PRESENTATION
BROCHURE
BIOSECURITY in Poultry Production BIOSECURITY in Poultry Production
Antonio Callejo Ramos Jordi Bou Riu Pedro Gil Sevillano Samuel Novoa Villares Sonia Téllez Peña
BIOSECURITY in Poultry Production
Biosecurity in Poultry Production
BIOSECURITY in Poultry Production Antonio Callejo Ramos Jordi Bou Riu Pedro Gil Sevillano Samuel Novoa Villares Sonia Téllez Peña
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This book presents different strategies and measures for reducing the risk of disease entering and spreading during the various stages of poultry production, while also trying to focus on biosecurity as part of the work culture rather than just a health strategy.
TARGET AUDIENCE:
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✱ Production animal vets Poultry ✱ Animal production technicians ✱ Veterinary students FORMAT: 22 × 28 cm NUMBER OF PAGES: 128 NUMBER OF IMAGES: approx. 150. BINDING: hardcover
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Author and collaborators ANTONIO CALLEJO RAMOS Antonio Callejo lectures in animal production at the Technical University of Madrid’s Higher Technical School of Agricultural, Food, and Biosystems Engineering. JORDI BOU RIU, PEDRO GIL SEVILLANO, SAMUEL NOVOA VILLARES, SONIA TÉLLEZ PEÑA
KEY FEATURES:
➜ Innovative guide with an alternative approach to biosecurity. ➜ Written by university lecturers and technical experts in poultry production. ➜ Brings together and summarises the most relevant information in a practical and educational manner.
Biosecurity in Poultry Production
Presentation of the book In recent years, intensive poultry production has faced some complicated health and commercial challenges. Maintaining the correct health status of hundreds of thousands of animals on a single farm is the first requisite to ensure food safety for consumers. And maintaining a disease-free population is no small challenge. It is therefore necessary to reduce the risk of pathogens entering farms and other poultry facilities (hatcheries, egg classification centres) and prevent their spread. In essence, we need to guarantee a sufficient level of biosecurity. Traditionally, action protocols used to stop the advance of diseases were based on initiating treatment programmes once the pathological process had already made itself evident. The industry subsequently promoted vaccination programmes, which are clearly applicable and necessary. In recent years, however, this strategy has been considered insufficient, especially when we find ourselves faced with processes with a multifactorial origin, where germs are one cause of disease, but not the only one and sometimes not even the most important cause. This book endeavours to bring together and summarise the plethora of information available on the topic in an educational and relatively succinct text, presenting a new approach compared to the more traditional theory of passive and active biosecurity (or that of sanitary barriers and hygienic measures). The work is a collaboration between university lecturers and technical experts from poultry companies. In addition, the book aims to go beyond considering biosecurity as just a technical concept or health strategy. In our opinion, BIOSECURITY (in uppercase letters) should be regarded as a mentality; as a work culture that should enable poultry farms to operate at their maximum output. Antonio Callejo Ramos
The author Antonio Callejo Ramos Dr Callejo has a PhD in agricultural engineering and lectures in animal production at the Higher Technical School of Agricultural, Food, and Biosystems Engineering within the Technical University of Madrid (ETSIAAB-UPM). His academic career spans more than 30 years lecturing in poultry production and he has supervised numerous bachelor theses in the area. Furthermore, he has directed several research projects with companies in the sector, all conducted at the Laying Hen Research Unit at ETSIAAB-UPM. As part of his professional activity, Dr Callejo has drafted various technical projects for livestock farms, as well as waste management and livestock farm improvement plans. He has written the following books: Cow comfort: el bienestar de la vaca lechera [Cow Comfort: Dairy Cow Welfare] (Editorial Servet, 2009), El confort del ganado lechero en épocas de calor: manejo del estrés térmico [Dairy Cow Comfort during Hot Periods: Handling Thermal Stress] (Editorial Agrícola, 2015), and Bioseguridad en las granjas de vacuno de leche [Biosecurity on Dairy Farms] (Editorial Servet, 2016). Dr Callejo has also published over 120 technical articles, monographs, and book chapters in the field of animal welfare, biosecurity, the design of livestock facilities, mechanical milking, waste management, and the environmental impact of livestock production, among other subjects. During his career he has delivered more than 90 courses and seminars. He is a member of the Spanish Association of Poultry Science (AECA), the Spanish branch of the World Poultry Science Association (WPSA).
Biosecurity in Poultry Production
Collaborators Pedro Gil Sevillano Pedro Gil earned his degree in veterinary medicine at the Complutense University of Madrid (UCM), Spain. He has worked as a poultry consultant for over 30 years. He is an associate lecturer at the Faculty of Veterinary Medicine at the UCM and vice-president of the Spanish Association of Poultry Science (AECA).
Samuel Novoa Villares Samuel Novoa obtained a degree in veterinary medicine at the University of Extremadura, Spain, in 2005. He currently works for Cobb Española S.A. as a veterinary technician in charge of grandparent farms and the technical service for clients in Spain and Portugal.
Sonia Téllez Peña
hkeita/shutterstock.com
Dr Sonie Téllez earned a PhD in veterinary medicine from the Complutense University of Madrid (UCM). From 2003 to 2014, she worked as a researcher at the UCM’s Centre for Veterinary Health Surveillance. Since 2014, she has been in charge of the Quality Control and R&D Department at the company Lípidos Toledo S.A.
Table of contents 1. Principles and foundations of biosecurity Definitions and concepts Importance of biosecurity. Objectives Training in biosecurity Main diseases to be dealt with. Sources of contamination Biosecurity and food safety Health legislation in poultry production
2. Biosecurity plan Assessing and establishing risk levels Biosecurity plan based on the HACCP system Developing a biosecurity plan Training: key to the success of biosecurity
3. Strategic biosecurity Location of the farm Design and orientation of the facilities
4. Structural biosecurity Outdoor facilities Changing rooms, offices, and other staff areas Feed silos and water tanks Cleaning and disinfection facilities Stores: eggs, materials, medicines Biosecurity and animal welfare: density, environmental monitoring, transport
5. Operational biosecurity (I) Control of primary materials: animals, feed, water, materials Control of entries. Risks associated with people and vehicles Flows and movements on the farm Pest control: birds, insects, rodents
6. Operational biosecurity (II) Cleaning and disinfection Control of biofilms Sample taking Waste management
7. Specific biosecurity Breeding farms Broiler farms Layer farms Egg classification centres Hatcheries
8. References
Editorial Servet
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Plaza Antonio Beltrán Martínez, 1 Centro Empresarial El Trovador planta 8, oficina 50002 Zaragoza, Spain
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+34 976 461 480
BIOSECURITY in Poultry Production Antonio Callejo Ramos Jordi Bou Riu Pedro Gil Sevillano Samuel Novoa Villares Sonia Téllez Peña
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Farms with other species. Certain diseases, for example, influenza and salmonella, can affect different species. Therefore, it is advisable to avoid other livestock farms within a minimum radius of 1 km (protection zone). Proximity of roads and transport links. The farm’s perimeter fence should be at least 50 m from any road, or 100 m in the case of roads with a significant flow of livestock. The circulation of livestock transport vehicles causes air and dust to move around, which consequently spreads pathogens expelled by sick animals, so access roads to the farm should preferably be paved. In rainy periods, mud on unpaved access roads means they become burdensome, even impassable, besides producing a lot of dirt.
The ideal location for a poultry farm is a dead-end road that only leads to the farm itself.
h
20 h
FIGURE 2. Protection from natural windbreaks; h: height of the trees; 20 h: distance between the trees and the farm (20 times greater than their height). Adapted from Íñigo, 2005.
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Slaughterhouses, feed mills, or livestock markets in the vicinity of the planned farm. Sources of contamination such as landfills, carcass disposal facilities, etc. Proximity of forests or bodies of water (canals, lakes, rivers) that host large numbers of wild and migratory birds, thus presenting a high risk of transmitting avian diseases. However, trees can be planted around the farm to serve as a windbreak and they even provide shade and create a cooler microclimate in the vicinity of the sheds. The installation of natural windbreaks (by planting trees and bushes) at a suitable distance (20 times greater than their expected height) and with an air permeability of 50 % can help filter out dust and aerosol particles that could potentially transport pathogens, provided that they do not reduce the quality of ventilation in the poultry houses (Fig. 2). Terrain topography and orientation. The variability of the microclimate where the farm is located could have a decisive influence on natural ventilation. Any sites that may increase the temperature and relative humidity, while reducing the frequency and speed of wind currents, carry an increased risk of thermal stress in summer.
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Local climate. Always consider the possibility of large temperature fluctuations throughout the year and even over a 24-hour period. Spain is a prime example of such fluctuations. Prevailing winds should be taken into account to decide on the orientation of poultry houses. Others. The choice of location for a poultry farm is also subject to a series of constraints such as town planning and land management regulations, the availability of infrastructure, waste disposal, and so on. Generally speaking, the ideal site would be on healthy land that is protected from strong winds but well ventilated, dry, and well drained, while avoiding: ■ Excessively close obstacles that could interfere with ventilation. Poultry houses should be separated from each other as well as from trees, walls, embankments, etc., by a distance that is at least five times the obstacle’s height. ■ Hills exposed to the wind that could result in too much air blowing through the houses. ■ Enclosed areas with insufficient ventilation, humidity, and high temperatures.
Bear in mind, as we shall explain in Chapter 3, the close relationship between animal welfare and biosecurity, hence the need to locate the farm on a site where the appropriate environmental conditions for the animals can be attained without too many complications.
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DESIGN OF THE FARM AND ORIENTATION OF THE FACILITIES The next step in strategic biosecurity is the organisation of the farm’s physical space and production cycle. The production areas must be isolated from the company’s other facilities. Common areas for the feed mill (if there is one), animals, offices, etc., may equate to financial savings, but make it almost impossible to implement effective biosecurity measures. An adequate farm design will allow flows (of animals, feed, manure, vehicles, people, etc.) between the different facilities to develop appropriately and coherently, both in space and in time, and without interferences. Animals, materials, people, and vehicles should all circulate in the same one-way direction between the farm’s buildings, although this proves quite difficult to implement in a daily routine. Trucks delivering feed have no alternative but to drive up to the stores or silos. Therefore, these facilities should be located close to the farm entrance, so the trucks do not pass through areas where animals are housed.
These measures should be considered at the outset, when dealing with the farm’s planning stage. Any errors committed during this initial stage are sometimes hard to correct and when they can be rectified they almost always prove expensive.
DESIGN OF THE FARM The design principle for a poultry farm is portrayed by the circles in Figure 3, which reflect two types of zone: a clean area and an unclean area. The clean area includes the poultry houses (where the animals are housed), which should be isolated as much as possible, and the internal supply zone, which contains the stores or feed silos. The clean area must be disease free, have minimal contact with the external environment, and subject to rigorous control. Its dimensions will be determined by the facilities used to establish the area. The unclean area serves to retain the threats from which the farm needs to be protected. This perimeter includes an external supply zone that immediately surrounds the clean area and will receive the most monitoring from within the farm. A 1-km radius should be assigned as a protection zone around the farm and any potential hazards (e.g. other farms) in this area should be studied.
A farm’s clean and unclean areas must be clearly delimited.
External supply zone Protection zone
UNCLEAN AREA
Internal supply zone
Biosecurity measures basically contemplate two key points, the implementation and application of which require the presence of certain facilities and/or outbuildings, as well as their correct location. Although they should be addressed in the planning stage (passive biosecurity), we have chosen to cover them in this section on active biosecurity in order to link them more clearly with the control of entry of people and vehicle and primary materials – the two main cornerstones of biosecurity.
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15
1 km
Production area CLEAN AREA
FIGURE 3. Conceptual diagram of the protection zones for a poultry farm (Javier Labairu, 2009).
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Based on this principle, the poultry farm clean area should have maximum protection and any exchanges with the exterior must be controlled at all times. To meet this end, farms should count on the following installations.
Perimeter fence
allow trucks transporting feed or animals to go about their work without entering the area housing the animals.
The use of off-farm tractors and trucks to collect and remove manure is particularly hazardous. The farm’s own vehicles should deposit manure outside the farm perimeter for subsequent collection by external vehicles.
The first biosecurity measure that should be considered is a perimeter fence. The fence should be continuous, measure at least 2.4 m high, and penetrate 50 cm into the ground, thus preventing animals from entering the farm. The mesh size should be no greater than 5 cm. A perimeter fence serves to physically obstruct the access of animate and inanimate vectors to the poultry houses and concentrates entry to the facilities at a single point, which must be well-lit and correctly controlled, that is, it must remain closed when not in use (Fig. 4). The incorporation of just a single entry point means it can be equipped with a disinfectant wheel dip. We recommend that external vehicles, such as those delivering or collecting livestock2 or removing carcasses, have limited access to the farm. An animal loading and unloading point should be included at the farm’s perimeter to fulfil this function. Therefore, when introducing or withdrawing animals, it is preferable to use cages that can be unloaded from the truck and placed inside the houses. This will keep trucks away from the houses. All cars must park outside the farm or in a designated car park located outside the clean area. This point must be considered when designing poultry farms, as should provisions to
The farm must have elements or facilities for disinfecting vehicles that need to gain entry to the site. A disinfection wheel dip or bath (Fig. 5) only disinfects the wheels and meets the corresponding regulatory requirements. However, they are of limited utility in the authors’ opinion, because pathogens are not only transported on wheels3, but also on the vehicle’s entire surface. Wheel dips also require constant and effective maintenance, as the disinfectants are easily inactivated by the organic matter found on the wheels. Hence, the water and disinfectant solution must be replaced frequently, but in some cases they can prove hard to empty and therefore the disinfectant is not replaced as often as it should be. In any case, a wheel dip must guarantee the entire perimeter and height of the tyres are disinfected, so they must be deep enough and long enough (approx. 4 m) to accommodate at least two full revolutions of the wheels.
FIGURE 4. All farm entry points should be kept closed.
FIGURE 5. A wheel dip disinfection bath.
Disinfection wheel dip
2
Any trucks that come to collect animals from the farm should be denied access if they are not completely empty.
3
Given that tyres reach high temperatures when in motion, they are probably the one part of the vehicle with the lowest microbial load.
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Pressurised cleaning equipment designed for wheels and underbodies can often be used instead of wheel dips. This method is undoubtedly more effective because it means more elements can be cleaned and disinfected. The problem with this option is that it sometimes goes unused or is not always available.
The most suitable piece of equipment is a disinfection arch (Fig. 6); this sprays the vehicle’s entire surface with disinfectant (including the underbody) and always applies a clean, new solution. They also tend to be more expensive.
Special attention must also be paid to other hazardous areas of the vehicle such as loading lifts or ramps, the cab and its mats, and the driver’s footwear and clothing. Therefore, drivers must not leave their cabs if they do not meet the farm’s rules. In Europe, current animal transport regulations require that vehicles are disinfected at an authorised centre4.
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Animal loading ramp Poultry farms do not usually have an animal loading ramp, as the birds enter and exit the houses inside large cages or in containers loaded with cages that are moved around on wheels. From a biosecurity perspective, it is better to avoid the use of poultry transport trucks that lack such containers, because they would have to enter the clean areas. Trucks that are equipped with these containers but lack a loading lift are not recommended either, because the outcome is the same if the farm does not have appropriate machinery (forklift truck or tractor).
Changing rooms and toilets Changing rooms and toilets are often only viewed as a facility required for the farm staffs’ health and convenience (obviously they are essential) and not as an element that should contribute to the farm’s health status. Everyone, including the farm’s employees, must shower each time they enter the poultry houses and put on clothes that are worn exclusively on the farm. This measure is also a requisite for anyone who is constantly visiting different farms as part of their work, such as visiting vets and technicians. Anyone who refuses to comply should be declined access. The changing rooms should therefore be located so that they act as an element of separation between the clean and unclean areas, while respecting the “one-way” system to avoid recontamination of the changing area (Fig. 7). Logically, the changing rooms must be situated at the installation’s perimeter, so people have to pass through them in order to reach the animals (Fig. 8). This important facility will be further addressed in the next chapter.
Location of silos and stores Feed silos should be positioned next to the poultry houses, allowing for complete automation of the food distribution process, but still within the fence and accessible from the exterior, so they can be refilled from the external supply zone situated between the two fences. This would mean that neither the truck nor the driver need to enter the farm (Fig. 9).
FIGURE 6. Disinfection arch. 4
European legislation requires member states to publish regulations concerning vehicle disinfection.
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a
b Boot wash area
Clean clothes
Clean area Showers Unclean area Shoe removal area
Entry through the showers Off-farm clothes
FIGURE 7. Diagram of a changing room. Oblique, 3D view (a: adapted from David Jiménez, 2017) and plan view (b: adapted from John Carr, 2016).
FIGURE 8. Changing rooms should be located at the farm entrance.
Manure If the manure is stored at the farm, the storage point should be located as far away as possible from the sheds. In the production models or stages that use litter, it is usually withdrawn at the end of the production cycle (although in some countries it is reused in several breeding stages due its cost), so its management forms part of the cleaning and disinfection process. Litter is usually a relatively dry waste product and therefore generates less odour problems than more humid waste. However, on layer farms most droppings (or all of them in caged production systems) fall onto collection belts. These droppings are normally removed at least twice a week, which means farms require an external storage system. Older farms
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FIGURE 9. A double fence is a useful biosecurity measure. Trucks with feed remain outside the farm’s inner fence.
often included a covered pit at one end of the shed. In modern poultry facilities, where the droppings are drier or have undergone a pre-drying process, they should be loaded onto a truck and quickly withdrawn from the vicinity of the shed. Trucks performing this task should be allowed access to the external supply zone but not to the production area.
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Carcass disposal
Other considerations
Carcass management is regulated by European legislation . Dead poultry should be deposited in a container suited to such a purpose, preferably within biodegradable bags to avoid contaminating the container. The container should be located in the external supply zone, hence the carcass collection truck will not have to enter the poultry production area, and close to the farm perimeter to facilitate its collection by the truck’s crane. Preferably, it should be isolated using a physical separation (fence, partition, etc.), situated on a surface that can be cleaned and disinfected easily (e.g. cement), and equipped with a drain to collect wastewater generated during cleaning. The installation of refrigeration or freezer units for carcass storage would represent an additional biosecurity measure because it would decrease the number of visits from the collection truck and therefore reduce the risk of introducing pathogens. On the other hand, the installation of an incinerator would eliminate the need for carcass collection, although the incineration process must be perfectly controlled to ensure it does not become a focus of sanitary problems.
The farm entrance should be well signposted with signs that announce the restricted entry. There should be a small hatch for the delivery and reception of small materials and a disinfection shed for materials entering the farm. All meters and inspection boxes should be located outside the farm, so they can be read from the external supply zone. Maintain a 5 m corridor around the fence free from any vegetation, thus avoiding situations like the one shown in Figure 10. Grass and vegetation growing in the vicinity of a poultry house could serve as a refuge for rodents and other animals. Laying concrete in all or part of this corridor should prevent the entry of rodents and provides a surface for washing and storing removable equipment (Fig. 11). Another option is to install a 1 m strip of weed control fabric covered with a 10 cm layer of gravel. Nevertheless, paved areas around the houses are much easier to clean.
FIGURE 10. Areas surrounding the fence and the sheds should be free from vegetation or well maintained (Bioseguridad en las granjas de vacuno de leche [Biosecurity on Dairy Farms]; Callejo, 2016).
FIGURE 11. The paved corridor surrounding the houses is easy to clean and prevents the growth of weeds.
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ORIENTATION OF POULTRY HOUSES The orientation of poultry houses is particularly important when ventilation is natural or static, as the movement of air inside a house will largely depend on the speed of the wind blowing
Regulation (EC) No. 1069/2009 of 21 October 2009 laying down health rules as regards animal byproducts and derived products not intended for human con-
sumption. Regulation (EU) No. 142/2011 of 25 February 2011 laying down the provisions for implementing regulation (EC) No. 1069/2009.
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across it (wind orientation). In principle, the longitudinal axis of the houses should be positioned perpendicular to the prevailing wind, with a tolerance of up to 45°. Houses located on the sides of a valley should run parallel to the direction of the valley, so that any ascending or descending currents cut across the buildings. Even so, in warm climates, poultry houses tend to be oriented in an east to west direction, unless other circumstances require a different approach. The values indicated in Figure 12 are the percentages of the total incident radiation falling on each wall and the roof of the building. The aim is to obtain a balance: ■ In winter, ideally, the south wall of the building should capture and use the sun’s radiation to reach a higher temperature than the north wall, thus favouring the movement of air in the absence of any wind. ■ In winter, the aim is to avoid an excess of sun, with proper thermal insulation on the roof and shade on the south wall.
Take advantage of the wind all year long, especially in summer.
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In any case, the relationship between ventilations patterns and the wind is rather complicated. Firstly, wind speed and direction change constantly. The speed often varies by as much as ± 100 % in the space of just 5 minutes. Similarly, although wind direction generally fluctuates by ± 25°, variations of 45° to 70° with respect to the dominant direction are relatively common. Alignment according to the sun should be considered before the wind. In buildings with dynamic ventilation, the eolic orientation is less important, so a beneficial solar orientation will take priority. In this case the wall ventilators should be sheltered from strong winds which could affect how they work and result in incorrect ventilation and energy wastage.
Evidently, all installations that could represent a source of contamination such as manure pits, carcass storage areas, and so on, must be located downwind (with respect to the prevailing wind) of poultry production areas.
Planners should ideally have a wind rose for the area which provides information on local wind frequency, strength, and direction; this will help establish the correct orientation for the poultry houses (Figs. 13 and 14).
a
b Winter: total radiation 6,587 W/m2
W
Summer: total radiation 13,464 W/m2 N
22.8 % 15.5 %
W
6.9 %
39.3 %
S
15.5 %
11.3 %
12.5 %
E
S
N
32.8 % 21.7 %
21.7 %
E
FIGURE 12. Summer (a) and winter (b) radiation patterns received by a farm oriented correctly with respect to the sun. (Climatización porcina volumen II [Environmental Control in Pig Housing: Volume II]; Escobet, 2017).
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a
N
b
N NNW
NNE
NNW NE
NW
NNE NE
NW
WNW
ENE
WNW
ENE
W
E
W
E
WSW
WSW
ESE
SE
SW SSW
c
S
21
ESE
SE
SW SSE
SSW
SSE
S
N NNW
NNE NE
NW
WNW
ENE
W
E
WSW
ESE
SE
SW SSW
a
S
SSE
FIGURE 13. Example of three building orientations, where the longitudinal axis is at 10° (a), 45° (b), and 90° (c) with respect to the prevailing wind. The frequency (%) is shown by the blue line, while the red line corresponds to wind speed (m/s). In this example orientation (c) is the best eolic alignment because the prevailing wind blows perpendicular to the shed, although it would be exposed to too much sun in the summer. Therefore, option (b) is recommended, in which the prevailing wind is sufficiently diagonal and less sun falls on the walls. (Climatización porcina volumen II [Environmental Control in Pig Housing: Volume II]; Escobet, 2017).
b
N NNW
NNE NE
NW
WNW
ENE
W
E
WSW
ESE
SE
SW SSW
S
SSE
c
FIGURE 14. Steps used to determine the correct orientation for four sheds in a property delimited by the yellow perimeter line. In theory, the best solar orientation for the four sheds is east to west (a). The wind rose for the area (b), where the blue line represents the frequency and the red line is the wind speed, imposes a 20° change in orientation towards north to achieve an ideal solar–eolic balance (c).
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Final considerations The aim of this chapter is to highlight the importance, in terms of biosecurity, of adequate planning in the construction of poultry farms, as any errors made at this stage cannot usually be corrected at a later date. A suitable location will provide greater geographical isolation and therefore serves as the first and most important measure in preventing infectious pathogens from entering the farm. Geographical isolation should be combined with physical isolation by means of a perimeter fence and suitable farm design that restricts and controls the entry of pathogen vectors. Finally, never forget that correct shed orientation should achieve better control over the environmental conditions in the poultry housing areas; it also reduces costs by essentially reducing the thermal load affecting the sheds during hot periods and the amount of heating required in winter. Once again, emphasis should be placed on the important role that comfort plays in the animals’ resistance to disease.
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