H. —29,

A semi-annual Johnin test is being applied to a number of herds, and reactors are being slaughtered. It is hoped in this way to eventually eradicate the disease from such herds. The draining or fencing of swampy areas and subsequent heavy dressing with lime are measures adopted with a view to eradication of the infection from contaminated farms. A series of semi-annual tests must be applied, and some time must elapse before any definite statement can be made. In order to prevent the spread of the disease it is now necessary to have all dairy cattle intended for shipment to the South Island tested by the double intradermal Johnin test prior to shipment. Although a limited amount of testing in this connection has been done, it is gratifying to know that so far no reactors have been found. This is evidence that the disease is confined to definite areas. Mammitis.—The position in regard to mammitis during the year would appear to be less satisfactory. The larger number of cases in many districts can be attributed to the very variable season with the higher rainfall in the spring and throughout the summer. Under such seasonal conditions the sanitation measures necessary in and about many milking-sheds cannot be maintained, and an increasing number of cows show mammitis as a consequence. In wet seasons there is an increase in the number of cows affected with pox on the udder and general abrasion of the teats, resulting in more cases of mammitis. A high standard of hygiene in the shed is difficult to attain in such a season. The facilities provided by the Wallaceville and Hamilton laboratories in the examination of milksamples for farmers are still being availed of and are much appreciated by owners desirous of a means of control. The mammitis-control scheme of the laboratory should be taken more advantage of by farmers as the value of hygienic measures in prevention cannot be given too much importance. Contagious Abortion. —This disease of cattle is in the same position as in former years. It would appear that a reduction in the number of outbreaks as compared with the previous season is to be recorded. The control of the disease must be based on hygienic measures adopted in the management, of the dairy herd, the isolation of affected animals, and the furtherance of the principle of selfmaintenance in regard to replacements in dairy herds. The testing of blood-samples by the application of the agglutination test is of considerable importance to the owner of the herd and also to the officer who is investigating the disease on affected farms. The control measures to be adopted depend largely upon the result of the blood test showing the extent of the disease in any herd. Temporary Sterility.—This trouble has been on a level with previous years. The investigations in regard to the several aspects of the aetiology of the condition of delayed conception in dairy herds are being continued. There is no doubt that delayed conception, as a breeding problem for the farmer, is not due to any specific cause, the female factor, the male factor, the disease factor, and the nutritional aspect all requiring to be further investigated. After investigation of the history of the trouble on many farms at the present time suitable remedial measures can be suggested. Cattle-tick. —The cattle-tick parasite was reported during the year to be present in some districts not previously infected or on farms where eradication measures had previously been adopted. It is difficult to understand the importance which is attached to this parasite in the light of present knowledge. The control measures of dipping and spraying affected stock and the burning of roughage so as to destroy the cover for the tick are effective measures so far as they apply, but it is a very difficult matter to control such disseminating agents as birds, hares, &c. Many owners in affected areas are now inclined to treat the presence of tick as of no consequence. Climatic conditions are, no doubt, a major factor in the limitation of the spread of this parasite. Grass Staggers in Cows (Grass Tetany).—The cases of this disease which occur in diary cows after calving have been seen in the Auckland district, mainly in the Waikato territory. Two cases are reported from the Wanganui district. The use of magnesium sulphate as a hypodermic injection to affected animals has given good results in a great many cases. Dolomite was used on fourteen farms as a preventive, and the results are generally favourable, reports Mr. Collins, District Superintendent, Auckland. Tympanitis (Bloat) in Cattle. —This condition did not cause any serious trouble during the year. It is remarkable that it has not been reported to the same extent as in previous years. A significant inference which might be drawn from this fact is that the incidence of the trouble was considerably lessened by the particularly wet spring and summer when the feed was remarkably soft and of a laxative nature. Much scouring took place in dairy herds during the spring and summer owing to feed conditions, and the production was not as high as expected on this account. " Foul Foot " in Cattle. —This condition, as was to be expected, was prevalent on many farms throughout the year. Farmers who had no trouble in previous years were confronted with the disease during the past season. The climatic conditions favouring muddy surroundings in and about the yards and paddocks are undoubtedly the cause of the increase in the number of cases. The use of a concrete walk-out from the shed and the more general use of concrete to control the muddy conditions associated with the movement of dairy herds will lessen the incidence of foot-troubles. Much advice in regard to the treatment of affected animals and also in regard to the prevention of the condition has been given by field officers. Ergotism and " Fescue Poisoning." —In districts where tall fescue is liable to become a rank growth and allowed to form seed heads there is always the danger of animals being affected with ergotism when the farmers use such growth for stock during the winter months of scarcity. There is not the same danger when the fescue growth has been controlled by suitable grazing throughout the season. Parasitic Disease in Young Cattle. —Parasitic gastro-enteritis and bronchitis still continue to be a problem for the producer who raises young stock. Many calves on dairy-farms are lost annually from this disease, and many more are of weak constitution following a severe attack of worms. In many cases weaning takes place too soon or supplementary feed is not supplied to make up for the deterioration in the feeding-value of pasture during the autumn and winter. Better-developed

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