FAC25-26: Practical Nutrition Flashcards
(41 cards)
What are the micro-organisms involved in rumen fermetnation and what is the job of each?
Anaerobic bacteria: cellulolytic enzymes that break down cellulose and hemicellulose into starch and sugar
Protozoa: ferment mainly starch and sugar
Anaerobic fungi
What is normal rumen pH and at what pH are rumen micro-organisms depressed?
normal: 7
depressed: 6
What are the end products of rumen fermentation
VFAs (acetat, butyrate, propionate)
Ammonia
Microbial cells
Gases (methane, CO2)
Name whats to ensure optimum rumen function.
- Rumen pH 6.5-7
- Enough effective long fibre
- Cow comfort and welfare
- Sufficient rumen degradable protein
- Excess highly fermentable energy can disturb rumen function
- Minimise any changes
What is the most important factor in diet formulation?
Dry Matter Intake
What are the cow factors that influence DMI?
- Body weight/ rumen volume
- Milk yield
- Stage of lactation
- Stage of pregnancy
- Body condition score
- Cow comfort
- Rumen health
What are the food factors affecting DMI?
- Digestibility of foods
- Concentrate feeding
- Forages
- Dietary deficiencies
- Palatability
What are the management factors in DMI?
- TMR
- Frequency of presentation of food
- Restriction of access
- Water
- Cow comfort
What is the daily maintenance requirement for Holstein cows?
70-80 MJ of ME
Proportional to bodyweight
What is the production requirements for Holstein cows?
5 MJ of ME per liter of milk
Proportional to Milk Quality and Milk Quantity
Define Metabolisable protein
It is the protein (mixture of amino acids) which the animal has absorbed into its body and is available to meet the needs for maintenance and to produce protein in milk, meat, and fiber
What is Metabolisable protein composed of?
Effective Rumen Degradable Protein and Digestible Undegradable Protein
Why is fiber important in cattle diet?
- Important source of energy for rumen
- Essential to promote rumination
- Formation of rumen mat
- Increases proportion of acetate produce in rumen > increase butterfat levels
- Separate feedstuffs into cellulosic and non-cellulosic feeds
How much water per kg of milk do cows require?
2-3 liters per kg of milk
What is the point of dry cow management?
The dry period is an opportunity for the cow to recuperate and restore resources
Critical for:
- Increased dry matter intake in early lactation
- Reduced disease problems in early lactation
- Increased milk production
How long is the dry period? What are the sub periods and how long does each last?
Dry period = 2 months
Far-off dry period = 2-1 month pre-calving
Near dry period = 2-4 weeks prior to calving
What are the aim of the far off dry period?
Recuperate ater lactation
Get cows in correct condtion score
What are the aims of the near dry period?
Provide cows with best nutrition and environment
What are the repercussions if a cow is too fat or too thin after far-off dry cow management?
Too Fat
- Excess loss of condition score
- Reduced DMI in early lactation
- Health problems
Too Thin
- Poor lactation yields
- Health and reproductive problems
What is the purpose of giving concentrated during near dry cow management?
- Increase energy density of diet
- Acclimatisation of rumen flora to concentrates
- Conditioning of rumen papillae > increase surface area of rumen lining > rapid absorption of VFAs and stable rumen pH
What are the different types of feeds for cows?
Forages
Grazing
Grass silage
Ensiled whole crop cereals (maize silage, whole crop cereals)
Hay
Straw
What is the purpose of long fiber in the cow diet?
To stimulate rumination (scratch factor)
To form floating mat in the rumen
To promote chewing and saliva production
What is the detriment of fine fiber in the cow diet?
Fine fiber > No rumination > Ruminal distension > acidosis
What are the different grazing systems?
Set stocking
Rotational grazing
Strip grazing
Zero grazing (grass brought to cows)
