Lecture 12 Flashcards
Where is phosphorus found in the body?
80-85% is in the skeleton. The remainder is found in either soft tissue or in fluids.
Where is phosphorous absorbed from and what is the uptake driven by?
Phosphorous is absorbed within the small intestine it’s uptake is driven by Vitamin D/calcitriol.
What are good dietary sources of phosphorous?
- milk
- cereal grains
- animal by-products
What are poor dietary sources of phosphorous?
- hays and straws
How available is phytates phosphorus?
Phytates phosphorous is very poorly available
What are the general deficiency signs that are observed with phosphorous?
Generally same as the calcium deficiency signs and also pica (a depraved appetite)
What are the clinical signs associated with an excess of phosphorous and Mg?
bladder stones/urinary crystals are often observed
Where is magnesium found within the body?
70% in skeleton 25% in muscles 4% in cells 1% in extracellular space all have important roles in enzyme activation
What dietary factors lead to a decrease in absorption of magnesium?
- Absorption is decreased by high potassium
- Absorption is decreased by high Ca and P
- Absorption is decreased by oxalates and phytates
What are some good dietary sources of magnesium?
good sources: cereal bran, dried yeast, milk
variable: grasses and forage crops
What are the common clinical signs of a magnesium deficiency?
- Anorexia and reduced weight gain
2. Hypomagnesaemic tetany
How is hypomagnesemia treated?
Treated with the use of magnesium salts, these are often combined with Ca salts.
What are the risk factors for hypomagesemia?
- High K
- Low Na
- Low Na:K
- High crude protein
- Low Fermentable CHO
- Low NDF/short rumen transit time
- High lipid/fatty acids
- No Mg supplement
How can Mg be supplemented in the diet?
- With the use of magnesium oxide or magnesium sulfate
2. Use of Mg-rich fertiliser on pasture
What are the vitamers for Vitamin A?
Retinoids
What sources can Vitamin A be derived from?
Pre-formed vitamin A = animal tissues and animal products
Pro-Vitamin A (carotenoids) = = plants
Synthetic vitamin A = supplements
How many molecules of Vitamin A can be made for one molecule of B-carotene?
1 molecule of B-carotene = 2 molecules of Vitamin A
What are the functions of Vitamin A?
- Vision
- Epithelial cell differentiation
- Growth
- Reproduction
- Immune response and healing
What is the effects of chronic Vitamin A toxicity?
- Anorexia, weight loss
- Skin thickening, scaly dermatitis
- Deforming cervical spondylosis in cats
Where is Vitamin K found?
Vitamin K1 = fresh, green, leafy plants
Vitamin K2 = Bacteria in the GIT
Vitamin K3 = supplements
What is the function of Vitamin K?
coagulation
When do Vitamin K deficiencies occur?
- Extended use of antibiotics
- prevention of coprophagy
- Pancreatic insufficiency and fat malabsorption
- Genetic abnormality
- Vitamin E supplements
What are common Vitamin K antagonists and inhibitors?
- Dicoumarol - Vitamin K antagonist
- Mycotoxins - Aspergillum in weather damaged hay
- Warfarin
- Vitamin E
Evaluate the possibility of Vitamin K toxicity:
1000 times dietary daily needed for toxicity.
