Intro to Bovine Lameness

Question 1

Top 3 problems facing the UK dairy industry?

Answer 1

Lameness.
Mastitis.
Fertility.

Question 2

Lameness as an impact on the cow.

Answer 2

Pain and discomfort.
Behaviour changes:
- increased lying times.
- reduced feed intake.
- suppression of oestrus expression.
- reduced visits to robot in automatic milking systems.
Increased susceptibility to other disease e.g. mastitis - laying more.

Question 3

Lameness and cost.

Answer 3

Direct:
- treatment cost.
- vet time.
- farmer time.
- milk discard.
- reduced milk yield.
Indirect:
- increased risk of culling.
- effects on fertility.
- risk of further lameness cases.
- risk of secondary disease.

Question 4

How can the case numbers of lameness be assessed?

Answer 4

By prevalence - % affected at a point in time.
- e.g. by mobility scoring.
By incidence - e.g. cases/100 cows/ year.
- treatment data needed.

Question 5

Where does bovine lameness occur?

Answer 5

Mostly in the foot.
- mostly hind.
- mostly outer claw on hind.

Question 6

Factors of normal anatomy to know when treating lameness and why you need to know them.

Answer 6

Identify component structures of the foot.
Recognise how the external and internal structures relate to each other.
Identify the “normal” distribution of weight to be able to trim a foot back to normal.
Illustrate horn growth, wear and repair.
Helps with knowing how lameness occurs and how to treat it.

Question 7

What is the coronary band?
What is the hoof wall?
What is the periople?

Answer 7

Coronary band:
- junction between skin and horn.
- produces the wall horn.
Wall:
- formed at a rate of 5mm/month.
- migrates down hoof.
Periople:
- junction between skin and horn at coronary band.
- forms waxy coat to hoof.

Question 8

What is the sole?
What is the white line?
What is the heel?

Answer 8

Sole:
- formed for papillae on sole.
- wall and sole meet at white line.
White line:
- join between wall and sole.
- point of weakness.
Heel:
- soft sponge horn.

Question 9

Pedal bone.

Answer 9

P3.
- centrally within hoof.
- mainly attached to dorsal wall but also held by tendons of suspensory apparatus.
- flexor tendon attached to palmar/plantar edge by flexor process.
- navicular bone between tendon and P2.

Question 10

Corium.

Answer 10

Produces horn of the sole.
Stratum germinativum.
Fills space between sole and P3.
- vulnerable to pinching.
Blood vessels, nerves and other support structures.
V sensitive.

Question 11

Digital cushion.
In which cows may the digital cushion be less effective.

Answer 11

Pad of fat and elastic tissue.
Shock absorber.
Pumps blood from the foot.
May be less effective in thin cows, heifers, old cows.

Question 12

Laminae.

Answer 12

Junction between wall and P3.
Sensitive and insensitive components.
- sensitive dermal laminae from P3.
- insensitive epidermal laminae from hoof wall.
They interdigitate like interlacing fingers.
Suspends P3 within the hoof wall capsule.
Affected by hormonal changes around calving.

Question 13

Normal size of hoof.

Answer 13

Anterior wall 80mm (60-90).
Anterior wall to ground angle 45-50 degrees.
Heel height:
- 25-35mm in young.
- 30-45mm in old.

Question 14

Hoof conformation.

Answer 14

Balance between growth and wear,
Overgrowth occurs when growth is more than wear.
Overgrowth predisposes to lameness.
Affects weight bearing and weight distribution.

Question 15

Horn growth.

Answer 15

Slow - approx. 5mm/month.
Growth rate affected by:
- loading – increased loading = increased growth (reactive).
- claw – outside more than inside on hind feet.
- nutrition.
- age/breed.
Wall horn growth is from the coronary band, down to toe.
Sole horn growth is from the sole corium, downwards and forwards.

Question 16

Cow factors of horn wear,

Answer 16

Horn quality.
Hoof conformation.
Limb conformation.
Udder size and structure.

Question 17

External factors of horn wear.

Answer 17

Underfoot conditions:
- surface abrasiveness – concrete vs grass.
- slurry depth.
Management factors:
- walking distances.
- foot trimming.
- housing programme.

Question 18

What is horn quality affected by?

Answer 18

Lameness.
Damage to corium or coronary band.
Underfoot conditions.
Foot bathing.
Systemic illness (hardship lines).
Nutrition (e.g. Low Biotin or High Concentrates).
Breed/age.

Question 19

Normal weight bearing.

Answer 19

Should occur around outside of the foot (abaxial wall) and around to the toe.
Small amount cranial axial wall (medial wall of claw).
Should occur on heel too.
Not on sole itself.
40% bwt onto FLs and 60% bwt on HLs.
More carried on inside claw on FLs.
More carries on outside claw on HLs.

Question 20

Hoof overgrowth at the toe.

Answer 20

In housed cattle, wall worn more rapidly at the heel.
Heel undermined by slurry heel in winter.
Further overgrowth at toe due to NWB.
Shifts weight further back so less than a 45 degree angle between toe and ground.
Sole corium pinched, producing pain whilst walking.
Sole bruising/haemorrhage causes inflammation / sole ulceration.
Get thickening of the sole in the region affected.

Question 21

Hoof overgrowth - disparity of claw size.

Answer 21

Weight bearing on lateral hind claw.
- irritation and sole overgrowth.
- increased pressure and pain in lateral claw.
- abduction of limb.
- increased weight on medial claw so decreased wear on later claw.
- overgrowth at toes force hocks together.
- increased weight bearing on the lateral claw.

Question 22

If a cow is walking on an overgrown claw, what structure is at risk of being damaged?

Answer 22

Corium.