Practical Beef Nutrition and Ration Formulation

ANSC 405 - Exam 5

list the nutrient requirements in order of importance

• energy

• protein

• major minerals

• minor minerals and vitamins

net energy for production

• weight gain

• body condition growth

• fetal growth

• milk production

net energy for maintenance

• basal metabolism

• environmental adjustments

list the major minerals needed in the diet

• calcium

• phosphorous

• magnesium

• salt

• potassium

• sulfur

calcium is required for

required for milk production and growth

phosphorous is required for

milk production and growth

grains are low in ___, forages are high in ___

Ca, Ca

grains and corn coproducts are high in __

P

why may Ca:P be important in steers"?

due to urinary calculi

magnesium is low in…

lush spring grass

what is a common deficiency when Magnesium is not supplied?

Grass Tetany

what are most feeds low in?

salt

what is high in forages and low in grains?

potassium

what is needed when urea is added to the diet?

sulfur

what trace minerals should be supplied in beef cattles’ diets?

Co, Cu, I, Fe, Mn, Se, Zn

what program should trace minerals be a part of?

sound mineral supplementation program

what vitamins are required in the diet?

vitamin A, D, and E

when would B vitamins be needed for beef cattle?

needed for stressed calves

what is the temperature range of the thermoneutral zone?

41-77 degrees F

what is the thermoneutral zone optimal for?

performance and health

define body condition scoring

a management tool for adjusting energy requirement of beef cows. also used to evaluate previous nutrition of feeder cattle.

what is the BCS range of thin cows?

1-3

what is the BCS range of borderline and optimum cows?

4-6

what is the BCS range for fat cows?

7-9

describe BCS 1

• severely emaciated

  • no palpable fat over back, hips, or ribs

  • tailhead and individual ribs prominently visible

  • animals are usually disease stricken

  • starving and weak

describe BCS 2

• emaciated

• not weakened

• little visible muscle tissue

• tailhead and ribs less prominent

describe BCS 3

• very thin

• no fat over ribs or in brisket

• backbone easily visible

• slight increase in muscling

describe BCS 4

• borderline

• individual ribs noticeable but overall fat cover is lacking

• increased musculature through shoulders and hindquarters

• hips and backbone slightly rounded

describe BCS 5

• optimum

• increased fat cover over ribs

• generally, only last 2 ribs (floating ribs) are visible

• tailhead full, not rounded

describe BCS 6

• back, ribs, and tailhead slightly rounded and spongy

• slight fat deposition in brisket

describe BCS 7

• fat

• cow appears fleshy and carries fat over the back tailhead, and brisket

• ribs are not visible

• area of vulva and external rectum contain moderate fat deposits

• may have slight fat in udder

describe BCS 8

• very fat

• squared appearance due to excess fat over back, tailhead, and hindquarters

• extreme fat deposition in brisket and throughout ribs

• excessive fat around vulva and rectum, and within udder

• motility may begin to be restricted

describe BCS 9

• obese

• majority of fat deposited in udder limits effective lactation

• similar to BCS 8, but to a greater degree

what condition score is optimum at calving?

5-6

what weight range, depending on cow size, is each BCS?

80 to 150lbs

when is it best to score cows and why?

best to score in the fall to allow sufficient time for condition score gain

heifers should be ___% of mature weight at _________, and ___% of mature weight at ______

60% at breeding; 85% at calving

what are the nutrition guidelines for preconditioning?

• creep feed and bring feeder into feedlot

• palatable diet

• feed long-stem hay and top dress grain for a few days

• feed in a bunk to get used to it

• free-choice watering system

• loose free-choice salt

• increased mineral needs prior to shipping

• avoid silage or fermented feeds

• caution with lots of grain

what are stocker cattle?

weaned calves that forage-fed for a period of time before being sold to enter a feedlot

describe the diet needed for spring born stocker cattle calves that were bought in the fall.

• winter on high-roughage diets in drylot

• winter graze on wheat/winter oats, or fescue

• winter on stocks (corn or milo) until gone, then feed silage with CP (legume/supplement) in feedlot

what is the goal when transitioning first time calves into a feedlot?

minimize disease and death loss

describe what a transition ration looks like

• medium quality roughage free-choice

• protein supplement if needed

• after 2-3 days, add grain at rate of .5lb/100lbs

what are backgrounded cattle?

weaned calves placed in drylot or pasture with more emphasis on growing than stocker calves

what are backgrounded cattle fed?

grain+roughage, move straight to finishing ration

what’s the target weight of backgrounded cattle?

800+ lbs

what are growing cattle?

growing calves in feedlot until switched to finishing ration

growing cattle are generally fed more _______ than concentrate

roughage

what are the 2 phases of feeding growing cattle?

phase 1 - feeding 50-60% concentrate from 450-800lbs

phase 2 - >75% concentrate over 800lbs

what is the target for finishing cattle?

to increase marbling/improve quality

what is the concentrate:roughage ratio in finishing cattle?

85:15

what problems can high concentrate diets lead to?

• acidosis

• founder

• liver abscesses

what are feed additives?

non-nutritive ingredients added to the diet

give some examples of feed additives

• medications

• flavorings

• colorings

• growth promotants

• antioxidants

ionophores

commonly fed to cattle, kill certain rumen bacteria

ionophores are considered as an __________

antibiotic

ionophores are toxic to _______

horses

MGA is an example of a…

hormonal effect additive

what is MGA used for?

fed to feedlot heifers, to suppress heat (acts like progesterone)

what are the two parts to adapting cattle to grain?

• manage feed consumption

• adjust rumen microbes to new substrate

how long will it take calves to adapt to grain? what about previously adapted yearlings?

calves: 2-3 weeks

previously adapted yearlings: 1-2 weeks

what is the rule of thumb for initial grain consumption?

.5-1% of bodyweight

list some nutritional problems in beef cattle?

• grass tetany

• urinary calculi

• sulfur toxicity

• Se deficiency

• acidosis and bloat

• nitrate and urea toxicosis

• molds and mycotoxins