be in each portion of a 4-try particle separator?
- Upper: 3-8%
- Middle: 45-65%
- Lower: 20-30%
- Pan: <10%
What percent of a haylage sample should be in each portion of a 4-try particle separator?
- Upper: 10-20%
- Middle: 45-75%
- Lower: 30-40%
- Pan: <10%
What percent of a TMR sample should be in each portion of a 4-try particle separator?
- Upper: 2-8%
- Middle: 30-50%
- Lower: 10-20%
- Pan: 20-40%
What is the purpose of using a particle separator to analyze feed?
determine physically effective fiber (scratch factor)
NDF is a determiner of _______.
ADF is a determiner of ________.
What is the equation for nutrient % on dry matter basis?
nutrient % on as-fed basis/ %DM in feed expressed as decimal
When formulating a ration, start with ________.
Forage: grain ratio should be ________.
Forages should be at least _______ of total DMI or __________.
Grain should be a maximum of ________ of total DMI and not more than _________.
ADF should be _________, and NDF should be _________.
What is the CP benchmark for early lactation?
Do not exceed ______ of diet dry matter as fat.
What are the ratio rules for CP-ADF-NDF for grasses and legumes?
- Grasses: 20-30-50; 20% CP- 30% ADF- 50% NDF
- Legumes: 20-30-40; 20% CP- 30% ADF- 40% NDF
Contrast NIR from wet chemistry feed analysis.
- NIR: grind sample and put in machine, where different wavelengths are passed through it and absorption is used to predict compounds; faster, less labor, less money; good for organic values
- wet chem: more accurate for inorganic (vit, minerals) values
Small grains (such as wheat and barley) are like grasses in that...
- 20-30-50 rules applies
- 20 % CP, 30% ADF, 50% NDF
- [protein may be lower, like 10-20%]
What is too much iron in the feed indicative of?
__________ is an indicator of heat damage.