Bovine nutrition Flashcards
RE DO THESE FLASHCARDS
AND SAVE THEM
where do cows get VFAs from
the MO bdown the short chain CHO into VFA
what type of CHO produces which VFA
starch - prop
fibre - acetate
?? butyric
how are VFAs absorbed
rumenal papilla
what is proprionate used for
to prob oxalo-acetate which is precursor for milk
butyrate + acetate form with what to produce acetyl coa
FFA (from fat metabo)
what is the capacity of the rumen
200L
how do you ID ME
bomb calorimetry
IR specrtometry
for a low and high yeiding cow, how much protein does she need
low (<8000L) - 16%
high - 18%
how much protein does silage have in it
16-18%
what cut silage is higher in E and protein
spring cut
what is RUDP
rumenal undig protein
digested in abomasum/SI
what do MO digest ERDP into
NH4+, which they ‘grow’ on
what is a dairy cows DMI req at diff stages
maintenance - 2% dry - early - 2% - last month 1.88% - last wk - 1% lactating - 30L/d 3% - 50L/d 4%
what is the MINIMUM DMI a cow should get
11kg/d!
what trough space do cows want each
70cm/cow
how can you improve DMI
palatability NO SARA good dry cow management comfy spacious
how much E does it take to produce 1L milk
5MJ/L
what is a cows maintenance E
70MJ
to gain (or lose) 1kg weight - how much E does it take
30MJ/kg BWt (to gain or lose)
what are the basic fag packet principles of cow nutrition
eat LOADS of low ME foodstuffs
what is an acceptable BTW loss for a cow in early lactation
0.5 BCS (thats5% of her prev BWt anyway!)
what is the DM and M/D of: grass silage
DM - 20-35%
MD - 10.5 MJ ME/kg
what is the DM and M/D of maize silage
DM - 30-35%
M/D - 11-11.5 MJ ME/kg
what is the DM and M/D of haylage
DM - 30-35%
MD - 9.5 MJ ME/kg
what is the DM and M/D of hay
DM - 85%
M/D - 8-9 MJ ME/kg DM
what is the DM and M/D of grass
DM - 20% (maximum)
M/D - 10-12.5 MJ ME/kg DM
what is the DM and M/D of`straw
DM - 85%
M/D - 5.5-6.5 MJ ME/kg DM
what is the DM and M/D of concentrates
DRY - like 100%ish
M/D - 12.5MJ ME/kg as fed
what is the protein content of grass silage and maize silage respectively
grass - 14-16%
maize - 8-9%
how can you remember a good way to estimate %DM
20% - sodden
30% - can grab chunks, squeeze liq
there are 4 method of feeding cattle, name and desc
TMR - 24/7 availability. set for a particular stage and yield. forage + conc
traditional - silage at barrier; conc in parlous (+- midday feed too)
hybrid - TMR at barrier + conc in parlous
buffer - TMR supplement to grazing in summer
what % of cows should be cudding at anyone time
75% (if not sleeping or actively eating)
how can you monitor nutritional status in cows?
milk quality
- protein - 3-4%. if low suggests long term deficit
- butter fat - acetate (synthesised from fibre - give more if low). if v high - early lactation and XS fat mobilisation?
BCS - never lose >1 BCS
biochem test
- metabolic profile (use 6cows from eage lact stage)
- BHOB - will ID sub-clinical ketosis
desc physiology of ketosis
XS fat mobilisation means not enough VFA (acetate and butryrate) to form with FFA (XS) and acetyl coA to enter krebs. this means the FFAs make ketones instead
what is BHOB
b-hydroxybutyrate
when blood or milk urea is elevated, what does that mean
protein (XS) without enough FME
– either or can be 1ry sign
what is a NEFA and why does it matter
non-esterified FA
- evidence of fat mobilisation in XS when the ketones go to the liver to be broken down
- look for in dry cows!
what are the factors which can be ID’d to assess silage quality
DM% - the dryer actually better as can eat more E/kg - eg after rain is bad!
fibre length
nice smell (no butyric)
time cut - spring best qual
how can you tell what time of year the silage was cut
spring - thick stems and leaves
summer/autumn - seeds
when/how long is the ‘transition’ diet
the last 3wks pregnancy
what is the most impt time of a cows year
dry period
- mamm recovery and development
- uterine recovery and next conception
- rumen development
early dry diet aims for a DMI of ???
10-14 DM kg/d
what type of fodder would you give eaalry dry cows
late cut silage + chopped straw
big bale silage
hay
why is it a risk to leave on good pastures when dry
get fat on grass alone
try and supplement with straw - fbre, no kcal
why is it so bad for cows to gain weight in dry period, afterall its all we try to make them do
fat goes viscerally in cows –> reduced DMI, inc dystocia, inc metabolic disease, obesity is inflammatory itself too
how do you manage transition cows - their E demand grows, but DMI decreased?
give lactator TMR + chopped straw
OR
early dry cow diet of silage + straw + concentrates
what M/D do early dry and transition cows required
early - 7.5 MJ/d
transition - 10.5 MJ/d
when is the peak DMI (post calving)
4-10wks post. she’ll be eating ~ 25kg/d DMI (4% Bwt)
what other factors about dry cow management will help DMI
remove stressors: stop milking, keep group stable, comfy, safe, plentyof barrier space
what is fat mobilisation syndrome?
fat cows in early lactation mobilise XS fat reserves and depositied in liver
also get bovine DM (from isulin-R down regulations) - due to high glucose levels in blood
theres breed variation bw location of fat. what are the differences bw Holstein, frieisan, beef, and channel islands?
Holstein - visceral fat +++ - so not as skinny as they look…
frieisian - NO visceral fat (barely)
beef - SC fat +++
channel - ++++++visceral fat! also yello!
what Is the % DM and ME of: alkalage
%DM - 80%
ME - 11.2
what Is the % DM and ME of: alkagrain
DM - 83%
ME - 13.5
