Cattle Nutrition

Ruminant Herbivores

Calf- young animal

Heifer- female calf that has not given birth and is less than 30 months old

Cow- older than 30 months old, or has given birth

Bull- intact male

Steer- castrated male up to 4 years old

Ox- 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 1

First 10 weeks of lactation

Peak milk production happens in this phase

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

What to feed in Phase 1

Increased 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 2

Begins 10 weeks post calving and can continue to 20th

week

Highest dry matter intake happens here

Nutrient intake is finally in balance with nutrient needs

What to feed in Phase 2

Lower protein levels because requirement is met by supplementation in Phase 1

Adequate fiber

Limited grain intake

Frequent feeding ( minimizes digestive upset)

Phase 3

“late lactation period”, cow is pregnant again

Nutrient intake exceeds requirement for production

Main period for restoring body reserves for next lactation

What to feed in Phase 2

Easiest phase to manage because cow is pregnant and milk production is declining

Increased amount of forage instead of concentrates

Lower protein

Phase 4

Most of the “ dry” period

Final regaining of any lost body weight happens here

Goal 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 4

High protein, energy, Ca and P needs

Combination 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 abomassumand ketosis

Phase 5

Last 1-3 weeks of “dry” period, just before calving

Referred 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 5

Gradual increase in grains

Small amounts of all ingredients used in the lactation ration

Maybe decrease Ca in “ milk fever” prone cows

Beef Cattle Nutrition

Most 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 conception

Nutrient 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 end

Lowest nutrient requirements at this point

Feed minimally

Easiest and most economical time to increase a thin cows BCS

Third Trimester ( 95 days)

Rapid fetal growth causes rapidly increasing nutrient needs

Watch BCS carefully, cow gains 1 lb per day

Too thin cows experience dystocias, weak calves and decreased milk production

Postpartum Period ( 80 days)

High lactation requirements

Feed intake is 35-50% higher than non-lactating cow

Nutritional stress at this point causes problems during the cow’s next breeding ( usually 80 days post partum)

Energy Requirement

Energy 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 Requirements

50% 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 requirements

Need abundant supply at once daily

Range 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 requirements

Salt- 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 continued

Copper- 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 Requirements

C, 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 Management

1. 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 continued

2. 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 continued

3. Rest rotation

- Uses 3-5 pastures

- 1 pasture is not grazed for an entire year, while herd uses other pastures

Grazing Systems continued

4. 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 continued

Grass 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

Nitrate toxicity

Nitrate toxicity

- Caused when intake of nitrate 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

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

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