Iowa Poultry Association Fall FestivalWest Des Moines, Iowa

September 20, 2018

Tom Tabler, Ph.D.Mississippi State University Extension Service

Poultry Science Department

Litter Management and Ventilation

Managing Litter Moisture is Key• Litter moisture > 25% will result in

increased ammonia production

• Ventilate to maintain 50-70% humidity inside the chicken house

• Litter conditions this flock have a carryover effect on the next flock

• Continuously increase ventilation rates throughout the flock to compensate for the increasing amount of moisture added daily by the birds

Litter Quality• Litter moisture should be at 20-

25% (not always possible due to cool cells, weather conditions, etc.)

• Rule of thumb; squeeze handful of litter- if it stays in a ball, it’s too wet- sticks together slightly, it’s OK- won’t stick at all, may be too dry

Antibiotic-Free Requires Different Thinking

• Reusing old litter is commonplace

• Requires better management

• Old litter appears beneficial with antibiotic-free production

• Some companies moving old litter onto new farms to seed new houses and help jump start chicks’ immune system under antibiotic-free production

Proper Litter Management• May need > ventilation first few days (NH3 level)• Check drinkers often• Remove wet litter after a spill • Heat will be needed at times• Let house air between flocks• Proper drinker height/pressure• Use air inlets• Use stir fans

Litter Preparation Starts Early• Do not start chicks on

cold or damp litter

• Recognize the importance of pre-heating the house on:

• Litter quality • Air quality (NH3)• House environment• Chick performance

Use Common Sense

• Keep accurate records (when, where, and how much was spread)…..follow your CNMP!

• Soil test and litter analysis

• Don’t leave litter exposed to the elements; keep it dry

• Be considerate of neighbors

Winter Management Basics• What makes winter litter management

challenging?

• Cold outside air

• Brood chamber at 90-92° for baby chicks

• Low air flow rates that make even distribution difficult

• Expensive propane

Facts about Propane• For every gallon of propane burned:

• 850 ft3/ hr of fresh air is consumed

• 92,000 Btu’s of heat is produced

• 108 ft3 of carbon dioxide is produced

• 6.8 lbs (0.8 gals) of water is produced

Controlling Moisture is Critical• Moisture is the key factor influencing litter

quality• Increases NH3 issues

• Promotes bacterial growth

• Increases pathogen development

• Caked litter traps moisture

• Litter that is too dry creates dust problems and air quality concerns

Winter Ventilation’s Primary Purpose is Moisture Control

• Where does the moisture come from?

• 1) Birds – birds consume 2 lbs of water for each lb of feed consumed

• 80% of this water is added to the house environment in the form of manure and respiration

• 2) Brooders – for each gal of propane burned, 6.8 lbs (0.8 gals) of water is produced

Controlling Moisture• How long should minimum ventilation rate be?

• As long as it takes to manage the ammonia situation and control relative humidity

• Ventilation should be such that you control relative humidity between 50-70%

• Waiting until the litter starts to slick over to properly ventilate means you have a high moisture problem you can’t ventilate your way out of

Use Vent Boxes Correctly

• Ceiling vents should open 1-2” while sidewall vents should open 1.5-2.5”

• Provides optimal airflow pattern with appropriate vent opening

50°F75%

60°F50%

80°F25%

40°F100%

Use Vent Boxes Correctly• If vent boxes are barely open, air might have

enough velocity but not enough mass (volume) to make it into the house center

50°F75%

60°F50%

Only partial air heating…. Only partial floor drying!

40°F100% Hot Air Pool (100+°)

doing no good!

Stir Fans• Gently push warm air near ceiling back down toward birds

• 35% of radiant heat goes up!

• Direct the flow horizontal toward end wall or slightly upward

• Run continuously or tie to controller and run alternately with vent doors

• Small 18-24” fans with ~ 1/4 hp motors

Maybe the best investment after tightening up house

Ventilation is Extremely Important• Challenging in winter due to high fuel prices

• Some growers may choose to conserve heatand sacrifice ventilation• Increases wet litter

• Winter a critical period for footpad dermatitis• Increased incidence in winter• House environment detrimental to paw quality• Stir fans may promote litter drying

Wet Litter = Poor Paw Quality• Air flow over litter lessens as birds age

• Older birds Wetter litter

• Wetter litter more ammonia higher bacterial load higher pH detrimental paw quality

• Wet litter alone can ulcerate footpads• Moisture softens footpads

• More sensitive to damage & developing FPD

Windrowing Litter

• Windrowing litter becoming more popular in the US

• In a recent litter study in Mississippi, 75% of growers windrowed litter (given enough time between flocks to do so)

• Beneficial if done correctly; waste of time otherwise

• Not without its challenges

Challenges to Windrowing• Grower expertise Takes practice with equipment Desire to do it right Beneficial if done right; waste of time if done wrong!

• Down time is an issue Takes time to build, turn, spread out, and dry windrows

• You’ll get dirty It’s not clean work…you’ll need a mask, maybe a

respirator, goggles, and maybe clean clothes before you go home or you may not be allowed in the house!

Main Benefit• Most (not all) of the pathogens present in litter can

be eliminated

• Pathogens affecting chickens grow best in the range of the chicken’s body temp (105-107°F)

• Heat 20-30 degrees higher than this will kill most microorganisms in the litter

• Heat is not the only kill method; also have ammonia (chemical kill) and microbial competition (kill off bad bugs and good bugs replace them)

Don’t Cut Corners• Pull litter from the sidewalls

• Incorporate hardpan and expose the floor

• Insecticides work better when footers are exposed• Spray insecticides on windrows within 24 hrs• Heat will drive beetles to top of windrow• Spraying windrows and footers early will provide

maximum kill

• Much of your ammonia problem is in the hardpan; windrowing hardpan releases ammonia

Time is a Factor• Maximum windrow temperatures are

usually reached in 2-3 days and start to fall by 4 days

• This is long enough to kill many pathogenic bacteria and viruses and reduce overall bacterial load

• Requires sufficient down time for turning, spreading back out, cooling down, and drying out

Follow Recommended Guidelines• Broiler supervisor OKs litter depth and timeline• Minimum out time – 10 days• Decake/1st windrows – within 2

days of harvest• 1st windrows sit at least 3 days• Turn and let sit at least 3 more days• Level litter at least 4 days prior to placement• Supervisor should check 1) timeline, 2) 1st

windrow, 3) 2nd windrow, 4) leveled litter

Timing Application of Litter Treatments

• Al+Clear (aluminum sulfate) - Dry Alum• Dry litter – 7 days prior to placement• 20-35% moisture – 5 days prior to placement

• A7 Liquid (aluminum sulfate + sulfuric acid)• 2-3 days prior to placement

• PLT (sodium bisulfate)• 24 hrs prior to placement

• Poultry Guard (sulfuric acid attached to clay)• 24 hrs prior to placement

Summertime Air Movement• Controlled air movement allows for

increase or decrease in bird cooling

• During hot weather, tunnel ventilation allows maximum air flow

• With older birds, want air speed of 800 to 1000 ft/min over birds

• This will exchange house air once per minute or more and prevent temperature buildup

Summertime Situations• Birds lose 1/3 of heat to air

but 2/3 of heat is lost through breathing

- 70°F is ideal for older birds

- 85°F - heat loss goes down

- body temp goes up

• End result - birds begin to pant which increases maintenance and feed conversion

Air Movement vs. Bird Age• Older birds better feathered &

insulated so difficult to stay cool

• As birds age, less space between individual birds

• Older birds have less surface area per lb of BW than younger birds and can’t lose heat as easily

• Heat stress more severe as birds age

Don’t Forget Fan Maintenance• No one would intentionally shut off 1/3

of their fans in the middle of summer

• This happens all the time from lack of maintenance

• Worn belts and pulleys/dirty shutters can reduce fan capacity by 25%

• Hard to recognize because performance loss occurs over time

Each Operation is Unique• Producers should weigh the

options and determine their needs • Consider:

• NPMs• Environmental concerns• Watershed location and

regulations• Litter preparation time• Fuel expenses• Is litter sold as income

supplement?

Litter Management• Consider carryover effects from previous flock• Use a litter amendment to lower pH and control ammonia• Ventilate from day 1 for moisture removal• Proper drinker height and pressure• Keep litter dry (burn gas as needed; cheaper in the long run)• Run a fan between flocks to keep ammonia pulled out• Start preparing for the next flock the day the current flock

leaves (decaking, windrowing, etc.); don’t wait a few days before starting

• USE COMMON SENSE (thankfully, most farmers still have some; that can’t be said for everyone today)

Summary• Ventilate – air exchange is critical in winter too!• Keep the floors dry• Moisture and humidity are your enemy (50-70% humidity)• Litter condition is the most important factor affecting paw quality• Utilize stir fans• Take advantage of litter treatments• Propane is less expensive than losing control of litter quality• Good litter management and air quality likely leads to increased

weight gain, better feed conversion, improved flock performance, and a bigger flock settlement check

Thank You!