Experiments were conducted to determine the effect of ambient temperature, 5, 20, or 35°C, on thyroxine secretion rate (TSR) and on thyroid epithelial-cell height. Male chicks were treated for a 10-day period for the TSR determination by the goiter prevention method, and for a 11-day period for the the measurement of epithelial-cell height.
Exposure to 35°C, starting at 28 days of age, caused a significant reduction in TSR and epithelial-cell height, when compared with exposure to 5 and 20°C. The results obtained at temperatures of 5 and 20°C were not significantly different.
The reduction in epithelial-cell height was observed on the 4th day of the treatment. A similar effect was obtained when the treatment (35°C) was started at 14 days of age.
Consequently, it was proved that the thyroid activity determined by two methods is reduced by ambient temperature of 35°C for a 10-day period, but not at 5 and 20°C When 14- or 28-days old chicks are employed.
A trial was made to investigate the influence of the administration of thiouracil from 28 days of age on feed consumption and body weight, when treated at 20°C. It was confirmed that the administration of thiouracil adversely affected on feed consumption and body weight during the first 2 days of treatment, subsequently recovered to some extent.

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The effect on the fertility and hatchability of white Leghorn fed yeast produced from pure n-paraffin was studied.
The contents of crude protein, metabolisable energy and vitamin B₁₂ of the yeast were 64%, 3.39kcal/g and 0.02μg/g on dry-basis, respectively.
When all of the fish meal and part of the soybean meal in the control ration was replaced by the yeast at the dietary levels of 10, 15 and 20%, actually no difference was observed in fertility of the hens fed either control or yeast ration. However, hatchability of fertile eggs of hens fed the yeast were much poorer than the control. The hatchability of eggs on 10 and 15% yeast diet was significantly poorer than that on the control diet, being about 50% of the control. Most of the dead germs was found from 19th to 21st day after setting eggs in the brooder. The content of vitamin B12 in the eggs on the rations contained 10 and 15% of yeast were much lower than that on the control diet, being 0.14and 0.22μg%, respectively. That of the control died was 0.86μg%.
Intra-musclar injection of 1μg of vitamin B₁₂ per bird on alternative days significantly improved the hatchability of fertile eggs on the yeast ration. The effect was so drastic that the hatchability was improved already at the 2nd day after the first injection of vitamin B₁₂.
Therefore low hatchability of fertile eggs was due to the lack of vitamin B₁₂ in the eggs. It was suggested that care must be taken especially on vitamin B₁₂, when petroleum yeast was fed in place of fish meal.

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Two experiments were conducted to evaluate the effect of feather meal on growth of chicks.
In the first experiment effects of feather meal as a source of protein with and without supplementation of four essential amino acids, DL-methionine (0.4%), L-lysine (1%), L-histidine (0.4%) and L-tryptophane (0.1%) were investigated.
The rate of growth was improved by adding lysine. This was augmented remarkably when both lysine and methionine were supplemented to the ration. Feed conversion was improved also by lysine supplementation. The digestibility of feather meal was estimated to be 78.4%.
In the second experiment effects of ferther meal substituting for soybean meal and effective dose of methionine and lysine supplementation to the ration were studied.
When a part of soybean meal was replaced by 5.5% of feather meal, no appreciable effect was observed on the rate of growth. The ration of 11% feather meal showed a significant decrease in the gain. When both methionine and lysine were added to the ration of 11% feather meal, body weight gain was improved significantly.

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Collaborative experiments at 6 Prefectural Poultry Experiment Stations were carried out with 1, 550 White Plymouth Rock pullets in total to compare the effects of 4 restricted feeding programs during the growing and laying stages on the performance of meat-type breeders, hatched in spring or autumn. In each of the Stations, pullets were grouped into 5 lots at 7 weeks of age. One lot was the control and fed ad libitum throughout the growing and laying periods until 72 weeks of age. To two lots out of five in each of the Stations, twice the quantity of daily supply of the grower diet restricted as shown in Table 1 was served on every other day. At 24 weeks of age, they were fed the layer diet ad libitum. After 44 weeks of age, feed supply of one of the 2 lots was restricted again as shown in Table 1. The pullets of the remaining 2 lots were fed the grower diet ad libitum on alternative day, i.e. on skip-a-day feeding program. Those of one of the 2 lots were fed the layer diet ad libitum every day after 24 weeks of age, while those of the other lot were fed alternatively throughout the laying period.
Restriction of daily supply of the grower diet resulted in the delay of sexual maturity for 26 days with heavier first egg and with 15% higher hatching egg production than those of the control. The feed cost per hatching egg was \3.35 lower on this feeding program than that of the control. Restriction of feed supply at the later half of the laying period reduced slight by the egg production, but the feed cost per hatching egg was reduced further by this feeding program, being \4.20 lower than that of the control.
The data supported the conclusion of the previous paper that restricted feeding program, which made the body weight at 24 weeks of age equal to or less than 70% of that on the ad libitum feeding program, is favorable to get maximum hatching egg production.
Skip-a-day feeding program was confirmed to be rather mild restriction, resulting in 9% restriction of body weight at 24 weeks of age and the delay of 16 days of the sexual maturity. Hatching egg production, when the pullets was fed the layer diet ad libitum, was 9% higher with \2.46 lower feed cost per egg than those of the control group.
Skip-a-day feeding program thoughout the growing and laying period resulted in the almost identical hatching egg production to that of the control, sparing about 10% of the layer diet and resulting in \1.92 lower feed cost per egg than those of the control.
Season of hatch had not the influence on the performance of the pullets regardless of various feeding program.

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Collaborative experiments were carried out in three Prefectural Poultry Experiment Stations in Kagoshima, Kumamoto, and Osaka in 1968 using total 480 White Plymouth Rock A and J line pullets to obtain a method of restricted feeding program for meattype growing pullets.
The experiment was performed to confirmed the findings obtained in the preliminary experiment reported in the second paper on this subject.
Control grower diet contained 16% of crude protein (CP) and 66% of total digestible nutrients (TDN) and high energy grower contained 10% of CP and 76% of TDN.
The grower diet was fed two duplicated lots of pullets from 8-to 24 weeks of age.
After 24 weeks of age, all the pullets were fed the layer diet of 18% CP and 66% TDN, and the experiment was separated two sections throughout 8-to 60 week-old, one of duplicated lots was fed every day, the other was alternative day feeding.
1) Pullets fed high energy diet in growing periods resulted in 18.7% less feed intake and 11.9% less body weight at 24 week-old than those of the control pullets fed every day.
Maturity was delayed at 21 days, while little difference in laying performance was observed.
2) Pullets on alternative day feeding in growing periods resulted in 11.8% less feed intake and 16.8% less body weight at 24 week-old than those of the pullets fed every day. Maturity was delayed at 18 days. Little difference in laying periods was observed.
3) Pullets on alternative day feeding throughout growing and laying period resulted in 9.7% less feed intake, 9.1% less body weight at 24 week-old and 7.7% less at 44 week-old than those of the pullets fed every day. Maturity was delayed at 17 days. Little difference was observed between the 2 groups in viability, egg production, feed conversiond and hatchability at laying periods. This alternative day feeding was expected to cut down the feed cost per hatchable egg due to lower feed intake in growing and laying period.
4) Pullets fed high energy diet an alternative day feeding at growing period resulted in 29.4% less feed intake 44.1% with less body weight at 24 week-old than those of the pullets fed control diet.
The last method was most expected to cut down the feed cost per hatchable egg due to lower feed intake and little difference in laying period.

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This is the first report of the collaborative works with Saga, Kumamoto and Kagoshima Prefectural Poultry Stations and Nagasaki Poultry Research Center to search for the optimum composition of the layer diet for meat-type breeding hens.
Six hundred and sixty-four 8-week-old White Plymouth Rock females hatched in spring 1969 were fed low-protein, high-energy grower diet ad libitum on alternative day until 24 weeks of age. Then, the pullets were divided into 8 lots in each of 4 stations and one of 4 experimental layer diets, containing 12, 15, 18 and 21% of crude protein, respectively, were fed to duplicated lots until 64 weeks of age. The level of total digestible nutrients in the experimental diets was kept constant at 66%.
Average body weight of the pullets fed the grower diet containing 10% of crude protein and 76% of total digestible nutrients on alternative day was 1.89kg at 24 weeks of age, which corresponded to 63% of that of the pullets reared conventionally in each of the stations. The pullets took 7.11kg of the grower diet in average during 16 weeks of rearing period. Their average viability was excellent, being 97%.
Laying performance of the pullets on each of the layer diets was essentially the same, except average body weight, which increased with increased level of dietary protein. Feed cost per hatching egg was the lowest on 15% crude protein layer diet and that on 12% diet was the next, although the difference was not significant statistically. The abdominal fat content of the hens at 68 weeks of age was almost constant regardless of dietary protein level, indicating no trouble by obesity.
Optimum protein level of layer diet for meat-type breeder was suspected to be about 15%, which was somewhat lower than that for egg-type hen.

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From July of 1970 to June of 1971, the interior quality of the eggs purchased from the 6 retail stores in Gifu-shi and Nagoya-shi was studied.
A significant seasonal variation either in Haugh units, albumin height, albumen index or yolk height of the eggs was observed.
The interior egg qualities of the eggs from the retail stores was low during the hot (June-September) months, and high during the cold (November-March) months. Haugh units of the eggs purchased in July was the lowest, and averaged 39.4.
Significantly highly (r_??_0.9) negative correlations were observed between the atomospheric temperature and several interior qualities of the eggs from the retail stores.

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