Ketosis

History

·    Have they recently calved? Are they in their lactation period? – most at risk peak lactation and immediately post calving (as E in < E out)

·    BCS? – if excess BCS then more at risk

·    Has there been a change in feed intake? – off food is CS

·    What are they fed? – type 3 ketosis due to poor quality silage

·    Any change in milk yield? – milk drop commonly seen

Investigations

·    Examine cow

o  Pear drop smell

o  Mentation

·    Take blood sample from tail vein

·    Diagnosis – usually ketone bodies

o  Blood – BHB, v quick, do cow side (>1.2 = subclinical, >3mmol/l = clinical ketosis)

o  Milk – BHB, semi-quantitative

o  Urine – acetoacetic acid, less accurate

·    Can measure NEFAs

o  Only in blood, more expensive, naturally decrease around calving

o  Can be useful to monitor NEB prevalence in herd

Treatment

·    Oral propylene glycol – 300g daily for 3-5d

·    50% dextrose – 500ml IV, alongside propylene glycol

o  Useful in short term, for crisis situations

·    Can also give pro-rumen – mix of vitamins, minerals, live yeast, milk powder – aids beneficial rumen bacteria, nutritional value, helpful for recovery of ketosis

Prevention

·    Type 1 – management of nutrition during lactation, prevent loosing >0.5 BCS between calving and peak-lactation

·    Type 2 – management of nutrition in transition period, ensure cow enters calving correct BCS

o  Want cows to calve in at BCS 2.5-3

·    Type 3 – proper silage management

3 types of ketosis

·    Type 1 – occurs at peak lactation (4-8w post-calving)

o  Incr. milk production but decr. energy intake ® decr. VFA production

o  Reduced gluconeogenesis in liver ® liver metabolises VFAs into ketones, and decr. NEFA uptake ® increased BHB and NEFA in blood

·    Type 2 – occurs during transition period (1-2w post-calving)

o  Cow in NEB ® incr. NEFA production

o  In liver, NEFAs are oxidised ® ketone bodies, or esterified ® TAGs

o  TAG accumulate in hepatocytes ® hepatic lipidosis ® rounded, enlarged liver

·    Type 3 – occurs any time

o  Poor quality silage (incr. nitrite, decr. sugar) contains more clostridial bacteria

o  Bacteria ferment carbohydrates ® butyric acid (instead of lactic acid) ® converted into BHB in rumen ® incr. ketones in blood