Set 3 Flashcards
Transition is?
change from being a dry cow in late pregnancy to milking
-3 weeks before and 3 weeks after calving
Far off dry
early dry period, refers to time to calving(8-4 weeks)
close up dry
late dry period (4 weeks to calving)
Challenges of transition(group)
- dietary adjustments
- group changes(social disruption)
Other challenges of transition
immune function due to stress and pregnancy
calving itself
reasons for intake drop
- acute stress of impending calving
- roles of insulin and leptin(changes how the animal metabolizes fat)
- increase in NEFA causes decrease in appetite
Exacerbating intake drop
- competition for space at feed bunk or stall space
- group changes and social disturbance
- lack of feed access
- dietary changes
- heat stress
Transition diseases
- ketosis
- displaced abomasum
- subacute ruminal acidosis
- milk fever
Milk fever(hypocalcemia)
- not an infectious disease
- parturient paresis
- large outflow of Ca into colostrum
- cow needs to replace the Ca through increased bone resporption and absorption from the diet
- jersey more prone
Ketosis
elevation in circulating levels of ketones(acetone, acetoacetate and beta-hydroxybutyrate)
-occurs due to excessive NEFA breakdown
Clinical milk fever stages
stage I -unsteady -cool extremities(skin, ears) -hyper-excitable stage 2(1-12 hours) -unable to rise(lying in sternal) -depressed, head on flank stage 3 -lying in lateral(chest up) -bloat -death if untreated
Treating milk fever
IV calcium infusion(stage II and III) Ca supplements(stage 1 and subclinical)
Dietary carbs(starch and fiber) are fermented to VFAs:
- acetate 70%
- butyrate 10%
- propionate 20%
glucose is produced through?
gluconeogenesis
-propionate + amino acids
When glucose isn’t available fats are mobilized as?
non-esterified fatty acids(NEFA)
NEFA leads to?
increased ketones +/- fatty liver
Clincial ketosis
occurs at different concentrations of BHB
- drop in feed intake
- drop in milk production
- dry manure
- loss of body condition
- nervous signs
Primary ketosis
due to maladaptation to NEB
Secondary ketosis
drop in feed due to other diseases
Risk factors for ketosis
increasing number of lactations history of being ketotic over conditioned cows : BCS >3.75 at dry off limiting feed intake during dry period higher producing cows(?)
