Chicken Exam 3

ratio of Ca:P in soft tissues and bones

Soft tissues: 1%Ca, 20% P

bones: 99%Ca, 80% P

name of Ca and P crystal and ratio in bones

hydroxyapatite crystal

2:1 ratio in bones

three roles of Ca in the body

muscle contraction, blood clotting, bone structure

three roles of P in the body

phospholipids, secondary messengers, high energy phosphate bonds

three hormones regulating Ca and P homeostasis

PTH, calcitriol, calcitonin

three benefits of utilizing low phytate grains or phytase enzyme

reduced pollution from P in environment

increases bioavailability in plant matter

improves bon strength and Feed:gain ratio

most important consideration for enzyme companies with phytase enzyme in pelleting

thermostability

high heat can denature the enzyme

how does the body increase Ca level when blood Ca is low

low Ca levels trigger PTH release which increases bone resorption and renal reabsorption of Ca while inhibiting resorption of P. PTH signals calcitriol to start GI absorption of Ca and P and PTH also tells the kidneys to sort out P and excrete it while holding on to Ca. This raises both Ca and P in the blood which signals the body to stop producing PTH.

net effect of PTH on serum Ca and P

increase serum Ca

decrease serum Pne

net effect of calcitriol on serum Ca and P

increases both serum Ca and P

three bone disorders related to Ca and P

rickets, osteoporosis, secondary nutritional hyperparathyroidism

major causes of osteoporosis in laying hens

genetic selection for small body weight, early egg production, and high egg production

suboptimal bone growth in early egg production

limited physical activity

three strategies to reduce osteoporosis risk in laying hens

larger particle size

well balanced diets

activity and movement

Ca supplement in poultry diet

oyster shell or calcium carbonate

P supplement in poultry diet

monosodium phosphate or disodium phosphate

supplements for both Ca and P in poultry diet

dicalcium phosphate or bone meal

distributions of Mg in bones, soft tissues, and blood

bones: 50%

soft tissues: 40%

blood: 10%

75% of Mg in an egg is in the shell

three functions of Mg

normal skeletal development

oxidative phosphorylation in mitochrondria, ATP production

activation of enzymes

Mg deficiency in chickens

calcification and necrosis of kidney

major electrolytes in poultry diets

sodium, potassim, chloride

why is electrolyte balance in the body important

regulates water balance in ECF and ICF and acid base balance because enzymes need a constant pH to function normally

major electrolyte in ECF

Na in plasma and interstitial fluids

also Clm

major electrolyte in ICF

potassium in muscle and nerve cells

sodium potassium pump powered by ATP is how

the body regulates electrolyte concentration

optimum electrolyte valye in poultry diet

250 mEq

what happens in poultry diets have electrolyte imbalance

poor growth and appetite

impaired health status (leg abnormalities)

respsonse to thermal stress (thin eggshell)

impaired nutrient metabolism

sulfur needed int he diets for

synthesis of sulfur AAs and vitamins via microbes

synthesis of collagen and mucopolysaccharides

three suflur sources

sulfur AA in non ruminants

organic and inorganic sulfur compounds

sulfated forms of minerals

water

why does the body need iodine what is one disorder

constituent of thyroxin in the thyroid gland

goiter

idodine deficiency symptoms

dry skin and brittle hair

goiter

repro issues

reduced growth

roles of Zn in the body

constituent of numerous metalloenzymes