ArticlePDF Available

Quality of different bedding materials and their influence on the compostability of horse manure

  • Equine Information Centre, Kuopio, Finland

Abstract and Figures

The air quality of the stable and management and composting of manure can be improved by choosing bedding material with certain desirable properties. The optimal bedding material doesn't cause hygiene problems in the stable. It absorbs ammonia, is economic in use, and decomposes quickly with manure. The objective of this trial was to compare both quality of different bedding materials and their influence on the composting process of horse manure. Bedding materials used in the study were wood chips, straw, peat, hemp, linen, sawdust, shredded newspaper and the mixtures, peat/wood chips, peat/sawdust, and peat/straw. Peat and peat mixtures had the best quality of ammonia absorption, water holding, and manure fertilization value. The number of fungi and bacteria were lower in shredded newspaper and wooden materials than in straw, linen, hemp, and peat. The composting temperature became high enough for at least a partial destruction of parasites and seeds within the rubbish heaps in all boxes. Only peat manure was ready for further plant production after one month's composting period. Other bedding materials were decomposed only partially or not at all during the study.
Content may be subject to copyright.
Volume 21, Number 3, 2001 125
The air quality of the stable and management and
composting of manure can be improved by choosing bedding
material with certain desirable properties. The optimal
bedding material doesn’t cause hygiene problems in the stable.
It absorbs ammonia, is economic in use, and decomposes
quickly with manure. The objective of this trial was to
compare both quality of different bedding materials and
their inuence on the composting process of horse manure.
Bedding materials used in the study were wood chips, straw,
peat, hemp, linen, sawdust, shredded newspaper and the
mixtures, peat/wood chips, peat/sawdust, and peat/straw.
Peat and peat mixtures had the best quality of ammonia
absorption, water holding, and manure fertilization value.
The number of fungi and bacteria were lower in shredded
newspaper and wooden materials than in straw, linen, hemp,
and peat. The composting temperature became high enough
for at least a partial destruction of parasites and seeds within
the rubbish heaps in all boxes. Only peat manure was ready
for further plant production after one month’s composting
period. Other bedding materials were decomposed only
partially or not at all during the study.
Problems with stable hygiene may often be linked with
bedding material used in the stable. Bedding has effects on
indoor air, and the volume and quality of manure removed
from the box stall. In Nordic climates, the storage of manure
must be done for up to nine months of the year, resulting in
high storage and disposal costs. The whole chain of manure
to eld should be done so that utilization of manure can be
environmentally accepted.
Ammonium gas, dust and biological aerosols reduce
the quality of indoor air and increase the possibility of
respiratory diseases. Bedding is known as a major source
of fungal spores along with hay in the stable.1 Straw may
contain greater respirable dust than wood shavings, paper,2
and sawdust.3 The ammonia concentration in indoor air
depends on the quality and amount4 of bedding material and
manure management conditions.5, 6, 7
A good manure management system is hygienic, easy
to accomplish technically, economical and without negative
environmental effects. Manure should be able to be exploited;
for example, as a fertilizer or soil improvement material after
treatment and storage. Because of constrains on the storage
capacity for manure, the time used for manure treatment and
storage should be as short as possible. Bedding materials
such as recycled phone book paper, sawdust, and straw
have been noticed to decompose poorly during two months’
composting process.8 Differences have been found in the
process temperatures during composting of dirty phone book
paper, sawdust, straw, and wood shavings, which may affect
the hygiene of the compost product.8, 9
The purpose of this study was to study how different
kinds of bedding materials inuence stable hygiene and
composting of horse manure.
Ten bedding materials used in the study were, wood
chips, straw, sphagnum peat, hemp, linen, sawdust, shredded
newspaper and mixtures (3:1), peat/wood chips, peat/sawdust,
S. Airaksinen, MSc1; H. Heinonen-Tanski, PhD2; M-L. Heiskanen, PhD1
Authors’ addresses: 1Equine Information Centre, Hingunniementie 98,
FIN-74700 Kiuruvesi, Finland. 2Department of Environmental Sciences,
University of Kuopio, PO Box 1627, FIN-70211 Kuopio, Finland.
Acknowledgements: The authors are most grateful for the support during this
work given by the Horse College of Kiuruvesi and professor Pekka Mäenpää
from the University of Kuopio.
and peat/straw. Straw used was cut up to 10 cm strips
for the mixtures.
The main qualities of ammonia absorption, water
holding capacity and hygienic quality of bedding material
were studied with wood chips, straw, peat, hemp, linen,
sawdust, and shredded newsprint paper. The statistical
treatments for the qualities of ammonia absorption and
water holding capacity were done with the non-parametric
Kruskal-Wallis Test.
Materials mentioned above were used in a bedding
study in a stable with 16 horses. Each bedding material was
tested with four horses. The manure produced in bedding
was collected into the composting boxes. Both studies were
conducted during two periods, rst in July 26 – Sept. 3 1998
and second in Oct. 2 – Nov. 5 1998. Outdoor temperature
during those studies is shown in Fig. 2 and Fig. 3.
Ammonia absorption and water holding capacity
Ammonia absorption capacity was measured with Dräger
diffusion tubes (NH3 20/a-D)a placed in a plastic bag including
200 ml bedding material (measured with loose bedding) and
800 ml fresh horse urine. Measurement (n=2) was done after
two hours’ incubation at +17.4oC. Total concentration of
ammonia in the plastic bag was measured with 0.8 dl of pure
horse urine (n=2). Ammonia absorption capacity of bedding
material was calculated by the following equation:
A= ---------- *100%, where
A= absorption capacity of material (%),
T= total concentration of ammonia in a plastic bag with
pure horse urine (ppm/h),
c= concentration of ammonia in a plastic bag with bedding
material and urine (ppm), and
t= time of incubation (h).
Water holding capacity of bedding material was measured
in a barrel with strainer bottom (V=10 liters). The barrel was
placed on a larger collecting vessel. One liter of bedding
material and two liters of water were added to the barrel,
and the water passing through the strainer was collected
and measured one hour later (n=3). Water was added to
the barrel by pouring it from a can. Bedding material was
wet before straining was started. Measurements were done
at room temperature.
Hygiene quality of bedding materials
Hygiene analyses of bedding materials were done by
Kuopio Regional Institute of Occupational Health.b Microbes
(mesophilic fungi, xerophilic fungi, thermotolerant fungi,
mesophilic bacteria and thermophilic actinomycetes) were
determined with ve growth media. Numbers of colony
forming units (cfu) were counted after incubation and
identied microscopically.
Management and composting
The box stalls (about 3x3 m2 each) were cleaned daily
during the bedding study. Feces and bedding with urine were
removed into the composting boxes during a week. Removal
of clean bedding was avoided.
Composting in a wooden box with a cover (1 m3) (Fig.
1) and fertilization value after composting were studied
from manure with wood chips, long straw, peat, hemp,
shredded newspaper, peat/wood chips, peat/sawdust, and
After a one-week period of manure collection, measure-
ment of temperatures from the composting mass was started.
Temperature was measured once a day (in the morning)
for 34-35 days. Measurements were done in depths of 10
cm, 22 cm (n=4) and 30 cm (n=2) from the top of the
composting mass.
Samples for nutrient analysis were collected from a depth
of 10 20 cm from the top of the composting mass zero days,
three weeks, and six weeks after starting the composting
study. The total potassium, total phosphorus, soluble nitrogen,
dry matter, and content weight (kg/m3) of the bedding manure
were analyzed by Soil Analysis Service.c
Biological activity of the composting mass, including
the number of mold colonies, formation of mushrooms
and ies was visualized daily. The number and vitality of
rubbish heap seeds in composted manure was studied with
a simple germination test, where bedding manure samples
after different times of composting were taken into the room
temperature, seeded and moisturized for ten days.
After 27 or 28 days of composting the masses were
turned totally upside down. That was done to avoid the
further decrease of the composting temperature caused by the
lack of oxygen or moisture in the mass.
There were signicant differences in ammonia absorption
Figure 1. Composting boxes with open covers.
Volume 21, Number 3, 2001 127
capacity and water holding capacity in studied bedding
materials (Table 1b). Peat absorbed all released ammonia
gas with the relative absorption capacity of 100%. The good
ammonia absorption capacity is similar to earlier ndings.4
The relative ammonia absorption capacity of wood chips
was 44%. The same value for long straw was only 4%. Linen
was the second best with the relative absorption capacity
76%, better than both sawdust and shredded newspaper
(Table 1a). Signicance of ammonia absorption capacity
of bedding material may rise when indoor temperature
in stable increases.
The water holding capacity was best for sawdust and
sphagnum peat. Bedding requirement for ten liters holding
was 9.7 liters sawdust and 14.7 liters peat. As expected,
long straw had the lowest holding capacity; 66.7 liters of
straw was needed for holding 10 liters of water. Detailed
results of bedding materials’ water holding capacity are
shown in Table 1a.
Wood materials contained lower amounts of microbes
than materials made of plant materials (Table 2). The ndings
agree with those of Clarke1 and Kotimaa et. al.3 Hygienic
quality of straw, linen and hemp may depend on weather during
harvest, method of harvesting (e.g. warm air drying), and
preservation. According to earlier ndings the microbes of peat
may contain only a few main species of fungi,4 but we found
fungi belonging to many different groups.
The manure with dirty straw was noticed to result in
about twice as much volume as manure with other bedding
materials. Total volume of dirty straw manure for one year
was calculated to be 19.5 m3. Manure with hemp and peat
bedding was calculated to produce only 9.1 m3 per year (Table
3). If more clean bedding material were removed during the
cleaning of box stalls, the amount of produced bedding manure
would increase from the values of Table 3. The amount of
removed bedding manure was similar to the amount of bedding
material used in the stable.
Shredded newspaper and straw didn’t emit any dust when
used in the box. The dust problem of hemp could be eliminated
Table 1a. Relative ammonia and water holding capacity of different bedding materials
Bedding Material Relative ammonia absorption at Water holding capacity (1 of bedding/capacity at
+17.4°C (%) 10 liter of water) at room temperature
Mean (n=3) Std. Deviation Mean (n=3) Stardard Deviation
(n=3) (n=3
Peat moss 100 0 14.8 0.97
Linen 76 0 19.0 1.40
Sawdust 64 0 9.7 0.28
Hemp 60 0 22.5 0.53
Shredded newspaper 52 0 27.2 3.43
Wood chips 44 11.1 31.9 3.72
Straw 4 11.3 69.7 10.01
Total 22.4 27.8 19.23
Table 1b. Test statisticsa,b,c in ammonia absorption capacity and water holding capacity.
Relative ammonia absorption Water holding capacity
capacity at +17.4°C
Chi-Square 12.855 19.498
df 6 6
Asymp. Sig. 0.045 0.003
Exact Sig. <0.0005 <0.0005c
aKruskal-Wallis Test
bGrouping variable: Bedding material
cBased on 10000 sampled tables with starting seed 2000000.
Table 2. Number of microbes and fungi in bedding materials.
Bedding Mesophilic Xerophilic Thermotolerant Mesophilic Thermophilic
material fungi (cfµ/g) fungi (cfµ/g) fungi (cfµ/g) bacteria (cfµ/g) actinomycetes (cfµ/g)
Peat 1*105 -2*108 2*105-3*106 0-9*105 5*104-1*108
Linen 6*105-1*107 5*105-1*107 3*104-1*106 7*107-2*108 1*106-6*107
Hemp 1*105-9*105 5*105-8*105 0-5*102 6*105-9*106 8*103-1*104
Straw 4*105-1*106 3*105-1*106 1*107-1*109 0-3*102
Wood chips 2*105-3*106 2*105-2*106 4* 102-4*103 5*103-6*106 0-2*103
Sawdust 1*104-4*104 4*102-3*103 0-1*102 4*104-3*106
Shredded 0-1*102 1*102-3*102 2*104-4*104 0-1*102
with water addition as advised in the label of the package.
Wood chips made some dust at the time spread into the box
stall. The peat used in this study was quite dusty. Peat dust
could be found in the stall as late as a week after it was
furnished with new bedding material. Dust from peat bedding
was seen as a signicant disadvantage in bedding materials’
properties because of the increased risk of respiratory
irritation in horses and personnel. The quality of peat used in
the study was also heterogeneous. Removal of dirty bedding
was easiest and quickest with the bedding materials peat and
hemp. Removal of dirty wood chips, shredded newspaper,
and straw took more time because of difculties in separation
of clean and dirty bedding material.
Composting of bedding manure started quite quickly in
every box despite the lower outdoor temperature during the
latter period. Temperature of the composting mass was higher
than +20 oC during the rst 2 – 3 weeks, and declined then to
the level of outdoor temperature. There were no remarkable
differences between the temperature curves of composting
boxes in the depths of 10, 22 and 30 cm indicating that the
microbial activity was as high in all these layers. Temperature
values during composting process in the depth of 22 cm are
shown in Fig. 2 and Fig. 3.
No great increase of temperature was noticed after
Figure 2. Composting study in July 26-August 30, 1998.
Mass temperature in the depth of 22 cm.
Figure 3. Composting study in October 2 - November 5,
1998. Mass temperature in the depth of 22 cm.
Figure 4. (left) The s ol uble
nitrogen (kg/m3) in the bedding
manure materials after three
weeks of composting.
Table 3. Annual amount of produced bedding manure per
horse when different bedding materials are used.
Bedding Bedding
material manure/horse/year (m3)
Hemp 9.1
Peat/wood chips (3:1) 9.1
Peat 9.8
Peat/straw (3:1) 11.7
Shredded newspaper 11.7
Peat/sawdust (3:1) 12.4
Wood chips 12.4
Long straw 19.5
Volume 21, Number 3, 2001 129
for ammonia emissions in air.
The content of phosphorus and potassium were quite
unchanged during storage of manure (Table 4). Differences
in the content of those main nutrients may be explained
by feeding.
Fungal fruiting bodies’ growth occurred into all bedding
manure materials after about one week of composting.
The number of ies ying on top of the composting mass
was not abnormally high. According to germination tests
the seeds of rubbish heaps from manure were destroyed
during composting.
The results of this study showed that there are differences
between the properties of bedding materials. Air quality in
the stable, and utilization of manure can be improved, and
emissions to the environment and storage problems can be
reduced by selecting a good bedding material.
Peat was found to have the best qualities as ammonia
absorbent, water absorbent, and soluble nitrogen container.
Cleaning was quickest and easiest when the bedding material
was peat, peat mixture, or hemp. The weaknesses of peat were
heterogeneous quality, dark color, and dust. Peat moss has
turning composting masses upside down on Day 27 or 28.
The lack of oxygen can’t therefore be the only reason for the
decreasing biological activity of the composting mass. After
three weeks of storage in the composting box the mass was
dry especially with the bedding materials hemp, straw,
wood chips, and shredded newspaper. After a month’s
composting period a large amount of horse manure had
crumbled and decomposed to smaller particles while the
bedding material had kept almost unchanged. Limiting
factors of composting after three weeks’ composting period
may have been moisture, oxygen content, and concentration
of soluble nitrogen in the mass. The selection of a right
bedding material is meaningful for utilization of composted
horse manure. Undecomposable bedding material may still
absorb soluble nitrogen from the soil which could mean very
low fertilization effect in the worst case.
There were some differences in the content of soluble
nitrogen in composted bedding manure (Fig. 4). The relative
content of soluble nitrogen was highest in peat manure
(100%) and lowest in hemp manure (23%) after three
weeks of composting. Differences in soluble nitrogen being
preserved could be explained by the ammonia absorption
capacity of the bedding materials. Ammonia emissions during
manure storage were lower from peat moss manure than
manure with wood chips or straw, which may be important
Table 4. The content of phosphorus and potassium in horse manure with a different bedding material and a
function of storage.
Bedding material with manure Time of Total P, Total K, Dry Total content
storage, weeks kg/m3 kg/m3 matter, % weight, kg/m3
Wood chips 0 0.64 2.2 27.0 480
3 0.65 2.2 34.0 330
6 0.70 3.4 33.3 410
Peat 0 0.27 4.4 23.7 600
3 0.51 3.7 28.9 400
6 0.56 3.6 30.3 460
Straw 0 0.14 1.3 36.8 170
3 0.37 2.6 16.5 470
6 0.36 2.1 29.8 270
Shredded newspaper 0 0.54 1.2 32.5 410
3 0.98 2.3 22.7 650
6 0.74 1.7 26.5 500
Hemp 0 0.58 1.2 35.3 340
3 0.26 0.92 18.8 440
6 0.49 1.8 34.4 340
Peat/Wood chips (3:1) 0 0.64 1.8 28.8 440
3 0.58 2.3 32.5 330
6 0.76 3.0 28.1 490
Peat/Straw 3:1) 0 0.43 0.89 28.9 410
3 0.40 1.1 26.7 370
6 0.62 1.2 36.0 400
Peat/Sawdust 3:1) 0 1.1 1.5 26.4 440
3 0.64 3.6 40.3 360
6 0.72 3.2 33.5 500
also been blamed for making wet horses dirty. The content
of dust decreased with water addition. Dust of peat bedding
may also be controlled by choosing a good peat type like
peat from Sphagnum fuscum.
Peat producers should pay special attention to providing
a homogeneous and dustless bedding product for horses. A
customer is not interested in a product which might expose
horses and the personnel to dust and the possibility of
respiratory diseases even if the other properties are excellent.
Good bedding peat has been reported to contain lower
amounts of microorganisms than straw or wood shavings.4
Using woody or other bedding materials as a thin surface
layer on peat litter could decrease the dust problem. On the
other hand a straw, wood chips, or hemp layer would increase
light in a box and improve the structure of bedding manure
being composted. Both ammonia and water absorption and
containing capacity of soluble nitrogen were poor in pure
straw. Also the high content of microbes3 decreases the value
of straw as a hygienic bedding material for horses.
Horse manure composted quite well within a month in a
closed composting box in the current study. Contrary to earlier
ndings8 there were no great differences in temperature
development between the bedding materials during the
composting study. According to the results of Moncol9 the
temperature in all composting boxes of this study became high
enough to destroy most of the potential strongyle ovae and
larvae. Temperature development of the mass in the beginning
of the composting process depends on the ratio of bedding
to manure. Horse manure itself has an excellent carbon to
nitrogen ratio for composting (about 25:1).
In agreement with Swinker et. al.,8 management practices
of bedding manure inuence composting and utilization of
horse manure. Pure manure may decompose and become
hygienic in a month if the amount of bedding is small enough
and the circumstances for composting are good. After that the
addition of urine and control of temperature and contents of
oxygen and moisture of compost are mostly needed because
of the decomposing of bedding material.
Only manure with peat bedding was ready for utilization
after one month’s composting period. Other bedding materials
were decomposed only to a small extent or not at all in
the composting boxes.
It is possible by optimization of bedding systems to
control both hygiene and environmental problems and
expenses caused by manure management and storage. It is
economically reasonable to bed horses’ box stalls with a
material which is both hygienic and efcient in ammonia
and water absorption capacities. Time for cleaning and
re-bedding decreases and the amount of bedding manure
needing storage is reduced. Using bedding material which
composts readily also reduces the likelihood of dumping
used bedding in urban dump sites.
aLiitin Oy, P.O. Box 33, 00391 Helsinki, Finland
bKuopio Regional Institute of Occupational Health, P.O. Box 93, 70210
Kuopio, Finland
cSoil Analysis Service, P.O.Box 500, 50101 Mikkeli, Finland
1. Clarke A: Air hygiene and equine respiratory disease. Equine
Practice 1987;196-203.
2. Webster AJF, Clarke AF, Madelin TM, Wathes CM: Air
hygiene in stables 1: Effects of stable design, ventilation and
management on the concentration of respirable dust. Equine vet
J 1987;19:448-453.
3. Kotimaa MH, Oksanen L, Koskela P: Feeding and bedding
materials as sources of microbial exposure on dairy farms. Scand J
Work Environ Health 1991;17:117-122.
4. Raymond SL, Curtis EF, Clarke AF: Trial: Monitoring the
effect of different amounts of a paper pulp product on ammonia
levels in a horse stall. Equine Research Centre at the University of
Guelph, Research report 1994;p7.
5. Louhelainen K: Farmers’ Exposure to dust and gases in dairy
farms. Kuopio University Publications C. Natural and Environmental
Sciences 1997;69:72.
6. Woods PSA, Robinson NE, Swanson MC, Reed CE,
Broadstone RV, Derksen FJ: Airborne dust an d aeroallergen
concentration in a horse stable under two different management
systems. Equine vet J 1993;25:208-213.
7. Raymond SL, Curtis EF, Clarke AF: Airborne dust and
ammonia concentrations measured when using two bedding types;
recycled paper and straw. Equine Research Centre at the University
of Guelph, Canada Research report 1994;p19.
8. Swinker AM, Tanner MK, Johnson DE, Benner L: Composting
characteristi cs of three bedding materials. J Equine Vet Sci
9. Moncol DJ: Composting equine stall waste using shredded
newsprint for bedding. Equine Practice 1996;18:18-22.
Figure 5. Scanning electron microscopy photograph on
the structure of peat.
... Woodchips have a high capacity for water absorbance: spruce, for example, is able to absorb water to reach 690 g moisture/kg after 48 h soaking, without reaching an equilibrium (Kumar and Flynn, 2006). The water holding capacity of various bedding types at room temperature, demonstrated sawdust and peat moss held three and two times more water than woodchip, respectively, whereas straw held half as much water as woodchip (Airaksinen, et al., 2001). Woodchip pads are commonly used for winter bedding of cattle intensively housed outdoors on 'out-wintering' or 'stand-off' pads in the UK and New Zealand (Smith et al., 2010). ...
Full-text available
Wet winter conditions can create animal welfare issues in feedlots if the pen surface becomes a deep, wet, penetrable substrate. Feedlot pens with a clay and gravel base ( N = 30) bedded with 150 mm (W15) and 300 mm (W30) depth of woodchips were compared to a control treatment with no bedding over a 109-day feeding period, while irrigated to supplement natural rainfall. The pad substrate was measured for variables which would affect cattle comfort and value of the substrate for composting. The penetrable depth of control pens was higher than both woodchip-bedded treatments from week 2, and increased until the end of the experiment. Meanwhile these scores were steady for W30 throughout the experiment, and increased for W15 only after week 10. Moisture content of the pad was higher throughout the experiment in the control pens than in the woodchip-bedded pens. In the control pens, the force required to pull a cattle leg analogue out of the pen substrate was three times that required in woodchip-bedded treatments. The W15 treatment increased C : N in the substrate to the upper limit of suitability for composting, and in W30, C : N was too high for composting after a 109-day feeding period. Overall, providing feedlot cattle with 150 or 300 mm of woodchip bedding during a 109-day feeding period improved the condition of the pad substrate for cattle comfort by reducing penetrable depth and moisture content of the substrate surface stratum, but composting value decreased in W30 over this feeding period duration.
... Typically, horses are routinely housed in individual stables with various soft bedding materials (Airaksinen et al., 2001). The polo pony in this report was relocated to a new standard stall and housed with only straw bedding at night. ...
Full-text available
A 19-year-old gelding polo pony was presented with a prominent protuberance at the tip of the right elbow and five days later, developed a marked swelling on the entire right foreleg with a high fever. Ultrasonography, performed on the caudal elbow region, demonstrated heterogeneous echogenic materials encapsulated in the fibrous capsule. The initial hematological analysis revealed anemia and a normal white blood count (WBC). Hyperbilirubinemia was detected biochemically. Pale yellow/turbid fluid was aspirated from the protuberance area, which showed septic exudate characteristics and contained Streptococcus spp. The pony was diagnosed with septic olecranon bursitis associated with streptococcal infection. The fluid-filled capsule was drained and flushed with normal saline mixed with an antiseptic once a day. Oral sulphonamide-trimethoprim was administered according to the drug sensitivity test for ten days. The capsule was filled with granulation tissue and the surgical wound completely healed 14 days after drainage. The WBC proportions were normal and anemia and hyperbilirubinemia were resolved following therapy. Diagnostic imaging and hematological and cytological analyses benefited the clinical investigation and therapeutic approaches in a pony with septic olecranon bursitis.
... Ely et al. microbial growth relative to chips or shavings from some (but not all) tree species (Yarnell et al. 2017). Odor suppression may be greater with hemp than other biological materials, but data on ammonia absorption appear mixed and a function of processing (Airaksinen et al. 2001;Fleming et al. 2008). Hemp bedding is generally more expensive than sawdust or shavings. ...
Hemp is a crop that in recent years has received renewed attention and been cultivated in numerous countries after having been abandoned by many during the twentieth century. This ‘rebirth’ is due to numerous factors: its favorable agronomical characteristics, its image of being a sustainable crop, and the plasticity of the products it can provide. However, due to its absence for a long time, there is a lack of expert knowledge on cultivating hemp. There is a lack of scientific knowledge regarding the specificities of its biology, and the strong interaction between genotype and environment remains a limiting factor of hemp cultivation, affecting both the yield and quality of the biomass produced. In this chapter, we have discussed the ins and outs of the cultivation of hemp through a scientific prism to address the principal factors, environmental and genotypic, that drive the agronomical characteristics of a hemp crop. Thereafter, we have focussed on the best crop management practices for optimizing hemp cultivation in terms of yield and quality parameters of the different fractions of the biomass that hemp can provide.KeywordsAgronomyCrop managementCultivationEcophysiologyIndustrial hemp
... Such composting systems need accurate management since the composting process works best at 45-55% moisture content, a minimum depth of 45-60 cm, and temperatures between 43-60 • C (Dairy NZ, 2015). However, due to the usually high C/N ratio of the woodchip matrix, optimum composting temperatures may not always be achieved (Airaksinen et al., 2001), hence resulting in a compost product that is low in available N (Sommerfeldt and MacKay, 1987;Sommer and Dahl, 1999;Smith et al., 2010). Furthermore, maintaining the composting systems can be labour intensive and, if not managed properly, may endanger stock health or milk quality due to high levels of bacteria in the bedding. ...
Full-text available
Intensive pastoral farming has been linked to adverse environmental effects such as soil degradation and increased fluxes of nitrogen, phosphorus, sediments, and pathogens into waterways, resulting in their degradation. Stand-off pads are engineered structures covered with bedding materials, available for occupation by stock to minimise those adverse effects to soil and water bodies. Wood chips are ideal for bedding due to their low cost, high water holding capacity, and stock preference as resting areas. While they reduce the mobility of both nutrients and pathogens, their effectiveness depends on the type of wood, size of the chips, pH, pad design, and feeding management used. Dissolved organic carbon, present in wood residue, may slow nitrogen mineralisation thereby decreasing loss via leachate. This effect depends on plant tannins and nutrients already stored within the plant tissue. Poplar and willow have high concentrations of tannins in leaves and bark with potential nitrification-inhibiting properties. When grown on-farm, these deep-rooted trees also reduce nitrogen leaching and prevent soil erosion. This review addresses the use of temporary stand-off pads within poplar or willow silvopastoral systems. Harvested trees can provide suitable wood chips for constructing the stand-off pad, while the deep rooting systems of the trees will reduce the moisture content of the pad, preventing waterlogging. A key objective is to discuss the feasibility and establishment of multiple temporary stand-off pads that allow for stock rotation from pad to pad, and subsequent on-site composting of wood-wastes into fertiliser, reducing both nutrient inputs and losses in agricultural systems. The review highlights the potential suitability of poplar and willow tree species for such a system.
... The T4 presented the smallest weekly averages and overall average during the two steps: pre-composting and composting ( Figure 2). The results (Figure 1) are in line with Airaksinen et al. (2001) who working with composting of different equine bedding, found that in the first 15 days of the process every windrows reached high temperatures (in excess of 50°C). Sanchuki et al. (2011) observed the same maximum 50°C during the first five days of poultry litter traditional composting process. ...
... The T4 presented the smallest weekly averages and overall average during the two steps: pre-composting and composting ( Figure 2). The results (Figure 1) are in line with Airaksinen et al. (2001) who working with composting of different equine bedding, found that in the first 15 days of the process every windrows reached high temperatures (in excess of 50°C). Sanchuki et al. (2011) observed the same maximum 50°C during the first five days of poultry litter traditional composting process. ...
Equine breeders seek alternatives to properly allocate saturated beds produced during the confinement and composting and vermicomposting can be viable alternatives. However, it is not elucidated what material used as bed provides better conditions for the waste treatment. This paper aimed to evaluate the performance of five equine beds during composting and vermicomposting made of: T1 – coffee hull; T2 – sawdust; T3 – sawdust and Brachiaria; T4 – rice straw; T5 – rice straw and Brachiaria. The waste was pre-composted in pile for 42 days. After this period, 15 vermireactors (triplicate) were mounted and the rest of the material remained in piles, to continue the process of composting for 58 days. Vermicomposting of T1 is not recommended because it wasn’t tolerated by the earthworms but showed good compost quality in composting. Equine beds with Brachiaria improve the conditions for waste treatment, as it increases aeration, provides easily degradable carbon and assists in the mineralisation of nitrogen.
... Alternative explanations are also possible, including hygienic quality. Straw is known to be at risk of low hygienic quality, i.e., contain fungi, mesophilic bacteria and actinomycetes which are associated with health problems [6,12,13]. Straw batches collected from horse stables may contain significant amounts of microbes, mycotoxins (e.g., deoxynivalenol) and lipopolysaccharides [13]. Little is known about how such factors affect the long term gastrointestinal health in horses. ...
Full-text available
Straw’s low energy content means it is a roughage option for horses with low energy requirements. Previously, in a field study, straw was associated with an increased risk for gastric ulcers. This study evaluated the effect on gastric ulcers, metabolic profile and behaviour of replacing, in a forage-only ration, 50% of the daily allowance with wheat straw. Six equines were studied in a 2 × 21-day cross-over design. The control diet (CON: 100% grass forage) and the straw diet (S: 50% grass forage and 50% straw [DM basis]) were iso-energetic. Gastroscopy was performed prior to the study and on day 21 and blood samples were collected and behavioural observations were performed. Diet did not affect squamous or glandular gastric ulcer scores (p > 0.05). Feed intake time was longer (p < 0.05) plus energy intake and plasma insulin concentrations were lower on diet S compared to CON (p < 0.0001). Plasma serotonin concentrations tended to be higher on diet S compared to CON (p = 0.05). The results suggest that good hygienic quality wheat straw can be included for up to 50% of the diet without causing gastric ulcers and that it can extend feeding time and promote a metabolic profile more suitable for overweight horses.
... In intensive animal production systems, straw is used as a structural component in ruminant diets (Dänicke et al. 2014). For horses, straw is frequently utilised not only as bedding material but also as a hay substitute in the feed (Airaksinen et al. 2001). For pigs, straw is usually not used as a ration component, but as bedding and manipulable material as it is also used for poultry and ostrich. ...
Straw is the main by-product of grain production, used as bedding material and animal feed. If produced or stored under adverse hygienic conditions, straw is prone to the growth of filamentous fungi. Some of them, e.g., Aspergillus, Fusarium, and Stachybotrys spp. are well-known mycotoxin producers. Since studies on mycotoxins in straw are scarce, 192 straw samples (wheat n = 80; barley n = 79; triticale n = 12; oat n = 11; rye n = 12) were collected across Germany within the German official feed surveillance and screened for the presence of 21 mycotoxins. The following mycotoxins (positive samples for at least one mycotoxin n = 184) were detected: zearalenone (n = 86, 6.0 – 785 μg/kg), nivalenol (n = 51, 30 – 2,600 μg/kg), deoxynivalenol (n = 156, 20 – 24,000 μg/kg), 15-acetyl-deoxynivalenol (n = 34, 20 – 2,400 μg/kg), 3-acetyl-deoxynivalenol (n = 16, 40 – 340 μg/kg), scirpentriol (n = 14, 40 – 680 μg/kg), T-2 toxin (n = 67, 10 – 250 μg/kg), HT-2 toxin (n = 92, 20 – 800 μg/kg), T-2 tetraol (n = 13, 70 – 480 μg/kg). 15-monoacetoxyscirpenol (30 μg/kg) and T-2 triol (60 μg/kg) were only detected in one barley sample. Macrocyclic trichothecenes (satratoxin G, F, roridin E, and verrucarin J) were also found in only one barley sample (quantified as roridin A equivalent: total 183 μg/kg). The occurrence of stachybotrylactam was monitored for the first time in four samples (n = 4, 0.96 – 7.4 μg/kg). Fusarenon-X, 4,15-diacetoxyscirpenol, neosolaniol, satratoxin H, and roridin-L2 were not detectable in the samples. The results indicate a non-negligible contribution of straw to oral and possibly inhalation exposure to mycotoxins of animals or humans handling contaminated straw.
... Anaerobic digestion (AD) has been proven to be one of the promising methods for organic waste treatment such as food waste, animal manures and organic fraction of municipal waste, not only for the safe disposal but also to recover bioenergy (methane or biogas). Various factors such as complex organic fraction of feedstock (lignocelluloses), higher concentrations of ammonia, chemical oxygen demand (COD), biochemical oxygen demand (BOD), alkalinity and salinity are the rate limiting factors for efficient AD of HM [1,5,6]. ...
Full-text available
This study aimed to investigate the impact of dilute acid-thermal pretreatment of horse manure (HM) on the characteristic changes followed by biomethanation of untreated (control) and pretreated HM using iron oxide (Fe3O4) nanoparticles (NPs) as additives at concentrations of 20 mg/L, 40 mg/L and 60 mg/L at mesophilic (35 ± 2 °C) and thermophilic (55 ± 2 °C) temperature conditions. The acid-thermal pretreatment enabled the depolymerisation of the lignocellulosic crystalline structure of HM resulting in the reduction of cellulose and hemicellulose by 93 % and 96 % respectively. Addition of deficient or surplus concentration of NPs or micronutrients may adversely influence the activity of microbes because the release of key enzymes is ion dependant. Addition of appropriate concentration of Fe3O4 NPs facilitates the release of Fe2+ and Fe3+ ions that contribute to the release of key enzymes, but the addition of surplus concentration results in the release of reactive and toxic-free radicals or intermediates that decline the activity of the microorganisms. Results disclosed that the maximum methane yield of 0.16 L/g CODreduced and 0.175 L/g CODreduced was achieved under mesophilic and thermophilic conditions from pretreated HM with an addition of 40 mg/L of Fe3O4 NPs with a COD reduction of 68 % and 56 %, respectively, whereas it was 0.14 L/g CODreduced and 0.15 L/g CODreduced with an addition of 60 mg/L of Fe3O4 NPs with corresponding COD reduction of 58 % and 62.5 %, respectively, from untreated HM. Based on the findings achieved in the study, it is proven that the HM is a potential feedstock for biogas/methane generation. Incorporating the advanced techniques such as acid-thermal pretreatment and addition of supplements in the form of NPs further enhances the biomethanation process making it more lucrative and feasible for implementation at full scale. Graphical abstract
After a decades-long legal hiatus, hemp (Cannabis sativa L.) has begun to experience a renaissance as a plant for all reasons. Although much hyperbole has been given to hemp’s potential to “save the world,” the crop has historical precedent as a source of fibers, feed/food, fuel, biomolecules, and more. The crop’s numerous potential uses and unique characteristics could help support the transition of our current linear consumer economies into more circular economies that allow for greater recycling or upcycling of products and lower carbon footprints. This chapter reviews a number of the current and potential uses for hemp and some of the challenges that may be faced on the path to making hemp a vital component of sustainable societies.
Full-text available
Occurrence of molds and actinomycetes in the breathing zone of farmers during the handling of hay, straw, or grain was studied with the use of an Andersen sampler on 35 farms in Finland. On 24 farms there was a person with recently diagnosed farmer's lung disease, and on 11 farms people were free of the disease. The total spore concentration and the concentrations of the spores of Thermoactinomyces (T) vulgaris, Micropolyspora (M) faeni, and Aspergillus (A) umbrosus were statistically significantly higher on the farms of patients with farmer's lung than on the disease-free farms. The mean proportions of the spores of thermotolerant and thermophilic microbes were greater on the farms of farmer's lung patients than on the reference farms. T vulgaris was the predominant actinomycete species. Both T vulgaris and A umbrosus were found on all farms of farmer's lung patients, but M faeni on only about half of such farms. The findings match the results of previous microbiological analyses of Finnish moldy hay and serological analyses of Finnish farmer's lung patients. It seems that T vulgaris, not M faeni, may be the main causative agent of farmer's lung in Finland. The possible etiologic role of A umbrosus requires further investigation. Because the farmers often failed to identify the moldiness of the plant material in contrast to researchers, it might be possible, through training, to improve farmers' ability to identify moldiness.
The use of shredded newspaper as horse stall bedding was evaluated for its compost quality and potential effects on strongyle ova. Small volumes of waste generated by one horse developed sufficient temperatures to prevent development of strongyle ova and killed greater than 99% of the larvae. Composting in a ground stack was nearly as effective as bin composting though a few larvae survived. Newspaper compost developed higher temperatures than either straw or wood shaving compost. The latter two bedding mediums did not successfully control strongyle larval development.
Horse manure management is becoming a major concern in suburban areas of the United States. An average horse can produce eight to ten tons of manure per year, accumulating at a rate of two cubic feet per day, including bedding. If properly composted, the manure and bedding can be transformed into a very useful, odorless, pathogenfree product. The objective of this trial was to compare the characteristics of recycled chopped phone book paper, sawdust and wheat straw bedding during composting. Six horses were stalled on three bedding types: recycled phone book paper, sawdust and straw. Each day manure and soiled bedding types were separately collected and transported to compost sites over an eight-day period. Three compositing bins were each hand constructed from wooden pallets with 10 cm slats. The front of the bin was left open for manipulation of materials during the composting process. Initial volumes of the soiled bedding materials were 1m3, 1m3, and 1.5m3 for paper, sawdust and straw, respectively. Temperatures were taken for each bedding materials using a 51 cm REOTEMP compost thermometer. Temperatures were taken on Day 0 and every four days over the 65-day trial (n=52). Temperature was used to determine the need for moisture addition and aerating by turning to keep the piles microbially active. On Day 37 the C:N ratio was adjusted by the addition of ammonium sulfate, 0.1 kg, 0.1 kg and 0.14 kg for sawdust, phone book paper and straw piles, respectively. Mean standard error and range for compost temperatures (C) were: phone book paper, 33.17±10.33 (13–52); sawdust, 45.6±9.35 (27–58); straw, 30.42±6.57 (16–39). The sawdust composted more readily as compared to the phone book paper or straw. The paper and straw had poorer structure, which caused compaction of the material when moistened; thus, porosity, oxygen supply and microbial activity were reduced.
Endotoxins are part of the outer membrane of Gram-negative bacteria and are present ubiquitously in the environment. The lipopolysaccharide (LPS) part of the molecule is responsible for its toxic properties. Environmental monitoring is usually performed by sampling airborne dust and subsequent analysis of aqueous extracts by using a LAL assay. The kinetic version of this assay can measure concentrations as low as in the pg/m3 range. A generally accepted protocol is not yet available. Endotoxin levels are related to the occurrence of Gram-negative bacteria. Animal faeces and bacteria contaminated plant materials contribute most to organic dust related endotoxin exposure. Endotoxin exposure is therefore most prevalent in agricultural and related industries. Acute health effects are dry cough and shortness of breath accompanied by a decrease in lung function, fever reaction and malaise, and sometimes dyspnea and headaches occurring a few hours after the start of the endotoxin exposure. Epidemiological and experimental studies suggest that chronic endotoxin exposure may lead to chronic bronchitis and reduced lung function. Depending of the relevant health effect, no effect levels range from 9 to 170 ng/m3. The Dutch Expert Committee on Occupational Standards (DECOS) of the National Health Council proposed a health based recommended limit value of 50 Endotoxin Units/m3 (4.5 ng/m3) over an 8 hour exposure period.
Hay, grain, silage, and bedding are the sources of mold dust in agriculture. The aim of the present study was to evaluate the effect of different farming methods on exposure to airborne microbes. The study material comprised 50 silage, 54 hay, 47 grain, and 70 bedding samples taken on 18 farms in the beginning, middle, and end of the indoor feeding season. The modified wind-tunnel technique and six-stage impactors were used to determine the number of mesophilic bacteria, xerophilic fungi, mesophilic fungi, thermotolerant fungi, and thermophilic actinomycetes liberated from each material. Baled hay and straw liberated the largest amounts of microbes. Hay, except when dried in storage, liberated great numbers of fungal spores. The proportion of respirable airborne microbe-bearing particles was greatest in the highest concentrations. Theoretically, choosing the best possible alternative work methods could diminish exposure to microbes to one-tenth of the present level.
The concentration of fungal spores, the main constituents of respirable dust in stables, is determined by rates of release from fodder and bedding and rate of clearance, principally by ventilation. This paper outlines the principles that govern the application of natural ventilation to the control of air hygiene in barns and individual boxes for horses. When release rates are low, ventilation rates over four air changes per hour are satisfactory. Ventilation was satisfactory in individual boxes but usually unsatisfactory in barns and specific recommendations are made for improvement. Preliminary observations in stables with clean, well-managed bedding revealed only small differences between straw, wood shavings and paper. In these circumstances hay tended to be the major source of respirable spores.
This paper describes and compares three techniques of categorisation of hay, straw and other feeds and beddings collected from stables. A hand-held sampler was used to categorise samples according to the presence of plant material, fungal spores and dust mites. An Andersen sampler was used to categorise samples according to the thermotolerances of fungi and actinomycetes. An aerodynamic particle sizer was used to categorise samples according to respirable particle release rates. The highest burden of respirable particles was associated with the presence of thermophilic and thermotolerant actinomycetes and fungi. The portable slit sampler proved to be an accurate, quick and simple semiquantitative method of assessing the mould contamination of source materials. This latter technique requires only a microscope and the sampler, and is thus ideal for veterinary practices and small diagnostic laboratories.
The occurrence of microfungi in the air and in feeding and bedding materials was studied on 32 Finnish dairy farms. Air samples for determining viable and total spore concentrations were collected on membrane filters and with a cascade impactor. Genera of mesophilic, xerophilic, and thermophilic fungi were identified in four culture media. Total spore counts were done with the aid of an epifluorescence microscope. To identify fungal flora in agricultural materials, feeding and bedding material samples were also taken from the farms. The airborne spore concentrations varied for viable mesophilic, xerophilic, and thermophilic fungi from 10(1) to 10(7) colony-forming units per cubic meter, and for total spores from 10(5) to 10(7) spores per cubic meter. Aspergillus, Penicillium, Cladosporium, Absidia species, Wallemia sebi and yeasts were the predominant fungi in the air, as well as in the material samples. In general, the airborne spore concentrations were high although the variation in the concentrations of different fungal groups was large between the farms. Along with using new growth media, two fungi whose prevalence was earlier poorly known in Finland were detected. W sebi proved to be the most abundant xerophilic fungi in the air and hay samples, while Fusarium spp were very common in grain and straw but rare in air.
Airborne dust concentration (ADC) was measured in 2 different horse management systems using an Andersen cascade impactor in the box-stall, and a personal Marple cascade impactor attached to the halter to measure ADC in the breathing zone. The levels of aeroallergens implicated in chronic obstructive pulmonary disease were measured by radioallergosorbent-inhibition immunoassay. A conventional management system (System C) utilising hay feed and straw bedding, and a recommended environment (System R) utilising wood shaving bedding and a complete pelleted diet were studied. In the stall, total and respirable ADC (geometric mean) were significantly higher in System C (2.55 mg/m3; 0.44 mg/m3, respectively) than in System R (0.70 mg/m3; 0.20 mg/m3, respectively). In System C, the total and respirable ADC in the breathing zone (17.51 mg/m3; 9.28 mg/m3) were much higher than in the stall, but values in both regions were similar in System R (0.52 mg/m3; 0.30 mg/m3). Major aeroallergens were significantly higher in System C than in System R: Micropolyspora faeni (1423 ng/m3 and 705 ng/m3), Aspergillus fumigatus (1823 ng/m3 and 748 ng/m3), and mite allergens (1420 ng/m3 and 761 ng/m3). Measurement of ADC with personal samplers indicates that the very high inhalation challenge in the breathing zone is not reflected in measurements of stall air quality. When compared with System C, System R produced only 3% of the respirable dust burden in the breathing zone and a decreased aeroallergen challenge.