A bloat prevention test, using one hundred ewes, was made in July, 1961, by successive administration of four anti-foaming agents, including soybean oil, before grazing in the morning. The preventive effects of these agents on bloat were compared between these ewes and untreated animals with regard to bloating frequency and the physical properties of the rumen juices collected three or eight hours after grazing. Pronon, a polypropylene derivative, manufactured by the Nippon Yushi Co., Ltd., was shown to be the most effective for prevention, since the surface tension and the foamy rate of rumen juices after pasturing decreased significantly. On the other hand, silicone agents manufactured by the Tnshiha Sei va ku Co Ltd Nonion. sorbitan-trioleate (manufactured by the Nippon Yushi Co., Ltd.), and soybean oil did not prevent bloat significantly. Successive administration of these anti-foaming agents, including soybean oil, never caused any inhibition of ruminal fermentation, but increased the body weight of the treated animal to essentially the same extent as that of the control one. The occurrence of bloat tended to increase in accordance with an increase in the percentage of Ladino clover on the pasture and to be associated with meteorological conditions. Throughout the bloat prevention test, forty-two per cent of the ewes used, including treated ones, did not bloat at all, while the other animals bloated one to eighteen.
TSC antigen, which the authors had prepared tentatively to use in the intradermal test for the purpose of making a diagnosis of toxoplasmosis on pigs, was applied to the hemagglutination test of the Boyden form. As a result, hemagglutination test was established for the diagnosis of toxoplasmosis in pigs, by modifying the original methods of Jacobs and Lunde. The principal points of modification were as follows. 1. In preparing tannic acid-treated red cells, all the procedures, such as sensitization of sheep blood cell suspension with tannic acid, washing, and resuspension, were performed in a refrigerator at 0°C. 2. To Saline solution was added normal swine serum (NSS, DT<4), in stead of normal rabbit serum (NRS). 3. The result of the test where sensitized red cells had been added to the serum to be tested was read after it was incubated at 37°C for three hours and allowed to stand at room temperature overnight. The test was read to be positive when the degree of agglutination was+or higher. A titer of 1: 64 or higher was regarded as positive evidence for the presence of antibodies against Toxoplasma organisms. Moreover, the results of the present investigation made clear the following points. a. Fourteen pigs artificially infected with toxoplasmosis were examined comparatively for the production of antibodies. As a result, hemagglutinating antibodies generally appeared a little later than dye-test antibodies and earlier than TSC skintest and complement-fixing antibodies and were retained for a long time. b. Eighty-seven pigs on field experiment were examined for the relationship between hemagglutination and dye-test titers and that between hemagglutination and TSC skin-test titers. As a result, a rate of coincidence of 90 per cent was shown in either relationship.