East coast fever: 3. Chemoprophylactic immunization of cattle using oxytetracycline and a combination of theilerial strains

In the first of two experiments performed, 29 animals were immunized by chemoprophylaxis against either a combination of three theilerial strains, Theileria parva (Muguga), T. parva (Kiambu 5) and T. lawrencei (Serengeti transformed), or against one or two elements of the combination separately, and then challenged with either T. parva (Kiambu 1) or T. lawrencei (Solio KB1), both of which were known to be heterologous to T. parva (Muguga). The animals immunized against the combination had mild or inapparent reactions to challenge, whilst the susceptible control cattle and many of those immunized against one or two strains either had severe reactions of died.In the second experiment, 17 cattle immunized by chemoprophylaxis against the combination were challenged with lethal doses of three theilerial strains, T. parva (Entebbe 1), T. parva (Entebbe 2) and T. parva (Ukunda), recently isolated from two widely separated areas of East Africa. They had mild or inapparent reactions whilst 13 of 15 susceptible control cattle died.Chemoprophylaxis using a combination of theilerial strains and a limited oxytetracycline regimen was shown to be an effective means of immunizing cattle against East African theilerioses. The use of this technique as a method of immunizing cattle before exposure in the field is proposed.     

奶牛乳房炎发泡药剂的研究Ⅱ.发泡药剂的研制与动物试验

研究了奶牛乳房炎发泡药剂的制备方法及其质量控制标准。该药剂是以碳酸氢钠和枸橼酸作发泡剂，研制药物的发泡量为原药液体积的8-12倍。经动物乳房给药试验证实，该药剂安全、无刺激性、在乳腺内分布效果明显优于常规剂型，室温保存有效期为2年。     

Concentration of steroid sex hormones in the plasma of hens in relation to oviduct tumours

1. The concentrations of 17 beta-oestradiol (E2) and progesterone (P) were determined in the plasma of layer breeder hens at the end of their first laying season, in relation to neoplasms of the oviduct, including magnum tumours and leiomyomas. 2. The plasma concentration of E2 was higher in tumorous than in non-tumorous hens indicating it may be involved in the development of oviduct tumours. 3. The plasma concentrations of P in tumorous and non-tumorous hens were not significantly different, suggesting no active role of P in the aetiology of the tumours. 4. The E2: P ratio was higher in tumorous than in non-tumorous hens. This ratio could be of value in predicting hens at risk of developing oviduct tumours.