Trace Element Deficiencies Flashcards
Which industry are TE deficiencies rare?
dariy cattle - usually supplemented
What are the macro minerals?
Ca, Mg, P
What are the microminerals or trace elements?
Co, Cu, Se/Vit E, Iodine
Fe, Mn, Zn
How are trace elements gained by grazing animals>
Soil/plants
Which trace elements are often limited in temperate grassland productin?
Cobalt, se/vit E, copper, iodine
Which elements may negatively affect copper absorption?
Mo, S, Fe in rumen
Why may TE deficiency occour?
1* - soil/plant deficiency (Co, Se, I, Cu) - different regions/districts = soil deficiency so local knowledge useful
2* - lack of absorption in animal (Cu)
What is the function of Cobalt? (Co) What problems may this cause?
- essential component Vit B12
- Vit B12 co-enzyme in pathway Propionate -> glucose
- Deficiency = shortage of glucose, poor thrift esp of growing animals
- Sheep most affected
- Lethargy, poor growth rate, v BCS
- Pale MMs and anaemia in late disease
- Eye discharge, epiphora
- Concurrent parasitism and under-nutrition `
How can Co deficienct be diagnosed?
- B12 assay on bloods
- MMA^ if B12v in urine
- B12 on liver smaple
- MOST COMMON: Supplementation trial over 8-10 weeks (10 lambs no supplement)
- PCV non specific, DDx. Haemonchosis, faciolosis
- PME: Bone marrow hypoplasia, liver enlargement in severe cases
How may Co deficineyc be treated or controlled?
- Vit B12 injection and CoS oral drench
- Monthly Co drenching
- Cobalt Oxide bolus
What is the function of selenium/vit E?
- Cellular antioxidants
- deficiency causes membrane damage and tissue necorisis (skeletal, cardiac and respiratory mm, RBCs)
What is Se/Vit E deficiency called?
White muscle disease, still lamb disease, nutiritonal muscular dystrophy
What occours with white muscle disease?
> CLINICAL - congential -> stillbirthds - more usually 2-6weeks neonatal death or sudden onset stiffness, lowered head carriage, pain - can be asscoaited with recent stress > SUBCLINICAL - poor growth rate - embryonic deaths - ^ disease susceptibility - v milk yield
How may Se/Vit E deficiency be diagnosed?
- clinical signs
- glutathione peroxidase levels DECREASED in blood
- CK ^ greatly in early stages
- Vit E assay in bloods
- Histopath on cardiac m (esp stillborn lamsb)
How may Se/Vit E deficiency be treated or controlled?
- Se/Vit E injection
- Supplement pregnant ewe/cows
- Drench growing lambs
- Boluses
- BEWARE TOXICITY*
What makes Se/Vit E deficiney more likely?
Root crops
What is the function of Cu?
> enzymes eg.
- cytochrome oxidase for myelin formation
- caeruloplasmin for Fe release into plasma during erythropoiesis
- Lysyl oxidase for elastin and collagen synthesis
- Tyrosinase for pigmentation
What problems are often seen associated with Cu deficieny?
- poor thrift, D+, poor coat colour [mainly growing cattle 6-18 months)
- Swayback (lambs born to Cu-deficient ewes, adult deer)
- bone fragility
What is Cu deficieny often assocated with?
- poor nutrition
- levels in liver decrease over winter
What other problems may Cu cause?
Toxicity esp in sheep and goats
-> depression, anorexia, haemolysis, haemoglobinuria, jaundice
Which animal feed has particularly high levels of cu?
Pigs
When may cows be affected by Cu toxicity? (^)
Drinking copper footbaths
What clinical signs may be seen with Cu toxicity?
- AST>1000U/l in serum
- low PCV
- serum Cu levels have limited value, kidney assay better
- Gastroenteritis
- Swollen, dark grey (“Gun metal”) kidneys
- Liver enlarged and friable
What is iodine required for?
Thyroid hormone synthesis
How may iodine deficiency present?
Clinically - goitre in new born lambs (weigh thyroids, histopath)
Sub-clinically - ^ perinatal mortality
Which species are particularly affected by a. Co b. Se c. Cu problems?
a. weaned lambs
b. all species
c. cattle (and sheep/goats with ^ levels -> toxicity)
What may gait abnormalities in new born indicate?
Se: white muscle disease
Cu: Swayback and spontaneous Fx
Testing what is most useful if TE deficiency suspected?
Animal (not plant or soil)
How are liver analyses usually carried out?
- biopsy (straightforward but uncommon)
- usually at PM or abattoir
What is the commonest way to diagnose a TE deficieny?
Treatemnt/control trial
- help quantiy magnitude of problem
- aid decision on likelhihood of economic response to suipplementation
Which TEs are toxic if overdosed?
Cu, Se
When should TE deficiency be suspected?
- more than 1 animal affected
- poor thrift
- gait abnormalities
- goitre
