[in Japanese]

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Seasonal variation of the semen and of the metabolism of dog spermatozoa have been studied using ten adult male Spitzdogs.
The results obtained are summarized as follows:
1. The average values of ejaculates in the spring, summer, autumn and winter season were as follows, respectively: total volume, 9.4, 7.0, 8.0 and 8.56 ml; sperm concentration, 267, 207, 188 and 237, ×10⁶ per ml; total sperm count, 437.2, 369.9, 336.4 and 390.3, × 10⁶ per ejaculate; motility index, 91, 88, 88 and 90; and percentages of morphologically abnormal sperm, 5.4, 7.0, 6.0 and 6.0. It was suggested that the semen quality was the best in the spring and the worst in the summer.
2. Oxgen uptake of unwashed dog spermatozoa was the highest in the spring without distinction of substrates, but glycolysis was higher in ther spring than the autumn and fluctolysis was higher in the autumn, conversely. Viability and metabolic activity of dog spermatozoa in the summer were the lowest throughout the year. These observations show that the summer sterility may appear in dog.
3. The metabolic activity of dog spermatozoa washed by calcium free Krebs Ringer Phosphate was unchanged or incresed slightly compared with that unwashed. Especially, the increasing rate were higher in fuctolysis than in glycolysis.
4. Larger quantity of glucose was utilized than fructose by washed and unwashed dog spermatozoa.The values of the oxygen uptake, sugar consumption and lactate accumulation obtained with the dog spermatozoa were similar to those obtained with bull, ram, goat, boar and rabbit spermatozoa.
5. The semen quality and the metabolic activity of dog spermatozoa were improved from the autumn to the spring. The semen characters were the best in the spring and the worst in the summer. Therefore, it may be pointout that the semen quality of the dog was more affected by the summer heat than on another farm animals for the lack of sweat glands. It is thought that seasonal effects are important factor for the studies on dog semen.

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The study presented was designed to ascertain the influences of a change in the milking condition on the intramammary pressure, milking rate and milk yield of seven Holstein cows. Experimental treatments consisted of abrupt changes in housing system by moving the cow from loose barn to tie-up stall and in milking procedure by altering from farm routine to experimal routine. The experimental routine incorporated to following treatments : (1) insertion of cannula to right-front teat for the measurement of imtramammary pressure (2) washing of the udder with warm water (3) teat cup application on theremaining three teats, after 30 sec. (4) machine milking with a De Laval portable unit, operated at a vacuum of 35 mm Hg. with pulsation ratio of 1 : 1, at 54 cyc. (5) stripping the last milk from udder by machine (6) removal of teat cup.
The results were as follows.
1. At the first milking, after a change in milking condition, there was considerable variation in the intramammary pressure change of various cows during milking routine. No discernible change was observed in two cows and a rise in pressure after a latent period of 1 min. 30 sec. was observed in three cows. The rise in pressure promptly after udder stimulation was observed in the two others. In one of these cows, the pressure rose gradually, whereas the pressure rose abruptly in another cow.
2. Intramammary pressure of cows was also variable in the course of adaptation. In the cow no descernible change in the pressure at the first milking, was observed extremely high but not abrupt rise in pressure at the second and the third milkings. At the fourth milking the cows began to responed to the experimental milking routine and was achieved the abrupt rise in pressure after the latent period of 1 min. 30 sec. The latency of cows attained to 30 sec at the fifth and the subsequent milkings.
On the other hand, slightly high pressure level and rise in pressure after the latency of 1 min. 30 sec. in the cows the latent period of 1 min. 30 sec. at the first milking, and then after the latency of 30 sec. at the third and the subsequent milkings. At the third milking, however, pressure level was slightly higher than at the subsequent milking.
3. Milking rate and milk yeild were more related to the degree of intramamary pressure rise than the reduction in latent time. On the other hand, when pressure level was extremely high, milking rate and milk yield have attained the level of normal, inspite of pressure being not rise after udder stimulation.
4. It appears that milking rate and milk yield in the course of adaptation associated with activation of the sympathetico-adrenal systerm, some special feature of morphology of the udder such as udder capacity, tonus of the tissue lining of the teat and gland cistern, and the amount of residual milk.

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[in Japanese]

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Histochemical observation was made on the occurrence of succinate, glucose-6-phosphate and lactatedehydrogenase activities in hamster eggs with the following results: these enzymes start to activate2 hours before ovulation, when mitotic figure has already been formed, but not the first polar bodyemmission.

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The uptake of 3H-estradiol in several tissues (uterus, pituitary, hypothalamus) and serum of rats was measured on 17, 21 and 25 days of age.
³H-estradiol (Estradiol-6, 7-3H 39.7 Ci/m mol) was soluted to twenty percent ethanol and 1 μCi/0. 1 ml per rat (Exp. I) and 1 μCi/0. 1 ml per 50 g body weight (Exp. II) was injected subcutaneously.
The tissue of autopsied rat was extracted with soultion of acetonethanol (1 : 1). The serum was collected 0.1 ml per rat. These samples were dried and the scintillating solution was added. The radioactivity of these samples was measured with liquid scintillation counter. In order to examine the relation between the time of injection and the time of the slaughter, the radioactivity was measured in rats slaughtered at 5, 30, 60 and 240 minutes after injection of 3H-estradiol (Fig. 1).
The equilibrium of uptake of 3H-estradiol reached in all tissues about 60 minutes after injection. Then, the uptake of 3H-estradiol per whole tissue and tissue weight (mg) was measured at 60 minutes after injection.
The results are as follows:
1. In uterus, the uptake of 3H-estradiol per tissue weight decreased significantly from 17 to 21 days of age (Exp. I, II). The increased level of counts per both whole tissue and tissue weight was observed at 25 days of age (Exp. II).
2. In pituitary, the uptake of 3H-estradiol per tissue weight was much higher than the uptake of hypothalumus and nearly equal to that of uterus in each day of age. The uptake of estradiol per whole tissue increased with age, but no for tissue weight (Exp. I, II).
3. In hypothalamus, the slight rise of counts per both whole tissues and tissue weight (Exp. II) was observed from 17 to 21 days.
4. In serum, a higher level of radioactivity was obtained at 17 days of age comparing with the levels of 21 and 25 days. Then, it is probable that the remarkable change in the metabolism of estrogen occures from 17 to 21 days of age.

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