Biosecure is sure

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biosecure, biosecurity, disinfectants, facts on fogging

The exclusion of pest, parasites, and diseases in an over riding priority for the poultry industry. Biosecurity is essential for safe and profitable production of all livestock, but poultry are especially at risk because:

• Intensive production, fast throughputs and short turaround times.
• Accentuated risk on multi-age farms for young birds entering houses recently vacated by mature flocks.
• Infection carried on vehicles previosly visiting other farms, regularly importing new birds and feed as well as taking broilers and eggs out.
• A large labour force in close contact with birds.
• Extra risk from contract worker brought in for catching and vaccination.
• Specific threat from avian influenza in wild bird populations and backyard poultry.
• Acute susceptibility to rodent-borne infections, fungal spores and mycotoxins.

Clean sheet

Biosecurity is easier said than done. Programmes must be strategic and far-reaching, and guided by basic principles of hygiene. Succes demands clear-cut priorities and correctly sequenced steps.

It means starting out with a ‘clean sheet’ and maintaining a tight cordon around the entire farm, as well as ensuring each poultry house has its own additional barrier to infection.

The purchase of new birds from diseases-free sources is essential. Vehicles bringing in new birds should be washed down, ensuring both tyres and wheel arches are sprayed thoroughly (to ‘run-ff’) with disinfectan.

Where possible, drivers should remain in the vehicle cab or otherwise be provided with waterproof protective clothing and boots.

The main aim is to provide pest- and-diseases-free housing for birds. New birds brought onto the farm should be isolated from other birds for 14 days so that blood testing, vaccination, preventative medication and anti-parasitic treatment can be carried out. During this time, their intended house should be emptied of birs and made biosecure for the new flock.

Disinfectant

Disinfectant use is essential but no a magic cure on its own. The cleanliness of surfaces to be disinfected and application methods will largely determine outcome.

Dirt and organic matter including dried faeces, mucous, feathers and spilt feed will inactivate the disinfectant, because there has to be direct contact between biocide and pathogen. Indeed, modern disinfectants are put through laboratory-based tests such as the Kelsey Sykes Test. These simulate conditions in poultry houses and measure biocidal activity in the face of repeated challenge by organic matter and the effect of hard water caused by high levels of calcium or magnesium.

Many chemicals including strong acids and bases, chlorine generators, phenols, aldehydes, quaternary ammonium compounds, iodophores and peroxygen compounds have disinfectant action. Some have a long history of use but limited action and a narrow range of kill. Others, like formaldehyde, though once used widely are now shunned for safety reasons.

Modern disinfectants are potent with broad-spectrum activity and a long contact time to kill pathogenic microbes. For instance, peroxygen compounds, which disrupt and destroy microbes through oxidation reaction, kill most type of pathogenic microbe – bacteria (e.g. Salmonella typhimurium and Escherichia coli) viruses (e.g. avian influenza and infectious bronchitis) and fungi (e.g. Aspergillus fumigatus and Candida albicans). Contact time is enhanced by the inclusion of surfactants, which are surface-active chemicals that lower surface tension and so enhance the penetration and spreading power of water-based disinfectants.

Facts on fogging

Power washing with detergent will remove dirt and organic matter, leaving accessible surfaces clean and ready for disinfectant action by ‘wet’ spraying. But poultry houses are riddle with ‘nooks and crannies’ that is, hard to reach places such as fan shaft, ducts and other areas inaccessible to standard cleaning and disinfectant spray programmes. These can only be covered by space-spraying using droplet small enough to penetrate all areas. ‘Dry’ application by thermal (hot) fogging achieves this goal.

Thermal fogger vaporise a liquid disinfectant mixture, which issues through the fogging pipe as hot gas. On contact with cold air, it condenses into a mass of tiny droplets, i.e. a fog.

The benefits of fogging disinfectant arise from two basic law of physics relating droplet number to droplet size, and suspension time with droplet size:

• Number of droplets generated from a given volume of spray liquid is inversely related to the cube of the droplet diameter (table 1)

• The smaller its size (and therefore mass), the longer a droplet is suspended in the air (table 2)

Hot foggers give droplets of 5-25mu. Larger droplets cover the walls, floor and ceiling to give residual disinfection. Smaller ones stay suspended in the air  for space disinfection, acting against airborne spores and dust-borne infections. Disinfectants with a relatively high vapour pressure perform best in fogging, but manufacturers provide fog-enhancing chemicals to improve performance. Disinfection by fogging is achieved at very low application volume rates of 20 litres/1000m3.

Complete programme

Cleaning

• Building is first emptied of all poultry and all litter removed
• Compressed air or brushing should be used to dislodge dust and dirt from beams and fittings and to clean the floor
• All easily removable equipment must be taken out to clean the floor
• Drinker lines are sanitised with disinfectant solution. The mixture should be left in the system for at least 12 hours then flushed with clean water.
• Electricity power supply must be switched off
• All surface should be soaked with solution of an agricultural detergent applied through power washer at low pressure, so surfaces remain wer or foam stands for at least 20 minutes.
• Surface should then be washed with clean, cold water at high pressure to remove soiling prior to disinfection.

Immediately after emptying the building of all birds but before embarking on the cleaning programme, producers can make a short time aerosol application of insecticide, e.g. phyrethroid or other approriate active ingredient. This will control all arthropod (insect and mite) pests, including those that are air-borne or resting in cracks and crevices. Swift application, while the building is still warm, ensure good control while the insect and mite pests are still present and active.

Disinfection

• Disinfetant must be sprayed at the recommended stregth (dilution) and at low pressure, covering all surface to ‘run-off’
• Roadways and aprons must be washed and disinfected
• Then, re-introduce and assemble all clean and disinfected fittings.
• Litter can be added and the house set up, ensuring all personnel entering the house have clean clothing and disinfected boots.
• Terminal disinfection should be carried out by thermal fogging, with the house sealed for one hour afterwards and ventilated for 30 minuets before re-stocking.

On-going programme

With a healthy new flock safely istalled in a pest-and disease-free building, it is now up to the producer to see it stays tha way by using the utmost caution with a good dose of ‘common-sense’ hygiene. These measure include:

• Keep visitors to an absolute minimum. Provide all authorised personnel with waterproof clothing and boots that can be easily and effectively cleaned and chaged regularly.
• Provide a foot-bath of disinfectant at the entrance to each house and a brush for cleaning boots prior to immersion in the foot-bath. Renew the disinfectant daily. Foot-bath are a constant reminder to staff of the needs for biosecurity.
• Wash down and disinfect all vehicle entering the farm so that they come in clean and leave dirty. Route those unloading at multiple points on the farm from areas of high vulnerability (young birds) to areas of lower vulnerability (mature flocks).
• Scrub drinkers daily with an approriate disinfectant mixed with detergent. Iodine is good because it removes algae and slime, is of low toxicity to birds and its brown colour allows managers to check that the job has been done.
• Remove all dead birds quickly and carefully. Seal in bags for disposal and incinerate well away from the poultry house to prevent cross-contamination with feathers or ash.
• An obvious risk often unnoticed is potential sources of infection within the farm environment, outside of the poultry house but posing threat of re-infection. Cleaning programmes must include these areas. Vegetation between houses should be well managed or preferably replaced by concrete that does not harbour infection so readily and is easily cleaned.
• Clear all equpment, remove rubbish and other vermin-attracting material away from the poultry houses and do not park vehicle and equpment from clean-up programmes near to house in case they caus re-infection.
• Remove all droppings, litter and other bedding at least 200 metres away from the house and stack carefully so that it cannot be dispersed by wind
• Store hay, straw bales and other bedding material in dry, closed places so that poultry houses are not at fisk from wind-borne fungal spores released from damp dan musty material.

Biosecurity programmes need to be well planned and encompass the entire farm environment as well as hazards from outside. But even the best-laid plans will go awry if procedures are not followed meticulously. For instance, carrying non-disinfected fittings back into the fogged poultry house or introducing litter after fogging will negate the whole programme.

Performance losses in incubation and brooding: Selected critical management points part 3

Tags

brooding, incubation, performance losses

Transfer day

As a general rule, the setter is a better environment than the hatcher. Whitin the normal transfer time for each machine, the longer that the eggs are in the setter, the better the result in hatchability and chick quality. Transfer time shoul be dictated by management, not embryo age. The embryo does not automatically need to be in a lower temperature environment at 17, 18 or 19 days. To optimise hatch and quality, the transfer should be adjusted to maintain the optimum embryo temperature whitin the system that you have.

At pip and hatch, the embryos are susceptible to chilling. The embryos should be kept at setter temperatures until hatch and then stepped down to maintain the comfort of the chick after hatch. When the temperature is arbitrarily dropped because of the timing of transfer, there can be losses. The best programme is to maintain them at the actual setter embryo temperature, not setter temperature until pip and then aggresively drop the temperature of 104 to 105 Degree Fahrenheit from hatch until pull. Because the machines are designed differenly, you cannot simply use the same set point as the setter in the hatcher. The embryos will be too hot. You must determine the optimum hatcher set point for the early and the late period that the eggs and chicks are in the hatcher.

Machine type

The machine design will limit the adjusment that can be made. Since designs are different, changes must be considered in relation to equipment design in addition to the impact of the embryo. When a change is made, it must be independently evaluated for the change it will cause in the machine and the embryo.

In all machine types, the room should not be used to trick the thermostats. This does not accomplish incubation and airflow; it only stops alarms. Alarms can be tricked by high room pressure, high exhaust plenum to room pressure differentials, and cool air-conditioned rooms.

Breed

In singe-stage incubation, we have found that different breeds have different preferences for incubation conditions. While this is important to understand, it is not practical to interpret to multi-stage incubation. The other factors such as variable airflow have more influence. For the purpose of incubation today, any breed that is commercially viable is a yield-type breed from the standpoint of incubation issues.

Altitude

With increasing altitude, the heat capacity of the air decreases. At an altitude of 2000 metres, the heat capacity of the air is only 78% of the heat capacity of the air at sea level. The lack of moisture in the air means that the machines sprays more and cooling is more diffuse with increased altitude. Thus, the concept of spray management is especially crucial with increasing altitude. The setter must be managed for optimum embryo temperature in the first 10 days of incubation. The hatcher and setter must be run with minimal spray inside the machine.

Hatching and the firs three days of brooding

The normal chick rectal temperature in the first 72 hours, whether in the hatcher, chick processing, chick delivery, or in brooding is 104 to 105 Degree Fahrenheit. During this time, the thyroid and intestinal tract are  still developing and it is crucial to maintain the chick’s body temperature. Problems that occur at this time affect the development of these vital systems and result in losses in performance that are not compensated later.

The age of the breeder flock impact the thermoregulatory abilities of the chicks. Chicks from young breeder flocks are less able to maintain rectal temperatures with cold stress than chicks from older breeder flocks.

The difference in breeder flock age is evident in the rectal temperatures of the chicks in the holding room. Low rectal temperatures during processing, holding, transportation and early brooding are one reason why embryo mortality in young flocks increases in the winter. The environment in all of these stages must maintain the rectal temperature in the weakest link, i.e. chicks from the youngest breeder flocks.

Hatcher

The energy reserves in the yolk will supply the chick for 3 days. If the chick is comfortable, the water reserve will last for 3 days. When the temperature surrounding the chick is 104oF, the water reserves are depleted in 8 to 10 hours. If the chicks were comfortable in the hatcher, it would not be detrimental to leave them there. The problem is that the air temperature can easily reach 104oF in areas of low airflow whitin the hatcher. Since the airflow through the egg mass in the hatcher is variable, the heat build-up in areas of low airflow result in the chicks overheating.

With the airflow variation whitin the hatcher, the rectal temperature of dry chicks will commonly range from 103 to 108oF. The chicks with a rectal temperature above 106oF are panting. Down collecting on the moisture at the corners of the beaks is another indication of heat stress. Changing the dry bulb set point of the hatcher and forcing the machine to cool with air sometime in the last day of incubation has the most potential benefit on feed conversion and carries little risk.

Processing dan Pulling

The environment of these rooms should be designed to maintain the optimum chick rectal temperatures at 104 to 105oF. Pulling rooms are generally not designed to hold chicks. If chicks are stacked in this area, some will be chilled and some will overheat. Because of the tray washer impact, the most common problem is overheating in the pull area.

I have measured chicks from young and old breeder flocks in the same environment in the chick holding room dan found the rectal temperatures to be 104oF in the chicks from the old flock and 101.5oF in the chick holding room temperature must be adequate to maintain the optimum rectal temperature in the youngest chicks.

Normally, rectal temperatures are lowest in the chicks in the top boxes, warmest in the middle and in between on the bottom. When you evaluate room conditions by chick rectal temperatures, sample stacks in good, stuffy and cool areas of the room, as well as those from old and young breeder flocks. You will find that there is a range of rectal temperatures. The only way to decrease the range is to decrease the variability in the room conditions by impacting the movement and temperature of the air.

Transportation

To monitor transportation condition, I measure the rectal temperature of the chicks as they are unloaded at the farm. Sample chicks from the top, middle and bottom of the stacks and from the front, middle and back of the truck. Optimum conditions will maintain the chick rectal temperatures at 104 to 105oF.

Brooding

In the first 3 days of brooding, the rectal temperature of the chicks should determine the optimum house conditions. This is the crucial period. After three days, the rectal temperatures will be 104 to 105oF, Even if poorly brooded birds. I have found that to have consistent, 104 to 105oF rectal temperatures on the first day in the house, the litter must be 90 to 92oF. Given a choice, this seems to be the temperature that the chicks prefer and it result in good rectal temperatures.

It is common to find low rectal level. The lack of moisture in the air means that the machine sprays more and cooling is more diffuse with increased altitude. Thus, the concept of spray management is especially crucial with increasing altitude. The setters must be managed for optimum embryo temperature in the first 10 days of incubation/ The hatcher and setter must be run with minimal spray inside the machine.

Summary

There are no easy answers to optimising incubation and brooding conditions with the yield breed although measuring rectal temperature and evaluating late dead breakouts. You can learn how to optimise the performance from your current system. With the yield breeds, the incubation programme neeeds to be adjusted depending on season and age of the flock. For multi-stage systems, there is a limit how much impact that you can have.

If we simply evaluate the impact of our processes on the chicks or the eggs, there are gains to be made in most hatcheries. The first step is to minimise variability by improving maintenance standards and the uniformity of airflow through the airflow, the more succesful that you will be when you do make season or age related process changes. Indeed, it is not advisable to make other changes until the varibility in egg mass has been minimised.

The next step is to minimise the detrimental impact of the spray and the machine response to the room. After these factors have been controlled, the general guidelines for optimal incubation is to manage the incubator for heat in the first 10 days of incubation and manage the hatchers for increased cooling after transfer**

Performance losses in incubation and brooding: Selected critical management points part 2

Tags

brooding, incubation, performance losses

This article continues from the one by the same author published in the July issue, which focussed on optimising machine function, taking into account egg variability and seasonal factors. This time, looks at the impact of the age on the breeder flock, machine type, breed and altitude as well as higlighting the importance of good management in those vital early stages. The chick’s temperature will give a good guide to the correct settings

With the trend towards the utilisation of so called ‘yield breeds’ in the broiler industry, more and more evidence has accumulated to link incubation and early brooding quality with production performance. Research into the causes of performance losses in these areas is building a very convincing database to identify solution to capture more of the genetic potential in the yield chicks.

Age of the breeder flock

Young breeder flocks are more susceptible to cool incubation in the first 9 days. Since the machines operate on the low end of the normal range, the problem is exacerbated in the winter.

Older breeder flocks tend to be less fertile and have large eggs. When eggs from the older flocks are incubated, the egg mass as a whole produces less heat. The machine tries to heat since it senses that the eggs are cold although the individual fertile eggs are larger and producing more heat. The more heat the individual egg produces, the more heat removal that it needs. This is specially a problem in the hatcher. Heat removal is best done by uniform airflow and cooling capacity. With a step down programme in the hatcher, the actual dry bulb is decreased but the fact  that this increases the airflow through the hatcher has the most impact. It is especially effective in old breeder flocks. While step down programmes can be beneficial, they can also chill the embryos if they are initiated too early after transfer, in a very young breeder flock or in the winter.

In my database, I find that chick length increases with breeder flock age when incubation is good. In a field visit, I sample a young, prime flock and an old flock. In all multi stage hatcheries that I have studied, chick length the old flock is smaller than the chick length in the prime flock. This indicates the difficulty in incubating eggs from older flocks, especially with regard to cooling in the end of incubation.

Since the major hatch loss problems are in the youngest and the oldest breeder flocks, both groups will benefit by being left in the setter for as long as possible. The setter is a better environment – more controlled with better airflow – than the hatcher.

Continue to next pages

Long term effects of beak trimming layers

Tags

beak trimming, beak trimming effects, debeaker

The ability of beak trimmed and intact laying hens to ingest feed pellet was examined by high-speed video filming of feeding birds at Silsoe Reasearch Institute in the UK.

Drs Prescott and Bonser found a negative correlation between mandible asymmetry and feeding succes. This may have important implications for poultry welfare, since bill asymmetry caused by beak trimming may result in inadvertent feed deprivation.

Optimum soy processing conditions for broiler

Tags

soy processing, soybean

In two experiments, Columbian scientists investigated the effects of different processing conditions of full-fat soybean meal on the performance of broilers and amino acid digestibility measured in roosters. They found that neither performance nor in vivo amino acid digestibility values demonstrated that the soybean meal had been over-processed, even thoug solubility values dropped as temperature treatment increased.

The soybean meal samples were obtained from two experiments that had already been published and they had been analysed in vitro for urease activity, Soy-Check score, trypsin inhibitor activity and KOH protein solubility. Samples from experiment 1 corresponded to six temperature treatments in a commercial extruder: raw, 118, 120, 122, 126, and 140 Degree Celcius. Samples from experiment 2 corresponded to six temperature treatments along with different retention times in a commercial toaster: raw 133, 120, 130, 135, and 150 Degree Celcius, and 0, 3.0, 4.5, 6.5, 7.0, and 9.5 minutes.