Lectures 3-5 Flashcards
factors affecting nutritional value
Type of feedstuff
Soil fertility
Growing conditions
Harvesting conditions
As grass ages, protein nutrient _____ and fiber nutrient _____
- decreases
- increases
know the proximate analysis chart
draw the chart
IN VIVO vs IN VITRO
IN VIVO: “Within the living”
IN VITRO: “within the grass”
Detergent method of analysis
(the Van soest method)
Focuses on forage fiber
Divides fiber into digestible and indigestible fractions
Predicts intake-NDF; index of gut fill
Predicts digestibility-ADF; forage digestibility
Extraction with detergents
what are the 2 phases in digestion or metabolism phase?
- Preliminary phase
- Collection phase
steps for Digestion or metabolism trial
- Proximate feed analysis to know what you start with
- Feed measured amount of feed/feed constant rate
- Collect fecal matter
- Proximate analysis on feces
- Difference is the apparent digestibility of the feed
Total tract of digestibility of swine
Nutrient losses during digestion
Disadvantages:
Large intestine fermentation included
Endogenous losses ignored (underestimate)
Interferes with digestibility measurements; AA
Ileal digestibility of swine
Collection of digesta at the terminal ileum
Disadvantages:
Surgically modified animals
No information on post-absorptive nutrient utilization
Measuring digestibility in ruminants
- in vivo
- in vitro
- in situ
in situ
HYBRID
Determine rate and extent of DM and other nutrient disappearance from nylon bags in the rumen
NOT used in monogastric digestion
Factors affecting digestibility
Age
Disease and/or parasites
Feed source and composition
Level of feed intake
Passage rate through GI tract
Nutrient excess or deficiency
Feed preparation and composition (chemical processing/treatment)
Maturity in plant
