- Shearing shed hygiene
|Last update: September 2, 2011 03:11:01 PM|
Shearing shed hygiene
EM van Tonder
THERE are many factors and circumstances involved in the shearing process, and in and around the shearing facilities, which are conducive to the incidence of specific disease conditions in small stock.
The ideal situation would have been to strictly reserve the shearing-shed and accompanying facilities for the purpose of shearing and crutching, but since this will require that these facilities are not occupied for the greater part of the year, it will be difficult to resist the temptation to also utilize it for other activities.
Whatever the circumstances on each particular property might be, it is nevertheless essential that a specific standard of hygiene should be maintained. It would therefore require that where shearing facilities are also used for other purposes, hygienic measures should be more conscientiously and regularly applied.
The shearing process and infections
There are various reasons why the shearing process and the shearing shed and surrounding facilities play such an important part in the incidence and spread of disease conditions. These include:
- The shearing process constitutes the one and only procedure on the farm where such a large number of wounds are inflicted to sheep and goats in such a relatively short period. This is particularly so where hand shears is used, but machine shearing is by no means excluded.
Apart from the actual wounds caused, it is also a fact that during shearing, especially with machine shearing, the protective waxy layer on the skin of the animal is also disrupted.
Shearing wounds constitute a direct port of entry into the body to infectious types of organisms, which may be present on the skin or in the fleece, while damage to the protective greasy layer decreases the natural resistance of the animal to penetrative organisms.
- Shearing equipment and protective clothing, covered with sticky skin secretions, constitute ideal sources of contamination and play an important role in mechanical spread of infection.
- The shearing-shed and immediate environment, on one or more occasions throughout the year, constitutes a seat of great concentration of stock. This does not only afford an ideal opportunity for transmission and spread of infection, but is also responsible for the fact that through the years specific types of infection particularly more resistant types of organisms, tend to accumulate at the site and form a concentrated source of infection.
- Shearing-sheds and adjacent kraals are often used for the collection and handling of other species of farm animals, protection of animals against inclement weather and isolation quarters for affected animals, which also contribute towards the establishment, and maintenance of these facilities as concentrated sources of infection.
- Shearing-sheds are also sometimes used for household slaughtering, skinning of other carcasses, and storage of skins and bones as well as feedstuff and implements. All these circumstances bring about unhygienic conditions and are conducive to various types of infection.
Hygiene in the shearing-shed and surrounding facilities
- The use of the shearing facilities for other purposes should be avoided at all cost, particularly with regard to the isolation of sick animals, skinning of carcasses and the storage of skins.
The shearing-shed should also be swept after shearing, after the clip has been processed and removed.
- The shearing-shed and surrounding area should be thoroughly cleaned and disinfected, approximately 2 to 14 days before the start of the shearing process. If not done before, all pieces of wool or mohair should be removed and the floors swept beforehand.
The entire shed, i.e. the floor, walls and even the roof should be thoroughly sprayed with a 3 to 5 percent formalin solution. Spraying should preferably be done by jetting, with sufficient pressure to apply the disinfectant from a comfortable distance. This is done to avoid undue irritation to the mucous surfaces of the eyes, nasal passages and mouth, which can cause great discomfort. Other effective disinfectants may also be used.
All windows and doors are tightly closed and left for at least 24 hours before they are re-opened to allow the irritant fumes to escape.
- The floors and walls of the collection kraals and shearing-pens are also thoroughly sprayed with the same solution.
- A 3 to 5 percent of formalin solution should also be placed in the shearing buckets in which shears are dipped in between consecutive animals. In the case of mechanical shearing, shallow pans or trays can be used, filled with the disinfectant to a depth sufficient to cover the blades or cutters and combs only. Objections are sometimes raised to the effect that the disinfectant affects the sharpness of the blades, but this claim has often been proved to be unsubstantiated.
- Each shearer should be provided with at least 2 to 3 overalls. These are changed in the shearing-shed only, at least once but preferably twice a week. Used overalls are cleaned by boiling in appropriate solutions of washing soda or any suitable detergent soap and hung out to dry. Protective clothing remains the property of the owner and is not to leave the shearing premises.
- Disinfection of wounds during shearing is often time-consuming and not practically possible. If, however, individual owners are intent to do it, many reasonably inexpensive remedies can be used for this purpose.
The most important general measure, which should be taken, is to reverse the sequence of shearing. Through the years, and for some minor reasons, it has become customary practice to shear animals in sequence of age, starting with the oldest animals first and ending with the youngest ones. This increases the risk of transmitting infection from the older and more often exposed animals to young susceptible ones. By reversing this order and starting with the young unaffected and susceptible animals first, followed by the older animals in order of age, the vicious circle is broken and positive steps taken to ensure that as far as certain infections are concerned, clean flocks are built up and maintained. Although it does present great practical difficulties, all possible efforts should at least be made to control flies in and around the shearing-shed during the shearing period. This will naturally include removal of collected manure and other breeding sources from time to time.
Angora goat and mohair journal 29 (1)