Ruminant Nutrition

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					Ruminant Nutrition
Ruminants
• Have 3 forestomachs or out-pouching of
  the esophagus and 1 glandular stomach
  same as non-ruminants
• Rumination =“chewing the cud”
  – Process of regurgitation and remastication of
    food
        Basic rumen Physiology
• True ruminants
  – Cattle, sheep, goats
• Functional ruminants
  – Camelids
       • Llamas, alpacas
• Both ruminate and ferment to produce:
  –   VFA
  –   Amino acids
  –   Vitamins
  –   Methane gas and CO2
       • eructated
  The Ruminant Digestive tract
• Tongue
  – prehensile organ for true ruminants
• Lips
  – Are used by functional ruminants to prehend food
• Rumen/ reticulum
  – pH 6.2 – 7.2 desired range
• Omasum
  – Filters or sieves food based on particle size
• Abomasum and SI same as non-ruminants
• Cecum and colon
  – VFA produced
http://www.geochembio.com/IMG/cow-
digestive-system.png
     Reticulum ("Honeycomb")
• Most cranial compartment
• Separated from rumen by
  rumenoreticular fold
• Interior has ridges or "honeycombs"
• Traps heavy objects like hardware
  – Because of its location
  – Hardware disease –
     • may involve heart or pericardium
• Other functions
  – Move ingesta into rumen
           Rumen ("Paunch")
• Large hollow, muscular compartment
• Functions
   – Fermentation chamber
     • Breakdown of fibrous feeds
     • Conversion to usable energy and cellular building
       materials
     • Rumination (cud chewing) makes smaller particles and
       increases surface area for microbial action, also
       provides saliva buffer
  – Bacterial synthesis of B vitamins & Vit K
  – Bacterial synthesis of AA's and Protein
          Protein formation/utilization
    • Making high quality protein
      in rumen from microbes
    • Bypass protein escapes
      digestion by microbes




http://images.wool.com/pub/nutrition_diagr
am.gif
                         Rumen
• Fully functional by 5 months
             esophagus      Rumen

                         Chew cud and eructate while lying down

                          Rumen mat
Esophageal
groove


 Reticulum


                         abomasum
            Rumen fermentation
• Particle size is important
   – Too small will pass through too quickly
• pH changes are important
• Feeding ruminants or “Management of the
  fermentation Vat”
   – Aqueous system
      •   Water must be supplied in large amounts
      •   Carbohydrates
      •   Protein
      •   Fats are less important
      •   Vitamins and minerals
   Carbohydrate Classification in
              Feed
• Order of complexity
  – Sugar –> starch-> pectin-> hemicellulose cellulose
     lignin
  – Sugar and starch are nitrogen free extract
     • Alpha bond
  – Pectin, hemicellulose and cellulose and lignin
     • Beta bonds
     • Neutral detergent fiber
  – Cellulose and lignin are ADF or acid detergent fiber
     • Broken down more slowly in rumen
           Rumen Fermentation
• Breakdown of insoluble carbs by microbial digestion
   – Volatile fatty acids  absorbed rapidly liver-> glucose
       • Acetate
       • Proprionate* accounts for most of the glucose production
       • Butyrate
• Too much soluble carbohydrates
   – Yields lactate instead
   – 10 times as acidic
   – Ruminal acidosis
       • Liver abscesses, villi damage, due to toxins and bacterial damage
       • Death of microorganisms and no more fermentation
       • Transfunation- taking rumen jucie of healthy animal- and giving it
         too cow w/ an acidosis cow
    Avoiding rumenal acidosis
• Concentrates BID
  – Bad idea
  – Produces indigestion because of rumenal
    acidosis
• TMR (bad)
  – Total mixed ration – concentrates, silage, hay
  – Consistency in feeding ruminants is essential
  – Every bite is the same in TMR
    Maintenance of a functional rumen
•   Proper feed
•   Appropriate feeding intervals
•   Appropriate dry matter intake
•   Regurgitation and chewing (remastication of cud or
    rumination)
•   Salivation to balance pH
•   Reswallowing
•   Continuous churning and mixing
•   Eructation belching
•   Outflow to GI tract
•   Sufficient water
     – 3 to 5 gallons per gallon of milk
      Omasum ("Manyplies")
• Smaller, muscular, spherical
  organ
• Functions
  – Reduce particle size before
    getting to abomasum
   – Some water absorption
   – Absorbs some VFA
   – Absorbs bicarbonate ions
• Small and less functional in
  pseudoruminants llamas etc.
                Abomasum
• "True or Glandular Stomach"
• 1st glandular portion of ruminant GI tract
  – Walls here do secrete enzymes
     • Gland regions here generally correspond to
       those of simple stomach of the non-ruminant
• In young ruminant
  – milk passes here via esophageal groove
  – Suckling stimulates safe passage
     • Bucket fed calves may be at a disadvantage
       Basic goals in feeding
             ruminants
• Least cost
• Best return
        Nutrients Used For:
• Developing body tissue
  – Growth
  – Repair
  – Maintenance
  – Production
    • Reproduction
    • Lactation
    • Wool/ meat production
Maintenance Nutrient requirements
• Level needed in diet to maintain body
  weight
• Approximately ½ amount consumed
• National Research Council Standards
  – Feeding standards for nutrient levels
                        Protein
• Special considerations
  – Highest need in growth and lactation
     • Need supplements and grains
     • Dietary protein degraded in rumen
     • Utilize NPN – non protein nitrogen, NH2-->NH3
         – Ureamicrobes protein
• Dietary sources
  – Meals- soybean, linseed, cottonseed
  – Grains
     • Corn, oats, wheat, barley
  – Alfalfa Hay
  – Grass hay has lowest amount of digestible protein
                    Fats
• Not greater than 6%
  – Do not want to slime the rumen microbes
• Essential fatty acids
  – Linoleic
  – Linolenic
            Carbohydrates
• Cereal grains and forages
  – High in CHO content
• Microflora in rumen
  – Fiber energy via VFA’a
                        Minerals
• Dairy cattle
   – Excess Ca in late dry period
      • Predispose to milk fever
      • Due to decreased ability to mobilize from bone
      • Alfalfa hay is high in Ca
• Avoid animal by products as mineral sources
   – May be a source of BSE
• Always supplement salt, minerals when needed
   – Salt brick/ mineral block
                  Vitamins
• Only require A and E
  – Remainder synthesized in the rumen or
    provided by sun (Vit D)
  – A & E are present in forages
    • E may be deficient --> white muscle disease
• Sick ruminants
  – may require B complex and Vitamin C
    supplementation
                  Water
• Required in large amounts
  – Lactating cow at peak lactation up to 45
    gallons/day
  – Exact amount depends on body weight and
    stage of lactation
Life stage: Pregnant and Lactating
• Energy
  – Maintenance needs will be met first
  – Need concentrates and high quality forage
     • Total mixed ration formula
        – Every bite is the same
        – Avoids indigestion form intermittent concentrates
          (acidosis in rumen)
  – Most important part of the ration
     • Unless needs are met, will not fully utilize other
       nutrients
     • Challenge feed based on production
     Body Condition Scoring
• Used to evaluate energy needs of animals
  based on body fat
      Body Condition Scoring
• Scales 1-9; 1-5
• 1 emaciated = all bones protruding, no
  subcutaneous fat evident
     BCS 1/5




      http://www.omafra.gov.on.ca/english/livestock/dairy/facts/00-
      109.htm
BCS 2/5 (thin)
BCS 3/5 (average)
BCS 4/5 (Heavy)
BCS 5 (Fat Cow)
 Bottom Line on Dairy Cows body
            Condition
• Wt gain before calving is usually lost at
  calving
• Obesity very undesirable
  – Leads to a metabolic disease called ketosis
  – Dry cows may be fed good quality forage
    alone if in good condition
             Feeding Calves
• Colostrum critical first 18 hours
  – 10 to 12 % of body weight
  – Preferable half of that within the first 4 to 6
    hours
     • Maximizes passive transfer
• Dairy Calves
  – Milk replacer
  – Waste milk
  – Until 1 month then calves start on forages
            Feeding calves
• Beef
  – Nurse
  – Creep feed
  – Wean at 6 to 8 months
               Feed Sources
• Roughages / Forages
  – Legumes
    • Alfalfa – hi protein and Calcium may  bloat
    • Clovers
    • Crown vetch
  – Grasses
    •   Bluegrass
    •   Timothy
    •   Rye
    •   Fescue
        Roughages / Forages
• Pasture hay
  – Protein content depends on harvesting stage
  – Early vs late
     • More cellulose in older plants
  – Quality
     • Type of plants
     • Stage of maturity
         – Affects protein and energy content
         – Based on stage of bloom
             » 50 % better than 100% bloom
     • Speed of harvest
     • Spoilage and loss during storage
              Concentrates
• Corn, barley , wheat, oats etc
  – Affected by processing
  – Fed primarily for energy and protein
          Energy value of Feed
• Fiber content
   – Non-fibrous components completely digestible
   – Fibrous components are variably fermented
   – Indigestible fiber = lignin
• Rate of fiber fermentation
   – Particle size
   – Fiber source and maturity
• Rate of fiber passage affected by rate of fiber
  fermentation and intake level
• Site of digestion
   – Rumen, cecum, colon or intestine
• Lipid content – 2.25 X as much energy in fat/gm
• Fermentation efficiency- heat and gas losses
              Forage Testing
• Neutral detergent fiber
  – Total cell wall content
  – All components of fiber
     • Cellulose, hemicellulose, lignin
  – Higher the NDF, lower the intake
  – Good or prime forage NDF < 40%
  – Poor NDF > 65%
         Acid detergent fiber
• All cell wall components except
  hemicellulose
• Portion left after being treated with an
  acidic detergent
• Estimated digestibility of a forage
  – Prime- ADF < 31%
  – Low > 45%
              Crude Fiber
• Only useful to classify feed as roughage or
  concentrate
• >18% crude fiber = roughage
• Concentrates < 18% crude fiber
             Crude protein
• Total amount of protein in the forage
  based on Nitrogen content
        Total Digestible Nutrients
• TDN
• Describes the energy value of a forage
• Sum total of
   –   Digestible portions of crude protein
   –   Crude fiber
   –   Nitrogen free extract or starch
   –   Fat
• Expressed as a percentage
   – Prime hay will have 65% or greater TDN
   – Poor hay <53% TDN
• Overestimates energy values because of losses during
  digestion
               Dry matter
• Forage nutrient content minus water
• When comparing feeds for nutrient content
  – Always compare on a dry matter basis
          Dry Matter Intake
• Estimate in percentage body weight of the
  intake of a forage
• Calculated by dividing 120 by forage NDF
• Prime forages will have a DMI of 3.0% of
  body weight
• Poor forages DMI <1.8%of body weight
• Example: 1000 lb cow should consume 30
  lbs of a prime forage
        Relative feed value
• An Index based on full bloom alfalfa
  =100%
• A hay with a RFV of 110% would have 10
  % more energy than full bloom alfalfa
• Prime hay=151 %
• Poor hay RFV of less than 75 %
• See forage analysis sheet

				
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posted:11/13/2011
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