Metabolic Diseases and Trace Elements of Cattle Flashcards
What is milk fever?
Hypocalcaemia +/- hypophosphataemia
How does PTH control calcium levels?
What does calcitonin do?
What does Vitamin D3 do?
PTH: Increases calcium absorption from the gut
Mobilises calcium from bone
Calcitonin: reduces calcium absorption
Vitamin D3: Increases calcium absorption from the gut
What are 4 differential diganosis for a recumbent cow after calving?
- Milk fever
- Acute coliform mastitis
- Botulism
- Calving injury (nerve damage, femoral head fracture/dislocation)
What is the treatment for milk fever?
What site is best for injection?
IV Calcium Borogluconate
Place in sternal recumbency
Jugular vein
What is the problem with using the milk vein for injections?
Risk of haematomas
Lack of drainage
Lying on that area can cause abscesses
What is the best prevention strategy for milk fever?
Low calcium and high magnesium diet pre-calving
Maximise DMI
What does Zeolite do?
What is a risk of using it?
In which cows is it contraindicated?
Binds calcium in ration
Improves mobility of calcium in order to prevent milk fever
Risk of hypophosphataemia
Don’t use in lactating ration!
What is the difference between hypocalcaemia in sheep and cattle?
Sheep: Pre-lambing (stress)
Cattle: At/after calving (poor mobilisation of and drained calcium reserves)
- What can cause grass staggers/hypomagnaesemia?
2. What can cause it in calves?
- High potassium (e.g. lush grass), reduces Mg absorption and STRESS
- Unsupplemented all milk diet (no Mg)
What are 5 differential diagnoses for a cow/sheep found dead in a field?
- Lightening strike
- Electrocution
- Toxaemia
- ANTHRAX!
- HypoMg
What are 2 differences between milk fever and grass staggers?
Diarrhoea in hypoMg (milk fever - no faeces)
Flaccid paralysis in milk fever, but hypoMg convulsive/paddling
How is glucose produced?
How is lactose synthesised?
Via gluconeogenesis from proprionate (in Krebs cycle)
From glucose
What happens if there is insufficient proprionate?
Insufficient oxalo-acetate
Acetyl CoA can’t enter Kreb’s cycle, metabolised to Ketones
Where does metabolisation of ketones and fat deposition occur?
Liver
What are NEFAs/FFAs produced from?
What are they metabolised to in the liver?
Lipolysis of adipose tissue
Metabolised to Ketones
What are ketones an energy source for?
Muscle (not milk production or brain)
Name 3 ways insulin decreases blood glucose
- Increases uptake of glucose into cells
- Decreases gluconeogenesis
- Suppresses lipolysis and ketogenesis
What are 3 treatments for clinical ketosis?
- Oral propylene glycol
- Corticosteroid (dexamethasone)
- B Vitamins: B12 (cobalamin), B1 (thiamine) for Kreb’s cycle
What are 4 clinical signs of ketosis?
- Reduced milk yield
- Refusal of concentrates
- “Pear drop” smell on breath (ketone bodies)
- “Shiny” firm faeces
What can propylene glycol toxicity cause?
Haemolysis
Release of sulphur
What is the treatment for nervous ketosis?
What are your differential diagnosis?
IV glucose 40%
DDx: HypoMg, listeriosis, BSE
How much BCS should cows lose between dry period and early lactation?
0.5
What BCS should cows be:
At calving?
Early lactation?
2.5-3
(lose 0.5)
2-2.5
- What is BHOB testing used for?
2. What is NEFA testing used for?
- Ketone body, NEB
2. Evidence of fat mobilisation
When should metabolic testing be carried out after a diet change?
2 weeks after a diet change
What does low butterfat in milk indicate?
If it is very high, what can this indicate?
What can low milk protein indicate?
Lack of fibre in diet
Excessive fat mobilisation
Energy deficit
What does high blood urea indicate?
Excess ERFP (effective rumen degradable protein)
Or insufficient ME (microbial energy)
Basically the rumen microbial ability to digest protein is overwhelmed!
Why do you want to reduced excretion of urea?
- Turns into ammonia, which is a greenhouse gas
2. Indicates non-absorption of protein, so protein in the ration is being wasted
What are 3 ways during the dry period to prevent FMS/Ketosis?
- Feed a low energy diet
- Maximise DMI
- Monitor BCS, avoid fat cows!
What are Scottish Blackface sheep susceptible to?
Copper deficiency
What breeds are susceptible to copper deficiency?
Texel, North Ronaldsey
Where is copper stored?
How do you diagnose copper deficiency?
Liver
Liver biopsy
What causes Copper:
- Deficiency?
- Toxicity
- Molybdenum (clinical signs) or iron-induced
2. Excessive supplementation
Which trace element is associated with teat keratin?
What is it also important in?
Zinc
Immune function
How are Selenium and Vitamin E related?
Vitamin E maintains Selenium in body in active form (GSHPx)
Selenium allows Vitamin E absorption
Why is Selenium crucial for thyroid function?
Selenium dependent enzyme (iodothyronine deiodinase)
Converts thyroxine to T3
What causes Blind Staggers?
Acute Selenium toxicity
Which trace element is MOST important for reproductive function?
Iodine
What is a goitrogen?
Interfere with iodine uptake by the thyroid
Pituitary gland releases TSH, promoting growth of thyroid tissue (goitre)
Give 3 examples of goitrogens
- Brassicas (kale, cabbage, turnips)
- Maize
- White clover
How can Potassium and Fertilizer (nitrogen) cause iodine deficiency?
Potassium increases excretion
Fertilizer reduces iodine in forage
What are 3 ways to diagnose iodine deficiency?
- Palpation of goitre (best?)
- T4 (thyroid function)
- Plasma inorganic I (recent intake)
What is the best test for Cobalt deficiency?
Why is testing serum not recommended in cattle?
Vitamin B12 in milk or Liver B12 (biopsy)
Serum binding proteins, discrepancies and underestimations
