Nutrition chp14

Why are energy requirements for poultry expressed in ME rather than DE whereas for swine, both are used?

Poultry excrete both feces and urine from a common opening, the cloaca => difficult to measure the gross energy of feces alone.

=> energy requirements for poultry are expressed as metabolizable energy (ME) rather than digestible energy (DE). -

ME:

• takes into account the energy lost through urine and gasses produced during digestion

  => more accurate measure of the energy available for the bird's metabolism.

Swine excrete feces and urine separately = measurement of DE using only feces or urine.

However, ME is still used in swine nutrition to provide a more precise estimate of the energy available for growth and production.

definitions

me;
amt of energy in the diet that dose not appear in faeces, uring or gas exprressed as MJ/kg

de; amount of energy in the diet that does not appear in faeces, expressed as MJ/Kg DM

• common method of expressing energy valuve of feeds for pigs

What types of diets would generally be supplemented with xanthophyll source?

Xanthophylls added to layer diets to enhance the yellow pigment of egg yolks, which is preferred by consumers.

Xanthophylls:

• red and yellow carotenoid pigments

• Sources: marigold petal meal , alfalfa , yellow corn

• no nutritional value only source of pigment- (may stimulate the immune system)

Synthetic xanthophylls, such as canthaxanthin are also used as pigmenting agents.

Aflatoxin contamination of feeds impair xanthophyll absorption

= pale bird syndrome.

not present in sufficient quantities in poultry diets to achieve the desired effect on egg yolk color.

How are the nutritional requirements of turkeys different from those of broiler chickens?

-Broiler Chickens:

• Raised for meat.

• Nutrient-rich diet required to meet genetic potential of rapid growth

• The 2-stage system is used with a starter and finisher diet.

• free feed access to ensure maximum growth rate.

• Coccidiostats - added to control coccidiosis.

• Diets are usually fed as mash and crumbles.

• High Ca requirements for laying hens.

Turkeys:

• Have a much higher protein requirement than chickens in the first 4 weeks:

• Starter diet 0-4 weeks

• 28% CP decreased to 14% and fat fed towards market weight.

• Reduce protein content by 2% each 4 weeks.

• High Ca and K requirements for turkeys.

• Amount of fat-soluble vitamin requirements is more than twice that of broilers

• Zn requirements are almost double for turkeys but decrease gradually as birds grow, while for broilers, it is maintained at the same level.

(shortened question) If you feed newly hatched emu chicks turkey feed they will obtain leg problems with weakness and deformities after a few weeks. Why? How could this be prevented in the future?

weakness → birds gain too much weight too quickly.

prevented by:

• letting the birds eat the turkey starter diet with at least 26% protein for 30 mins twice a day

• for the rest of the day have free access to alfalfa pellets at 3 weeks old until 8 weeks old, then they can go over to a turkey grower diet instead.

(shortened question) If ducklings are fed only cracked wheat, what deficiencies and symptoms would you expect them to have? How could the problem be solved?

(not sure)

Leg weakness could be a problem due to rapid growth rate

Vitamin requirements are higher in waterfowl so could be deficient in these

Supplement with choline and niacin

What causes perosis in avian species and how can it be prevented?

- Perosis (slipped tendon)

→ choline or manganese deficiency.

→ some extent biotin , niacin , B6 , and folic acid.

Perosis is a condition where the tendons that hold the bird's hock joint in place become weak, leading to joint deformities and lameness

Poultry have a higher requirement for manganese:

→ high dietary calcium levels

→ high levels of iron

reduce manganese absorption.

Providing water containing vitamin supplements can aid in the prevention of perosis.