Animal nutrition - feeding of dairy cows Flashcards
Transition period, what is this?
starts 2-3 weeks before expected calving
and ends 2-3 weeks after calving
so the periparturient period
which is a turning point in cows from one lactation to the next lactation
what determines the size of milk
production in the peak period of lactation
feeding
what has a major impact on various metabolic
diseases occurring after calving, and also on
productivity and profitability
a cow’s transition period
name 3 Key principles for a successful
transition period:
- The appropriate choice of feeding strategy.
- Good environmental conditions and low stress.
- An integrated veterinary programme to monitor cows and prevent diseases.
Prior to calving the DM intake…?
decreases
7…10 days prior to calving DM intake will decrease from 1.9% (dry cow) to ?%
1.4% (directly before parturition even less)
– in case of a 600kg cow, from 11.4 kg to 8.4 kg, i.e. 26%
What contributes to DM intake decrease in cows nearing parturition? (3)
rapid growth of the foetus, which takes space from the rumen, and hormonal and physiological factors
After calving, DM intake…?
increases
After calving DM intake increases at a rate of..?
Reaches a maximum when?
1.5 to 2.5 kg per week, it reaches a maximum at 80-100 days of lactation
After calving DM intake reaches a
maximum at ? days of lactation
80-100 days of lactation
DM intake increases faster in what type of cows?
DM intake increases faster in multiparous cows compared to heifers
At the end of the dry period the cows begin to prepare themselves for the new lactation, why
extensive changes in energy and protein metabolism occur
before calving the requirement for energy and nutrients increases sharply, for foetal and udder growth and development
energy and nutrients are also required for colostrum synthesis
ME and MP requirement before and after calving increase by how much?
Requirement increases by 2.7 times
Prior to calving plasma glucose concentration does what
Prior to calving the plasma glucose gradually decreases and due to
this also plasma insulin concentration,
(stimulates lipolysis in adipose tissue)
The content of somatotropin changes how in the middle of the transition period (around and after calving)?
increases abruptly in the middle of the transition period.
When is Progesterone high?
When does it fall sharply?
high in the precalving period, falls sharply after calving
In the prepartum period, what two hormones in addition to somatotropin are higher than normal
estrogens and glucocorticoids are higher than normal
blood glucose level is low and due to this insulin levels in blood decrease which in turn activates..?
the enzyme lipase in adipose tissue -> lipolysis
NEFA
non-esterified fatty acid or free fatty acids
When are NEFA released into the blood?
non-esterified fatty acid or free fatty acids are released e.g. in association with lipolysis in the transition/peripartum period
Dry off period ration contains mainly roughage. This changes the rumen microbial population how? (3)
▪ more cellulolytic bacteria, and
▪ fewer amylolytic and
lactolytic bacteria
Dry off period ration contains mainly roughage. This changes the rumen microbial population to produce mainly what from VFAs?
mainly acetic acid is produced from VFAs
acetate < propionate < butyrate
when do rumen papillae degenerate and why?
during a cow’s dry off period, because the absorptive surface does not have to be so large for the production of VFAs when milk production has ceased.
The task of the close-up dry period ration is
to
prepare the rumen to digest the high
amount of concentrates and low-fibre rations.
– concentrate -> propionic and butyric acids needs a large absorption surface
What is the close-up dry period
prepartum transition period, -21 days
Peculiarities of feeding in the close-up dry period
DCAB
dietary cation (K+, Na+) and anion (Cl-, S2- = sulfide ion) balance
check this in the close-up dry period
if necessary, use anionic mineral salts, which cause a change in the acid-base balance in the organism. Helps to avoid milk fever and hypocalcaemia!
the recommended DCAB before calving is
dietary cation (K+, Na+) and anion (Cl-, S2-) balance
100 mEq/kg in DM (max +250 mEq/kg)
if necessary, use anionic mineral salts, which cause a change in the acid-base balance in the organism. Helps to avoid milk fever and hypocalcaemia!
in the close-up dry period, Vitamin-mineral feed must be
more concentrated, due to low feed intake
in the close-up dry period, Check the Ca:P ratio, which is generally
1.3 -1.4 : 1
▪ in kg DM,
Ca 5-6g,
P 3.5-4.0g,
Mg 4.0-4.5g,
K < 12g
What can happen if we don’t use a close-up dry cow ration (6)
Cows remains unprepared for the next
lactation, the change is too rapid.
Increases the risk of:
acidosis
displaced abomasum
fertility problems
reduced DM intake
SARA
Sub-acute ruminal acidosis
at what pH does SARA occur
Sub-acute ruminal acidosis at pH of 5.5-5.6
▪ when the pH ↓ the number of lactate producing & consuming bacteria ↑.
▪ at pH 5.5-5.6 SARA occurs, below that the
lactate consuming bacteria die, if pH < 5.0 then ↓ (clinical acidosis)
lactate consuming bacteria die at a pH of?
< 5.0, then ↓ (clinical acidosis)
displaced abomasum may appear when
a large amount of rumen fermentable
concentrates is suddenly added to the ration and the fibre, especially effective fibre, is low
NEB period
negative energy balance
as a rule, after calving, the use of body reserves is more active and NEB period longer if a close-up dry cow ration hasn’t been implemented leading to decreased fertility
postpartum transition period
up to +21 days from calving; incl. fresh cows up to 7 days from calving
Compared to the dry period the nutrient
requirement increases by the fourth day after
calving as follows:
- amino acid requirement doubles,
- glucose requirement triples,
- calcium requirement increased four-fold
- fatty acid requirement increases five-fold
NB! The immune system is weakened!
During the negative energy balance period the cows’ feed intake is first regulated by –?–, and
later by –?–
During the negative energy balance period the cows’ feed intake is first regulated by metabolic load, and later by the physical fill of the rumen.
the liver has a limit to how much it is able to synthesise glucose from concentrate-produced what
the liver has a limit to how much it is able to synthesise glucose from concentrate-produced propionate, and propionate into ATP
From hay, what acid is produced
From hay, acetic acid is produced and this can be more easily handled than other acids.
How to motivate recently calved animals to eat
Use good quality forages (silage, hay), which have higher energy concentrations, this increases intakes (earlier growth phase).
Silage fermentation quality is very important
(restricted fermentation, fewer acids allow cows to eat more).
calving cows should not have what type of BCS
calving cows should not be fat
and obviously not sickly skinny either
Peculiarities of feeding in the postpartum transition period.
if one silage batch is used then the DM should be
30…35%
Peculiarities of feeding in the postpartum transition period.
If one silage batch is used then the ME should be?
crude protein content?
ME ≥9,5MJ per kg DM,
crude protein content 14-15%,
restricted fermentation
Peculiarities of feeding in the postpartum transition period.
The proportion of concentrates should not exceed
50% of the ration DM, because
– ruminal papillae are not adapted to receiving a high amount of VFAs
(in particular, propionate and butyrate)
Peculiarities of feeding in the postpartum transition period.
Concentrate should contain ?% by-pass starch
Concentrate should contain 50% by-pass starch
(maize, potatoes) -> absorbed in the small intestine.
A large amount of rumen fermentable concentrates increases the risk of displaced abomasum.
A large amount of rumen fermentable concentrates increases the risk of
displaced abomasum and acidosis
is rumen degradability higher or lower in heat-treated rapeseed cake, rapeseed meal etc.
lower
Peculiarities of feeding in the postpartum transition period.
favor what type of protein sources? why?
those in which rumen degradability is lower (e.g. heat-treated rapeseed cake, rapeseed meal etc.)
because microbial protein synthesis is not yet at a maximum in the rumen, and
AAs are also used for ATP energy synthesis
(labile protein)
The amount of body protein which can be used for energy synthesis.
– in total, the cow body contains about 80…100kg protein
– the labile protein content in the organism is 20…25kg
– during the NEB period cows can mobilise about 10kg of labile protein without problems in health and production
during the NEB/neg. energy balance period cows can mobilise about ?kg out of 20-25 kg of labile protein without problems in health and production
10kg of labile protein without problems in health and production
peak lactation period Length depends on
farm feeding management (animal grouping)
Maximum DM intake is achieved in which lactation week?
the 7th (..9th) lactation week ->
4% of body weight DM intake achieved
e.g. 600kg cow consumes then 24kg DM per day
the sooner the better, the shorter is the NEB
cows who are milked 3X per day eat ?% more DM than cows milked 2X per day
cows who are milked 3X per day eat 5…6% more DM than cows milked 2X per day
cows usually want to eat directly after
milking
▪ feed must be freely available
▪ cows with good production eat up to 12X per day, 23min in each feeding bout
▪ primiparous cows spend 10…15% more time on eating than multiparous cows
TMR (ration) means?
total mixed ration or complete ration
in peak lactation Feed ration contains ? MJ/kg ME in DM
Feed ration contains 11.5-12.0 MJ/kg ME in DM
maximum concentrate rate in the ration DM is ?%
and if maize silage is used then?
maximum concentrate rate in the ration DM is 60%, if maize silage is used then 50% is the maximum
– starch+sugars < 300 g/kg ration DM
starch+sugars should never exceed?
starch+sugars < 300 g/kg ration DM
By-pass protein is needed because
microbial protein does not cover the cows’ AA requirement for milk protein synthesis
in peak lactation, Feed ration must contain ?% of crude protein
ca 17% of crude protein
in peak lactation, cows’ base ration contains ?% crude fat
cows’ base ration contains crude fat (CF) 3…4%
high yielding dairy cow ration may contain CF 5 (…7)%
rumen inert fat is the same as
by-pass fat
physical fibre also known as
physical or “effective fibre”
“effective fibre” increases what milk fraction
increases milk fat content
if there is less than 7% long feed particles in the TMR, there is a high risk of
subclinical acidosis
prepared TMR should prick your own hand
Count the ruminating cows -> at least ?% of laying cows and ?% of standing but not eating
cows should be ruminating
at least 50% of laying cows and 40% of standing but not eating cows should be ruminating
Peculiarities of feeding in the second half of the lactation.
Cows are milking in what type of energy balance
Cows are milking in positive energy balance
Peculiarities of feeding in the second half of the lactation.
DM intake is ?% of body weight
DM intake is a bit lower
(3.0…3.5% of body weight)
Cows must achieve normal BCS at
the end of lactation and this must remain the same until calving.
Thin cows -> BCS under
3.25
Fat cows -> BCS over
3.50
dry period = resting period of how many days
39-46 days
– cows are not milked, the udder glandular cells regress
– the nutrient factor requirement is low (95-100 MJ/day)
in the dry period, usually only what are fed
roughages and minerals
Energy requirement of dry cow
▪ maintenance requirement 82 MJ/day
▪ foetal requirement 18 MJ/day
▪ TOTAL 100 MJ/day
Energy requirement of pre-partum cow
▪ maintenance requirement 82 MJ/day
▪ foetal requirement 18 MJ/day
▪ regeneration of udder glandular tissue 12 MJ/day
▪ TOTAL 112 MJ/day
Protein requirement of dry cow
(125…) 130 g/kg in DM
requirement will be covered at the expense of synthesised microbial protein
Protein requirement of pre-partum cow
~145 g/kg in DM
by-pass protein feed should be additionally added into the ration to cover the cows’ requirement for glycogenic AAs around
calving
What can happen if we don’t use a dry cow ration so cows are fed above their
requirements
– body weight increase (obese)
– lower DM intake in the postpartum period
– diseases connected with fat metabolism (ketosis, fatty liver)
- dystocia
ketosis -> is connected with energy whats
energy shortages and use of body reserves due to decreased intake
fatty liver -> occurs with NEB when,
during intensive use of body fat, the liver is unable to get rid of the accumulated free FAs
What triggers the use of body fats?
A. Blood low glucose level
B. Blood low insulin level
C. Blood low glucose and insulin level
D. Blood low level of growth hormone
B. Blood low insulin level
Which cereal should we use in the close-up dry period?
A. Maize meal
B. Barley meal
C. Mix of maize and barley meal
B. Barley meal
What is the recommended concentrates to
roughage ratio in the postpartum transition
period?
A. 40:60
B. 50:50
C. 60:40
B. 50:50
If we expect more milk from cows, then the fed concentrate must contain more …
A. rumen degradable nutrients
B. rumen undegradable nutrients
B. rumen undegradable nutrients
If the cows are too thin at the end of lactation we should …
A. increase ration energy and decrease protein
content
B. decrease ration energy and increase protein
content
A. increase ration energy and decrease protein
content
During the far-off dry period, the cows body condition should …
A. increase
B. remain the same
C. decrease
B. remain the same
