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