MOISTURE EFFECTS ON BIRD
PRODUCTIVITY AND HEALTH
Dr. Jenny Fricke
Why are we talking about moisture?
• We live in a dry climate!
• BUT…as a general rule of thumb:
• For every kg of feed a bird consumes, approximately 2 kg of
water is consumed
• ~80% of the water consumed by birds is added back to the barn
by respiration and excretion in the feces
- Michael Czarick, Extension Engineer, University of Georgia
Why are we talking about moisture?
Liters of Water
Water consumption and Moisture added to barn
(based on 20,000 bird population)
8000
7000
6000
5000
4000
3000
2000
1000
0
Daily water
consumption (L)
Moisture added
back to barn (L)
Bird age (days)
Why are we talking about moisture?
90
% Relative Humidity
80
70
60
50-70% RH = sweet spot
50
%RH A
%RH B
40
30
20
10
0
0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34
Age (DAYS)
So?
• Ventilation to remove moisture is an important job!
• Lots of moisture added to barn
• Lots to remove
• Consequences of too much moisture?
• Consequences of too little moisture?
Consequences of too much moisture
• Too much moisture can have many impacts on bird health
• Focus on a few of those today
• Impacts on the respiratory system and susceptibility to disease
• Impacts on the gastrointestinal system
• Impacts on the skin
• Impacts on the respiratory system
• First…a review of the avian respiratory tract
The Avian Respiratory System
Fedde, 1998
Inspiration #1
Expiration #1
Fedde, 1998
Inspiration #2
Expiration #2
Fedde, 1998
The Avian Respiratory System
• Upper respiratory tract
• An important first line of defense
• Protecting the intra-abdominal portions of respiratory tract!
• Mucociliary apparatus – an important component
• Where do you find it?
• Nasal cavity
• Trachea
• Primary and part of secondary bronchi
The Avian Respiratory System
Nostrils/Nares
Larynx, tracheal
opening
Choana
The Avian Respiratory System
Images from Avian Histopathology – 3rd ed.
The Avian Respiratory System
• What the mucociliary apparatus does for you and your
birds! (how it works!)
Consequences of too much moisture
• Nitrogenous waste from the bird = uric acid
• Microbes in the feces and litter produce enzymes which
break down uric acid
• This process required moisture, and the end product is
ammonia
• Ammonia can have negative impact on both birds, and
people
• Its corrosive
Uric acid
CO2
H2O
+ O2
Uricase
Allantoin
H2O
Allantoinase
Allantoic acid
CO2+ 2
NH3
H2O
Allantoate Aminohydrolase
Uriedoglycolate
Ureidoglycolase
Glyoxylate + Urea
H2O
2 NH3 + CO2
Urease
Consequences of too much moisture
• Too much moisture = increased ammonia levels
• Increased ammonia…
• 20-25ppm = ciliostasis
• 40ppm+ = de-ciliation
Consequences of too much moisture
Normal chicken trachea
Epithelial hyperplasia
Diffuse lymphocytic tracheitis
Images from Avian Histopathology – 3rd ed.
Consequences of too much moisture
• Airsacculitis leads to other problems…
• Infection of airsacs can lead to bacterial infection of the bones
(osteomyelitis) and vice versa! (McLelland, 1990)
http://www.ucmp.berkeley.edu/science/profiles/wedel_0609.php
Consequences of too much moisture
• On the respiratory tract, in a nut shell:
• too much moisture  increased ammonia  damage to respiratory
defense system  increased risk of secondary infection!
Consequences of too much moisture
• On the gastrointestinal tract – example: cocci
• Coccidia are parasitic organisms that infect the gut
• Impact digestion and absorption of nutrients
• Disrupt protective gut barrier
• So what – feed has anticoccidial medication in it to prevent that
problem!
• WRONG!
Consequences of too much moisture
• Coccidial parasites
• Found wherever chickens are raised
• Here in SK, generally broiler feed is medicated to prevent severe
disease…but this is only one part of cocci prevention
Infective
Non-infective
Cartoon image from: Diseases of poultry 10th Ed.
Consequences of too much moisture
Reproductive Potential
1 oocyst can produce
• E. acervulina 400,000
• E. maxima 12,000
• E. tenella 72,000
• Day 20 ~ 30,000
oocyst/gram litter
• 1 sq. ft. x 2 inch litter
weighs ~ 1.5 kg
40 X 400 ft= 16,000 sq. ft.
~ total oocysts in barn
720,000,000,000
Slide courtesy of Dr. Greg Mathis, Southern Poultry Research, Inc.
Consequences of too much moisture
• Coccidial parasites
• # infective coccidial organisms in the barn depends on:
• Temperature
• Barn clean out
• Litter quality
• Feed Availability
• Coccidial control program
• Other disease/stress
• Bird density
+
• Moisture!
Un-infective
=
Infective
Consequences of too much moisture
• Coccidial parasites
• # infective coccidial organisms in the barn depends on:
• Temperature
• Barn clean out
• Litter quality
• Feed Availability
• Coccidial control program
• Other disease/stress
• Bird density
• Moisture!
+
Un-infective
=
Un-infective
Consequences of too much moisture
• Coccidial parasites
• # infective coccidial organisms in the barn depends on:
• Temperature
• Barn clean out
• Litter quality
• Feed Availability
• Coccidial control program
• Other disease/stress
• Bird density
• Moisture!
+
Un-infective
=
Infective
Effect of +1 Microscopic Coccidiosis Score
Teeter et. al. 2007
-43g/day
3500
-34g/day
-301g
-25g/day
3000
2500
-238g
-16g/day
-175g
2000
-9g/day
1500
-112g
-63g
1000
500
- 0.14 lb
- 0.24 lb
- 0.39 lb - 0.52 lb
- 0.66 lb
Cobb 500
Each Increase In Microscopic Lesion Score, decreases ADG by
1.5% of Body Weight Throughout the Period
48
45
42
39
36
33
30
27
24
21
18
15
12
9
6
3
0
0
Consequences of too much moisture
Liters of Water
Water consumption and Moisture added to barn
(based on 20,000 bird population)
8000
7000
6000
5000
4000
3000
2000
1000
0
Daily water
consumption (L)
Moisture added
back to barn (L)
Bird age (days)
Consequences of too much moisture
• On the gastrointestinal tract, in a nut shell:
• too much moisture  increased pathogen load  damage to
intestinal defense system  impact on feed conversion and gain,
and increased risk of secondary infection!
Consequences of too much moisture
• On the skin – Foot pad dermatitis, Pododermatitis or
Contact dermatitis
Consequences of too much moisture
• On the skin – Foot pad dermatitis, Pododermatitis or
Contact dermatitis
• Nutritional factors can play a role
• Minerals
• Biotin
• Sodium
• Protein
• Non-starch polysaccharides
• Management factors can play a role
• Drinkers
• Stocking density
• Season
• Litter material
• Litter management – ventilation, humidity…
Consequences of too much moisture
• On the skin – Foot pad dermatitis, Pododermatitis or
Contact dermatitis
• Moisture softens foot pad
• Facilitates coating the foot pad with irritating substances/pathogens
• Damages the defense system!
• Controlling litter moisture will improve
• Flock health
• Environmental conditions in the barn
• Productivity
• Animal Welfare!
Take Home Message
• Anything that disrupts a protective barrier (internally =
gastrointestinal and respiratory surfaces, externally = skin),
opens the door for infection/disease, and ultimately will impact
flock profitability
• Too much moisture can play a key role in disrupting protective
barriers
Comments, Questions?