Nutrition Flashcards
(288 cards)
what is the capacity of the rumen?
200+ litres
what type of fermentation occurs in the rumen?
anaerobic
what is the role of the fibre in the rumen?
traps food and provides a home for the rumen microbes (bugs)
what side of the abdomen is the rumen on?
left
what contractions occur in the primary rumen cycle?
first reticular contraction
second reticular contraction
dorsal rumen contraction
ventral rumen contraction
what is the ration of primary to secondary rumen contraction cycles?
2 primary : 1 secondary
what contracts in the secondary rumen cycle?
dorsal rumen
what does the first reticular contraction do?
moves coarse material into the dorsal sac
what does the second reticular contraction do?
move fine material into the cranio-dorsal blind sac and omasum
what does the dorsal rumen contraction in the primary cycle do?
move fine material from crania-dorsal blind sac to reticulum
what does the ventral rumen contraction do?
move fine material into the cranial blind sac with some exchange with the dorsal sac
what is the function of the secondary rumen contraction cycle?
eructation (push gas up oesophagus)
what do the rumen bugs break down food into?
volatile fatty acids
methane
carbon dioxide
what does the cow do with the VFAs produced by rumen bugs?
absorbs them and uses the to supply energy or fat/glucose synthesis
why do dietary changes need to be implemented slowly?
allow the rumen microbes to adapt
what is milk production determined by?
genetic merit
nutrition
health
what is the order of consideration, when formulating a diet?
dry matter intake
energy
protein
minerals
vitamins
how can DMI of a cow be estimated?
percentage of bodyweight
what is the estimated DMI of a dry cow?
2% bodyweight
what is the estimated DMI of a cow producing 25L a day?
3% bodyweight
what is the estimated DMI of a cow producing 50L a day?
4% bodyweight
what are some factors that influence DMI?
body weight/fatness (fat cows eat less)
milk yield/stage of production
type of food (digestibility…)
palatability
access/availability
social factors and stress
rumen health
what is metabolisable energy?
energy available to the cow for metabolism (maintenance, growth, lactation…)
what is metabolisable energy measured in?
MJ/Kg DM