Bovine Nutrition and Metabolism 6

Question 1

WHat is ketosis in cattle caused by?

Answer 1

Incomplete metabolism of VFAs

Question 2

What are the three types of ketone bodies in cattle?

Answer 2

Acetoacetate
B-hydroxybutyrate
Acetone

Question 3

What is the incidence of ketosis among all dairy cows in the UK?

Answer 3

1-5% incidence

Question 4

List 6 nervous signs of ketosis

Answer 4

Sudden onset
Delirium
Circling
Leaning and crossing legs
Licking and chewing manias
Blindness

Question 5

List 5 signs on biochemistry of cattle that shows ketosis

Answer 5

Hyperketonaemia
Hypoglycaemia
Ketonuria
Ketones in milk
Hypocalcaemia

Question 6

Describe how the pathology of the liver, kidney and heart would appear of a cow with ‘fat cow syndrome’

Answer 6

Liver - rounded edges, prominent yellow reticular pattern.
Kidney - radial yellow-tan streaking of the cortex and medulla
Heart - yellow-tan streaking of the myocardium

Question 7

Describe how the microscopic findings of the liver, kidney and heart would appear of a cow with ‘fat cow syndrome’

Answer 7

Liver - single/multiple round cytoplasmic vacuoles
Kidney - multiple variably sized lipid droplets within epithelial cells
Heart - numerous fine vacuoles in sarcoplasm of myocytes

Question 8

List 5 methods of the treatment of ketosis and fat cow syndrome.

Answer 8

Intravenous glucose (dextrose)
Glucose precursors
Glucocorticoids
Insulin
Nutrition

Question 9

List three factors that metabolic profiles should be interpreted in light of on farms

Answer 9

All management factors
Milk yield
Physiological state

Question 10

How should you select cows for metabolic profiling?

Answer 10

5-10 cows from each of late dry cows, early lactation and mid-late lactation

Question 11

List 4 alternative names for hypomagnesaemia

Answer 11

Lactation tetany
Grass staggers
Grass tetany
Hereford disease

Question 12

Describe the three forms of hypomagnesaemia

Answer 12

Acute: Spring and Autumn affecting both diary and beef suckler cows
Chronic: End of Winter usually in suckler cows wintered on poor diets
Subclinical: Late dry period especially in pregnant dairy cows at grass

Question 13

List four things that hypomagnesaemia may interfere with

Answer 13

Release of PTH
Hydroxylation of vitamin D in the liver
Mobilisation of calcium from bones
Absorption of calcium from the gut

Question 14

List 2 things that will predispose to hypomagnesemia

Answer 14

Adverse weather
Grass/soil species

Question 15

List four risk periods for hypomegnesaemia

Answer 15

Lactating dairy or suckler cows for 6-8 weeks after spring turn-out
Summer-Autumn calving dairy cows on lush Autumn aftermath (post harvest regrowth)
Outwintered suckler cows calving Sept-March
2-3 days after the stress of weaning in Suckler cows.

Question 16

List 6 differential diagnoses of the acute clinical signs of hypomagnesaemia.

Answer 16

Milk fever
Nervous ketosis (acetonaemia)
Acute listeriosis
BSE
Acute Lead Poisoning
Stray voltage

Question 17

How should you treat hypomagnesaemia?

Answer 17

Give 400ml of 20% calcium with magnesium hypophosphite slowly IV followed by 200ml 25% magnesium sulphate SC

Question 18

What are the two methods of prevention of hypomagnesaemia?

Answer 18

Fertiliser usage
Magnesium supplementation

Question 19

List 8 ways to supplement cattle’s magnesium levels.

Answer 19

Concentrates
Mg bullets
Medicated drinking water
Free access licks
Application of calcined magnesite to pasture
Sprinkling calcined magnesite on silage
Improve Mg content of sward
Buffer feeding