Ruminant Animal Feed Management Issues and Practices CNMP Core Curriculum Feed Management –...
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Transcript of Ruminant Animal Feed Management Issues and Practices CNMP Core Curriculum Feed Management –...
Ruminant Animal Feed Management Issues and
Practices
CNMP Core Curriculum
Feed Management – Section 6.2
CNMP Development Core Training Curriculum
These course materials have been developed as a cooperative effort between five land-grant universities and The Natural Resources Conservation Service.
Ames, Iowa 50011, (515) 294-4111.
Copyright © 1995-2006, Iowa State University of Science and Technology. All rights reserved.
Copyright Information
Objectives
• Diet composition for ruminants
• Review digestion processes and excretion of N and P of the ruminant
• Discuss aspects of ration balancing
• Discuss reasons for overfeeding of nutrients
• Provide strategies for reducing nutrient excretion
Supplemental Materials
• NRC Nutrient Requirements of Dairy Cattle
• NRCS Nutrient Management Technical Note 5
• LPES Lesson No. 12 Feeding Dairy Cows to Reduce Nutrient Excretion NRC Nutrient Requirements of Beef Cattle
• NRCS Nutrient Management Technical Note 2
• LPES Lesson No. 13 Using Dietary Strategies to Reduce the Nutrient Excretion of Feedlot Cattle
Ruminant Nutrition
You are NOT just feeding the steer or cow! You are also feeding the microorganisms in the rumen.
You must feed and meet the needs of the ruminal microorganisms and the animal.
Dairy DietsDigestibility (availability of nutrients) of forages:• Amount of forage• Type of forage• Maturity of forage
Higher digestibilities increase utilization and
decrease nutrient excretion. Lower digestibilities
decrease utilization and increase nutrient excretion.
Dairy DietsConcentrates 45-60
Grains (corn, milo, barley, etc)Protein meals (soybean meal, Soypass,
Cottonseed, distillers grains, etc.)Byproducts (corn gluten feed, beet pulp,
soyhulls, etc.)
Forages 40-55alfalfa hay, corn silage, haylage, grasses
grazing? Supplement 2-10
dry-pellet, dry-meals, liquidminerals, protein?, vitamins, additives
0
50
100
150
200
250
300
350
400
14-Apr 24-Apr 4-May 14-May 24-May 3-J un 13-J un
Date
CelluloseCPLignin
Relationship between advancing maturity of first cut orchard grass and chemical
composition.
TSP Question to Producer
• How do you manage your forages?
• Buy or home grown?
• Are you maximizing the amount of home grown forages in the ration?
Feedlot Diets
Corn/Milo 50-85High-moistureDry-rolledSteam-flakedWhole
Roughage (alfalfa hay, corn silage) 0-10Byproducts (distillers/gluten feed) 15-40Molasses/Liquid 0-5Supplement 3-8
dry-pelletliquid
A Few Terms and Definitions
• Crude protein (CP) = N x 6.25
• Some protein is used by microorganisms in rumen and some are absorbed in small intestine
• Rumen degradable protein (RDP) = CP that is degraded in the rumen; required by bacteria to grow (DIP in beef)
• Rumen undegradable protein (RUP) = “escape or bypass” CP that is NOT degraded in rumen but passes to lower tract (UIP in beef)
Digestive Process of Ruminants
Rumen
MCPAA
Ammonia
RDPNPN
Degraded by microorganisms
MCPAARUPUrea
Fecal N
Sm Intestine
BUN
Milk Urea NMilk and
Meat
Diet CP
Ruminant Nutrition
• Goals– Provide adequate amount of rumen
degradable protein:• For optimal rumen health• For optimal rumen efficiency
– Provide adequate amount of rumen undegradable protein:
• To obtain the desired animal productivity
Protein
Ruminant Nutrition
• Excess N excretion typically due to imbalance of RDP and RUP and too much of one, or both– Excess RDP increases ammonia production
in rumen which leads to:• Decrease reproductive performance (toxic effect)• Decrease lactation performance (energy cost)• Increases urinary N excretion
– Excess RUP:• Not utilized by animal • Increases fecal and urine N excretion
Protein
Intake
Retention
Excretion
Intake-Retention=Excretion
Excretion in feces & urine
Ruminant Nutrition
• Estimate N excretion (dairy):– Milk production– Days in milk– Dry matter intake – Body weight – Milk protein content– Concentration of CP in ration
Protein
Ruminant Nutrition
• Estimate N excretion (beef):– Dry matter intake– Concentration of CP in ration– Days on feed for individual ration– Purchase weight (initial weight)– Market weight (ending weight)– Standard reference weight for expected final
body fat
Protein
Overfeeding protein increases N losses!Nutrition may:
decrease N inputs by 10 to 20%reduces N excretion by 12 to 21%reduces N volatilization by 15 to 33%
Based on annual occupancy, lose 50% of N excreted
• 53.5% annually for control animals, or 103 g/hd/d
• 48.2% annually for phase-fed animals, or 78 g/hd/d
2-year beef study(protein level)
Digestive Process of RuminantsPhosphorus
Rumen
Salivary P
M/O
Sm Intestine
Excess P
Fecal P Productive
functions
Milk(0.085 to 0.1%)
Diet P
Ruminant Nutrition
• Estimated P excretion (dairy):– Dry matter intake– Amount of P in ration– Milk production– Amount of P in milk (~ 0.10%)
Phosphorus
Ruminant Nutrition
• Estimated P excretion (beef):– Dry matter intake– Concentration of P in ration– Days on individual ration– Purchase weight (initial weight)– Market weight (final weight)– Standard reference weight
Phosphorus
TSP Question to Producer• Are the rations reformulated when there are
different ingredient changes?
• Are rations changed at different stages in the
production cycle?
• What is the laboratory analysis schedule for the feed management plan?
• Are by-product feeds being used in the ration?
Dietary P in Feedlot Diets
0.27 0.35
0.520.59
0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
85% Corn 85% Corn +Supplement
Byproduct Byproduct +Supplement
% d
iet
P (
DM
-bas
is)
SupplementByproductCornRoughage
NRC
0.00
0.50
1.00
1.50
2.00
2.50
3.00
3.50
4.00
0.00 0.05 0.10 0.15 0.20 0.25 0.30 0.35 0.40
P, % of diet DM
AD
G, l
b/da
y
P requirements
NRC corn industry
P Mass Balance: Summer Yearlings
Feedlot Pen
7.2 lb Pintake
1.9 lb P retained5.3 lb
excreted
12.8 lb Pintake
1.9 lb P
retained10.9 lb
excreted0.35% P diet
0.24% P diet
REDUCED44%
Values for the entire feeding period
P Mass Balance: Winter/Spring Calves
Feedlot Pen
9.9 lb Pintake
2.4 lb P retained7.5 lb
excreted
15.0 lb Pintake
2.5 lb Pretained12.5 lb
excreted0.40% P diet
0.26% P diet
REDUCED33%
Values for the entire feeding period
Dietary P effect on excretion
0
10
20
30
40
0 10 20 30 40 50P intake (g/d)
P e
xcre
tio
n (
g/d
)
Y = 0.0111x2 + 0.0522x + 6.6726; r2 = 0.74
2500 10,000 25,000
0 byp 0.29 P 1,320 5,300 13,200
20 byp 0.39 P 1,900 7,600 19,000
40 byp 0.49 P 2,500 10,000 25,000
Land Requirements, 4 yr P basis(acres)
2500 10,000 25,000COSTS0 byp 0.29 P 3.00 2.10 3.0020 byp 0.39 P 3.50 2.70 4.3040 byp 0.49 P 3.90 3.30 5.75NET VALUE0 byp 0.29 P 2.50 3.50 2.5020 byp 0.39 P 4.30 5.10 3.5040 byp 0.49 P 6.10 6.80 4.30
Costs and Net Value, C-SB rotation4-Yr P Basis, ($/hd)
Ration Balancing
Balancing Ruminant Rations
Book values vs Ingredient testing:
• Book values have limited value
• Ingredient testing only as good as the sample taken
Ingredient Challenges
Balancing Ruminant Rations
“Unbreakable Law of Sampling: You never know the true value of anything”
-Bill Weiss, OSU
Ingredient Challenges
Balancing Ruminant Rations
Numbers are not absolute!
Ingredient Challenges
20 tons of feedstuff 1 lb sample
sent to lab
(1/40,000)
1 g sub-sample analyzed
(1/18,000,000)
Balancing Ruminant RationsMeeting the Requirements of the Herd
If herd average is 77 lbs:Overfeeding cows producing 55 lbs
Excess nutrients leads to weight gain leading to health problems and lowered production
Underfeeding cows that could produce 120 lbs Not providing enough nutrients to meet genetic potential Not taking advantage of “money-makers”
Fresh cows producing 77 lbs have different requirements If do not meet nutritional needs of fresh cow, entire
lactation will be negatively affected: lost production and health issues
Who do you balance the ration for?
Feeding Management: The Bottom Line
The milking herd should be grouped by production level so that multiple rations can be formulated over the complete lactation.
Similarly, growing feedlot beef cattle should be grouped by sex, age and production potential so that multiple rations can be fed over the growth period.
Reducing N and P Excretion with Feed Management
Nitrogen Strategies for Dairy
• Increase dry matter uptake.
• Improve forage quality.
• Evaluate balance of types of home grown forages and other feed ingredients available.
• Consider forage protein fraction.
• Consider feeding method (phase and TMR).
• Consider supplemental protein source.
• Monitor blood urea nitrogen (BUN) and milk urea nitrogen (MUN).
Beef Strategies• Test feed for nutrients and dry matter.
• Use supplemental protein to balance RDP and RUP.
• Discontinue supplemental P.
• Consider phase feeding.
• Use available tools to evaluate your rations.
Questions?
P Mass Balance – Example CNMPManure
P2O5 Produced
= (44.82 lbs. avg. feed intake (%dm) x 0.0036*) - (65 lbs. avg. milk prod. per cow/day** x 0.001***) x 2.29****
= 0.0963 lbs. P per day per cow x 2.29
= 0.22 lbs. P2O5 per day per cow x 175 cows x 365 days
= 14,094 lbs P2O5 per year
Acres Required for P2O5 Mass Balance
= 14,094 / 65 lbs. P2O5 removed by crop
= 217 acres X 50% confinement
= 108 acres
*0.36 % of P in total feed ration from feed analysis
**Based on 2000/2001 rolling herd average of 26700 lbs. of milk produced per cow per year
***0.10 % of P in milk; ****conversion of P to P2O5
Class Exercise (Ruminants)• Calculate P excretion for the example
CNMP dairy if they use 25% DDGS in place of corn silage and milled feed.
• Calculate the amount of land needed to apply the P2O5 (assume 65 lbs of P2O5 needed for corn silage/acre) from the manure from cows fed this new ration (assume that only 50% of the time the cows are in confinement)
Class Exercise (Ruminants)• Calculate P excretion for the example
CNMP dairy if they use 25% DDGS in place of corn silage and milled feed.
What do you need to know?
DMI, diet composition, milk production
Class Exercise (Ruminants)• Calculate P excretion for the example
CNMP dairy if they use 25% DDGS in place of corn silage and milled feed.
What do you need to know?
DMI = 44.82 lb per dayDiet composition (DDGS contains 0.90% P, so diet will be 0.51% P)Milk production = 65 lb per day175 cows still
Class Exercise (Ruminants)
• Calculate P205 excretion for the example CNMP dairy with 0.51% P in the diet
• Calculate the amount of land needed to apply the P2O5 (assume 65 lbs of P2O5 needed for corn silage/acre) from the manure from cows fed this new ration (assume that only 50% of the time the cows are in confinement)
Class Exercise (Answer)Manure
P2O5 Produced
= (44.82 lbs. avg. feed intake (%dm) x 0.0051*) - (65 lbs. avg. milk prod. per cow/day** x 0.001***) x 2.29****
= 0.1636 lbs. P per day per cow x 2.29
= 0..375 lbs. P2O5 per day per cow x 175 cows x 365 days
= 23,953 lbs P2O5 per year
Acres Required for P2O5 Mass Balance
= 23,953 / 65 lbs. P2O5 removed by crop
= 368 acres X 50% confinement
= 184 acres
*0.51 % of P in total feed ration from feed analysis
**Based on 2000/2001 rolling herd average of 26700 lbs. of milk produced per cow per year
***0.10 % of P in milk; ****conversion of P to P2O5
Class Exercise (Answer)• Difference in P2O5 produced:
• 23,953 lbs – 14,094 lbs = 9,859 lbs more produced; however, only 50% confinement, so 4,930 lbs collected and stored.
• Difference in acres of land required (assuming 50% confinement):
• 184 acres – 108 acres = 76 acres more needed
• If all the manure was collected (100% confinement, then 151 acres more needed
Computer Software Tools• Dairy Whole Farm Balance Nutrition
Education Tool (WFBNET) – www.puyallup.wsu.edu/joeharrison/software
• Whole Farm Balance – on CNMP Course CD and at http://cnmp.unl.edu
• Nutrient and Land Estimator – on CNMP Course CD and at http://cnmp.unl.edu