Transcript The importance of identifying and eliminating spores when

The importance of identifying and
eliminating spores when dealing
with the problem of poor
performance in the race horse.
Dr Meriel Moore-Colyer
‘No general fact appears better
established in hippopathology than the
one evidencing that disease is the
penalty that nature has attached to the
domestication of the horse’
(Percivall, 1853)
Dust related poor performance
• Reduced capacity for exercise
Coughing
Nasal discharge
= Recurrent Airways Obstruction (RAO)
(also known as COPD or IAD)
% of air in the horse's lungs that
can be expired during half a stride
120
normal
% of air expired
100
80
Loss of performance
60
RAO horse
40
20
0
0
10
20
30
% of stride
40
50
Snow and Vogel (1987)
RAO
• Hypersensitivity reaction to stable dust (bacteria,
fungal spores, plant particles and insect
fragments)
• Clarke and Madelin (1987) identified over 50
different species of microorganisms in the stable
air
• numerous respirable particles (5µm diameter)
from hay and straw (Slater, 1996)
Aspergillus
Mite
Bacteria (clostridium spp)
Dust levels in the environment
•
•
•
•
•
Season
Weather
Geographical location
Source of spores (crops, stores)
Stable:
Pony bedded on shavings and fed pelleted
hay the dust got a 97% reduction in dust
levels in the breathing zone than when on
straw and long hay (Woods et al.,1993)
Dust in hay and straw
• Spores on grass when cut
• Leaf shatter when drying
• Soil particles
• Damp = mould and bacteria growth
Dust in hay
• Baled and stacked = heat production
• Heat encourages mould growth
• 42°C Thermophilic actinomycetes (aspergillus
spp) >10 10/ m3 in stable (108 / m3 allergenic)
• Aspergillus spp produce spores 1 – 5 µm
diameter
Dust in hay cont.
• Spores of 5 µm fall 0.1 cm / second
• 3000 respirable particles per ml of air
• Horse tidal volume of 4 litres = 12 million
particles in every breath.
Stable environment
Dust minimising regime
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•
•
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Good ventilation = 5 changes air / hr
Hay store far away
Muck out when horse is out
Dust-free bedding
Dust-free (low-dust) forage
Dust-free stable
Dust-free bedding
•
•
•
•
Shavings
Paper
Hemp
Rubber mats
(Never deep-litter as it encourages mould and
bacteria growth)
Dust-free stable
Dust-free forage ??
Difficult to find
Answer don’t feed forage!
But must feed forage as horses:
• Need to chew
• Gut health - peristalsis
- dispel gas
- alkaline gut
- reduce gastric ulcers
Low dust forage
• Chopped fibre / fibre cubes (chew?)
• Haylage (bulky,
slow release energy)
• Hay - dust extracted
- soaked
- steamed
Reducing dust in hay
• Mechanical dust extraction - 95% dust
reduction (Gregory and Lacey, 1968)
• Soak
• Steam
Table 1. Respirable particle numbers and mineral levels
(g/kg 95%DM) in 2.5 kg hay nets after four different
soaking treatments (Moore-Colyer, 1996)
Soak
(hrs)
Spore
(nos)
Na
K
P
Mg
Ca
N
0
32652
6.3
14.5
2.8
1.6
3.7
13.6
0.5
3908
(90%)
3.6
10.5
2.4
1.6
3.8
14.6
3
3484
(90%)
2.5
6.1
1.8
1.3
3.8
14.1
12
2092
(94%)
1.9
5.3
1.7
1.2
3.7
14.8
s.e.d
s.e
3695
0.26
1.09
0.10
0.05
0.64
0.68
Table 2. Respirable particle numbers and mineral levels
(g/kg 85%DM) in 2.5 kg hay nets after four different
wetting treatments.
(Blackman and Moore-Colyer, 1998)
Soak Spore
(mins) (nos)
Ca
Fe
Cu
Zn
Mn
0
25971
5.2
88
3.7
21
77
10
1862
(93%)
4.8
77
2.7
21
81
30
1163
(96%)
5.0
101
2.6
19
78
1309
80
steam (95%)
5.2
72
3.1
20
81
Soaking hay
• > 90% reduction in respirable particles
• Sig loss of Na, K, Mg, P, Cu
• 10 minute soak = effective as 30 minutes
• Post soak water is a biological hazard
Steaming hay
• 80 minute steam = soaking for 10 / 30 minutes
• No loss of nutrients
• No effluent
• Handler subjected occupational asthma (2.5 kg
hay net)
Steaming hay
• Specialized steamer whole bale
Haygain methodology
• Complete strung bale
• 80 minute cycle
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•
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TVC (bacteria)
Fungi
Yeasts
Incubated at 22 and 330C on petri-films
Haygain steamer
Micoorganism
Dry hay
Steamed
hay
Sig
TVC
4,261,600
800
0.008
Fungi
10,173,333
0
0.008
Yeast
6,893,333
0
0.008
Haygain scientific facts
• Spores are killed
• Aspergillus spp killed (Creighton, 2009
Irish Equine Centre)
• Temp inside bale > 95°C (spores killed by
10 min exposure to wet heat at temp 70 -
90°C
Haygain observations
‘Horses love the steamed hay and don’t cough’
James Fanshawe, Rose Dobbin, Tom Symonds
‘Coughing horses have now stopped
completely….improved performances and no
interruption in training schedules’
Tom George
Haygain observations
‘ An immediate positive effect in horses with
irritable airways…when we stopped using it
those horses started coughing again within 4
days…indispensible
Hughie Morrison
‘seen the benefits from cleaner scopes……saves
on scoping so pays for itself
Fanshaw, Andrew Boxhall
Haygain explanations
• All biological proteins to lose function
when denatured
• Heat causing denaturing spore protein
• Altering allergenicity of spores? (on-going
work)
Advantages of steaming
• Killing fungal, bacterial and yeast spores
• No loss of nutrients
• Handler not exposed to dust
• No effluent
• Safely feed long fibre ie hay to racehorses
Acknowledgements
Thank you for listening !