The purpose of this study was to measure the serum content of progesterone, estradiol 17${\beta}$ and cortisol. Blood samples collected from day 20 prepartum to day 20 postpartum in 8 sows. Progesterone and estradiol-17${\beta}$ were assayed by radioimmunoassay methods and cortisol was determined by competitive protein-binding methods. Progesterone levels began to decline on day -4, reached 1.9ng/ml by day +2 and remained quite constant thereafter. Progesterone levels remained fairly constant(18.4 to 20.0 ng/ml) from 20 to 6 days before parturition. Estrdiol-17${\beta}$ increased from 205 pg/ml at day 6 prepartum to 425 pg/ml at the time of parturition. Cortisol reached a peak level of 86.5 ng/ml at day 0.

The Purpose of this study was to determine the serum content of LH, FSH and prolactin. Blood samples collected from day 20 prepartum to 20 postrtum in 8 sows. LH, FSH and prolactin were assayed by radioimmunoassay methods. LH levels increased from 2.3 mIU/$m\ell$ day 6 prepartum to 5.8 mIU/$m\ell$ by day +2 and remained quite constant thereafter. The mean serum FSH increased from 7.5mIU/$m\ell$ day 6 prepartum to 10.0 mIU/$m\ell$ at the time of parturition, but the difference in LH and FSH patterns reported here provide further evidence that the controlling mechanisms for the two gonadotropins are independent. Prolactin reached a peak mean level of 68.5ng/$m\ell$ at day 0.

This experiment was carried out to determine the optimum interval between inseminations in artifical insemination of hens. Two hundred and forty hens of Hisex commercial stock at 25 weeks of age and 20 cocks of the Rhode Island Red at 40 weeks of age were used for the experiment, and a total of 6,784 eggs were obtained. The intervals between inseminations compared in this study were: 3 days (T1), 5 days (T2), and 7 days(T3). Mixed raw semen was inseminated and the semen does was 0.03ml per insemination per hen. The inseminations were conducted at 15:00 at each time. The total number of insemination performed was 9 for the T1, 6 for the T2 and 5 for the T3, and eggs were collected over a period of 31 days, 32 days and 35 dyas, respectively. The average egg production of the hens during the experiment was 85.9% and the average temperature during the experiment was around 30$^{\circ}C$. The average sperm count was 3.69 billion per ml. The results obtained in this experiment can be summarized as follows: The fertility over the entire experimental period bythe treatment was 91.7% for the T1, 84.4% for the T2, and 75.2% for the T3. The difference between T1 and T3 in fertility was significant at 5% level. The average fertility on the second, third and fourth day after the insemination in the T2 and T3 was maintained at a relatively high level, but it tended to decline rapidly from the fifth day after the insemination. The average fertility for one week after the last insemination was 88.8% for the T1, 88.8% for the T2 and 78.6% for the T3, and none of the differences among the treatments were statistically significant. On the basis of the results from this study, it is recommended to adjust the insemination intervals within the range from the 3 to 5 days in order to maintain a highest level of fertility in the hens at an early stage of egg production as in the case of the hens used in this experiment. An insemination interval of 3 days is recommended, especially at an initial stage of insemination. For the hens with a low fertility, shortening, of the insemination interval to 3 or 2 days is desirable.

This study aimed to determine the effects of adrenalectomy on the sexual gland, the thyroid gland and the serum components. A total of 192 Wister strain albino rats were evenly divided into 4 sexually equal groups for the comparisons. Each groups was divided into a control and a treatment group by sexuality. Each tissue of the sexual gland and the thyroid gland was microscopically examined, and at the same time body weight and serum components were also examined on the 1st, 7th, 14th, 28th, 42nd, 56th, 70th and 84th day respectively following adrenalectomy. The results obtained were as follows: 1. The body weight was sufficiently retarded in decreasingly after the adrenalectomy as compared to that of control. 2. The histological change of testis started atrophy of spermatogonia and degeneration of spermatocyte. There was a, pp.ared no cell division activity. Spermatozoa in the seminiferous tuble was not noticed but degeneration of interstitial cell was started and spermatozoa in the epididymal duct disa, pp.ared. 3. Degeneration of oocyte and follicular cell was noticed as the histological change of ovary. There was not a, pp.arance of primary follicle and corpus Iuteum but interstitial cell was proliferated. 4. For the effect of adrenalectomy on the histological change of the thyroid gland, the number of small follicle decreased and that of large follicle increased as the time passed following the adrenalectomy. And the follicular epithelial cell became squamous as typical condition of functional decreased. 5. It was shown that in the total contents of serum protein no difference with control occurred with in the 70th day for male and female adrenalectomized, respectively. But the differences in protein contents were significanly decreased on the 70th day. 6. No difference occurred in the total serum lipids on the 7th day, but they decreased significantly on the 42nd day, and (P<0.01) on the 56th, and 70th day. A tendency to decrease was noted as time elapsed following adrenalectomy. 7. Increase and decrease were intercrossed in the serum cholesterol contents between the control and th treatment groups on the 28th day. But the difference significantly decreased on the 42nd, 56th, and 70th day after adrelalectomized. The contents showed tendency to decrease as time elapsed following adrenalectomy. 8. The blood glucose contents rapidly decreased with time. The difference were significant on the 28th and 42nd day, and highly significant on the 56th and 70th day for male adrenalectomized. 9. In case of solium, there was no noticeable sexual distinction. There was slight in creasing or decreasing for the control group. But the treatment group tended continuously to decrease for male and female. 10. It was shown that potassium contents tended to increase on the 28th day for male and female, but the differences were small. 11. As for chlorine, it tended to decrease rapidly on 7th day for male and female adrenalectomized, and the tendency continued.

This experiment was carried out to study on changing phases of the concentrations of serum testosterone and metabolites in the various grwoing stages of male pigs. The eight males were used to obtain serial blood samples at a, pp.oximately 20kg body weight intervals from birth to 130kg body weight. The blood samples were taken from the jugular veins and serum was stored at -20$^{\circ}C$ until assay. Testosterone concentrations in the serum were analyzed by radioimmunoassay. The result obtained are as follows: 1. Serum testosterone concentrations were elevated at birth and were reached a maximum level between 50 and 70kg body weight, which was when sexual maturity was reached. 2. Calcium values did not vary a, pp.eciably with body weight, and ranged from 9.6${\pm}$0.6 to 11.9${\pm}$0.8mg/100$m\ell$. Potassium and sodium concentrations ranged from 38.5${\pm}$2.9 and 233.9${\pm}$2.1mg/100$m\ell$ to 64.2${\pm}$6.5 and 269.1${\pm}$9.5mg/100$m\ell$, respectively. Magnesium values dro, pp.d at birth and then rose to peak at 15kg of body weight. Iron concentrations was 0.12${\pm}$0.02mg/100$m\ell$ at birth, rose to 0.20${\pm}$0.04mg/100$m\ell$ at 15kg of body weight and then gradually increased to 0.29${\pm}$0.04mg/100$m\ell$ at 30kg of body weight. Serum zinc concentrations rose from a low of 56${\pm}$3.3mg/100$m\ell$ at birth to a high of 83.3${\pm}$3.4mcg/100$m\ell$ at 15kg of body weight. Co, pp.r values rose from a low of 25${\pm}$2.5mcg/100$m\ell$ at birth to a high of 183${\pm}$4.3mcg/100$m\ell$ at 15kg of body weight. 3. Serum cholesterol concenrtration did not vary a, pp.eciably with body weight, and ranged from 90.5${\pm}$6.0mg/100$m\ell$ to 95.0${\pm}$6.3mg/100$m\ell$. Glucose concentrations ranged from 80.5${\pm}$1.2mg/100$m\ell$ to 108.7${\pm}$8.4mg/100$m\ell$. Serum total protein rose from alow of 2.7${\pm}$0.8mg/100$m\ell$ at birth to a rapidly high of 4.3${\pm}$0.1mg/100$m\ell$ at 15kg of body weight and then gradually increased to 7.3${\pm}$0.4mg/100$m\ell$ at 130kg of body weight. Serum albumin values ranged from 0.5${\pm}$0.1$m\ell$ to 3.0${\pm}$0.3mg/100$m\ell$. 4. The total concentrations of essential/nonessential amino acid were 944.7mg/100$m\ell$ and 934.4mg/100$m\ell$ at birth, respectively. The values of essential/nonessential amino acid gradually rose from a low level at birth to a high level at 130kg of body weight. The total concentrations of essential/non-essential amino acid ratios remained from birth to 130kg of body weight.

This study was conducted to find out the effects of estrogen and progesterone on body weight, uterine weight and serum prolactin levels on the growing female rats which were ovariectomized. For this purpose, 125 heads of rats (Wistar-Imamichi strain), 28 days old, were devided into 5 groups; OVariectomy(Ovx.), ovariectomy treated with estrogen(Ovx.+Est.), ovariectomy treated with progesterone(Ovx.+Prog.), ovariectomy treated with estrogen and progesterone(Ovx.+Est.+Prog.) and control group. Twenty-five heads of rats were arranged to each group, and changes of body weights were weekly checked. On the other hand, every 5 heads of rats in each group were sacrificed at 1, 2, 3, 4 and 5 weeks after treatments with time elapse for measuring concentrations of serum prolactin and for investigating the weights of ulterus. Prolactin concentrations in the serum were analyzed by radioimmunoassay. The results obtained are as follows; 1. The body weights were increased slightly in Ovx. in comparison with Ovx.+Prog., Ovx.+Est.+Prog., Ovx.+Est. and control groups, but there were not significant among the compared groups at all observation times. 2. The uterine weights in all treatment groups were decreased significantly (P<0.01) compared with control groups at all observation times. But the weights in Ovx. and Ovx.+Prog. groups were lower than those in Ovx.+Est. and Ovx.+Est.+Prog.. 3. Serum prolactin concentrations were increased slightly in control group in comparison with other groups at 1 and 2 weeks increased slightly in control group in comparison with other groups at 1 and 2 weeks after treatment. But compared with control group, the concentrations Ovx.+Est. and Ovx.+Est.+Prog. were high level, and those in other groups were low level in the order of Ovx. and Ovx.+Prog. groups at 3, 4 and 5 weeks after treatment. There were not significant among the compared groups at all observation times. 4. The results obtained in this study suggest that when ovariectomized rats receive 1$\mu$g estrogen and 3mg progesterone daily, that had no effect on body weight and serum prolactin concentrations while significantly effect on the weight of uterus.