Agriculture Reference
In-Depth Information
Advisory Committee on the Microbiological Safety of
Food recommends that a period between 6 and 10 hours
should be allowed between feeding and kill.
reduce the numbers of pathogenic bacteria which may be
present, although it does not provide a total kill. To
achieve this, a separate heat treatment process involving
holding the feed for a minimum time at a minimum tem-
perature is required. This is an effective way of tackling
the problem of
Salmonella
contamination of poultry feed.
Catching and crating
This operation should be carried out with care in order
to avoid injuries and unnecessary suffering to the birds.
Crates must be in good repair and of good design and
must not be over- or under-filled, since both situations
can lead to injury. The catchers must be well trained and
supervised to avoid injury and downgrading of the birds.
Only healthy birds should be crated; diseased or other-
wise abnormal birds should be killed on the farm.
One of the most difficult, labour-intensive and
unpleasant tasks as far as working conditions and unso-
ciable hours are concerned is that of collecting, crating
and loading birds at the point of production. Depending
on the quality and commitment of the staff employed,
this area can be one where bird welfare is of a high or a
low order, the latter often resulting in high levels of
downgrading of carcases because of the injuries inflicted.
The majority of bruises resulting in downgrading
occur during catching and transportation. The incidence
of bruising is also directly related to the length of the
j our ne y.
In recent years, systems have been developed to improve
catching (or harvesting) and transportation. For the time
being, however, broilers are still caught by hand and
carried by one leg. This has to be done with great care to
avoid injury. Turkeys must always be carried by two legs.
Poultry harvesting procedures can be divided into
four basic systems (Loose crates, Fixed crates, Modular
system, Novel mechanical methods).
Poultry flock health
All poultry farms should have a veterinarian, specialising in
poultry, who will advise on the health and management of
the flock. Visits should be made, at least annually, to ensure
the knowledge of practices and facilities on the farm. All
events which are outside the normal, for example, increased
mortality, poor weights or poor feed conversion, should be
thoroughly investigated. The chances of eliminating micro-
bial contamination from poultry meat will be improved if
steps are taken to ensure that birds entering the slaughter
and processing chain are either free from infection or are
identified as contaminated and treated accordingly.
The situation in the United Kingdom, where there has
been considerable success in tackling the
Salmonella
problem, involves testing all flocks of broilers and tur-
keys for
Salmonella
1 or 2 weeks prior to slaughter. This
enables positive flocks to be handled with special care
and attention during processing. This will entail slaugh-
ter at the end of the day or week, maximum chlorine lev-
els of 0.5 ppm in the water and perhaps lower line speed
and/or attention to prevent rupture of the intestines.
Healthier birds are produced on a single-age farm
('all-in/all-out' system). The farm is depopulated at the
end of each crop or cycle and thoroughly cleaned and
disinfected. Tests are carried out to ensure freedom from,
for example,
Salmonella
, prior to restocking. Should
Salmonella
be isolated, cleaning and disinfection are
repeated until a negative result is obtained.
The need for close liaison with the farm is even more
important in the case of poultry than with other species
because of their size, large numbers involved in slaughter
and dressing, high rates of slaughter and the use of
antibiotics, anticoccidial drugs, etc. in their rearing.
Adequate withdrawal periods are essential for all drugs.
This period of time should be adhered to when 'thinning'
occurs, that is, when a number of birds are removed
from the house in order to give extra room to allow the
remaining birds grow larger.
The withdrawal of feed prior to loading for transport
to slaughter, in order to reduce crop and intestinal tract
contents, can also help to reduce the level of contamina-
tion. Published FAO literature recommends a minimum
period of 4 hours prior to birds arriving at the poultry
plant, but extending the period to 10 hours may result in
faeces becoming more fluid, thus increasing the chances
of cross-contamination between birds in transit. The UK
Loose crates
Empty plastic crates are taken from the lorry into the
shed, where a team of catchers fill the individual crates.
As with all systems, fewer birds are placed in each crate
in summer to reduce the risk of heat stress. The birds are
passed into the crate through a flapped opening at the
top. For unloading, there is a larger aperture in the side
or top of the crate through which the birds may be
removed. Once a crate has been filled, it is taken to the
lorry. Self-stacking crates can be placed on pallets in the
shed for handling by a forklift vehicle. Loose crates pro-
vide a flexible system at low capital cost but a high labour
input (Fig. 10.5).
Fixed crates
The crates are fixed on to the lorry. The birds are carried
out of the shed to the lorry and are placed by the handful
into one of the lower crates. Numbers in each crate
depend on size and weather conditions. When the
