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Noxious Weeds Weather conditions in general during the year have favoured the growth of all plant life, and noxious weeds such as ragwort and the various thistles in particular have responded to an abnormal extent. Limited quantities of sodium chlorate became available during the year, and this was made full use of by County Councils and others, but apart from work on ragwort in the North Island little work was done on the other major weeds such as blackberry, gorse, and sweetbrier. Activity in connection with the control of nassella tussock in North Canterbury and Marlborough has been continued during the year and some progress made. Financial assistance has been granted to the Nasella Tussock Committee in North Canterbury and to the counties concerned in Marlborough, and these grants have been used to check the spread of this weed. A special departmental committee has been set up to go into the whole question of nassella tussock control. There is evidence of a more enlightened outlook by County Councils on the necessity for some concerted co-operative action by groups of counties in regard to noxious weed control, and with labour conditions improving some improvement should take place in the clearing of land that is of a productive value, whether it be for grazing, cropping, or afforestation purposes.

ANIMAL RESEARCH DIVISION REPORT OF J. F. FILMER, DIRECTOR With the return of some research workers who have been on active service overseas and the prospect of relatively early termination of hostilities, it is now possible to embark on the planning of long-term research. This is absolutely necessary for the solution of some of the major problems of animal industry in New Zealand. During the year the Chemical Section was transferred to Ruakura. The section is at present accommodated some two miles from Ruakura in some disused factory buildings which have been converted into make-shift laboratories. It is hoped that it may be possible to construct an up-to-date laboratory at Ruakura to house all the research workers in the not-too-distant future. Both Wallaceville and Ruakura now have their own chemical staff, and this should result in greatly increased efficiency. Diagnostic Section, Wallaceville During the year 7,576 specimens were received for diagnosis. This included nearly 3,000 specimens from poultry. Ninety-five thousand doses of black leg vaccine and 23,750 doses of scabby mouth vaccine were prepared and issued. Research Work Facial Eczema. —Most of the North Island experienced a very wet summer, but in Poverty Bay a dry summer was followed by a dry autumn. It was therefore not surprising that very few clinical cases of facial eczema occurred during the autumn of 1945. The Department has purchased an area of 68 acres at Manutuke, nine miles south of Gisborne, for its facial eczema field experiments. The developmental work required there and the climatic conditions hampered the investigations. However, some toxic grass was collected and dried. Grazing experiments indicated that Japanese millet, rape, and turnips provide safe grazing through a period when pasture causes liver damage. Collodion casts of bile ducts and bile vessels of affected livers have been prepared. Preliminary investigations have been made with a view to devising a satisfactory method for chemical fractionation of dried toxic pasture. Inheritance of Photosensitivity in Southdowns. —Breeding results for the year further tend to support the theory that this disease is due to an inherited liver defect which behaves as a simple Mendelian recessive. A further season's breeding work should be sufficient to finalize this aspect of the work. Affected animals will then be bred in sufficient numbers to provide material for studying the physiology of the condition. St. John's Wort Photosensitivity. —Typical symptoms of hypericism have been produced in white sheep fed dried St. John's wort. Convulsions occurred when such sheep were dipped. Black sheep dosed with St. John's wort showed no response to sunlight and behaved normally in the dip. Sheep made photosensitive by other agents such as eosin and rose bengale, and sheep with facial eczema, showed some reaction in the dip." The response was not so violent as in sheep fed St. John's wort. Sheep Unthriftiness, Canterbury. —Excessive summer rains resulted in a considerable number of deaths in young sheep in the late summer and autumn of 1945. These were apparently due to two conditions, one resembling entero toxaemia and one in which wasting, scouring, and heavy gastrointestinal parasitism were prominent conditions. Though lambs did not fatten well, unfortunately the diseases causing mortality elsewhere did not occur on the experimental farm. Some investigations were conducted on other properties. Further studies were made of sheep feeding under Canterbury conditions. Bone Disease in Sheep. —Further work at Kirwee confirmed the value of a single massive dose of calciferol in the prevention of rickets in sheep. Sheep received one million units in 2 c.c. olive oil subcutaneously or in 30 c.c. by mouth.

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