8. feed intake

Question 1

what factors affect digestibility

Answer 1

• food composition
• diet/ration composition
• preparation (rolling/crushing/heating)
• enzyme supplementation
• animal facotrs (individual/species variation)
• level of feeding

Question 2

what is lignin

Answer 2

• not a carbohydrate
• a complex cross linked polymer of three derivatives of phenylpropane
• has high resistance to chemical degradation (poorly digestible)
• wood, straw and hay are high in lignin

Question 3

how is food intake controlled

Answer 3

• physical (stomach size/rumen size/crop size/pregnancy)
• chemical (glucose, CCK, VFAs)
• nervous/hormonal (leptin/ghrelin)
• physiological (energy density = low density food eat more of)
• sensory appraisal/palatability, appetitie, illness, heat, obesity, availibility

Question 4

why do we need to predict/estimate food intake

Answer 4

• diet formulation
• feed availibility
• feed budgeting
• reducing feed waste
• determining stock desnities
• conservation management

Question 5

how do we predict food intake

Answer 5

• based on animal weight
• rule of thumb ~ 2-3% bodyweight

Question 6

how do we optimise voluntary food intake

Answer 6

• clean troughs
• enough space (reduce competition)
• keeping feed infront of animals at all times (minimise time between orts)
• adequate, clean potable water
• good quality feed (no mould)
• mixed forages
• short chop length
• increase palatability
• TMR

Question 7

what is the issue with feeding short chop length to adult ruminants

Answer 7

decreases transit time therefore decreases direstability
- longer fibres have to stay in the GIT for longer