§ LORD RUSSELL OF LIVERPOOLasked Her Majesty's Government:
Whether they will publish any statistics available in the Ministry of Agriculture, Fisheries and Food, covering the past twelve months, regarding the comparative severity of outbreaks of fowl pest on poultry farms in Great Britain and Northern Ireland where all birds have been properly and adequately vaccinated and on farms where no vaccination has been carried out.
LORD ST. OSWALDStatistics covering the first nine months of the new vaccination policy, the period April-December, 1963, were published in April, 1964. These showed that in cases where the disease occurred in vaccinated flocks it was considerably less severe than in unvaccinated flocks. Of the 1,520 outbreaks confirmed in England and Wales during this period, severe disease was experienced in approximately one-third of the outbreaks in unvaccinated flocks, and in only about one-twelfth of the outbreaks in flocks reported to have been fully vaccinated in accordance with manufacturers' recommendations. A more detailed country-wide random survey of about 300 flocks affected during the same period showed that mortality was over 11 per cent. in unvaccinated flocks but was much lower in flocks regarded as being at the maximum degree of protection from vaccination; in once-vaccinated, predominantly young stock, mortality was 6.7 Per cent., and in older birds twice and three times vaccinated the figure was 2.3 per cent. and 0.5 per cent. respectively. In a similar random survey of 187 laying flocks, egg production fell to nil in 81 per cent. of unvaccinated flocks and in only 18 per cent. of fully vaccinated flocks.
Similar statistics covering the first twelve months of the vaccination policy will be published shortly.