1. LECTURE 25 FEEDLOT CATTLE NUTRITIONpp

2. GOALS WHEN FEEDING FINISHING CATTLE
Maintain animal health
Produce a desirable carcass
Choice grade (5.0 to 8.5% intramuscular fat, 28% body fat)
Body weight will vary with genetics, growth rate, and implants
Yield grade 3 or less
Acceptable maturity (< 30 months)
White fat and bright red muscle
Carcass weight between 650 and 875 lbs
Minimize production costs
Feed
Non-feed costs (Facility depreciation, Interest etc)
Minimize environmental impacts
Maximize feed efficiency

3. TRADITIONAL SYSTEM OF FEEDLOT FINISHING OF BEEF CATTLE
Feeder calf or yearling
( lb)
Implanted with estrogen w/ or
w/o Trenbolone acetate
Feed high grain diet (80-90% grain)
with ionophore
Gain 3-4 lb/day
Feed/gain 6-7
Harvested at 1200 –1400 lb
producing a carcass with a
choice quality grade and a
yield grade of 2 or 3
Season prices:
High in March and April
Low in July

4. FEED INTAKE OF FEEDLOT CATTLE
Normal intake is 2 to 3% of body weight
Factors
Degree of finish as affected by body weight, cattle type, implants etc.
Feeding after a period of restricted gain (backgrounding or grazing)
Part of compensatory gain
Diet
Ionophores
Forage concentration
Fat concentration
Nutritional imbalance
Potassium deficiency
Environmental
Temperature (base is 15 to 25 C)
Decreases by 10 to 35% if temperature increases to 35C
Increases by 15% is temperature decreases to -5 to -15C
Mud
Decreases by 15% if mud depth is 4 to 8 inches

5. EFFECT OF BODY WEIGHT AND FATNESS ON FEED INTAKE ON STEER FINISHING AT 1200 LB
Body fat
DMI

6. Maintenance energy requirement of finishing beef cattle
NEm, Mcal/day = .077BW.75
Modified by a large number of factors

7. ( Another part of compensatory gain) Cold temp, snowy coat, BCS 5
Maintenance Modifiers
Modifier
Modification
Change in NEm reqt.
Breed
Beef breed
Base
Dairy breed
Increase by 20%
Brahman breed
Decrease by 10%
Sex
Bull
Increase by 15%
Previous nutrition
BCS<5
Decrease by 5%/BCS unit
( Another part of compensatory gain)
BCS>5
Increase by 5%/BCS unit
Environmental stress
Cold temp, dry coat, BCS 5
(Include temp, wind, BCS, hide & coat thickness, coat cover and heat increment)
Cold temp, dry coat, BCS 4
Cold temp, snowy coat, BCS 5
Increase by 96%
Heat stress
Increase by 11 to 25%

8. EFFECTS OF BODYWEIGHT ON THE NEm and NEg REQUIREMENT TO GAIN 3
EFFECTS OF BODYWEIGHT ON THE NEm and NEg REQUIREMENT TO GAIN 3.5 lb/day FOR STEERS AT EITHER AT FINISHED WEIGHT OF 1200 OR 1400 LB

9. ENERGY SOURCES FOR FEEDLOT DIETS
Grains
Traditionally fed at levels up to 95% of the diet
Usually are processed
Grinding, cracking or rolling
High moisture corn
Steam-flaking
Cattle must be properly adapted to diet
Limits
Grain
Maximum fed, % of DM
Consideration
Corn grain 92
Milo
Wheat 50
Highly fermentable starch
Oats 25
High fiber, low energy
Ground ear corn 95
(If no forage fed)
High fiber

10. Distillers dried grains w/ solubles (DDGS)
Grain processing byproducts
Alkali-treated corn stalks
Used at levels up to 20% of DM
Grain byproduct
Maximum fed, % of DM
Consideration
Distillers dried grains w/ solubles (DDGS) 40
High sulfur,
High fat
Corn gluten feed
20-30
High fiber
Distillers solubles 20
(If DDGS not in diet)
High sulfur, high fat
Soy hulls 25

11. Fat supplements (Tallow, Vegetable-Animal Fat)
Increase energy concentration
Reduce dustiness
Limit to 5% of DM
Molasses
Increase palatability
Increase binding of pellets

12. ADAPTATION TO HIGH GRAIN DIETS
Rumen microbial population must be slowly adapted to high grain diets to prevent:
Lactic acidosis
Founder
Polioencephalomalacia
Bloat
Systems
Hand feeding
Cattle fed forage for 4 to 7 days
Start feeding grain at 0.5% BW
Amount of grain increased at 1 lb/day to 1% of BW
Amount of grain increased at 1/2 lb/day to full feed
Decrease forage as grain increased
Feed bunks must be monitored to ensure feed consumption
If intake decreases or ceases, slow rate of increase

13. Roughage:Concentrate
Self-feeding a mixed ration
Supplementing Vitamin A at 30,000 to 50,000 IU/hd/day and Vitamin E at 400 to 800 IU/hd/day can assist in managing stress
Days
Roughage:Concentrate
1-4
100% hay
5-8
50:50
9-13
40:60
14-17
30:70
18-21
20:80
22-25
15:85 26
10:90

14. MEETING THE FIBER REQUIREMENTS OF FEEDLOT CATTLE
Need for fiber in ruminant diets
Stimulate rumination and saliva secretion
Prevents
Parakeratosis of rumen wall
Liver absess
Acidosis
Bloat
Requirement is for effective NDF (eNDF)
Includes fiber content and physical form of fiber
NDF that remains on top of a 1.18 mm screen
Requirements
8% eNDF if:
Good bunk management, ionophore fed
20% eNDF if:
Variable bunk management, no ionophore

15. eNDF concentrations of common feeds in feedlot diets
Feed eNDF, % of DM
Ground corn stalks 65
Ground hay 51
Corn silage 33
Soy hulls
Corn gluten feed 13
Whole corn grain 10
Cracked corn
Ground corn
Distillers dried grains w/solubles 4
Soybean meal

16. Metabolizable protein supply dependent on:
Ruminally undegraded protein
Microbial protein synthesis

17. FACTORS AFFECTING THE PROTEIN REQUIREMENTS OF GROWING BEEF CATTLE
Animal age and weight
Compensatory gain
Use of hormone implants
Feed intake

18. PRACTICAL IMPLICATIONS OF MP REQTS. OF FINISHING BEEF CATTLE
Cattle at light weights relative to finishing weight will benefit from sources of rumen undegradable protein
Distillers grains w/solubles
Corn gluten meal
Expeller processed soybean meal
Blood meal
Cattle at moderate weights only need to be supplemented with rumen degradable protein sources
NPN
Recall rules for safe use of NPN
Cattle near finishing weights obtain adequate metabolizable protein from a corn-corn silage diet with no protein supplementation
If DDGS are fed at 20 to 40% of the DM at any time during feeding, no protein supplementation is necessary

19. MINERAL NUTRITION OF FEEDLOT CATTLE
Salt (NaCl)
Should be supplied at 0.25% of diet DM
Calcium and phosphorus
Feeds commonly used for feedlot diets contain low amounts of CA and adequate to high amounts of P
Add limestone to maintain Ca:P ratio of 2:1
Prevents urinary calculi
Potassium
Borderline on high grain and corn silage diets
Monitor and supplement if:
Low feed intake
Heat stress
Ca, % of DM
P, % of DM
Reqt
0.4 – 0.6
0.24 – 0.30
Corn grain
0.03
0.32
Corn silage
0.25
0.22
DDGS
0.26
1.0

20. Sulfur Trace minerals Toxic is fed at greater than 0.4% of diet
Causes polioencephalomalacia
Occurs at lower dietary levels of S if S content of water is high
May be a problem in diets containing high levels of Distillers dried grain w/ solubles
DDGS contain as much as 1.0% S
Management
Do not feed > 40% DDGS in cattle diets
Increase forage content of diet (15%)
Delay addition of high levels of DDGS until cattle adapted to grain
Use DDGS from plants that contain consistent levels of S
Supplement cattle fed DDGS with 150 – 200 mg thiamine/day
Trace minerals
Cu, Zn, Fe, Mn, Co, and I should be supplemented in a premix

21. VITAMIN NUTRITION OF FEEDLOT CATTLE
Vitamin A
Supplement at 30,000 – 50,000 IU/d during adjustment
Supplement at 20,000 – 30,000 IU/d after adjustment
Vitamin E
Supplement at 400 – 800 IU/d for first 30 days in feedlot
Supplement at 500 IU/d during last 100 days in feedlot will improve product shelf life
Vitamin D
No need for supplementation if exposed to sunlight
B vitamins
Thiamin supplementation at 150 – 200 mg/d may reduce the risk of polioencephalomalacia in cattle fed DDGS
Other B vitamins not needed

22. FEED ADDITIVES AND IMPLANTS FOR FEEDLOT CATTLE (Take care to follow all dosage and use instructions)
Class
Products
Effects
Feed additives
Ionophores
Monensin, Lasalocid, Salinomycin
Increase propionic acid and decrease methane production in rumen, decrease feed intake, increase feed efficiency, increase ADG in cattle on high forage diets
Progestogen
Melengesterol acetate (MGA)
Prevents estrus in heifers, increase ADG and feed efficiency
B-agonist
Ractopamine (Optiflex), Zilpaterol (Zilmax)
Fed during last 28 – 42 days in feedlot. Increases ADG, feed efficiency, ribeye size and retail meat yield
Hormones
Tylosin
Reduces liver abscesses
Implants
Estrogen
Estradiol
Increase rate of gain, feed efficiency, and protein gain
Progesterone
Androgens
Trenbolone acetate