Trace elements in cattle Flashcards
1
Q
What trace elements can cows be deficient in?
A
- Selenium
- Iodine
- Manganese
- Cobalt
- Zinc
- Copper
2
Q
What trace element are toxic to cattle?
A
- Copper
- Selenium
- Iodine
- Cobalt
- Cadmium
- Lead
3
Q
What element are often in excess in cattle?
A
- Iron
- Sulphur
- Molybdenum
- Aluminium
- Selenium
4
Q
What are specific syndromes of trace element deficiencies?
+ General impact of deficiencies?
A
- Copper = swayback, coat colour, falling disease
- Selenium - white muscle disease, cardiomyopathies
- Cobalt = reduced growth, wool changes ‘pine’
- Iodine - weak neonates
- Iodine + selenium = stillbirth / weak calf syndrome
- Reduced growth + production + Immunity
5
Q
What are different sources of trace elements?
A
- Free access minerals
- Mineral blocks / buckets
- Boluses - dietetic under feed regs
- Drenches
- ‘Supplements’
- Water – esp. bore hole
- Authorised Veterinary products
- Grass
- Forages
- Straight feed materials
- Compound feeds (complete & complementary)
- Blends (supplemented or not)
- In-feed minerals
6
Q
What animals are at risk of trace element deficiencies?
A
- Animals grazing (+not getting much concentrates)
- beef cows + calves
- fattening cattle
- New Zealand style dairy cows
- Dairy heifers prior to first calving if at pasture
7
Q
How are trace element deficiencies diagnosed?
A
- HISTORY – at pasture with no supplements
- Blood samples
– Se – GSHPx – tells us about 60 days ago
– Cu – tells us how much is being transported
– Does not tell us how much is in liver – liver biopsy needed
– Caeruloplasmin
– Co – Vitamin B12
– Iodine –Plasma Inorganic Iodine (& thyroid weight & histopathology)
8
Q
Where is copper stored? What can toxicity cause? What are predisposed breeds?
A
- Stored in liver
- Toxicity = haemolytic crisis = jaundice + death
- Predisposed to toxicity = Texel + North Ronaldsey
- Predisposed to deficiency = Scottish blackface = swayback
9
Q
What is the availability of copper in different forages?
A
- Grass silage = 49%
- Maize silage = 87%
- Whole crop silage = 69%
10
Q
What is copper bound to in the rumen?
A
- Molybdenum - thiomolybdates (w sulphur)
- Iron
= deficiency
11
Q
How can you check liver copper status?
A
- Liver biopsy
- Liver from cull cows
12
Q
How can you supplement copper?
A
- Pasture dressing
- S/C injections
- Intra-ruminal bolus
13
Q
How can over supplementation occur?
A
- Multiple supplementary feeds =
- Compound feeds
- Supplemented blends
- Free access minerals
- Licks
- Boluses
- Drenches
14
Q
What are the consequences of zinc deficiency?
A
- Appetite and feed intake
- Immune status
- Teratogenic effects - congenital abnormalities
- Immune function effects - endometritis, mastitis
- Hoot, horn + hair integrity
- Teat keratin plus
15
Q
What are symptoms of selenium deficiency?
A
- White muscle disease (other muscle myopathies)
- Ill thrift
- Retained placenta and (resulting endometritis)
- Impaired immune function (mastitis)
- Poor fertility
- High S and/or Ca reduce Se absorption (Pb also)
- Selenium dependant enzyme, iodothyronine deiodinase, crucial for thyroid function, converts thyroxine to T3, is inhibited in selenium deficient cattle
