[in Japanese]

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Authors reported previously on the effect of forced molting induced in spring on the layers. This paper deals with the performance of the laying hens following the forced molting which was induced in autumn.
One hundred twenty commercial laying hens (DeKalb 151) which laid eggs for longer than one year, divided into three groups. In Group 1 and 2, the birds were deprived of both feed and water for 3 days and of feed for succeeding 2 days. The birds in Group 3 were fed ad libitum. The experiment was conducted from October 18, 1967 to the end of October 1968. All birds recieved normal daylight before the start of this experiment. In Group 1 daylength was supplemented with incandescent lamp to give a 14 hours per day at the beginning of the experiment and to increase lighting 15 minutes per week to reach 17 hours of light per day. The birds in Group 2 and 3 were recieved supplemented light to give 15 hours light per day. Egg production, egg weight and feed conversion were recorded, egg quality also checked.
1) Eggs laid within 48 hours after depriving of feed and water were normal, but after 48 hours thin shell eggs and soft shell eggs were laid. The bird stopped laying within 96 hours. Many birds showed severe feathering from 10 to 15 days after deprivation. Most of birds treated recovered egg production before all primary flight feathers did not fall down.
2) No significant difference between Group 1 and 2 was observed in nonlaying days following treatment. Higher egg production in one year after treatment was recorded in treated groups than in control. A significant difference in egg production was observed between Group 2 and 3.
3) There were little differences in feed intake, egg weight and viability among the groups. In height of egg yolk and white (Haugh units), significant differences were observed between the treated groups and control.

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White Leghorn female chicks were raised for 5 months with the diet to which mikamycin was added at the concentration of 1ppm and 10ppm, and the gonadotrophic potency of the anterior pituitary at 3, 4 and 5 months of age was measured by the chick assay method of NAKAJO and IMAI (1956).
The gonadotrophic potency at 4 months of age and at 5 months of age was significantly greater in the pullets on mikamycin than in the pullets without mikamycine. The dietary mikamycin may cause an increase in the secretion of gonadotrophic hormones from the anterior pituitary of chickens.

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The condition of the semen stored by the present freezing method which requires only 17 minutes from the collection of semen until the completion of freezing was compared with that stored by the previous freezing method which required about 87 minutes to finish the same processes. Comparison was made in respect of the motility of spermatozoa after thawing, the percentage of the abnormal spermatozoa, especially neck-bending spermatozoa, and the fertility. The results are as follows.
1. The motility of spermatozoa upon thawing was higher in the semen stored for 7, 41, 46, 55 and 62 days by the present freezing method than in the semen stored by the previous method for the same period. On the average the motility was 88.3% in the former and 80.8% in the latter.
2. Examination of the thawed semens mentioned in the preceding paragraph showed that the percentage of neck-bending spermatozoa averaged 14.9% in the semens frozen by the present method and 29.0% in those frozen by the previous freezing method. Thus, there was observed striking difference between the two treatments.
3. Insemination experiment using the semen frozen by the present method gave 60.0% of the fertility in the first week following insemination; this result may be regarded as a remarkable progress over the previous method which usually gives the corresponding fertility of less than 30%.
4. The duration of fertility was 6 days on the average and the longest of it was 10 days in the present experiment.

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Newer data of random sample egg laying tests held in Japan from 1965 to 1967 were analysed to know the ralative economic importance of each of the traits considered and to see if there are any changes in relative economic importance of different traits compared with the results of previous analysis.
The multiple regression with 500-day feed conversion, egg production rate, laying, viability, egg weight and growing viability explained 89.8% of 500-day income variation. Feed conversion was the most important trait followed by egg production rate, laying viability, egg weight and growing viability in the order mentioned. Since the relative importance of egg production rate and egg weight was greater than in the previous data, rank of characters in their relative importance became more similar to the U.S. data (1963-1965) analysed previously.
In 270- and 300-day records, egg production rate and egg mass improved considerably during this three-year period, while no changes in 500-day production rate, egg mass and feed conversion were recognized, suggesting a change of production pattern.
Five hundred-day income was predicted by 270- and 300-day records, too. Sixty four percent and 72% of income variation were explained by 270- and 300 day records, respectively. It was noticed that partial regression coefficient of income on age at 50% production was negligible in 500-day record, but in part records it took positive values. This means that, among the birds showing the same production by 270- or 300 days of age, early maturing ones tend to produce less in the later stage of the test period than late maturing ones.
Use of part records was studied, and rather mild culling with part records was recommended.

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By starch gel electrophoretic method, one of us examined previously the chicken plasma esterases and observed two genetically controlled variations of the esterases. The loci controlling those variations were designated as Es-1 and Es-2. A close linkage relationship of those loci was suggested. This report is concerned with the linkage data involving loci Es-1 and Es-2.
The chickens used in this study were Single Comb White Leghorns. Sires (Es-1^S/ Es-1^S•Es-2^A/Es-2^A) were mated to dams (Es-1^F/Es-1^F•Es-2^a/Es-2^a). F₁ progeny thus obtained were crossed to chickens of genotype of Es-1^F/Es-1^F•Es-2^a/Es-2^a. The preparation of blood sample, electrophoretic procedure, and staining technique used in this study were identical to those described for the eserine resistant esterases (KIMURA, 1969).
The results showed that Es-1 locus was closely linked to Es-2 locus. The rate of crossing over showed a higher value in the male. Recombination frequencies of 0.0358 for the male and 0.0047 for the female were obtained. One of the two possible recombinant types was not detected.

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Laying hens of 51-week-old and chicks of 3-week-old were frozen and chopped into homogenious chicken-burger. An aliquot of the sample was taken for chemical analyses of moisture, fat, protein and gross energy.
The components of variance due to sampling error, σ² and due to between-lot error, σ_L² were estimated statistically from the data. The sampling error σ² was found to be comparable to or somewhat larger than that of the error variance in chemical analysis of finely ground feed4). Therefore, the procedure of preparing the sample of carcass described in this paper is almost satisfactory.
Average of gross energy in carcass fat of 35 estimates and in dry lean carcass of 28 estimates were 9.33 and 4.74kcal/g, respectively. Difference between carcass energy determined directly by bomb-calorimeter and that calculated from carcass fat and dry lean carcass was -0.0003kcal/g in average, suggesting that the calculation from carcass fat and dry lean carcass with caloric value mentioned above is quite reliable.

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