poor thrift, trace elements 1&2

Question 1

how is poor thrift in young animals defined?

Answer 1

animals that are not meeting their daily weight gain targets

Question 2

Why don’t NZ farmers feed their livestock food that is the highest possible quality, to allow animal growth rates to meet their genetic potential?

Answer 2

we primarily feed pasture (cheap, easy to grow)
- this varies in quality but is rarely high enough to meet full genetic potential
- not financially viable in NZ to feed very high quality feeds (eg grain)

Question 3

In livestock, how is feed quality assessed?
a. Calories of digestible energy/kg dry matter (CalDE/kgDM)
b. Megajoules of metabolisable energy/kg dry matter (MJME/kgDM)
c. Calories of metabolisable energy/kg dry matter (CalME/kgDM)
d. Megajoules of digestible energy/kg dry matter (MJDE/kgDM)

Answer 3

b. Megajoules of metabolisable energy/kg dry matter (MJME/kgDM)

Question 4

what would be approximate target weight gains per day for young cattle?
a. 60-100g/day
b. 100-300 g/day
c. 0.5-2 kg/day
d. 2-4 kg/day

Answer 4

c. 0.5-2 kg/day (imagine putting on two kg daily!)

Question 5

what would be approximate target weight gains per day for young sheep?
a. 30-60 g/day
b.100-300 g/day
c. 300-400 g/day
d. 400-900 g/day

Answer 5

b.100-300 g/day

Question 6

what would be approximate target weight gains per day for young deer?
a. 60-100g/day
b.100-300 g/day
c. 200-500 g/day
d. 400-900 g/day

Answer 6

c. 200-500 g/day - that’s a solid block of butter!

Question 7

how is poor thrift defined in adult animals?

Answer 7

poorer than expected BCS

Question 8

ideal BSC for cattle?
a: 2.0-3.5 out of 9
b: 3.5-5.0 out of 9
c: 5.0-6.5 out of 9
d: 6.5-8.0 out of 9

Answer 8

c: 5.0-6.5 out of 9

Question 9

ideal BSC for sheep?
a: 1.0-2.0 out of 5
b: 2.0-3.0 out of 5
c: 3.0-4.0 out of 5
d: 4.0-5.0 out of 5

Answer 9

c: 3.0-4.0 out of 5

Question 10

ideal BSC for deer?
a: 1.0-2.0 out of 5
b: 2.0-3.0 out of 5
c: 3.0-4.0 out of 5
d: 4.0-5.0 out of 5

Answer 10

c: 3.0-4.0 out of 5

Question 11

For health problems affecting multiple animals in herds/flocks, we are often able to formulate a list of likely differential diagnoses based on only a brief presenting problem. select the FALSE reason why:
a. there are a limited number of credible ddx for many presenting problems with herds/flocks
b. LA vets get to know the clients and their farms quite well
c. most of NZ production animal systems are seasonal, meaning their common diseases are too
d. large animal vets are just really smart

Answer 11

d. large animal vets are just really smart - practice over smart!!

Question 12

A farmer requests a vet visit to investigate poor growth rates in their weaner deer. They have 120 weaner deer whose growth rates have been 30% below the farmer’s target over the past month. Drag and drop to show likely and unlikely aetiological diagnoses.

Answer 12

likely - nutritional, infectious
unlikely - neoplasia, degenerative, anomalous/congenital, trauma, vascular

Question 13

true or false - poor thrift is a non-specific clinical sign, equivalent to weight loss in companion animals?

Answer 13

true

Question 14

Which of the following pastures is likely to have the highest MJME/kgDM?
a. Mostly leaf
b. Mostly stalk
c. About 50:50 leaf and stalk

Answer 14

a. Mostly leaf

Question 15

why should you always check teeth if you’re doing an examination on an adult ewe with poor thrift?

Answer 15

common cause, esp. when on short pasture
*poor incisors - reduced ability to graze
*poor molars (can only examine post mortem) - can’t chew cud, grass pieces stay too big and microbes can’t digest them as well. can sometimes see green staining down the side of the mouth, eg old sheila

Question 16

what are trace elements?

Answer 16

elements required by the body in very small amounts - but are essential for normal function

Question 17

which type of TE deficiency happens when there are inadequate TE concentrations in either the soil or the plant/s?
a. primary trace element deficiency
b. secondary trace element deficiency

Answer 17

a. primary trace element deficiency - Soil types vary across NZ and many are low in TE’s, especially Se and Co. Therefore we can map distinct parts of the country where animals are at high risk of deficiency.

Question 18

which type of TE deficiency happens when there are adequate TE concentrations in soil or plants, but the animal is unable to absorb or utilise sufficient amounts due to other factors?
a. primary trace element deficiency
b. secondary trace element deficiency

Answer 18

b. secondary trace element deficiency - most NZ soils contain adequate Cu but other elements can bind to the Cu in the rumen so the animal is unable to absorb it.

Question 19

Se and Cu can be toxic in overdose so they should be used with caution. Which formulation of a Se or Cu supplement is likely to be highest risk for resulting in toxicity?
a. Injectable
b. Oral
c. Pour on
d. Slow release rumen bolus

Answer 19

a. Injectable

Question 20

As part of a preventative health plan, a vet tests the Cu concentrations in a beef cow herd in autumn to check they are high enough to maintain good production. What was the purpose of testing in this case?
a. Diagnose deficiency
b. Ensure sufficiency
c. Monitoring
d. Diagnose toxicity

Answer 20

b. Ensure sufficiency

Question 21

A vet visits a farm to investigate deaths in weaner deer. The deer have recently been injected with Cu and as part of their investigation they test Cu concentrations, which are very high. What was the purpose of testing in this case?
a. Diagnose deficiency
b. Ensure sufficiency
c. Monitoring
d. Diagnose toxicity

Answer 21

d. Diagnose toxicity
couple more examples:

Question 22

livestock in NZ are usually entirely reliant on ingesting enough of the elements via the pasture/forage and being able to absorb what they ingest. The quantities in the pasture/forage will depend on the quantities in the soil… which trace elements are the most limiting in NZ?

Answer 22

• selenium (Se)
• cobalt (Co)
• copper (Cu)
• iodine (I)

Question 23

if you’re trying to get a sample to test copper levels, what should you get?
a. a blood sample
b. a liver sample

Answer 23

b. a liver sample - copper is stored in the liver

Question 24

if you’re trying to test selenium (or cobalt), what sample should you get?
a. a blood sample
b. a liver sample

Answer 24

a. a blood sample - selenium is not stored in the body, and only a limited amount of cobalt is

Question 25

is selenium deficiency normally primary or secondary?

Answer 25

primary - most NZ soils are low or marginal

Question 26

- key component of glutathione peroxidase (GPx) which helps protect cells against damage from free radicals (antioxidant) - immune function - growth and good reproductive health which trace element? a. copper b. cobalt c. selenium d. iodine

Answer 26

c. selenium

Question 27

poor thrift in young growing livestock, sometimes accompanied by diarrhoea. This is likely to be the most common clinical sign that vets are presented with reduced milk production in dairy cows increase in retained fetal membranes (RFMs) in dairy cows early embryonic death in sheep white muscle disease which trace element? a. copper b. cobalt c. selenium d. iodine

Answer 27

c. selenium

Question 28

which three are NOT linked to selenium (Se) deficiency? - poor thrift in young animals - retained fetal membranes - early embryonic death - neurological signs - reduced milk production - faded coat colour - white muscle disease - constipation

Answer 28

- neurological signs, constipation, faded coat colour are NOT

Question 29

During a poor thrift investigation, a vet wants to assess the Se status of a mob of R1 steers. The steers have not been growing well for some months so the vet wishes to assess their Se intake over that time. They have not received any Se supplementation. Which would be the most appropriate test to use? a. Serum Se b. Glutathione peroxidase (Se) c. Liver Se

Answer 29

b. Glutathione peroxidase (Se) - this reflects the Se incorporated into RBCs so is a good assessment of intake over the past several months

Question 30

During a poor thrift investigation, a vet wants to assess the Se status of a mob of R2 dairy heifers. About 6 weeks ago the heifers were given a Se supplement with a 4-week efficacy and the vet wants to know if they require further supplementation. Which would be the most appropriate test to use? a. Serum Se b. Glutathione peroxidase (Se) c. Liver Se

Answer 30

a. Serum Se - this would reflect their current intake

Question 31

why can you get away with low numbers of samples to test Se? (five samples is fine)

Answer 31

There is relatively little variation in Se concentrations between animals in the same mob, or indeed between all the animals across a whole farm (assuming the farm comprises similar soil types and the animals are managed similarly).

Question 32

is cobalt a primary or secondary deficiency?

Answer 32

primary - another soil one.

Question 33

____?_____ is an essential component of vitamin B12. Vitamin B12 is an essential component of a co-enzyme in the propionate to glucose pathway. When vitamin B12 is deficient, less propionic acid (an essential volatile fatty acid produced in the rumen) can be converted to glucose. Propionic acid is the only direct source of glucose available to ruminants and is required for optimal growth of young animals. Vitamin B12 also has a role in red blood cell formation and protein synthesis. which trace element? a. copper b. selenium c. cobalt d. iodine

Answer 33

c. cobalt

Question 34

A mob of lambs has Co/vitamin B12 deficiency and receive supplementation via the oral route. Should this be given as Co or vitamin B12? a. Co b. Vitamin B12

Answer 34

a. Co - given orally the Co will enter the rumen and the rumen microbes will incorporate it into vit B12

Question 35

A mob of lambs has Co/vitamin B12 deficiency and receive supplementation via the injectable route. Should this be given as Co or vitamin B12? a. Co b. Vitamin B12

Answer 35

b. Vitamin B12 - via injection it will be absorbed into the bloodstream and therefore needs to be given as vit B12

Question 36

Which animals are most likely to show clinical signs of Co/vitamin B12 deficiency? a. High milk-producing dairy cows b. Young growing cattle c. High lamb-producing adult ewes d. Young growing sheep e. Young growing deer

Answer 36

d. Young growing sheep - sheep have a much higher Co requirement than other species, and a deficiency reduces growth rates so lambs/hoggets most likely to be affected

Question 37

true or false - cobalt is not a toxicity risk

Answer 37

true

Question 38

The only clearly-evidenced clinical presentation for Co/vitamin B12 deficiency in NZ is poor thrift in young growing sheep - true or false?

Answer 38

true - can also reduce growth rates in severely deficient cattle and deer

Question 39

During a poor thrift investigation, a vet wants to assess the Co/vitamin B12 status of a mob of 800 lambs. How many samples should they collect and what test should they request? a. 5 samples, serum Co b. 5 samples, serum vitamin B12 c. 10 samples, serum Co d. 10 samples, serum vitamin B12 e. 20 samples, serum Co f. 20 samples, serum vitamin B12

Answer 39

d. 10 samples, serum vitamin B12 - rumen microbes incorporate Co into vit B12 which is absorbed into the bloodstream hence we test serum vit B12. 10 is just a good number to balance cost and accuracy - Co has more variation than Se

Question 40

GPx (Glutathione peroxidase) can be used to estimate Se intake over time whereas serum Se is reflective of recent Se intake. how does this work?

Answer 40

GPx is incorporated into red blood cells, which have a life span of around 3 months. Se is not stored in the body so serum Se reflects the animal's Se current status - how much Se it has absorbed in the last day or so

Question 41

which is which? a. 2 is Se, 1 is Co deficiency b. 1 is Se, 2 is Co deficiency

Answer 41

b. 1 is Se, 2 is Co deficiency

Question 42

which is which? a. 2 is Se, 1 is Co deficiency b. 1 is Se, 2 is Co deficiency

Answer 42

b. 1 is Se, 2 is Co deficiency

Question 43

true or false - If animals have been yarded for >6 hours their vitamin B12 (cobalt) concentrations are elevated.

Answer 43

true!

Question 44

is copper normally primary or secondary deficiency?

Answer 44

secondary - most NZ soil has enough

Question 45

which TE is involved in energy metabolism, myelin formation, elastin and collagen synthesis, and pigmentation? a. selenium b. copper c. cobalt d. iodine

Answer 45

b. copper

Question 46

In NZ, high concentrations of which element (found in soil/plants) is most commonly associated with inducing secondary Cu deficiency? a. Magnesium b. Molybdenum c. Iron d. Sulphur e. Manganese

Answer 46

b. Molybdenum (Mo) - iron, sulfur can as well but Mo most significant

Question 47

Which livestock species is the LEAST likely to be affected by Cu deficiency? a. Deer b. Cattle c. Sheep

Answer 47

c. Sheep - cattle and deer are most affected

Question 48

what time of year is Cu deficiency most likely to develop? a. winter b. spring c. summer d. autumn

Answer 48

b. spring - Cu stores in the liver deplete over the winter, and concentrations are usually at the lowest in spring

Question 49

Which trace element/s can cause clinical signs related to toxicity? a. Copper and cobalt/vitamin B12 b. Selenium and cobalt/vitamin B12 c. Selenium and copper d. Copper only e. Selenium only f. Cobalt/vitamin B12 only

Answer 49

c. Selenium and copper - cobalt is non toxic

Question 50

what signs are linked to copper deficiency? (hint, 6)

Answer 50

- swayback (nerve issues, usually deer over 9 months) - faded coat colour - bone and cartilage defects/fragility - reduced milk production in cows - reduced conception rates in cows - poor thrift in young or adult animals (usually alongside severe diarrhoea in cattle)

Question 51

which side is copper deficiency? a. 1 b. 2

Answer 51

a. 1 - Cu deficieny 2 - not related to Cu deficiency

Question 52

what's the copper "water tank and tap" analogy?

Answer 52

liver - the water tank blood copper concentration - the tap the blood copper concentrations will stay the same till the liver is almost fully depleted

Question 53

how many animals should you test for Cu?

Answer 53

- 16 ideally, 10 if you're short on money - large variation in ability to store copper between different animals

Question 54

Under what circumstances would measurement of serum or blood Cu concentrations be of value? a. To check if the animal has sufficient Cu stores b. To diagnose deficiency c. To monitor the effectiveness of a supplementation programme

Answer 54

b. To diagnose deficiency - anything else you need to check the liver, blood Cu stays constant unless the liver is fully empty

Question 55

For which TE/s are the reference ranges for laboratory testing not based on production responses to supplementation? a. Cobalt b. Selenium c. Copper d. Cobalt and copper e. Selenium and copper f. Cobalt and selenium

Answer 55

c. Copper - it's based on the Cu concentrations in animals showing clinical signs of deficiency

Question 56

because Cu concentrations in animals deplete over the winter, in cattle (and sometimes deer) it is reasonably common to test liver Cu stores in autumn to ensure they are sufficient to last through the winter. what liver concentration is considered adequate? a. >1000 umol/kg autumn, so doesn't drop below 500 umol/kg at end of winter b. >300umol/kg in autumn, so don't drop below 95umol/kg by the end of winter c. >100umol/kg in autumn to ensure they don't drop below 20umol/kg by the end of winter

Answer 56

b. >300umol/kg in autumn, so don't drop below 95umol/kg by the end of winter

Question 57

what is iodine used for?

Answer 57

the synthesis of thyroid hormones

Question 58

is iodine: a. primary deficiency only b. primary and secondary deficiency c. secondary deficiency only

Answer 58

b. primary (nz soil can be low) and secondary deficiency (exposure to goitrogens from brassicas and some clovers, stops iodine uptake)

Question 59

which TE in developing fetuses are important for: energy metabolism development of fetal brain, lungs, heart, wool/hair follicles stimulation of production of fetal lung surfactant a. Cobalt (vit B12) b. iodine (thyroid hormones) c. neither

Answer 59

b. iodine (thyroid hormones)

Question 60

which of the following is a probable clinical sign associated with iodine deficiency of pregnant ewes? a. Swayback in offspring b. Joint infections in offspring c. Perinatal mortality (stillbirths/death in first week of life) of offspring d. White muscle disease in offspring e. Pneumonia in offspring

Answer 60

c. Perinatal mortality (stillbirths/death in first week of life) of offspring - fetuses that have been exposed to inadequate iodine and therefore unable to synthesise enough thyroid hormones will have poor energy metabolism, poor development of critical organs, difficulty breathing = high death rate

Question 61

what is the only 2 clearly-evidenced clinical presentation for iodine deficiency in NZ?

Answer 61

- goitre (enlarged thyroid glands - increased perinatal mortality rates (both usually in lambs or goat kids)

Question 62

For which TE is addition to fertiliser likely to be an ineffective method at significantly raising animal concentrations? a. Selenium b. Cobalt c. Copper

Answer 62

c. Copper - Cu deficiency in NZ is almost always a secondary deficiency and it is very difficult to add enough to fertiliser to get soil levels high enough to counteract the high Mo (or Fe or S) concentrations that bind the Cu in the rumen

Question 63

which is correct vs incorrect for Cu?

Answer 63

1 - correct 2 - incorrect

Question 64

To ensure the Cu status of livestock is sufficient, it is recommended to test liver rather than blood Cu concentrations. Explain why this is.

Answer 64

Cu is stored in the body, mainly in the liver. The body's homeostatic mechanisms will keep blood Cu concentrations normal until the liver stores are almost entirely depleted. Blood is OK for confirming deficiency but otherwise tells us nothing about the liver stores.

Question 65

Which species are most likely to show clinical signs of I deficiency? a. Deer b. Goats and sheep c. Cattle d. All species are equally affected

Answer 65

b. Goats and sheep

Question 66

Which one of the following methods is recommended to diagnose I deficiency in sheep? a. PM 15-20 dead lambs and submit their thyroid glands for histology b. Euthanise 15-20 dams of dead lambs and assess their thyroid gland size c. Blood sample 15-20 dams of dead lambs and assess their serum inorganic I concentrations d. PM 15-20 dead lambs and assess their thyroid:bodyweight ratios e. Blood sample 15-20 dead lambs and measure their serum thyroid hormone concentrations

Answer 66

d. PM 15-20 dead lambs and assess their thyroid:bodyweight ratios

Question 67

true or false - TE supplements do not have withholding times

Answer 67

true

Question 68

A vet is investigating poor thrift affecting an entire mob of young cattle. Which TE deficiency/deficiencies would be included on the differential diagnoses list? a. Se only b. Co/vitamin B12 only c. Cu only d. Se and Co/vitamin B12 e. Se and Cu f. Co/vitamin B12 and Cu g. Se, Co/vitamin B12 and Cu

Answer 68

e. Se and Cu - rare for young cattle to have Co/B12 related growth issues

Question 69

A vet is investigating poor thrift affecting an entire mob of young sheep. Which TE deficiency/deficiencies would be included on the differential diagnoses list? a. Se only b. Co/vitamin B12 only c. Cu only d. Se and Co/vitamin B12 e. Se and Cu f. Co/vitamin B12 and Cu g. Se, Co/vitamin B12 and Cu

Answer 69

d. Se and Co/vitamin B12 - both of these can cause poor growth rates in sheep, whereas they're normally good at storing Cu

Question 70

provides protection against free radicals - is it: a. selenium b. cobalt c. copper d. iodine

Answer 70

a. selenium

Question 71

part of a co-enzyme required to convert propionic acid to glucose - is it: a. iodine b. selenium c. cobalt d. copper

Answer 71

c. cobalt

Question 72

involved in a range of enzyme systems including those required for energy metabolism, myelin formation, and collagen synthesis - is it: a. iodine b. selenium c. cobalt d. copper

Answer 72

d. copper