Chapter 6.3.

Hygiene and disease security procedures
in poultry breeding flocks and hatcheries

Article 6.3.1.

1. The choice of a suitably isolated geographical location, taking into account the direction of the prevailing winds, facilitates hygiene and disease control. The establishment should be surrounded by a security fence and a gateway to control traffic and access to the site. A sign indicating restricted entry should be posted at the entrance.

2. Poultry breeding establishments should be single purpose - single species enterprises, and ideally an all in all out single age group principle should be adopted whenever possible.

3. Where several flocks are maintained on one establishment, the individual flocks should be managed as separate entities.

4. Buildings housing poultry or those used to store feed or eggs should be free of vermin and not accessible to wild birds.

5. Poultry houses should be constructed so that all surfaces inside the buildings are of an impervious smooth material so that cleaning and disinfection can be carried out adequately.

6. The area immediately surrounding the poultry houses should be free from vegetation and debris and ideally this should consist of an area of concrete or other similar material. An exception to this would be trees for heat control, with the exception of fruit trees which could be attractive to birds.

7. Domestic animals should not be permitted access to poultry houses.

8. Appropriate disease security precautions, which could include showering and changing facilities, should be adopted for all visitors to the establishment and for all staff entering individual poultry houses.

9. When a poultry house or establishment is depopulated, all manure should be removed from the houses and effective cleaning and disinfection procedures applied. Bacteriological monitoring of the efficacy of disinfection procedures is recommended. When necessary, rodent and insect control procedures should also be carried out.

10. Repopulation of poultry houses or establishments should only be made from poultry flocks of known high health status and which are regularly monitored for salmonella and other poultry pathogens.

11. All feed used in poultry houses and establishments should be monitored for salmonella prior to use. The use of pelletised feeds or feeds subjected to other salmonella decontamination procedures is recommended. Feed should be stored in clean closed containers.

12. The water supply to poultry houses should be of a satisfactory potable status.

13. Sick and dead birds should be removed from poultry houses as soon as possible and effective and safe disposal procedures implemented.

14. Full records relating to mortality, disease diagnosis, treatments and vaccinations should be maintained on an individual flock basis within the establishment. Such records should be readily available for inspection.

Article 6.3.2.

1. The litter in the laying house should be kept dry and in good condition. The nest box litter should be clean and adequate in quantity.

2. Eggs should be collected at frequent intervals of not less than twice per day and placed in clean disinfected containers.

3. Dirty, broken, cracked, leaking and dented eggs should be collected in a separate container and should not be used for hatching purposes.

4. The clean eggs should be sanitised as soon as possible after collection. The methods of sanitisation are described in Article 6.3.7.

5. The sanitised eggs should be stored in a clean, dust free room used exclusively for this purpose and kept at a temperature of 13-15°C (55°-60°F) and at a relative humidity of 70-80%.

6. The eggs should be transported to the hatchery in new or clean cases which have been fumigated or sanitised with a liquid disinfectant (see Table 1). The cleaning and disinfection of vehicles must be a regular part of the hatchery routine.

Article 6.3.3.

Article 6.3.4.

Article 6.3.5.

1. Clean coveralls or overalls, hats and footwear must be provided for all personnel and visitors entering the establishment or the hatchery.

2. A disinfectant foot-bath for footwear is necessary and the disinfectant solution should be changed frequently. Washing the hands in disinfectant solution or with soap and water should be required.

3. Personnel and visitors should have no direct contact with other poultry or poultry products.

Article 6.3.6.

1. Egg handlers in the hatchery should wash their hands with soap and water and change to clean outer garments before handling hatching eggs received from the poultry farm.

2. Chick sexers and chick handlers must wash and disinfect their hands and change into clean protective clothing and boots before commencing work and between different lots of chicks.

3. Day-old chicks or other poultry must be delivered or distributed in new chick boxes; or in used boxes made of suitable material which have been thoroughly cleaned and disinfected or fumigated.

4. The chicks should be delivered directly from the hatchery by personnel wearing clean, disinfected outer clothing. Outer clothing should be changed or disinfected between each delivery.

5. The delivery truck must be cleaned, and disinfected before loading each consignment of chicks.

Article 6.3.7.

1. fumigation with formaldehyde, or

2. spraying with or immersion in an egg shell disinfectant in accordance with the manufacturers instructions, or

3. made hygienic by another method approved by the Veterinary Authority.

Formaldehyde gas has been used for many years for the disinfection of hatching eggs and hatchery equipment. As a fumigant, formaldehyde gas has proved to be a very effective means of destroying micro-organisms on eggs, egg cases, chick boxes, hatching machines and other hatchery equipment, provided these items have been subjected to preliminary cleaning. When the correct mixture of formalin and potassium permanganate is used, a dry brown powder will remain after the reaction is completed.

At the present time, there is lack of uniform opinion on the optimum concentration of formaldehyde required for the sanitisation of eggs and hatchery equipment. In general, three levels of concentration have been used. Also, two methods of use have been adopted.

1. Method 1

   1. Concentration A

      53 ml formalin (37.5%) and 35 g potassium permanganate per m³ of space.

      This can be expressed as:

      5.25 oz by volume (148.5 ml) formalin (37.5%) and 3.5 oz by weight (98 g) potassium permanganate per 100 ft³ (2.8 m³) of space.

   2. Concentration B

      43 ml formalin (37.5%) and 21 g potassium permanganate per m³ of space.

      This can be expressed as:

      4 oz by volume (120 ml) formalin (37.5%) and 2 oz (60 g) potassium permanganate per 100 ft³ (2.8 m³) of space.

   3. Concentration C

      45 ml formalin (40%) and 30 g potassium permanganate per m³ of space.

      This can be expressed as:

      4.5 oz by volume formalin and 3 oz potassium permanganate per 100 ft³.

   4. Procedure

      Fumigation of hatching eggs and equipment should be carried out in a special chamber or in a room or building constructed of impermeable material which can be made as airtight as possible. A fan is necessary to circulate the gas during fumigation and to expel it after fumigation is completed.

      The total volume of the room is determined accurately from the internal measurements. The space occupied by trays, or eggs, or articles to be fumigated, is to be disregarded. The quantities of materials required are based on the total volume.

      Place in the centre of the floor, one or preferably several large metal basins, metal trays or containers of earthenware, enamelware, asbestos or other non-inflammable material.

      PLASTIC OR POLYETHYLEN CONTAINERS ARE NOT TO BE USED due to the heat generated by the chemical reaction. To avoid possible fire hazards, the containers should slope outwards. Also, the containers must be large enough so that the two chemicals occupy no more than one quarter of the volume of the container. Preferably, the container should have a capacity of at least 10 times the volume of the total ingredients.

      The eggs should be placed on wire racks, in wire baskets or on cup-type egg flats stacked in a manner that will permit air circulation and exposure to the formaldehyde gas.

      An electric or hot water heater should be available in the chamber to maintain the temperature at 75°-100°F (24°-38°C). Water pans or other equipment should be available to provide a relative humidity of 60-80%.

      Place required amount of potassium permanganate into the containers BEFORE adding the formalin.

      Pour the required amount of formalin onto the potassium permanganate in the containers.

      Leave the chamber as quickly as possible and close the door. Some operators may wish to use a gas mask when pouring the formalin into the containers.

      The door of the chamber should be securely closed and permanently labelled to prevent accidental opening.

      The fans should be operated to circulate the formaldehyde and the fumigation time should be 20 minutes.

      After 20 minutes, the gas should be expelled through a controlled vent leading to the outside of the building.

      The door may be opened to facilitate expelling the formaldehyde to the outside.

2. Method 2

   An alternative method to the above is to use formaldehyde gas produced by the evaporation of paraformaldehyde. Proprietary preparations are available and the operation is carried out by placing the requisite amount of powder on a pre-heated hot plate.

   In this method it is necessary to ensure that the relative humidity of the chamber is sufficiently high (60-80%).

   Ten g paraformaldehyde powder or pellet is used per m³ of space.

3. Warning

   In carrying out fumigation, the following points should be borne in mind:

   1. Caution is necessary when formalin and potassium permanganate are mixed together in large amounts because of the risk of personal injury and fire through careless use. Formaldehyde gas causes irritation to the eyes and nose of the operator and the use of a gas mask is advised.

   2. Effective fumigation depends on optimum conditions of temperature and humidity. Formaldehyde gas rapidly loses its efficiency at low temperatures or in a very dry atmosphere.

Article 6.3.8.

1. Fumigation of eggs in setting machines

   Eggs should be fumigated within 12 hours after setting and after the temperature and humidity has returned to normal operating levels. The temperature of the machines must remain at the operating level.

   The setting machine doors and ventilators should be closed, but the circulation fan should be kept operating.

   After fumigation for 20 minutes, the ventilators should be opened to the normal operating position in order to release the gas.

   Warning

   Do not fumigate eggs that have been incubated for 24 to 96 hours, as this can result in embryo mortality.

2. Fumigation of eggs in hatching machines

   This is a common practice in certain areas and under certain conditions. The eggs should be fumigated after being transferred from the setting machine to the hatching machine and before 10% of the chicks have begun to break the shell. After transfer of the eggs, the hatching machines are permitted to return to normal operating temperatures and humidity. The ventilators are closed and fumigation is conducted with the fans running. In some countries, the standard amounts of formalin (53 ml) and potassium permanganate (35 g) per m³ are used. Fumigation time is 20 minutes. In other countries, 0.8 cc formalin (37.5%) is added to 0.4 g potassium permanganate for each ft³ of space; or 25 ml formalin to 12.5 g potassium permanganate per m³. Fumigation time is 20 minutes.

3. Fumigation of empty setting and hatching machines

   Following removal of all the eggs or the chicks and the subsequent cleaning and disinfection of the empty machine, the disinfected egg trays are replaced and the machine prepared for the next batch of incubating eggs.

   The doors and ventilators should be closed and the temperature and humidity returned to normal operating levels. Fumigation time should be at least 3 hours or preferably overnight, using the standard amounts of formalin and potassium permanganate (Concentration A).

   The machines should be well ventilated before use to remove any residual fumigant.

   Warning

   The above fumigation procedure applies to a machine in which there are no hatching eggs. Eggs and chicks cannot be fumigated using the above fumigation time.

4. Neutralisation of formaldehyde gas

   This can be achieved with a 25% solution of ammonium hydroxide using an amount not more than one half the volume of formalin used. The ammonia can be spread on the floor of the machine and the doors closed quickly.

Table 1. Properties and uses of disinfectants

Properties	Chlorine	Iodine	Phenol	Quats	Formaldehyde
Bactericidal	+	+	+	+	+
Bacteriostatic	-	-	+	+	+
Fungicidal	-	+	+	±	+
Virucidal	±	+	+	±	+
Toxicity	+	-	+	-	+
Activity with organic matter*	++++	++	+	+++	+
Use area
Hatchery equipment	+	+	+	+	±
Water equipment	+	+	-	+	-
Personnel	+	+	-	+	-
Egg washing	+	-	-	+	+
Floor	-	-	+	+	+
Foot baths	-	-	+	+	-
Rooms	±	+	±	+	+

Quats	=	Quaternary ammonium compounds
*	=	Number of + indicates degree of affinity for organic material and the corresponding loss of disinfecting action
+	=	Positive property
-	=	Negative property
±	=	Limited activity for specific property

Article 6.3.9.

1. At the present time the only method for monitoring poultry breeding flocks and hatcheries for salmonella is by means of bacteriological examination of samples obtained from these establishments.

2. Samples for bacteriological monitoring of poultry flocks are obtained in the case of rearing flocks from the premises in which the birds are housed or in the case of adult laying birds either from the premises in which the birds are housed or from the hatchery to which the hatching eggs from that flock are consigned.

3. The samples to be taken are:

   1. on the premises in which birds are housed - fresh faeces (each sample at least one gram), dead or culled birds, or in the case of day-old birds the chick box liners;

   2. at the hatchery - meconium, dead in shell and culled chicks.

   Additionally, it is recommended that environmental samples such as drag swabs, litter, feather, down and dust, are also taken in both the premises and the hatchery at a similar frequency. Where the laying flock is sampled only on the premises, environmental sampling of the hatchery is required.

4. The total number of samples to be taken on each occasion is shown in Table 2 and is based on the random statistical sample required to give a probability of 95% to detect one positive sample given that infection is present in the population at a level of 5% or greater.

Table 2. Number of samples

Number of birds in the flock	Number of samples to be taken on each occasion
25-29	20
30-39	25
40-49	30
50-59	35
60-89	40
90-199	50
200-499	55
500 or more	60

5. All samples should be selected at random to represent the house or in the case of samples taken at the hatchery to represent the hatching eggs from that poultry flock.

6. The following minimum frequency of sampling is recommended:

   1. Rearing flocks

      At day-old and 3 weeks before moving to laying accomodation.

      Where birds are moved from the rearing premises other than direct to laying accomodation, a further sample should be taken 3 weeks before such a movement.

   2. Breeding flocks in lay

      The laying flocks should be sampled at least at monthly intervals during the laying period.

7. All samples should be fully marked and identified as to the date of sampling and the flock to which the samples relate.

8. Samples should be stored in a refrigerator at between 1°C and 4°C until they are dispatched to the laboratory (not more than 5 days).

9. All samples should be examined in a laboratory authorised for that purpose by the Veterinary Authority.