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PRIMARY PRODUCTION
animals with exotic stock; pure strains of the Chinese type are becoming difficult to find. The value of locally-produced pigs killed in 1978 amounted to $200 million.
With an annual production value of $363 million, the poultry industry - including ducks, pigeons and quail - is continuing to develop. Farmers are adopting advanced methods of management and are successfully adapting them to local conditions, taking the process through from locally-bred chicks to table birds with both local breeds and imported hybrids.
Imported Friesians are kept by dairies. The largest dairy is on Hong Kong Island and others are located in the New Territories. Regular tuberculin testing is carried out on all dairy animals.
Sporadic outbreaks of a mild type of foot-and-mouth disease (type O) and swine fever still occur, but these have been kept under control by vaccination. Newcastle disease in poultry has been controlled by the use of Ranikhet and intranasal-drop vaccines. No outbreaks of Rinderpest have occurred since 1950. Tissue culture vaccine is still being used in some young dairy cattle to give life-long protection. Investigations to establish the incidence of intercurrent disease in both pigs and poultry are undertaken at the government's veterinary laboratory.
All imported dogs and cats, other than those from Britain, Australia and New Zealand, are subject to six months' quarantine. To prevent the re-introduction of rabies, which was eradicated in 1955, stray dogs are caught and, if unclaimed, are destroyed under a rabies control policy. Any dog that bites a person is required to be detained for observation in government kennels. An annual rabies awareness cam- paign is designed to bring home to the public the dangers of the disease.
All cattle and pigs imported for food also are quarantined on arrival in Hong Kong. Any imported for breeding purposes are subject to strict procedures.
Agricultural Waste Treatment
The Agricultural Waste Treatment Unit continued experimental work on the handling and treatment of solid manures, slurries and waste water, in order to make available to farmers informātion and advice on the environmentally and economically most acceptable means of handling, storing, transporting, treating and disposing of the components of their farm wastes after separation at source into liquid and solid products.
Data on solid waste handling and treatment was obtained from two approximately equal capacity pilot schemes: one a continuous-process rotary drying and bagging plant at Pat Heung and the other a batch-type drying and bagging plant at Sai Kung Government Farm. The dried products from these schemes are disposed of as fertiliser.
Trials with the air-drying of pig and poultry manures were made and possible sub- stantial savings in the costs of subsequent handling, transporting and thermal drying were proved.
Work on the treatment of slurries and waste waters was extended to include experiments with additional aerating equipment and bio-filtration towers, incorporat- ing both commercially produced filter media and locally available recycled scrap materials, both organic and inorganic.