Poultry nutrition

1. POULTRY NUTRITION

2. CONTENTS
Digestive System
 Structure of digestive tract
Functions of digestive tract
Nutrition requirements of poultry
Energy, proteins, vitamins and minerals
Importance of waterFeed intake factors
Feed form - pellet v/s mash
Diet formulation
- Rations for broilers
 Rations for layers
Odds n ends
Welfare codes

3.  Feed accounts for over 70% of the cost of
producing poultry meat and over 60% of egg
production costs.
The poultry digestive system is relatively
simple and short, but extremely efficient.

4. Food Conversion
Poultry are extremely efficient feed
converters.
There have been huge advances made
through selective breeding.
Example:-
• Broiler food conversion is 1.7 (it takes 1.7kgs
of feed to put on 1kg of body weight gain)

5. Structure of digestive tract

6. Digestion
Digestion - The process of breaking down
complex nutrients into a simpler organic
compounds, so they can pass through the
membrane of the gut into the blood
(absorption).
The digestive tract is the “tube” which
extends from the mouth to the cloaca / anus
and is lined with mucus membrane.
Process in digestion may be grouped as –
mechanical, chemical and microbial.

7. Digestion in Poultry
Poultry have a monogastric digestive system.
In poultry the digestive tract differs from
mammals in a number of ways.
In poultry the lips and the cheeks are
replaced by the beak and teeth are absent
(do have tongue) but no chewing of food.
Food is coated with saliva in the mouth and
passes down the oesophagus.

8. Sustainable food
Poultry meat is the most environmentally
efficient of all meat proteins.
Improvements in poultry production yields and
efficiency have resulted in major environmental
benefits and reduced some land use change
impacts.
Poultry meat consumption contributes just 1%
of total UK greenhouse gas emissions.
Soybean meal is the most nutritionally and
environmentally efficient protein crop for
inclusion in poultry feed and other livestock
feeds globally.

9. Crop-
• a diversion of the oesophagus
• pear- shaped sack
• function to store food
• filled and emptied by peristalsis
• Food can by-pass the crop when lower parts of
the digestive tract are empty
Salivary amylase continues to act on starch
Mainly lactobacilli adhere to the crop wall –
microbial fermentation products are lactic and
acetic acids

10. Proventriculus or “glandular stomach”
• produces hydrochloric acid and pepsinogen (enzymes)
• Minimal “own” movement – so food passes through
quickly by oesophageal contractions
• Gizzard
• Muscular organ, with internal ridges, and a hard internal surface
• Rhythmic contractions to grind food with moisture into a smooth
paste (i.e. mechanical digestion)
• Presence of grit in the gizzard (although not essential) has been
shown to increase the breakdown of whole grains by 10%
• Proteolysis occurs in the gizzard.
 Thus the proventriculus and gizzard are equivalent in
function to the mammalian stomach

11. When ground sufficiently small, digest-a pass
into small intestine
Reflux between gizzard and intestine can occur
Pancreatic juice containing enzymes and bile
flows into the small intestine (for digestion of
proteins, fats and carbohydrates)
The small intestine is where most of the
breakdown of food occurs and the nutrients are
absorbed (major absorptive site is at the
jejunum)
Surface specially adapted for absorption by
folding and the presence of villi

12.  Caeca
• 2 long blind sacs where the small intestine joins the
large intestine
• Function as absorptive organs
• Not essential organs (as surgical removal causes no
harmful effects)
• Cellulose-digesting bacteria on surface mix with
digest-a by peristalsis, this leads to fermentation,
with the production of volatile fatty acids (VFAs)
• Experiments with poultry have shown that cellulose
in cereal grains is not broken down by microbial
activity to a great extent (so it is unlikely that the
VFAs contribute much to satisfying the energy
requirements of poultry)

13. • The caeca are emptied by peristalsis into the
relatively short colon (or “large intestine”)
• Main function of the colon is to transport digest-a
to its termination at the cloaca
• Faeces and urine are excreted together from the
cloaca
• the cloaca combines the function of the rectum and
bladder
• Overall passage of food through the digestive
system ranges from 2-24 hoursIt is fastest in
growing and laying chickens

14. Nutrient
Requirements of
Poultry

15. Nutrient Requirements of Poultry
INTRODUCTION
Housed livestock are entirely dependent on
their compound feed containing the correct
amounts & proportions of nutrients
They have no access to herbage or soil, or
sunlight

16. Nutrient Requirements of Poultry
ENERGY
Energy is assessed using the Metabolisable
Energy (ME) system
• Energy is first used for maintenance of normal
body functions
• Amounts above this are used for production, i.e.
eggs or growth
• Excessive energy supply leads to undesirable fat
deposition
• ME content of rations generally in the range
MJ/ME/kg

17. Nutrient Requirements of Poultry
PROTEIN
 Protein is required for body development in growing birds, and a
good proportion is also required by layers as eggs contain 13-14%
protein
 Protein Quality
• 2 most important amino acids are lysine & methionine (L&M).
• Cereals (wheat, maize) are a poor source of the correct amino
acids
• Soya bean is the best vegetable protein source (although poor for
meth, so cannot be used as the only source)
• Animal protein (fishmeal) is the richest source of L&M
• Synthetic amino acids are added to feeds to improve protein
quality
• Sunflower meal is high in methionine (but high fibre content limits
its use)

18. Nutrient Requirements of Poultry VITAMINS
• Sources of vitamins may be naturally occurring, or synthetic
forms
Vitamin Function Source
A Growth, resistance to
disease
Green veg, maize, fish liver
oil, synthetic
D(in the form of D3 ) Utilises Ca & P properly –
vital for bone and egg shell
Sunlight, fish liver oil,
synthetic
E Deficiency affects nervous
system, also for hatching
eggs
Cereals, Will be destroyed by
bad storage or overheating
K Blood clotting (deficiency =
haemorrhaging
Green foods, Lucerne meal,
synthetic
B group (incl. Biotin, Choline
& folic Acid)
Optimum growth,
metabolism of
carbohydrates, feathering,
hatchability, red blood cells,
biotin prevents fatty liver
syndrome.
Cereals, synthetic

19. Nutrient Requirements of Poultry MINERALS
Calcium and phosphorus
• Necessary for bone formation (assoc. with leg
weakness) and egg shell
• Calcium to phosphorus ratio should be 2:1
• Animal derivatives are the richest in calcium when
compared to plant sources, although all foods have
some calcium content
• Phosphorus in cereals may be in a form that is poorly
absorbed, so supplements may be needed
• Absorption of Ca & P requires vitamin D3 and
manganese
• Di-calcium phosphate or fishmeal can be added to the
diet as an extra source

20. Nutrient Requirements of Poultry Minerals
MINERALS FUNCTIONS
Manganese Involved with calcium metabolism
Good hatchability of eggs
Shell strength
To promote bone formation
Source – Wheat, Limestone and
manganese sulphate
Iron, Copper and Cobalt Essential for formation of haemoglobin
Iodine Associated with poor hatchabilitySource –
usual feeds but especially fishmeal
Common salt (sodium chloride) Essential for protein digestion
Excess salt causes thirst and wet
droppings (max 0.5% in diet)
Excess or deficiency seriously affects
productivity (both growth and egg
production).

21. Calculation of Nutrient
Requirements
• Energy
• Amino acids
SEE HANDOUTS FOR CALCULATIONS

22. Water
 Access to fresh clean water at all times is absolutely
essential in intensive livestock production systems
• poultry must have a constant water supply to maintain
efficient production
• Young chicks or birds in hot weather can die in only a few
hours if water is absent
 Water consumption of the flock should be
monitored and recorded daily
 A change in water consumption is a crucial early
indicator of a health problem, or heat stress

23. Approx. Daily water consumption
• Water consumption increases with
bodyweight (i.e. age)
• SEE HANDOUT - TABLE OF BROILER WATER
CONSUMPTION

24. Drinker Management
• Check position and height of drinkers
• Check drinkers for water daily (nipple drinkers can be
drywithout you noticing)
• Leaky drinkers create wet litter – management problem
• Protect pipes from freezing
• Clean and disinfect water equipment between crops
Bell drinker Nipple drinker

25. Feed Enzymes
Incorporated into poultry diets for the
following reasons:
 Enzymes act on cereal proteins within the bird’s digestive
tract, complementing the bird’s own digestive enzymes
 Safe, non-toxic to man, no harmful residues
 Granular or liquid forms
o Granular can be included in vitamin/mineral premix
o Heat conditioning during pelleting damages enzymes, so
must be added afterwards
o Benefits efficiency of feed utilisation
o Can partially act as a replacement for antibiotic growth
enhancers (all are now banned in EU since Jan 2006)

26. Factors affecting feed intake
 The energy concentration of the ration is an
important characteristic, because if it is
increased/decreased poultry will tend to adjust their
intakes to provide a constant energy intake.
 Appetite is influenced by contractions of an empty
crop (physical receptors)
 Layers have a specific appetite for calcium
 Poultry seem to have the ability to select for a
balanced diet (i.e. meet their energy and protein
requirements) when offered a range of feeds
 Learn food preferences from previous experiences

27. Factors affecting feed intake
Physical form of food: Pellet v mash, fine
particles in the feed
Environment – temperature, humidity,
ventilation, light
Equipment
• feed space per bird,
• trough position - base height level with
bird’s back (reduces spillage)

28. Feed equipment
Type of feeder
• Pan feeder
• Chain feeder (“trough” type)
 Look up suppliers of poultry equipment
 www.bigdutchman.com

29. Practical Feeding
 Layers and broilers generally fed ad-lib
 Broilers generally fed “starter”, “grower” & “finisher”
rations
 However, broiler breeders are restricted on low energy
and protein diets, to control bodyweight (as fast growth is
undesirable)
 Broilers fed crumbs (smaller pellets) for chicks, then
pellets. Layers usually fed mash (coarse ground grains)
 Poultry rations are complex – so few farms mix their own
diets, and also the competitiveness of feed companies
ensures lowest possible cost.
 Farms must follow the detailed programme suggested by
the breeding companies for their own strain of birds

30. Feeding
SEE HANDOUTS – nutrient requirements
• Note – in poultry diets there must be a
correct ratio between metabolisable energy
(kcal/kg) and crude protein of the diet, which
varies depending on age or type of bird
• 1 MJ = 240 kcal (kilo-calorie), and 1 kcal =
1000 calories

31. Diet Formulation
Necessary to have all info so far + up to date
costs of ingredients
A diet has to be formulated that is:
a) of minimal (or, at least, favourable) cost
b) satisfies all the nutrient standards given
c) Stays between the min & max inclusion
rates for any ingredients
d) Represents uniform content throughout
batches

32. Diet Formulation
• Because the possible range of ingredients is
so large, an enormous number of calculations
are involved in working out all the options
• Feed companies will use computer software
to do this efficiently and quickly!!!