Trace Element Deficiencies

Question 1

Which industry are TE deficiencies rare?

Answer 1

dariy cattle - usually supplemented

Question 2

What are the macro minerals?

Answer 2

Ca, Mg, P

Question 3

What are the microminerals or trace elements?

Answer 3

Co, Cu, Se/Vit E, Iodine

Fe, Mn, Zn

Question 4

How are trace elements gained by grazing animals>

Answer 4

Soil/plants

Question 5

Which trace elements are often limited in temperate grassland productin?

Answer 5

Cobalt, se/vit E, copper, iodine

Question 6

Which elements may negatively affect copper absorption?

Answer 6

Mo, S, Fe in rumen

Question 7

Why may TE deficiency occour?

Answer 7

1* - soil/plant deficiency (Co, Se, I, Cu) - different regions/districts = soil deficiency so local knowledge useful
2* - lack of absorption in animal (Cu)

Question 8

What is the function of Cobalt? (Co) What problems may this cause?

Answer 8

• 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 `

Question 9

How can Co deficienct be diagnosed?

Answer 9

• 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

Question 10

How may Co deficineyc be treated or controlled?

Answer 10

• Vit B12 injection and CoS oral drench
• Monthly Co drenching
• Cobalt Oxide bolus

Question 11

What is the function of selenium/vit E?

Answer 11

• Cellular antioxidants

- deficiency causes membrane damage and tissue necorisis (skeletal, cardiac and respiratory mm, RBCs)

Question 12

What is Se/Vit E deficiency called?

Answer 12

White muscle disease, still lamb disease, nutiritonal muscular dystrophy

Question 13

What occours with white muscle disease?

Answer 13

> 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

Question 14

How may Se/Vit E deficiency be diagnosed?

Answer 14

• 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)

Question 15

How may Se/Vit E deficiency be treated or controlled?

Answer 15

• Se/Vit E injection
• Supplement pregnant ewe/cows
• Drench growing lambs
• Boluses
• BEWARE TOXICITY*

Question 16

What makes Se/Vit E deficiney more likely?

Answer 16

Root crops

Question 17

What is the function of Cu?

Answer 17

> 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

Question 18

What problems are often seen associated with Cu deficieny?

Answer 18

• poor thrift, D+, poor coat colour [mainly growing cattle 6-18 months)
• Swayback (lambs born to Cu-deficient ewes, adult deer)
• bone fragility

Question 19

What is Cu deficieny often assocated with?

Answer 19

• poor nutrition

- levels in liver decrease over winter

Question 20

What other problems may Cu cause?

Answer 20

Toxicity esp in sheep and goats

-> depression, anorexia, haemolysis, haemoglobinuria, jaundice

Question 21

Which animal feed has particularly high levels of cu?

Answer 21

Pigs

Question 22

When may cows be affected by Cu toxicity? (^)

Answer 22

Drinking copper footbaths

Question 23

What clinical signs may be seen with Cu toxicity?

Answer 23

• 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

Question 24

What is iodine required for?

Answer 24

Thyroid hormone synthesis

Question 25

How may iodine deficiency present?

Answer 25

Clinically - goitre in new born lambs (weigh thyroids, histopath)
Sub-clinically - ^ perinatal mortality

Question 26

Which species are particularly affected by a. Co b. Se c. Cu problems?

Answer 26

a. weaned lambs
b. all species
c. cattle (and sheep/goats with ^ levels -> toxicity)

Question 27

What may gait abnormalities in new born indicate?

Answer 27

Se: white muscle disease
Cu: Swayback and spontaneous Fx

Question 28

Testing what is most useful if TE deficiency suspected?

Answer 28

Animal (not plant or soil)

Question 29

How are liver analyses usually carried out?

Answer 29

• biopsy (straightforward but uncommon)

- usually at PM or abattoir

Question 30

What is the commonest way to diagnose a TE deficieny?

Answer 30

Treatemnt/control trial

• help quantiy magnitude of problem
• aid decision on likelhihood of economic response to suipplementation

Question 31

Which TEs are toxic if overdosed?

Answer 31

Cu, Se

Question 32

When should TE deficiency be suspected?

Answer 32

• more than 1 animal affected
• poor thrift
• gait abnormalities
• goitre