Bacterial and Protozoal Intestinal Disease in Commercial Poultry Flashcards
What is poultry metabolism like compared to mammals?
Metabolism is high compared to mammalian species due to energy demands of flight and the GI tract is relatively short with a low volume to keep weight low
What are some considerations when thinking about poultry litter management?
- What type of litter is typically used in a broiler house?
- Amount of litter-how deep is his litter spread?
- Ventilation-what control do producers have over ventilation?
- Leaks from house / drinkers
- Temperatures-what temperature would you run a house for 25 day old broilers?
What are some desirable traits for litter for poultry?
- Absorbant
- Biodegradable
- Minimal dust
- Bio-secure source
- Pure source
- Comfortable
- Affordable
- Concrete floors underneath for more effective biosecurity and litter management
When is enteritis seen most commonly in chicks?
Enteritis is seen around 24-25 days old, when chicks are just over 1kg in BW
What type of litter is typically used in a broiler house?
What about commercial turkey and duck?
Majority are on wood shavings – good absorbent substrate but varies in price
Chopped paper, rice husks, grass, chopped straw can also be used
Commercial turkeys and ducks – hopped straw as high requirement for bedding, so wood shavings is too expensive
How much litter should there be in a broiler house?
How does this change?
When they first go in – only a couple of centimetres, houses are heated
Want droppings to hit the litter – want composting of the faecal material mixing in with the shavings to produce a deep litter so by the time they are caught up at 40 days – there should be a deep litter, composting.
Can top up shavings if need to – but extra cost, try to get it running efficiently
Why does litter become wet?
In simplest terms moisture / water in the litter
- Water from drinkers
- Water from environment
- Water from birds-possibly exacerbated by disease
Once depopulated, what happens to the litter?
- Colossal amount of it!
- Can be sold as compost in garden centers – small amount of it though
- Most of it is tumped up on arable land that will carry on composting process prior to being used as fertilizer
- Other half is sold to power plants – powers them. Another reason why it has to be kept relatively dry as the powerplant will only pay for littler that is relatively dry, need to burn it to make electricity
Why is poultry litter only used for arable land?
Due to risk of botulism! High risk of carcasses in litter
What are some important points about drinker management in a poultry house - why does litter become wet because of the drinkers?
E.g. heigh, leakage, pressure, temperature?
- water spillage may be an important part of litter deterioration, A key area for workers is how they manage the drinkers
- possible breed effect?
- drinker heights – spillage – want them to reach it and it be able to flow down their neck easily, they cannot lap water – if its at ground level they have to flick it up and swallow it – often has to be changed in height as they grow!
- nipple leakage – damage / limescale – if they have the cups under the nipples, some birds will come along and drink this and it will be warm and contaminated
- water pressure – leakage – birds will under perform if it isn’t high enough pressure as they wont get the right amount of water
- condensation from manifolds/high water flow – insulation important
- Pulling cold water into warm house on a cold day – so water hits the litter
Why does the litter become wet because of the environment - why is early litter maintenance critical?
- Early litter maintenance is critical
- Dry warm concrete prior to applying shavings
- Else direct moistening / condensation
- Litter may be damp before 7 days
- Will lead to pododermatitis / increased coccidial development / increased environmental bacterial and viral challenge
- Dry warm concrete prior to applying shavings
Why does the litter become wet because of the environment - why should we consider the heat source?
Consider heat source
- Most sites used to employ gas brooders or warm air convectors
- Heat not located close to litter
- Produce water
- Now biomass is the most common heat source – huge number of existing broiler sheds have been fitted with these. Can use biomass to make energy. A radiating source of heat – so no moisture produced
- Some sites have underfloor heating – relative inefficient as have underfloor heating, then layer of shavings
What do most broiler sites use now to keep it warm?
- Most sites used to employ gas brooders or warm air convectors:
- Heat not located close to litter
- Produce water
- Now biomass is the most common
heat source – huge number of existing broiler sheds have been fitted with these. Can use biomass to make energy. A radiating source of heat – so no moisture produced
Why does little become wet because of the ventilation?
- Humid air cooled will release moisture
- Difficult in temperate climate
- If humid air is allowed to fall onto cold litter, it will condense
- Air distribution affects bird distribution
- Using a smoke machine allows air movement to be visualised - smoke should be forced in and starts to roll, drop as its cold, picks up heat and moisture, rolls up and is ventilated out of the house
- Relative humidity - want to draw air from outside and create turbulence so cold air drops to floor, then as it heats, it gains moisture and then it ends up getting it out of the house
What is chick paper and what is it used for?
Place on litter and shavings, has feed on it – so they are standing on a floor of food so they cant help but eat it. Also very absorptive to help stop litter from being wet. If too much of it, affects absorptive capacity of it
Why does the litter become wet because of the birds?
- Breed and genetic progression
- Some negative traits developed with regards to leg health – want to stop this
- Nutrition
- Always trying to keep up with genetics and evolving diets to allow them to get as close as possible to genetic potential – but has to be done on a budget! We import cereals and soil – might change and be very difficult with Brexit!
- Gut health / disease
- A lot of endemic viruses and bacteria that can ause gut disease
What is the maximal stocking density for broilers in the UK?
If you have 500 or more conventionally reared meat chickens on your holding you can stock birds at up to 33kg per square metre. You can increase this up to 39kg birds per square metre but there are extra requirements
When stocking above 33kg per square metre you must keep documents in the housing with technical details and information on equipment, including what?
- a plan that shows the dimensions of the surfaces the chickens occupy
- a ventilation plan and target air quality levels (including airflow, air speed and temperature) and details of cooling and heating systems and their location.
- the location and nature of feeding and watering systems (eg automatic or manual, how many feeders, how each is operated)
- alarm and backup systems if any equipment essential for the chickens’ health and wellbeing fails
- floor type and litter normally used
- records of technical inspections of the ventilation and alarm systems
What is the nutrition like for broilers?
- Mineral density
- Be wary of wheat dilution
- Avian anatomy:
- Urinary system as well as gastrointestinal system contributes to dropping consistency
- High levels of vegetable protein
- High wheat dependency in UK
- Be aware that different feeds vary in quality! Which will affect muscle development
How do the colour of chickens vary between the UK and USA and why?
In USA – the colour of chickens is yellow, genetically the same as UK, but yellow because fed corn diet, but in UK they are fed wheat diet.
How does breed and genetic progression play a role in litter quality?
- Different breeds housed in different sheds on same site give consistently different litter quality
- Stocking rate is important but not necessarily a critical feature
- Slow growing breeds used in freedom foods stocking densities vs. use of standard bird at same stocking density
What is the role on enteric disease in broiler house?
- Probably overstated, but can be important
- We commonly see similar gross enteric signs in routine health checks of birds on very good litter, that are attributed to the cause of poor litter in other houses, especially where different breeds are involved
A broiler client reports ‘wet litter’….
What questions do you ask initially?
Have you checked your drinkers? Are they leaking? Does this explain it? What is the ventilation like – is he ventilating the house as best as he can? What vaccinations have they had? Any other signs of disease?
A broiler client reports ‘wet litter’
What recorded information so you want from him?
What vaccinations have they had?
Any other signs of disease?
A broiler client reports ‘wet litter’
What sample do you want from him?
A representative sample for PM
Fresh euthanised birds – not the best ones! The ones you think are the cause of the wet litter
Label the following
What is your diagnosis?
What is the problem with gut health and disease in broiler houses?
- Is always multifactorial and is poorly understood
- protozoal / bacterial / viral mix
- Bacteria / viruses often non-pathogenic, but driven to overgrowth by environmental conditions
- We commonly monitor “enteritis” developing as a result of poor environment, not the cause
- Good chance other things going on also, and with coccidia, likely there is also bacterial infection also
What is Dysbacteriosis?
An upset in the balance of the bacteria in the bird’s gut that results in diarrhoea leading to wet litter and poor performance
All lagging as when manifested it’s too late to take corrective actions
What kind or organism is clostridium perfringens?
Where is it present?
•Ubiquitous organism
- Present in the intestines & environment
- Where there are chickens, there will be Cp
What does uncontrolled growth of clostridium perfringens lead to?
- Uncontrolled growth leads to intestinal integrity disruption. Cp await an opportunity to flourish
- e.g. coccidial challenge, immunological stress (vaccine)
- Fast proliferating organism:
- In 1 hour it can multiply from 1million to 64 million organisms under ideal conditions
When is likely the only time we see clostridial enteritis in broiler chickens in the EU?
Growth promoters removed from poultry feeds in EU. Only time we see Clostridial Enteritis in broiler chickens is when new season wheat starts to be blended into feed – quite different in consistency to previous season. If CE very severe, will also get liver damage as well – turns into VPH issue here – as then get Cholangiohepatitis as then there are liver and whole bird rejects
Name some Eimeria species from the chicken
What is the procedure of anticoccidial sensitivity testing?
What can we do against coccidiosis?
- Vaccines
- Alternative products – most of it doesn’t work really! Oregano or garlic based products to control coccidiosis – just not efficacious!
- Anticoccidial Drugs
