Cattle NutritionRuminant HerbivoresCalf- young animalHeifer- female calf that has not given

birth and is less than 30 months oldCow- older than 30 months old, or has

given birthBull- intact maleSteer- castrated male up to 4 years oldOx- castrated male, more than 4 years

old

Dairy Cattle

Main objective- increase dry matter intake to produce higher levels of milk production

Key factors: energy, ration digestibility, rumen fill, palatability, body weight( BCS), environment, frequency of feeding and water

Phase feeding program

Phase feeding- Changing the nutrient

concentration in a series of diets formulated to meet an animal’s nutrient requirements more precisely at a particular stage of growth or production

- Based on lactation and gestation cycle

Phase 1First 10 weeks of lactationPeak milk production happens in

this phaseNegative energy balance

develops, so cow uses body stores to make up difference ( can borrow fat, but cannot borrow protein)

What to feed in Phase 1Increased grain for energy ( corn,

wheat, soybeans)Protein supplementation to meet amino

acid requirements ( dried brewers grain, distillers grain, corn gluten meal)

Increased concentrates and fats to increase energy density of feed ( soybeans, sunflower seeds)

Sodium bicarbonate “ buffer” to reduce acidosis and maintain ruminal ph

Phase 2Begins 10 weeks post calving

and can continue to 20th weekHighest dry matter intake

happens hereNutrient intake is finally in

balance with nutrient needs

What to feed in Phase 2Lower protein levels because

requirement is met by supplementation in Phase 1

Adequate fiberLimited grain intakeFrequent feeding ( minimizes

digestive upset)

Phase 3“late lactation period”, cow is

pregnant againNutrient intake exceeds

requirement for productionMain period for restoring body

reserves for next lactation

What to feed in Phase 2Easiest phase to manage

because cow is pregnant and milk production is declining

Increased amount of forage instead of concentrates

Lower protein

Phase 4Most of the “ dry” periodFinal regaining of any lost body

weight happens hereGoal is to get cow in good

condition for parturition, but not excessively fat ( BCS of 3.5 out of 5.O scale)

What to feed in Phase 4High protein, energy, Ca and P

needsCombination of legume-grass hay

and corn silage ( with added vitamins and P0

Long stem grass hay ( length of hay matters)

Limit grain to energy and protein needs

Body Condition Scoring

A numeric system to subjectively assess and animal’s degree of fatness

Fat Cow Syndrome- High blood lipids and fatty liver

from eating excess energy from grain or corn silage

- Can lead to calving difficulties, displaced abomassum and ketosis

Phase 5Last 1-3 weeks of “dry” period,

just before calvingReferred to as a “transition

period”Increase grain intake to prepare

rumen for high energy diets that will be needed postpartum

What to feed in Phase 5Gradual increase in grainsSmall amounts of all ingredients

used in the lactation rationMaybe decrease Ca in “ milk

fever” prone cows

Beef Cattle NutritionMost critical factor influencing

performance of cattle on forage diet is the amount of Dry Matter Intake

Young, growing grass and pasture crops usually have ample nutrients

old pastures, crop residues and harvesting methods cause reduction in nutrients

Biological Cycle

Goal: optimal nutrition at each stage, not maximum nutrition

Cycle is made up of 4 periods that span 1 year: 3 trimesters and 1 postpartum period

First Trimester ( 95 days)Begins the 1st day of conceptionNutrient needs are for

maintenance and lactation if the cow has a calf with her

Milk production is declining at this stage

Second Trimester ( 95 days)Calf is weaned, lactation

requirements endLowest nutrient requirements at

this pointFeed minimally Easiest and most economical

time to increase a thin cows BCS

Third Trimester ( 95 days)Rapid fetal growth causes rapidly

increasing nutrient needsWatch BCS carefully, cow gains 1

lb per dayToo thin cows experience

dystocias, weak calves and decreased milk production

Postpartum Period ( 80 days)High lactation requirementsFeed intake is 35-50% higher

than non-lactating cowNutritional stress at this point

causes problems during the cow’s next breeding ( usually 80 days post partum)

Energy RequirementEnergy is considered first in

balancing diet for beef cattle, it’s the largest portion of the ration

Energy utilization determines cow’s ability to use other nutrients

Good quality forage satisfies adult energy requirements

Poor quality forages need to be supplemented with concentrates

Protein Requirements50% of all protein and amino acid

needs are met by microbial protein synthesis

Protein deficiency is common when cows consume straw and low quality hay

Urea is commonly used as a protein supplement

Beef Cattle, Water requirementsNeed abundant supply at once

dailyRange cows consume 2 ½ gallons

daily in winter and up to 12 gallons per head in summer

When salt is added, water need is increased

Fresh succulent feeds or silage help reduce need

Beef Cattle mineral requirementsSalt- need more when eating

succulent forages than when eating drier forage

Calcium- depends of Ca concentration in soil, higher needs in growing and lactating cows

Phosphorus- Low P levels in roughage, so P is often offered free choice in a mineral mix

Cobalt- required for rumen microorganisms to synthesize vitamin B 12

Minerals continuedCopper- Simental and Charlois

have a higher requirement than Angus

Iodine- deficiencies in Northwest and Great Lakes area soil; supply via iodized salt

Beef Cattle Vitamin RequirementsC, D, E, K and B complex- no need for

supplementation; ruminal microflora synthesizes B complex and K, Vitamin C is synthesized in tissues, Sun dried forages contain lots of Vit D and E

A- roughage and grains are low in Vit A, causing a deficiency. Cattle on pasture can store large amounts of Vit A for 2 months in liver, so deficiency isn’t immediately apparent. Look for signs of rough coat, diarrhea, excessive lacrimation

Grazing Systems and Management1. Continuous Grazing- Most common type of grazing

scheme- Cow grazes 1 area for the entire

season up to 1 year- Low maintenance, but

production suffers

Grazing systems continued2. Deferred rotational grazing- 4 pasture system- 1 pasture would not be grazed from

spring to mid summer in order to allow desirable plants to flower and reach seed maturity

- The following year another pasture would not be grazed

- After 4 years, all four pastures will have had time to rest

Grazing systems continued3. Rest rotation- Uses 3-5 pastures- 1 pasture is not grazed for an

entire year, while herd uses other pastures

Grazing Systems continued4. Short duration grazing- Developed in France- 8-40 pastures grazed intensively

for 2-3 days, then not grazed again for several weeks

Nutritional Disorders

1. Pasture bloat- Comes from consuming lush

legumes ( alfalfa, red clover)- Relieve bloat by inserting stomach

tube into rumen and giving anti-foam material ( ex vegetable oil)

- A trocar is used in extreme cases to release pressure ( large “needle” puncture through skin and gas rushes out)

Nutritional disorders continuedGrass tetany- Low Mg levels in blood from

grazing lush green grass pastures- Common in cows nursing calves

under 2 months- Symptoms: excitability, cows act

blind- Fix by feeding free choice mineral

supplement containing Mg, early in grazing season

Nitrite toxicity- Caused when intake of nitrite is in

excess of the rumen’s ability to convert it to ammonia

- Causes hemoglobin in blood to change into a form which cannot transport oxygen to the tissues

- Cow dies from asphyxiation- Treat with injection of IV

methylene blue

Fescue toxicity- Caused by grazing or consuming

harvested hay from tall fescue pastures

- Cow eats the endophytic fungus that grows between the fescue cells

- signs: soreness in hind limbs, “ fescue foot” hooves and tail slough off, hypersalivation and polyuria

Acute Pulmonary Emphysema “ Asthma’- Occurs in western US when cattle are

moved from dry rangelands to lush meadow pastures abruptly

- Signs seen in 4-5 days after diet change- Symptoms: labored breathing, extended

neck, open mouth breathing, grunting- Prevention: ( no treatment) slowly

introduce cattle to new pasture and supplement with monensin