Intensive / Disease Control
Biosecurity and Eradication
Obviously the best way to deal with a disease is to avoid it. Care should always be exercised to prevent introducing new diseases onto a pullet or layer farm. Common disease carriers include people, vehicles, equipment, wild birds, animals, and chickens themselves. New flocks should be tested before being brought onto a farm and should have a known vaccination programme.
SanitationCleanliness, sanitation and strict traffic control are the most effective and least expensive tools in a disease prevention programme. Physical removal of all litter, manure, dust feathers and other poultry house debris to a spot remote from the poultry house is the first step in an efficient clean-cut programme.
An effective sanitation programme must include removal, dismantling and disinfecting all equipment in the house, before the house itself is cleaned and disinfected. High pressure sprayers and an effective disinfectant are necessities for eliminating disease carryover. This must be supplemented by a rodent and insect control programme. These efforts must be continued for maximum effect.
After housing the flock, dead birds must be removed and incinerated daily. Rubbish and debris should be moved out on a regular basis and not allowed to accumulate.
Traffic Control
Foot and vehicular traffic threaten constant import of disease organisms. Locked doors and a policy of no visitors is advisable. When it becomes necessary to permit entrance of visitors, clean disinfected footwear and outer garments should be provided. Feed and egg trucks and their drivers, must be isolated from the bird area.
Portable equipment should be confined to as few houses as possible and should be cleaned and disinfected when transported between houses.
Vertically Transmitted DiseasesSome diseases are known to be transmitted from infected breeders to their progeny. This requires the production and maintenance of disease-free breeders as a first step in the control of thesediseases at the commercial level. All breeders directly under Hy-Line’s control are free of mycoplasma gallisepticum, Mycoplasma synoviae, S. pullorum, S. gallinarum (typhoid), S. enteritidis, and lymphoid leukosis. Due to the possibility of horizontal transmission of any of these diseases. later generations may not remain free.
It is the responsibility of the breeding stock and commercial flock owner to prevent horizontal transmission of these diseases and continue testing to be assured of a negative status.
Vaccination Programmes
Vaccination programmes need to be individually designed with consideration for maternal immunities of the chicks, disease exposures expected, vaccines available, routes of administration preferred and planned use of inactivated injectable products.
Because of the extreme variability of these factors among producers worldwide, we cannot recommend one programme which would be satisfactory for all. We therefore recommend that you consult your Veterinary Adviser on a programme suitable for your particular circumstances.
Regardless of the exact programme, care always needs to be exercised to ensure each bird is given an adequate dose of viable vaccine. In our experience, most vaccination failures relate to improper administration techniques.
Infectious Bursal DiseasesSpecial attention should be paid to IBD control. This disease can have many subtle effects which are detrimental to pullet health. The primary feature of IBD is immuno-suppression caused by damage to the bursa of Fabricius which leaves the bird unable to fend off other disease challenges. Secondary diseases such as gangrenous dermatitis, bacterial arthritis and even Marek’s often result. Virtually all flocks are exposed to IBD and therefore, should be protected by vaccination. Most breeding stock receives a killed
IBD vaccine to boost maternal titers in the chicks. Research at Hy-Line international has shown the optimum time to vaccinate such chicks with intermediate strain live vaccines is at 18 - 20 days and again at 28 - 30 days of age. An extremely severe IBD challenge may require an additional vaccination during this period.
Bursas can be examined later to determine the extent of protection.
Disease Control
A flock of pullets or layers can only perform up to its genetic potential when disease influence is minimized.
The appearance of various diseases can vary from a subclinical effect on performance to outright severe mortality. The diseases of economic importance vary widely between locations, but in every case the challenge is to identify and control those diseases.