Poultry Flashcards
What are the main energy and protein sources used within the poultry industry?
Energy - maize, sorghum, wheat, barley, fats and oils.
Protein - soybean meal, canola meal, corn gluten meal, cottonseed meal, meat meal and fish meal.
True or false, poultry completely depend upon the dietary sources for all nutrients?
True
What energy basis are poultry rations calculated on?
ME
When fed free choice, what do chooks do?
Eat to satisfy their energy needs.
What kind of feeding space should chickens be supplied with?
1inch feeder space/chick for 2weeks of age.
2 inches after that.
How much water do poultry consume?
Twice as much water by weight of feed consumed.
What are some standard chook rations?
Starter diet - up to 6weeks of age.
Layer starter - 20% protein, encourages egg production.
Broiler starter - 22-24% protein, encourages rapid growth.
Grower pullet - 6 to 14weeks
Layers - 18% protein
Developer/finisher pullet rations - 15-22weeks
Adult layer - 22weeks onwards, 16-18% protein.
What is the aim of egg laying nutrition?
Grow slowly enough to develop good strong bones and to reach a normal body weight before they begin producing eggs.
Get them to grow without too much fat.
What are some considerations when formulating broiler rations for broiler hybrids?
Grow extremely quickly, require precise diets.
After 1st 6 weeks need 18-20% protein until butchered.
Should not contain antibiotics or meat residues.
What are some considerations when formulating broiler rations for traditional and free-range meat birds?
Grow more slowly and add less muscle - longer time to slaughter weight.
After 1st 6 weeks do 18-20% protein then go to 16% protein at 12weeks until slaughter.
What is the standard lifespan of an egg producing hen?
15months
Begin producing at 22weeks, peak at 28-30weeks then gradually decline.
Why are more eggs layer over summer?
Increased light -> increased feed intake -> increased stimulation of pituitary gland -> increased eggs laid.
Discuss egg shell quality.
Major economic concern to commercial egg producers.
Serious economic losses due to levels of downgraded eggs (6-20%).
Affected by levels of vitamin D, Ca, P (deficiency can decrease shell thickness and misshapen eggs).
Low Mn causes thin and brittle shells.
Blood CaCO3 is the source of Ca in shell formation.
Hot weather increases respiration rate and increases CO2 loss - this decreases blood bicarb levels and decreases egg shell formation.
Sulphonamide drugs - decrease quality
Insecticides/fungicides - malformed eggs.
Rancid cod liver oil in diet - rough shells.
Diseases - poor quality shells.
Why does egg shell quality decrease at the end of the laying period?
Failure in Ca metabolism and decreased Ca of ration - poor egg shell quality.
What is the primary energy source for poultry in Australia? What are some problems that can be associated with this and how can they be addressed?
Wheat
Up to 80% of diet for finishing broilers.
Increased NSC (pentosans) - can absorb 10x their weight in water and so decrease overall diet digestibility.
Produce high-moisture manure
Address by adding NSP (non-starch polysaccharides)-degrading enzymes - this reduces viscosity and improves nutrient availability and growth.
Xylanase can also be added to aid in breakdown of outer husks (Structural CHO) - improves feed:grain ratio.
Biotin - limited bioavailabilty in wheat (less than 15%).
What are the implications of feeding processed wheat?
Finely ground wheat can lead to beak impaction - decreases feeding activity and provides a site for mould and mycotoxin development.
Feeding whole wheat may control coccidiosis and stimulates gizzard and gastric motility, promotes acidic environment to decrease oocyte viability.
Can barley be fed to poultry? What are the advantages/disadvantages of this?
Yes - medium energy and protein.
Starch content 52-60%
Contains Beta-glucans bind with water, increasing viscosity of intestinal contents, leads to poor digestion and absorption of nutrients as it reduces mixing of intestinal contents and alters transport properties of nutrients at the mucous surface.
Negatively affects intestinal morphology and decreases endogenous enzyme activity.
Add synthetic beta-glucanase enzymes to diets contain >15-20% barley.
Contains trypsin inhibitor - issues with sequestering arginine (essential AA).
Poor source of P - 60-80% bound as phytate.
Discuss the feeding of maize/corn to poultry.
Preferred energy grain globally.
High energy, low fibre, pigments (increase yellow colour of yolk).
At high inclusion levels (60-70%) provides 30% protein.
Low in lysine and tryptophan - requires supplementing.
Discuss the feeding of sorghum to poultry.
Energy slightly less than maize.
Decreased digestibility due to protein-starch interactions in the endosperm.
Digestibility of protein/AA inferior to other cereal grains - improves with dry heat processing.
Cannot be steam processed - causes toxicity.
Kafirin - major protein, poorly digested and deficient in lysine.
Contains more phenolic compounds and phytate than other cereal grains.
Condensed tannins - present in outer seed coat, interfere with protein availability.
Why feed fats and oils to poultry?
High energy value.
Important source of linoleic acid (omega-6) - only FA for which a requirement has been shown in poultry.
Improves palatability, reduces dustiness.
Minimum 1% added fat, maximum of 3-4% added fat.
All fats and oils need to be treated with an antioxidant.
What types of fats and oils can be fed to poultry?
Fish oil - not to much though as causes an odour in meat and eggs if >1%.
Vege oil - polyunsaturated fats that are ideal for young birds.
Coconut oil/Palm oil - highly saturated, may not be digested in younger birds.
Animal/Vege Blend fats - synergistic effects.
Conjugated linoleic acid (CLA) - isomer of linoleic acid, bioaccumulation in eggs.
Poultry fat - ideal but not economically viable.
