Cereal Grains Flashcards
Most worldwide fed grain
corn
western canada main grain
barley
eastern canada main grain
corn
cereal grain composition trend
- high starch
- low fibre
- intermediate protein
grains can be fed up to ___% of the diet DM
90
foundation crop of canadas feedlot industry
barley
importance of corn
highest level of starch and energy, but lowest rumen degradable starch
corn rations typically require supplemental ___
protein
importance of wheat
- primarily used for human food
- in animals used more in poultry and swine
- risk of acidosis
beef producers often limit wheat content of a diet to ___%
<50%
___ ferments rapidly in the rumen, leading to ___ and ___
wheat
bloat, acidosis
corn in western canada
corn silage used but not grain because we dont have enough heat units to produce grain
cereal structure outside (5 layers)
1) pericarp
2) testa
3) nucellus
4) aleurone
5) endosperm
what part of grain is high in oil
embryo
why crack barley?
increase digestion and efficiency of use
2 types of corn endosperm
floury and vitreous
floury endosperm
more open and opaque
vitreous endosperm
hard endosperm and translucent
amylose vs amylopectin
amlyose is linear, digests slower
amylopectin has branching and digests faster
husk and pericarp make up ___% weight of a barley kernel
10%
testa and aleurone make up ___% of weight of a barley kernel
14%
aleurone layer is rich in
protein
B glucans in barley
ruminants can handle, not monogastrics
starchy endosperms of barley make up ___% of kernel weight
73%
embryo in barley makes up ___% of kernel weight
3%
what is test weight?
measure of grain density
imperial bushel weight is ….
36.369 L
Minimum standards fro bushel weight depend on…….
- Commodity being measured
- Moisture content
Limiting factors of accessibility of amylolytic bacteria to starch granules (2)
- Husk/Bran/Pericarp (resistant to microbial attachment and penetration)
- Encased in protein matrix
Penetration of protein matrix
Barley/Wheat: penetrated by rumen proteolytic bacteria
Corn/Sorghum: penetrated only by rumen fungi
Rumen fermentation of starch depends on….
- Cereal grain type
- degree of processing
- microbial colonization
Fastest and slowest digested cereal grains
Fastest: dry rolled wheat
Slowest: dry rolled sorghum
______ can help to slow down the rate of ruminal starch fermentation by……
Protozoa
engulfing starch granules
Why process cereal grains?
crack seed coat to provide access to endosperm for rumen bacteria
4 methods of processing
1) dry rolling
2) steam rolling
3) grinding
4) high moisture/reconstituted grain
Grinding
performed using hammer mill
