Ruminant Nutrition

Dry Period

The last 50-60 days of gestation when the cow is not lactating

Dry Cow

A cow that is not lactating and is pregnant

Far-off/Light

Dry cow in early part of the dry period (i.e. 20-60 days from expected calving)

Springer/Close-up

Dry cow or a first parity heifer that is <3 weeks from expected calving

Fresh Cow

A cow that has just calved and is lactating

AFI

As Fed IntakeThe amount of actual feed that the cow eats in a day

DMI

Dry Matter IntakeThe amount of feed (100% DM) that is being eaten

Legume

Nitrogen fixing grass that is high in protein, calcium, and potassium (i.e. alfalfa, clover, trefoil)

By-Product Feed

Feeds that are by-products of a primary industry

NPN

Non-Protein NitrogenNitrogen sources for ruminants that are not derived from protein. These are toxic to monogastric animals.i.e. urea, ammoniated hays and silages

Degradable Intake Protein

Protein that is degraded in the rumen and is utilized by the rumen microflora to create bacterial protein (aka Degradable Protein).i.e. Soybean meal, grain and forage proteins

Undegradable Intake Protein

Protein that is not digested in the rumen and is not available to rumen microbes (aka Undegradable or Insoluble Protein)i.e. Distillers grains, corn gluten feed, feather meal, fish meal, processed soybeans

Buffers

Compounds fed to buffer rumen or intestinal contents

Rumen Buffers

NaHCO3 (bicarb)MgO (Mag ox)

Intestinal Buffer

CaCO3 (limestone)

CP

Crude ProteinMeasured as % of DM

NEI

Net Energy of LactationMeasured in Mcal/lb (Mcal/kg)

NDF

Neutral Detergent FiberMeasured as % DM. Used to estimate DMI

EffNDF

Effective NDFA measure of effective particle size of a feed or ration. That portion of the diet that stimulates cud chewing and rumen motility

TMR

Total Mixed RationAll feed ingredients are mixed together and fed as a blended feed. Opposite of cafeteria style feeding

What are other names for Milk Fever?

Parturient ParesisPost-Parturient Hypocalcemia

Milk Fever

A metabolic disease usually occurring within 72 hours following calving. Characterized by hypocalcemia, general muscular weakness, and depression of consciousness

What happens if milk fever occurs just prior to parturition?

Results in dystocia due to uterine inertia

Predisposing factors for milk fever

High milk production>4 yearsInappetanceDiet high in Ca with +DCADStabled cows in winterStress from parturitionJersey >>> other breeds

Etiology of Milk Fever

Increased output of Ca from blood poolDecreased input of Ca from bone and dietIncrease in Ca Requirement after calving

Three hormones/vitamins involved in Milk Fever

Parathormone (increase serum Ca)Thyrocalcitonin (decrease serum Ca)Vitamin D (increase serum Ca)

Do cationic or anionic rations increase the incidence of milk fever?

Cationic

What are the 4 stages of milk fever?

1) Early stage2) Excitement stage3) Recumbant stage4) Unconscious stage

What are signs that the cow is responding to treatment for milk fever?

Belching, shivering, standing up, urinating, defecating, heart rate slows

Is dextrose needed for treatment of milk fever?

No because the cow is hyperglycemic

DCAD

Dietary Cation-Anion DIfference(Na + K) - (Cl + SO4)

What is another name for negative DCAD rations?

Acidogenic" rations

What are two methods to prevent milk fever?

1) Limit Ca during late dry period2) Feed negative DCAD

What is another name for Ketosis?

Acetonemia

What are the types of ketosis?

1) Starvation (mainly in sheep)2) Secondary (LDA, metritis, etc.)3) Primary (spontaneous)

Which VFAs are ketogenic?

Acetic AcidButyric Acid

What are some factors that lead to ketosis?

#NAME?

What are the two forms of clinical signs for ketosis?

1) Wasting form (most common)2) Nervous form

What field tests can you do for ketosis?

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What are some types of treatments for ketosis?

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Pregnancy Toxemia

A ketotic condition in does and ewes (occasionally in cows) that occurs in late gestation in animals receiving inadequate energy in their diets

Signalment of Pregnancy Toxemia

-Ewe in last trimester of pregnancy-Often a flock problem-Often occurs after "bad weather"-Parasitism can predispose to problem

What are some of the clinical signs for pregnancy toxemia?

You don't see anything until it has advanced-Blind-Head press-Demented-Will not eat-Episodic convulsions-Death

What are field tests that can test for pregnancy toxemia?

AcetestMultistix

How do you treat pregnancy toxemia?

Caesarian SectionGlucose IVOral propylene glycolHand feed concentrate

How do you prevent pregnancy toxemia?

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Metabolic diseases of ruminants

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What are other names for Hypomagnesemia?

Grass tetanyGrass staggersWheat poisoningLactation tetany

Hypomagnesemia

#NAME?

Where is magnesium found in animals?

60% in bone40% in soft tissues1% ECF

How well is magnesium mobilized?

Young - 30% rapidly mobilizedOld - inert

How much milk does it take to use all of the total available body Mg?

15 lbs of milk

What decreases Mg absorption?

-High dietary Ca-Dietary Na:K ratios (if <5:1)-Increase in rumen NH3-Alkalosis

What are the types of clinical signs for hypomagnesemia?

AcuteSub-acuteChronic

Acute Hypomagnesemia symptoms

-Develop in a few hours-Convulsions with frothing at mouth-Death may occur within 30-60 min-In absence of hypocalcemia, minimal to no tetanic activity is seen

What is the number one cause of death in beef cows in USA?

Acute Hypomagnesemia

Sub-Acute Hypomagnesemia

-Occur gradually over 3-4 days-Exaggerated limb movements, muscle tremors-Treatment effective, but tendency to relapse

Chronic Hypomagnesemia symptoms

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Treatment for Hypomagnesemia

MgSO4 solution IVCa solution with Mg addedMgCl enema

Hypomagnesemia prevention

-Feed Mg salts daily during danger period-Top dress pasture with 25 lbs Mg rich fertilizer per acre-Delay calving until danger period is over if possible-Provide shelter in winter