Minerals Flashcards
What are the main functions of minerals?
- constituents of skeleton structures
- maintenance of osmotic pressure
- regulation of acid base balance
- components of enzymes
- activators of enzymes
- components of biological units
What are the main functions of minerals?
- constituents of skeleton structures
- maintenance of osmotic pressure
- regulation of acid base balance
- components of enzymes
- activators of enzymes
- components of biological units
What are the macro-minerals?
> 5g in body
Ca, P, Mg, K, Na, Cl, S
Which minerals are concentrated by plants and why?
Cu, Zn, Fe, Mn, Mb
- mineral by products from industry and manufacturing
Which minerals are concentrated by plants and why?
Cu, Zn, Fe, Mn, Mb
- mineral by products from industry and manufacturing
What minerals are involved in bone metabolism
The most important role of minerals in the horse’s diet is the development in mineralized tissues
Bone in metabolically active tissue and requires:
- supply of Ca and P
- other minerals - F, Mg, Mn, Zn
- osteoblasts, osteoclasts
- calcitonin, parathyroid hormons
What are the micro- minerals
Which minerals are concentrated by plants and why?
Cu, Zn, Fe, Mn, Mb
- mineral by products from industry and manufacturing
Relationship between dietary levels and absorptive efficiency
absorptive efficiency tends to decrease when intake increases
What minerals are involved in bone metabolism
The most important role of minerals in the horse’s diet is the development in mineralized tissues
Bone in metabolically active tissue and requires:
- supply of Ca and P
- other minerals - F, Mg, Mn, Zn
- osteoblasts, osteoclasts
- calcitonin, parathyroid hormons
What happens to bone resorption during times of physiological stress?
The skeleton maintains structural integrity and regulates calcium homeostasis –> bone can be resorbed and remodelled
What are the functions of calcium?
Structural function - bone crystals = hydroxyapatite
- 99% in bone/teeth
= 1% found in soft tissues where it is involved in muscular activity, blood clotting, hormone secretion and enzyme activation
- Ca:P in bone = 2:1
What is the result of calcium deficiency?
Although horses are good at recognizing some deficiencies (Na) they are not good at recognizing Ca
- rickets
- osteomalacia (in mature animals)
- nutritional secondary hyperparathyroidism
- lactating mares –> decrease milk production (but Ca and P remain the same)
What hormone regulates calcium concentrations?
PTH
- maintains calcium homeostasis in blood
- mediated by vitamin D (calcitriol)
- PTH + calcitriol act on the bone and kidneys to maintain plasma Ca levels
low Ca –> parathyroid –> calcitriol –> Ca binding protein –> Ca reabsorption + absorption
Where does Ca absorption occur?
small intestine
- passive and facilitated diffusion
Ca absorption efficiency varies with:
- age (70% in young, 50% in mature)
- diet (low Ca increases absorption; high P binds Ca)
- stage of training
- stages of gestation/lactation
What is the result of calcium deficiency?
Although horses are good at recognizing some deficiencies (Na) they are not good at recognizing Ca
- rickets
- osteomalacia (in mature animals)
- nutritional secondary hyperparathyroidism
What is rickets?
- failure of vascular invasion and mineralization in the area of calcification of the physis
- bone pain, stiff gait, swelling in the area of the metaphyses, difficulty rising, bowed limbs, pathologic fractures
What is nutritional secondary hyperparathyroidism?
AKA Miller’s Disease, Bran Disease or Big Head Syndrome
- results from excess P
- lameness
- enlarged facial bone –> fibrous connective tissue invades area where bone was resorbed
- P binds to Ca –> Ca from bone is resorbed to compensate for deficiency
Calcium toxicity
- high dietary Ca levels interfere with absorption of other minerals (e.g. P, Mg, Mn, Zn)
- brittle bones
- horses can handle high calcium levels (up to 7:1)