1. Poultry Nutrition

2. Contents Digestive System Feed intake factors
- Structure of digestive tract
- Functions of digestive tract
Nutrition requirements of poultry
Energy, protein, vitamins & minerals
Importance of water
Feed 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. Structure of digestive tract

7. 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.

8. 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.

9. 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.
Most alternative protein crops that could be grown in UK contain more significant anti-nutritional factors that severely limits the proportion that could be included in poultry feed in place of soybean meal.

10. 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

11. 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

12. 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

13. 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)

14. The ceaca 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 hours
It is fastest in growing and laying chickens

15. Nutrient Requirements of Poultry

16. 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

17. 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

18. 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)

19. 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

20. 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

21. Nutrient Requirements of Poultry 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 hatchability
Source – 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).

22. SEE HANDOUTS FOR CALCULATIONS
Calculation of Nutrient Requirements
Energy
Amino acids
SEE HANDOUTS FOR CALCULATIONS

23. 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

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

25. Drinker Management Check position and height of drinkers
Check drinkers for water daily (nipple drinkers can be dry
without you noticing)
Leaky drinkers create wet litter – management problem
Protect pipes from freezing
Clean and disinfect water
equipment between crops
Nipple drinker
Bell drinker

26. 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
Granular can be included in vitamin/mineral premix
Heat conditioning during pelleting damages enzymes, so must be added afterwards
Benefits efficiency of feed utilisation
Can partially act as a replacement for antibiotic growth enhancers (all are now banned in EU since Jan 2006)

27. 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

28. 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)

29. Feed equipment Type of feeder Pan feeder Chain feeder (“trough” type)
Look up suppliers of poultry
equipment

30. 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

31. 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

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

33. 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!!!

34. A few notes on diets Cereals usually make up 50-75% of a poultry diet
Cereals supply a high proportion of starch (the lowest cost form of dietary energy)
Cereals may supply up to 50% of the protein required, however the quality is poorer (deficient in essential amino acids), so oilseed meals (e.g. soya-bean ≈ 50%CP) and fishmeal are used as protein concentrates
Max inclusion rate for fat (source of energy) is 6%
Above this level feed is sticky (machinery can’t work with it) and it can be difficult to form hard pellets

35. Feeding plan Layers

36. Feeding plan Broilers

37. “Grain Balancer Rations”
A technique that can be used for poultry is the addition of whole wheat to the diet
e.g. Broilers
when fed at up to 30% of diet it costs 3.5p less to rear a broiler to 49 days, with no loss of feed efficiency
makes a cheaper ration, can be scattered on floor to occupy the birds, but need separate storage bin

38. Mycotoxins as contaminants of feed
Mycotoxins are the toxic metabolites of fungi
Over 200 types are known
Responsible for significant financial loss to the poultry industry
decreased growth rate, food conversion efficiency, livability, reproductive potential
Feed importers may test deliveries for presence of mould, silos should be cleaned regularly
Feed additive – look up “Mycosorb”

39. Welfare Codes
Feed & Water Provision
SEE HANDOUT

40. The condition of the droppings is a good guide to state of health
Wet droppings
Nutritional abnormality or general infection
Green droppings
Liver (bile) disorder
White droppings
Kidney infection
Red droppings
Indicate presence of blood – may be due to coccidiosis or an acute bacterial infection

41. Conclusions
You just never know when these lecture notes may come in handy... livestock feed companies and nutrition companies are a major employer of Ag graduates.
Total deliveries of feed compound and other processed animal feedstuffs by NI feedstuffs manufacturers in 2012
Total deliveries –
(in Thousand Tonnes)
All cattle (beef, dairy and calves)
1190.6
Poultry
692.8
Pig
165.4
Sheep 75
NI Animal Feed Statistics 2012, DARD