Poultry Nutrition Flashcards
Major components of poultry diet
Feed grains
- 60% of diet
- Energy
- Wheat (most popular) & sorghum
Protein meals
- 30% of diet
- Soybean (expensive because imported) and canola meal (less expensive but has anti-nutritional factors like tannins & phytase)
- Other meals: peas, lupines, meat & bone meal
Fats & oils
- 4-5%
- Energy
- Vegetable, soy, canola oil or poultry tallow
Minor components of poultry diet
Limestone (calcium)
Salt and sodium bicarbonate
Enzymes (phytase/carbohydrases) – supplement endogenous enzymes in body to break down food
Synthetic amino acids e.g. methionine (limiting amino acid)
Vitamin and mineral premix
Antibiotics – being phased out
Canola meal as alternative to expensive soybean meal
Canola meal good source of protein with a decent
amino acid profile
Plenty grown in Australia
Can be included in broiler diets although usually
limited due to concern of anti-nutritional factors;
tannins, phytate, sinapine
new varieties have lower levels of these antinutritional
factors and so with further development
we can increase usage of canola meal – reduce
dependency on SBM (expensive, imported)
3 types of poultry feed
Pelleted feeds:
- Concentrates of high quality grain
- Vitamins and minerals added
Crumbles:
- Pellets are broken, making it easier to eat
- Baby chicks
Mash:
- Crumbles finely mashed to make a meal
- Fed to layers to lower intake (layers are kept at maintenance weight)
Poultry - whole grain feeding
Done to increase gizzard weight to improve energy utilization and feed conversion ratio. Also increases gut health because eats more quickly and slowly digested in crop
Bird - gizzard function
Needed to grind up
and mechanically digest food
Bird - crop
A feed storage organ
Allows lots of feed to be eaten quickly (cropping up)
and then stored to be digested later
A small amount of feed is gradually released from the
crop into the proventriculus and gizzard
Bird - Proventriculus
True stomach
Bird - Gizzard
Muscular grinding organ
Located after the proventriculus
(true stomach)
Described as the ‘pace-maker’
of gut motility
Intent of whole grain feeding regimes (poultry)
Increased gizzard
weights and an improved digestive efficiency
Enhanced energy utilisation and feed conversion
Poultry - reverse peristalsis
Intestines push food back up
What is Australia’s first preference in meat ?
Chicken
Broiler growth
Broilers grow from 40 g day-old
chicks to 3 kg birds in 42 days
Poultry nutrition at hatching
Yolk sack provides nutrients after hatching but absorbed after 3 days
Have a very small digestive tract at birth and grows quickly – important to get them to eat and drink quickly and provide high quality digestible feed
Poultry - water intake
Important – won’t eat if no water
Needs to be cool & easily accessed (wont drink warm water)
Water intake can double under hot conditions
First limiting amino acid in poultry
Insufficient amount in cereal grains and soybean
meal to meet requirements for growth
Insufficient supply will lead to suboptimal
performance
Insufficient methionine intake can lead to
accumulation of fat on the carcass
Supplementation with synthetic methionine will
ensure requirements are met
Lysine also supplemented
How crude protein requirements change with age (poultry)?
Reduces with age
How oil requirements change with age (poultry)
Increases with age
Crude fiber requirements change with age
No remain the same
Nutrition of layer hen
Feed efficiency: 2.1
Egg numbers = 300 eggs per year
Calcium & phosphorous higher - critical for egg production
- Increases with age
Methionine contributes to egg size
Less protein and energy (maintenance)
Egg size
Eggs will increase in weight with hen age
Also influenced by:
- environment
- diet:methionine
- lighting
Moulting (layer hens)
Shedding of old feathers to grow new
Occurs once a year
Hens stop laying eggs for a month
Induced when production drops by manipulating the lighting – helps to boost production
Can be induced by less feed, dietary changes or hormones
3 laying periods with moults in between then culled (140 weeks)
