Nutrition

Intro to nutrition
1. Common Feedstuffs
  1. Grass (rygrass, timothee) - forage
  2. Legumes- forage
  3. Cereals- cereal grains are concentrates
  4. Maize
  5. Roots/ tubers
  6. Brassicas- forage
2. Proximate Analysis
  1. 1- take food sample and dry at 80-100 degrees- remaining sample is they Dry Matter
  2. 2-Kjendahl procedure removes crude protein 6.25 x N
  3. 3-Ether Extract (removes fats and lipids)
  4. 4-Boil in acid/ alkali= Crude fibre and ash
  5. 5- burn at 550 = Ash vs Crude Fibre
  6. Nitrogen free extract (Dry matter- ash-crude protein-Crude fibre- ether extract) = soluble carbohydrates
3. Uses
  1. Crude Protein= maintanence/ growth/ activity/ pregnancy will be most expensive
    1. Protein Quality
      1. Biological Value= Protein Quality the bigger the better
      2. MFN= metabolic faecal nitrogen- N excreted irrespective of nitrogen intake (dead cells/ bacteria etc.)
      3. EUN- endogenous urinary nitrogen represents N involved in maintenance in the body
      4. BV= N intake- (faecal N- MFN) - (Urinary N- EUN)/ N intake - (faecal N- MFN)
  2. Crude Fibre= cellulose, hemicellulose, pectin, ligning important in ruminant function and GI motility in non ruminants
  3. Ash= minerals
  4. EE= fats, oils or fat soluble vitamins. source of energy
  5. Nitrogen Free Extract- soluble carbohydrates
4. Digestibility = DM consumed- DM excreted/ DM consumed
Ruminant Nutrition
1. Digestion of carbohydrates/ Fibre
  1. Typical carbohydrates & Fibre in rumen diet: Cellulose/ Hemicellulose/ Starch/ Soluble Sugars/ Lignin
  2. Crude Fibre split into Neutral Detergent Fibre and Acid Detergent Fibre
    1. Neutral Detergent- structural components of plant, slowly digested. Increase NDF decreases voluntary food intake
    2. Acid Detergent Fibre- least digestible components e.g. lignin, often excreted poor energy source
  3. Fermentation
    1. Straw/ Fibrous Hay: Cellulose
      1. VFA in the rumen
        Annotations:
        LOTS OF ACETATE bacteria that produce acetate are very sensitive to pH changes, acidosis or high fat diets will struggle to digest cellulose
        Glucose formation/ Enter Krebs cycle
    2. Lush pasture: Hemicellulose
      1. VFA
        Glucose/ Enter Krebs Cycle
    3. Potatoes/ Beet: Starch
      1. VFAs
        Annotations:
        lots of propionate bacteria that do this are more tolerant so could feed even if pH was quite off
        Glucose/ Enter Krebs Cycle
    4. Molasses= Sugars
      1. Direct to glucose very fast
    5. What happens to volatile fatty acids produced?
      Annotations:
      - must be absorbed quickly to avoid rumen acidosis
      1. Acetate- 60-70% increases with roughage in diet important determinant of milk fat content
        Converted to Acetyl CoA can enter krebs
        10 ATP per mole
      2. Butylrate -stays pretty constant 10-15% provides papillae of rumen with energy
        Converted to Acetyl CoA can enter Krebs
        25 ATP per mole
      3. Propionate 15-20% increase with concentrate important for lactose in milk
        convert to OAA either gluconeogenesis or used in krebs
        18 ATP per mole
      4. absorbed across rumen wall and transported to liver for gluconeogenesis/ lipogeneis/ other processes
2. Protein
  1. UNDEGRADED DIETARY PROTEIN- this protein is not degraded by rumen bacteria, instead continuous through tract and digested in the abomasum
  2. RUMEN DEGRADABLE PROTEIN- broken down by microbes for growth
  3. MICROBIAL PROTEIN- microbes pass into abomasum and are digested
  4. NON PROTEIN NITROGEN- ammonia converted into microbial crude protein
  5. if there is insufficient protein in diet, ammonia is returned to rumen to increase microbial crude protein
3. Lipids
  1. Little digestion in rumen- avoid long chain fatty acids since too many inhibit rumen microbes
  2. saturated in rumen then hydrolysed by lipases in small intestine
4. Forage should be 60%, Concentrates 40%
5. RUMEN DIET
  1. Voluntary feed intake 3% BW per day
  2. Total Mixed Ration
    1. Mix of forage and concentrate
    2. More Effective Digestion since decrease in rumen pH fluctuations
  3. GROSS ENERGY= total energy in food
  4. DIGESTIBLE ENERGY- Gross energy- undigestable food
  5. METABOLISABLE ENERGY- Digestible energy- losses in methane and urine
  6. Net Energy= Metabolisable - Heat Lost
  7. Fermentable metabolisable energy= proportion of organic matter fermented
  8. Effective Rumen Degradable Protein- microbial requirement for protein
  9. Must balance FME and ERDP- to avoid excess aid in rumen must have enough fibre and sufficient protein for breakdown
  10. aim for 16% crude protein in diet
  11. DIET PROBLEMS
    1. ideally diet would provide lots of energy that would be digested quickly but this can cause problems
    2. 30% NDF promotes rumination and good rumen health but much slower energy release
    3. concentrates are higher in energy but produce lots of proionate which irritates acetate releasing microbes. acetate decreases which is needed to maintain milk fat
    4. Too much protein- excessive deammonation decreases liver function and fertility
    5. Too much fat will decrease appetite and decrease milk fat content
  12. NEONATES
    1. Osophageal groove- closes when drinking for hunger not thirst, bypasses rumen and omasum
    2. Abomasum- clot forms due to pH when milk is ingested. The clot is made of renin and pepsin but is digested by lipase and protein. whey made of lactose moves to the SI
    3. Milk Replacers- More that 22 % protein, more than 20% milk
    4. 500-1000g growth a day
    5. Rumen Development
      1. give ad lib water to encourage bacteria to set up in rumen
      2. Feed concentrates- allow microbes to respire anaerobically
      3. Ferment carbohydrates and protein release propionate vital for rumen papillae development
Small Animal Nutrition
1. Factors affecting nutrition
  1. animal factors
  2. diet
  3. feeding methods
  4. owner
  5. communication of vet with owner
2. growing young animal most important stage for good nutrition
  1. greatest impact on health
  2. feeding practices between owner and pet formed early on and difficult to break
3. Energy Requirements
  1. Basal energy - keep metabolic activity ticking over
  2. resting energy requirement- based on bodyweight
  3. maintanence requirements- 1/1.2 x RER for normal activity
4. Food Componants
  1. carbohydrates- energy source and fibre
  2. protein- amino acid source for structural and functional roles
  3. lipids- high energy source and lipid soluble vitamins
5. Types of food
  1. Conventional commercial- you get what you pay for
  2. non- conventional niche foods like vegetarian- owner driven
  3. home made- vet formulated- should be fine specific to health problems etc
  4. home made concocted-most incomplete
  5. BARF- bones and raw food. doesn't account for domestication and evolution/ may be low in calcium/ bacterial contamination zoonotic risk
Monogastric Nutrition
1. Horses
  1. Hindgut fermenters
    1. no microbial protien
    2. huge caecum very important on right hand side
  2. Feeding
    1. 1.5/2% body weight in forage
    2. BW/100 x1.5= DM requirement per day in kg
    3. BW/100 x 3.34 energy requirement in Mcal per day
2. pigs
  1. caecum on other side
  2. glandular and non-glandular regions
3. chickens
  1. proventriculus and ventriculus, crop stores food. paired caeca
  2. layers- need a lot of calcium in diet
  3. broilers- need low body fat but high muscle content- focus on energy and protein

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	Created by Clodagh Mullins over 7 years ago