Post on 21-Jan-2015
description
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 forageCalcium- 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