[in Japanese]

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[in Japanese]

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This experiment was attempted to clarify the effect of estrogenic substances in leguminous grasson cattle fertility. Two Holstein cows were grazed on a pasture having 10-30 percent ratio of Ladino clover during an estrous cycle (control period). For the next cycle, the cows were removed to another pasture with 40-55 percent of Ladino clover (experiment period). Free estrogen level in blood samples taken about every three days during the both periods was bio-assayed by Sulman's method. The changes in estrogen level in each cycle showed approximately a uniform pattern with two definite peaks at the follicular stage and the 9-10th day of the luteal stage. This pattern was similar to that of normal cows. Cyclic changes in the ovaries and the sign of heat, also, seemed to be normal.

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An experiment of oestrus synchronisation by CAP (chlormadine) and the following fertility were carried out with 7 Japanese Native cattle. The range of months after the last calvings in these cows varied from 2 to 7 months, and the stage of the cycle laid between 2nd and 16th day when the treatment started. 0.05 mg/Kg body weight of CAP was daily given for 15 days per os. The oestrus appeared between 3rd and 6th day after the end of the treatment (excluded one cow of accident). Conception rate (examined by rectal palpation and non-return over 50 days) at the first oestrus was 2/6, and at 2nd 3 out of 6 (included 2 cows which return to oestrus after 51, 75 day-possibly due to early embryonic death).
Judging from the results of ovarian changes detected by rectal palplation, CAP did not depress the follicular development, however, did ovulation and oestrus. In addition, cows of younger (a few) months after the last delivery (lactating) seemed difficult to be conceived at earlier insemination.
The treated cows showed a considerable increase (ca 30 Kg in average) in body weight during and especially after the administration (so far 18 days after the end of treatment when weight measured), although slight changes were seen in controls (dry and wet, 10 each).
The case numbers of the present experiment were not enough to draw any definite conclusion, but evidences which should be carefully considered in the future trial were pointed out.

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Tail-to-tail agglomeration of bull spermatozoa by soybean lectins (No. 4, No. 11 and No. 22) and improved vetch (No. 22-Nasu 6 Go) showed a individuality of bull at the quantitative significance of absorption test.
Similarity of agglomeration reaction of spermatozoa was demonstrated within father and son.

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The ovulation by the supplemental administration of LH (HCG) in the immature animal pretreated with PMS is being adopted as a new biological assaying for gonadotropic hormones. This technic shows a high sensitivity compared with the former methods judging from the increase in weight of sex glands in the test animal. However, there remain some problems, such as age or size of animal, dosage of hormone, etc., to accomplish its procedure as an universal method. The present study was undertaken to determine the optimal dose of PMS and HCG inducing the ovulation in the immature mouse.
Approximately 335 female mice weighing 8 to 10g at 20 to 22 days of age were used. They are Kasukabe strain which has been kept at the National Institute of Animal Industry. The PMS (Tomoda Pharm. Co. Ltd.) dissolved in physiological saline was injected subcutaneously at the abdominal part of the animal. The animals pretreated with various doses of PMS were injected intraperitonealy with HCG (Tomada Pharm. Co. Ltd.) 54 hours later. Then the animals were killed at 20 hours after the injection of HCG. The number of ova released and percentage of ovulating mice were inspected. At the same time, ovary and uterus were weighed with the torsion balance.
1. The supplemental injection of 0.5 to 0.9I.U. of HCG in the mouse pretreated with a little dose of 0.5I.U. of PMS induced a 100% ovulating response. The treatment of 0.1 to 0.9I.U. of HCG to the priming dose of 4.0I.U. of PMS caused a 100% ovulation in all lots (Table 1). There appeared a regression curve as shown in Fig. 1 between amounts of PMS and percentage of mice ovulating. The injection of dosages over 4.0I.U. of PMS brought about a harmful response to the ovulation.
2. Relation between number of ova released and does of the hormone injected has a close resemblance to that shown in the regression curve in the percentage of ovulation (Fig. 2). The assaying by the response based on the number of ova released may be superior to that by the percentageof mice ovulating. But it is in need of more detailed examination.
3. Considering these two ovulating responses as mentioned above the supplemental injection of 0.3 to 0.5I.U. of HCG in the immature mouse pretreated with 3.0I.U. of PMS will induce the reasonable ovulating result. However, it is desirable to use the suitable amount of PMS for priming in an actual assaying of gonadotropic substance.
4. It is important to choose the uniform animal in size and sensitivity for assaying of gonadotropic hormones.

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